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Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	44	</ol>
				45	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	46	<li><a href="#t_derived">Derived Types</a>
				47	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	48	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	49	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	50	<li><a href="#t_function">Function Type</a></li>
				51	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	52	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	53	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	54	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	55	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	56	</ol>
				57	</li>
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	58	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	59	</ol>
				60	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	61	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	62	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	63	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	64	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	65	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				66	<li><a href="#undefvalues">Undefined Values</a></li>
				67	<li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame^]	68	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	69	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	70	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	71	<li><a href="#othervalues">Other Values</a>
				72	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	73	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	74	</ol>
				75	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	76	<li><a href="#instref">Instruction Reference</a>
				77	<ol>
				78	<li><a href="#terminators">Terminator Instructions</a>
				79	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	80	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				81	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	82	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				83	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	84	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	85	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	86	</ol>
				87	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	88	<li><a href="#binaryops">Binary Operations</a>
				89	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	90	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				91	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				92	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	93	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				94	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				95	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	96	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				97	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				98	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	99	</ol>
				100	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	101	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				102	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	103	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				104	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				105	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	106	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	107	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	108	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	109	</ol>
				110	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	111	<li><a href="#vectorops">Vector Operations</a>
				112	<ol>
				113	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				114	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				115	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	116	</ol>
				117	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	118	<li><a href="#aggregateops">Aggregate Operations</a>
				119	<ol>
				120	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				121	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				122	</ol>
				123	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	124	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	125	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	126	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				127	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				128	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	129	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				130	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				131	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	132	</ol>
				133	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	134	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	135	<ol>
				136	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	141	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	145	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				146	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	147	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	148	</ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	149	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	150	<li><a href="#otherops">Other Operations</a>
				151	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	152	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				153	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	154	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				155	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	156	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	157	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	158	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	159	<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]	160	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	161	</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	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	164	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	165	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	166	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				167	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	168	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				169	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				170	<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]	171	</ol>
				172	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	173	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				174	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	175	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				176	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				177	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	178	</ol>
				179	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	180	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				181	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	182	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				183	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				184	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				185	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				186	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				187	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				188	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	189	</ol>
				190	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	191	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				192	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	193	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				194	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	198	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				200	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	201	</ol>
				202	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	203	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	204	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	205	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	206	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				207	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				208	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	209	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				210	<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]	211	</ol>
				212	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	213	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				214	<ol>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	215	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				216	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				217	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				219	<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]	220	<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]	221	</ol>
				222	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	223	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	224	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	225	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	226	<ol>
				227	<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]	228	</ol>
				229	</li>
Bill Wendling	3c44f5b	2008-11-18 22:10:53 +0000	[diff] [blame]	230	<li><a href="#int_atomics">Atomic intrinsics</a>
				231	<ol>
				232	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				233	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				234	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				235	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				236	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				237	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				238	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				239	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				240	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				241	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				242	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				243	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				244	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				245	</ol>
				246	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	247	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	248	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	249	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	250	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	251	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	252	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	253	<li><a href="#int_trap">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				255	<li><a href="#int_stackprotector">
				256	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	257	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	258	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	259	</ol>
				260	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	261	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	262
				263	<div class="doc_author">
				264	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				265	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	266	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	267
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	268	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	269	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				270	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	272	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	274	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	275	type safety, low-level operations, flexibility, and the capability of
				276	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	277	representation used throughout all phases of the LLVM compilation
				278	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	279	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	280
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	281	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	282	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				283	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	285	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	286
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	287	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	288	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]	289	representation (suitable for fast loading by a Just-In-Time compiler),
				290	and as a human readable assembly language representation. This allows
				291	LLVM to provide a powerful intermediate representation for efficient
				292	compiler transformations and analysis, while providing a natural means
				293	to debug and visualize the transformations. The three different forms
				294	of LLVM are all equivalent. This document describes the human readable
				295	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	296
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	297	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	298	while being expressive, typed, and extensible at the same time. It
				299	aims to be a "universal IR" of sorts, by being at a low enough level
				300	that high-level ideas may be cleanly mapped to it (similar to how
				301	microprocessors are "universal IR's", allowing many source languages to
				302	be mapped to them). By providing type information, LLVM can be used as
				303	the target of optimizations: for example, through pointer analysis, it
				304	can be proven that a C automatic variable is never accessed outside of
				305	the current function... allowing it to be promoted to a simple SSA
				306	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	307
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	308	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	310	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	311	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	312
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	313	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	314
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	315	<p>It is important to note that this document describes 'well formed'
				316	LLVM assembly language. There is a difference between what the parser
				317	accepts and what is considered 'well formed'. For example, the
				318	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	320	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	321	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	322	%x = <a href="#i_add">add</a> i32 1, %x
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	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	326	<p>...because the definition of <tt>%x</tt> does not dominate all of
				327	its uses. The LLVM infrastructure provides a verification pass that may
				328	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]	329	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	330	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	331	by the verifier pass indicate bugs in transformation passes or input to
				332	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	333	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	334
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	335	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	336
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	337	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	338	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	339	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	341	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	342
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	343	<p>LLVM identifiers come in two basic types: global and local. Global
				344	identifiers (functions, global variables) begin with the @ character. Local
				345	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	346	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	347
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	348	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	349	<li>Named values are represented as a string of characters with their prefix.
				350	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				351	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]	352	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	2008-10-14 23:51:43 +0000	[diff] [blame]	353	with quotes. Special characters may be escaped using "\xx" where xx is the
				354	ASCII code for the character in hexadecimal. In this way, any character can
				355	be used in a name value, even quotes themselves.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	356
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	357	<li>Unnamed values are represented as an unsigned numeric value with their
				358	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	359
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	360	<li>Constants, which are described in a <a href="#constants">section about
				361	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	362	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	364	<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]	365	don't need to worry about name clashes with reserved words, and the set of
				366	reserved words may be expanded in the future without penalty. Additionally,
				367	unnamed identifiers allow a compiler to quickly come up with a temporary
				368	variable without having to avoid symbol table conflicts.</p>
				369
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	370	<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]	371	languages. There are keywords for different opcodes
				372	('<tt><a href="#i_add">add</a></tt>',
				373	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				374	'<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]	375	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]	376	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	377	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	378
				379	<p>Here is an example of LLVM code to multiply the integer variable
				380	'<tt>%X</tt>' by 8:</p>
				381
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	383
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	384	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	385	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	386	%result = <a href="#i_mul">mul</a> i32 %X, 8
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	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	390	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	392	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	394	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
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	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	397
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	398	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	399
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	400	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	401	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	402	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				403	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				404	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	405	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	406	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	407
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	408	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				409	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	410
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	411	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	412
				413	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				414	line.</li>
				415
				416	<li>Unnamed temporaries are created when the result of a computation is not
				417	assigned to a named value.</li>
				418
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	419	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	420
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	421	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	422
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	423	<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]	424	demonstrating instructions, we will follow an instruction with a comment that
				425	defines the type and name of value produced. Comments are shown in italic
				426	text.</p>
				427
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	428	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	429
				430	<!-- *********************************************************************** -->
				431	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				432	<!-- *********************************************************************** -->
				433
				434	<!-- ======================================================================= -->
				435	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				436	</div>
				437
				438	<div class="doc_text">
				439
				440	<p>LLVM programs are composed of "Module"s, each of which is a
				441	translation unit of the input programs. Each module consists of
				442	functions, global variables, and symbol table entries. Modules may be
				443	combined together with the LLVM linker, which merges function (and
				444	global variable) definitions, resolves forward declarations, and merges
				445	symbol table entries. Here is an example of the "hello world" module:</p>
				446
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	447	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	449	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				450	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]	451
				452	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	453	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	454
				455	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	456	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	457	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	458	%cast210 = <a
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	459	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]	460
				461	<i>; Call puts function to write out the string to stdout...</i>
				462	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	463	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	464	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	465	href="#i_ret">ret</a> i32 0<br>}<br>
				466	</pre>
				467	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	468
				469	<p>This example is made up of a <a href="#globalvars">global variable</a>
				470	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				471	function, and a <a href="#functionstructure">function definition</a>
				472	for "<tt>main</tt>".</p>
				473
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	474	<p>In general, a module is made up of a list of global values,
				475	where both functions and global variables are global values. Global values are
				476	represented by a pointer to a memory location (in this case, a pointer to an
				477	array of char, and a pointer to a function), and have one of the following <a
				478	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	479
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	480	</div>
				481
				482	<!-- ======================================================================= -->
				483	<div class="doc_subsection">
				484	<a name="linkage">Linkage Types</a>
				485	</div>
				486
				487	<div class="doc_text">
				488
				489	<p>
				490	All Global Variables and Functions have one of the following types of linkage:
				491	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	492
				493	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	494
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	495	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				496
				497	<dd>Global values with private linkage are only directly accessible by
				498	objects in the current module. In particular, linking code into a module with
				499	an private global value may cause the private to be renamed as necessary to
				500	avoid collisions. Because the symbol is private to the module, all
				501	references can be updated. This doesn't show up in any symbol table in the
				502	object file.
				503	</dd>
				504
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	505	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	506
Duncan Sands	81d05c2	2009-01-16 09:29:46 +0000	[diff] [blame]	507	<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]	508	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]	509	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	510	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	511
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	512	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	513
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	514	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				515	the same name when linkage occurs. This is typically used to implement
				516	inline functions, templates, or other code which must be generated in each
				517	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				518	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	519	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	520
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	521	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				522
				523	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				524	linkage, except that unreferenced <tt>common</tt> globals may not be
				525	discarded. This is used for globals that may be emitted in multiple
				526	translation units, but that are not guaranteed to be emitted into every
				527	translation unit that uses them. One example of this is tentative
				528	definitions in C, such as "<tt>int X;</tt>" at global scope.
				529	</dd>
				530
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	531	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	532
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	533	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				534	that some targets may choose to emit different assembly sequences for them
				535	for target-dependent reasons. This is used for globals that are declared
				536	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	537	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	538
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	539	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	540
				541	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				542	pointer to array type. When two global variables with appending linkage are
				543	linked together, the two global arrays are appended together. This is the
				544	LLVM, typesafe, equivalent of having the system linker append together
				545	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	546	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	547
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	548	<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]	549
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	550	<dd>The semantics of this linkage follow the ELF object file model: the
				551	symbol is weak until linked, if not linked, the symbol becomes null instead
				552	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	553	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	554
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	555	<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]	556	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	557	<dd>Some languages allow inequivalent globals to be merged, such as two
				558	functions with different semantics. Other languages, such as <tt>C++</tt>,
				559	ensure that only equivalent globals are ever merged (the "one definition
Duncan Sands	4dc2b39	2009-03-11 20:14:15 +0000	[diff] [blame]	560	rule" - <tt>odr</tt>). Such languages can use the <tt>linkonce_odr</tt>
				561	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				562	be merged with equivalent globals. These linkage types are otherwise the
				563	same as their non-<tt>odr</tt> versions.
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	564	</dd>
				565
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	566	<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]	567
				568	<dd>If none of the above identifiers are used, the global is externally
				569	visible, meaning that it participates in linkage and can be used to resolve
				570	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	571	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	572	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	573
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	574	<p>
				575	The next two types of linkage are targeted for Microsoft Windows platform
				576	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	577	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	578	</p>
				579
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	580	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	581	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				582
				583	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				584	or variable via a global pointer to a pointer that is set up by the DLL
				585	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	586	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	587	</dd>
				588
				589	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				590
				591	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				592	pointer to a pointer in a DLL, so that it can be referenced with the
				593	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	594	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]	595	name.
				596	</dd>
				597
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	598	</dl>
				599
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	600	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	601	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				602	variable and was linked with this one, one of the two would be renamed,
				603	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				604	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	605	outside of the current module.</p>
				606	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	5f4ee1f	2009-03-11 08:08:06 +0000	[diff] [blame]	607	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				608	or <tt>extern_weak</tt>.</p>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	609	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				610	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	611	</div>
				612
				613	<!-- ======================================================================= -->
				614	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	615	<a name="callingconv">Calling Conventions</a>
				616	</div>
				617
				618	<div class="doc_text">
				619
				620	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				621	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				622	specified for the call. The calling convention of any pair of dynamic
				623	caller/callee must match, or the behavior of the program is undefined. The
				624	following calling conventions are supported by LLVM, and more may be added in
				625	the future:</p>
				626
				627	<dl>
				628	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				629
				630	<dd>This calling convention (the default if no other calling convention is
				631	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	632	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	633	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	634	</dd>
				635
				636	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				637
				638	<dd>This calling convention attempts to make calls as fast as possible
				639	(e.g. by passing things in registers). This calling convention allows the
				640	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]	641	without having to conform to an externally specified ABI (Application Binary
				642	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	643	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				644	supported. This calling convention does not support varargs and requires the
				645	prototype of all callees to exactly match the prototype of the function
				646	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	647	</dd>
				648
				649	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				650
				651	<dd>This calling convention attempts to make code in the caller as efficient
				652	as possible under the assumption that the call is not commonly executed. As
				653	such, these calls often preserve all registers so that the call does not break
				654	any live ranges in the caller side. This calling convention does not support
				655	varargs and requires the prototype of all callees to exactly match the
				656	prototype of the function definition.
				657	</dd>
				658
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	659	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	660
				661	<dd>Any calling convention may be specified by number, allowing
				662	target-specific calling conventions to be used. Target specific calling
				663	conventions start at 64.
				664	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	665	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	666
				667	<p>More calling conventions can be added/defined on an as-needed basis, to
				668	support pascal conventions or any other well-known target-independent
				669	convention.</p>
				670
				671	</div>
				672
				673	<!-- ======================================================================= -->
				674	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	675	<a name="visibility">Visibility Styles</a>
				676	</div>
				677
				678	<div class="doc_text">
				679
				680	<p>
				681	All Global Variables and Functions have one of the following visibility styles:
				682	</p>
				683
				684	<dl>
				685	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				686
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	687	<dd>On targets that use the ELF object file format, default visibility means
				688	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	689	modules and, in shared libraries, means that the declared entity may be
				690	overridden. On Darwin, default visibility means that the declaration is
				691	visible to other modules. Default visibility corresponds to "external
				692	linkage" in the language.
				693	</dd>
				694
				695	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				696
				697	<dd>Two declarations of an object with hidden visibility refer to the same
				698	object if they are in the same shared object. Usually, hidden visibility
				699	indicates that the symbol will not be placed into the dynamic symbol table,
				700	so no other module (executable or shared library) can reference it
				701	directly.
				702	</dd>
				703
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	704	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				705
				706	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				707	the dynamic symbol table, but that references within the defining module will
				708	bind to the local symbol. That is, the symbol cannot be overridden by another
				709	module.
				710	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	711	</dl>
				712
				713	</div>
				714
				715	<!-- ======================================================================= -->
				716	<div class="doc_subsection">
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	717	<a name="namedtypes">Named Types</a>
				718	</div>
				719
				720	<div class="doc_text">
				721
				722	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				723	it easier to read the IR and make the IR more condensed (particularly when
				724	recursive types are involved). An example of a name specification is:
				725	</p>
				726
				727	<div class="doc_code">
				728	<pre>
				729	%mytype = type { %mytype*, i32 }
				730	</pre>
				731	</div>
				732
				733	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				734	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				735	expected with the syntax "%mytype".</p>
				736
				737	<p>Note that type names are aliases for the structural type that they indicate,
				738	and that you can therefore specify multiple names for the same type. This often
				739	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				740	structural typing, the name is not part of the type. When printing out LLVM IR,
				741	the printer will pick <em>one name</em> to render all types of a particular
				742	shape. This means that if you have code where two different source types end up
				743	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				744	unexpected type. This is an important design point and isn't going to
				745	change.</p>
				746
				747	</div>
				748
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	749	<!-- ======================================================================= -->
				750	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	751	<a name="globalvars">Global Variables</a>
				752	</div>
				753
				754	<div class="doc_text">
				755
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	756	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	757	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	758	an explicit section to be placed in, and may have an optional explicit alignment
				759	specified. A variable may be defined as "thread_local", which means that it
				760	will not be shared by threads (each thread will have a separated copy of the
				761	variable). A variable may be defined as a global "constant," which indicates
				762	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]	763	optimization, allowing the global data to be placed in the read-only section of
				764	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	765	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]	766
				767	<p>
				768	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				769	constant, even if the final definition of the global is not. This capability
				770	can be used to enable slightly better optimization of the program, but requires
				771	the language definition to guarantee that optimizations based on the
				772	'constantness' are valid for the translation units that do not include the
				773	definition.
				774	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	775
				776	<p>As SSA values, global variables define pointer values that are in
				777	scope (i.e. they dominate) all basic blocks in the program. Global
				778	variables always define a pointer to their "content" type because they
				779	describe a region of memory, and all memory objects in LLVM are
				780	accessed through pointers.</p>
				781
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	782	<p>A global variable may be declared to reside in a target-specifc numbered
				783	address space. For targets that support them, address spaces may affect how
				784	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	785	the variable. The default address space is zero. The address space qualifier
				786	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	787
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	788	<p>LLVM allows an explicit section to be specified for globals. If the target
				789	supports it, it will emit globals to the section specified.</p>
				790
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	791	<p>An explicit alignment may be specified for a global. If not present, or if
				792	the alignment is set to zero, the alignment of the global is set by the target
				793	to whatever it feels convenient. If an explicit alignment is specified, the
				794	global is forced to have at least that much alignment. All alignments must be
				795	a power of 2.</p>
				796
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	797	<p>For example, the following defines a global in a numbered address space with
				798	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	799
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	800	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	801	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	802	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	803	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	804	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	805
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	806	</div>
				807
				808
				809	<!-- ======================================================================= -->
				810	<div class="doc_subsection">
				811	<a name="functionstructure">Functions</a>
				812	</div>
				813
				814	<div class="doc_text">
				815
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	816	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				817	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	818	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	819	<a href="#callingconv">calling convention</a>, a return type, an optional
				820	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				821	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	822	<a href="#paramattrs">parameter attributes</a>), optional
				823	<a href="#fnattrs">function attributes</a>, an optional section,
				824	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	825	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]	826
				827	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				828	optional <a href="#linkage">linkage type</a>, an optional
				829	<a href="#visibility">visibility style</a>, an optional
				830	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	831	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	832	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]	833	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	834
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	835	<p>A function definition contains a list of basic blocks, forming the CFG
				836	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	837	the function. Each basic block may optionally start with a label (giving the
				838	basic block a symbol table entry), contains a list of instructions, and ends
				839	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				840	function return).</p>
				841
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	842	<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]	843	executed on entrance to the function, and it is not allowed to have predecessor
				844	basic blocks (i.e. there can not be any branches to the entry block of a
				845	function). Because the block can have no predecessors, it also cannot have any
				846	<a href="#i_phi">PHI nodes</a>.</p>
				847
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	848	<p>LLVM allows an explicit section to be specified for functions. If the target
				849	supports it, it will emit functions to the section specified.</p>
				850
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	851	<p>An explicit alignment may be specified for a function. If not present, or if
				852	the alignment is set to zero, the alignment of the function is set by the target
				853	to whatever it feels convenient. If an explicit alignment is specified, the
				854	function is forced to have at least that much alignment. All alignments must be
				855	a power of 2.</p>
				856
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	857	<h5>Syntax:</h5>
				858
				859	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	860	<tt>
				861	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				862	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				863	<ResultType> @<FunctionName> ([argument list])
				864	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				865	[<a href="#gc">gc</a>] { ... }
				866	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	867	</div>
				868
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	869	</div>
				870
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	871
				872	<!-- ======================================================================= -->
				873	<div class="doc_subsection">
				874	<a name="aliasstructure">Aliases</a>
				875	</div>
				876	<div class="doc_text">
				877	<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]	878	function, global variable, another alias or bitcast of global value). Aliases
				879	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	880	optional <a href="#visibility">visibility style</a>.</p>
				881
				882	<h5>Syntax:</h5>
				883
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	884	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	885	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	886	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	887	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	888	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	889
				890	</div>
				891
				892
				893
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	894	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	895	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				896	<div class="doc_text">
				897	<p>The return type and each parameter of a function type may have a set of
				898	<i>parameter attributes</i> associated with them. Parameter attributes are
				899	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	900	a function. Parameter attributes are considered to be part of the function,
				901	not of the function type, so functions with different parameter attributes
				902	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	903
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	904	<p>Parameter attributes are simple keywords that follow the type specified. If
				905	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	906	example:</p>
				907
				908	<div class="doc_code">
				909	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	910	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	911	declare i32 @atoi(i8 zeroext)
				912	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	913	</pre>
				914	</div>
				915
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	916	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				917	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	918
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	919	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	920	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	921	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	922	<dd>This indicates to the code generator that the parameter or return value
				923	should be zero-extended to a 32-bit value by the caller (for a parameter)
				924	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	925
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	926	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	927	<dd>This indicates to the code generator that the parameter or return value
				928	should be sign-extended to a 32-bit value by the caller (for a parameter)
				929	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	930
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	931	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	932	<dd>This indicates that this parameter or return value should be treated
				933	in a special target-dependent fashion during while emitting code for a
				934	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]	935	to memory, though some targets use it to distinguish between two different
				936	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	937
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	938	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	939	<dd>This indicates that the pointer parameter should really be passed by
				940	value to the function. The attribute implies that a hidden copy of the
				941	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]	942	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]	943	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	944	value, but is also valid on pointers to scalars. The copy is considered to
				945	belong to the caller not the callee (for example,
				946	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	947	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	2009-02-05 05:42:28 +0000	[diff] [blame]	948	values. The byval attribute also supports specifying an alignment with the
				949	align attribute. This has a target-specific effect on the code generator
				950	that usually indicates a desired alignment for the synthesized stack
				951	slot.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	952
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	953	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	954	<dd>This indicates that the pointer parameter specifies the address of a
				955	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]	956	This pointer must be guaranteed by the caller to be valid: loads and stores
				957	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]	958	be applied to the first parameter. This is not a valid attribute for
				959	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	960
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	961	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	962	<dd>This indicates that the pointer does not alias any global or any other
				963	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	b2b32fd	2008-11-24 05:00:44 +0000	[diff] [blame]	964	case. On a function return value, <tt>noalias</tt> additionally indicates
				965	that the pointer does not alias any other pointers visible to the
Nick Lewycky	f23d0d3	2008-12-19 06:39:12 +0000	[diff] [blame]	966	caller. For further details, please see the discussion of the NoAlias
				967	response in
				968	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				969	analysis</a>.</dd>
				970
				971	<dt><tt>nocapture</tt></dt>
				972	<dd>This indicates that the callee does not make any copies of the pointer
				973	that outlive the callee itself. This is not a valid attribute for return
				974	values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	975
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	976	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	977	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	978	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				979	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	980	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	981
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	982	</div>
				983
				984	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	985	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	986	<a name="gc">Garbage Collector Names</a>
				987	</div>
				988
				989	<div class="doc_text">
				990	<p>Each function may specify a garbage collector name, which is simply a
				991	string.</p>
				992
				993	<div class="doc_code"><pre
				994	>define void @f() gc "name" { ...</pre></div>
				995
				996	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				997	collector which will cause the compiler to alter its output in order to support
				998	the named garbage collection algorithm.</p>
				999	</div>
				1000
				1001	<!-- ======================================================================= -->
				1002	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1003	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1004	</div>
				1005
				1006	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1007
				1008	<p>Function attributes are set to communicate additional information about
				1009	a function. Function attributes are considered to be part of the function,
				1010	not of the function type, so functions with different parameter attributes
				1011	can have the same function type.</p>
				1012
				1013	<p>Function attributes are simple keywords that follow the type specified. If
				1014	multiple attributes are needed, they are space separated. For
				1015	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1016
				1017	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1018	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1019	define void @f() noinline { ... }
				1020	define void @f() alwaysinline { ... }
				1021	define void @f() alwaysinline optsize { ... }
				1022	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1023	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1024	</div>
				1025
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1026	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1027	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1028	<dd>This attribute indicates that the inliner should attempt to inline this
				1029	function into callers whenever possible, ignoring any active inlining size
				1030	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1031
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1032	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1033	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1034	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1035	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1036
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1037	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1038	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1039	make choices that keep the code size of this function low, and otherwise do
				1040	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1041
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1042	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1043	<dd>This function attribute indicates that the function never returns normally.
				1044	This produces undefined behavior at runtime if the function ever does
				1045	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1046
				1047	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1048	<dd>This function attribute indicates that the function never returns with an
				1049	unwind or exceptional control flow. If the function does unwind, its runtime
				1050	behavior is undefined.</dd>
				1051
				1052	<dt><tt>readnone</tt></dt>
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1053	<dd>This attribute indicates that the function computes its result (or the
				1054	exception it throws) based strictly on its arguments, without dereferencing any
				1055	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1056	registers, etc) visible to caller functions. It does not write through any
				1057	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
				1058	never changes any state visible to callers.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1059
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1060	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1061	<dd>This attribute indicates that the function does not write through any
				1062	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1063	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1064	caller functions. It may dereference pointer arguments and read state that may
				1065	be set in the caller. A readonly function always returns the same value (or
				1066	throws the same exception) when called with the same set of arguments and global
				1067	state.</dd>
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1068
				1069	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1070	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1071	protector. It is in the form of a "canary"—a random value placed on the
				1072	stack before the local variables that's checked upon return from the function to
				1073	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]	1074	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1075
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1076	<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
				1077	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
				1078	have an <tt>ssp</tt> attribute.</p></dd>
				1079
				1080	<dt><tt>sspreq</tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1081	<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]	1082	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]	1083	function attribute.
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1084
				1085	<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
				1086	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1087	an <tt>ssp</tt> attribute, then the resulting function will have
				1088	an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1089	</dl>
				1090
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1091	</div>
				1092
				1093	<!-- ======================================================================= -->
				1094	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1095	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1096	</div>
				1097
				1098	<div class="doc_text">
				1099	<p>
				1100	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1101	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1102	LLVM and treated as a single unit, but may be separated in the .ll file if
				1103	desired. The syntax is very simple:
				1104	</p>
				1105
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1106	<div class="doc_code">
				1107	<pre>
				1108	module asm "inline asm code goes here"
				1109	module asm "more can go here"
				1110	</pre>
				1111	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1112
				1113	<p>The strings can contain any character by escaping non-printable characters.
				1114	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1115	for the number.
				1116	</p>
				1117
				1118	<p>
				1119	The inline asm code is simply printed to the machine code .s file when
				1120	assembly code is generated.
				1121	</p>
				1122	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1123
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1124	<!-- ======================================================================= -->
				1125	<div class="doc_subsection">
				1126	<a name="datalayout">Data Layout</a>
				1127	</div>
				1128
				1129	<div class="doc_text">
				1130	<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]	1131	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1132	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1133	<p>The <i>layout specification</i> consists of a list of specifications
				1134	separated by the minus sign character ('-'). Each specification starts with a
				1135	letter and may include other information after the letter to define some
				1136	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1137	<dl>
				1138	<dt><tt>E</tt></dt>
				1139	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1140	bits with the most significance have the lowest address location.</dd>
				1141	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1142	<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]	1143	the bits with the least significance have the lowest address location.</dd>
				1144	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1145	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1146	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1147	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1148	too.</dd>
				1149	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1150	<dd>This specifies the alignment for an integer type of a given bit
				1151	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1152	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1153	<dd>This specifies the alignment for a vector type of a given bit
				1154	<i>size</i>.</dd>
				1155	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1156	<dd>This specifies the alignment for a floating point type of a given bit
				1157	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1158	(double).</dd>
				1159	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1160	<dd>This specifies the alignment for an aggregate type of a given bit
				1161	<i>size</i>.</dd>
				1162	</dl>
				1163	<p>When constructing the data layout for a given target, LLVM starts with a
				1164	default set of specifications which are then (possibly) overriden by the
				1165	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1166	are given in this list:</p>
				1167	<ul>
				1168	<li><tt>E</tt> - big endian</li>
				1169	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1170	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1171	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1172	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1173	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1174	<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]	1175	alignment of 64-bits</li>
				1176	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1177	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1178	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1179	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1180	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1181	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1182	<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]	1183	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1184	<ol>
				1185	<li>If the type sought is an exact match for one of the specifications, that
				1186	specification is used.</li>
				1187	<li>If no match is found, and the type sought is an integer type, then the
				1188	smallest integer type that is larger than the bitwidth of the sought type is
				1189	used. If none of the specifications are larger than the bitwidth then the the
				1190	largest integer type is used. For example, given the default specifications
				1191	above, the i7 type will use the alignment of i8 (next largest) while both
				1192	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1193	<li>If no match is found, and the type sought is a vector type, then the
				1194	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]	1195	as a fall back. This happens because <128 x double> can be implemented
				1196	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1197	</ol>
				1198	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1199
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1200	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1201	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1202	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1203
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1204	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1205
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1206	<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]	1207	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1208	optimizations to be performed on the intermediate representation directly,
				1209	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1210	extra analyses on the side before the transformation. A strong type
				1211	system makes it easier to read the generated code and enables novel
				1212	analyses and transformations that are not feasible to perform on normal
				1213	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1214
				1215	</div>
				1216
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1217	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1218	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1219	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1220	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1221	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1222	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1223
				1224	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1225	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1226	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1227	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1228	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1229	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1230	</tr>
				1231	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1232	<td><a href="#t_floating">floating point</a></td>
				1233	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1234	</tr>
				1235	<tr>
				1236	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1237	<td><a href="#t_integer">integer</a>,
				1238	<a href="#t_floating">floating point</a>,
				1239	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1240	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1241	<a href="#t_struct">structure</a>,
				1242	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1243	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1244	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1245	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1246	<tr>
				1247	<td><a href="#t_primitive">primitive</a></td>
				1248	<td><a href="#t_label">label</a>,
				1249	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1250	<a href="#t_floating">floating point</a>.</td>
				1251	</tr>
				1252	<tr>
				1253	<td><a href="#t_derived">derived</a></td>
				1254	<td><a href="#t_integer">integer</a>,
				1255	<a href="#t_array">array</a>,
				1256	<a href="#t_function">function</a>,
				1257	<a href="#t_pointer">pointer</a>,
				1258	<a href="#t_struct">structure</a>,
				1259	<a href="#t_pstruct">packed structure</a>,
				1260	<a href="#t_vector">vector</a>,
				1261	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1262	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1263	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1264	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1265	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1266
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1267	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1268	most important. Values of these types are the only ones which can be
				1269	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1270	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1271	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1272
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1273	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1274	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1275
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1276	<div class="doc_text">
				1277	<p>The primitive types are the fundamental building blocks of the LLVM
				1278	system.</p>
				1279
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1280	</div>
				1281
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1282	<!-- _______________________________________________________________________ -->
				1283	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1284
				1285	<div class="doc_text">
				1286	<table>
				1287	<tbody>
				1288	<tr><th>Type</th><th>Description</th></tr>
				1289	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1290	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1291	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1292	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1293	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1294	</tbody>
				1295	</table>
				1296	</div>
				1297
				1298	<!-- _______________________________________________________________________ -->
				1299	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1300
				1301	<div class="doc_text">
				1302	<h5>Overview:</h5>
				1303	<p>The void type does not represent any value and has no size.</p>
				1304
				1305	<h5>Syntax:</h5>
				1306
				1307	<pre>
				1308	void
				1309	</pre>
				1310	</div>
				1311
				1312	<!-- _______________________________________________________________________ -->
				1313	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1314
				1315	<div class="doc_text">
				1316	<h5>Overview:</h5>
				1317	<p>The label type represents code labels.</p>
				1318
				1319	<h5>Syntax:</h5>
				1320
				1321	<pre>
				1322	label
				1323	</pre>
				1324	</div>
				1325
				1326
				1327	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1328	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1329
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1330	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1331
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1332	<p>The real power in LLVM comes from the derived types in the system.
				1333	This is what allows a programmer to represent arrays, functions,
				1334	pointers, and other useful types. Note that these derived types may be
				1335	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]	1336
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1337	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1338
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1339	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1340	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1341
				1342	<div class="doc_text">
				1343
				1344	<h5>Overview:</h5>
				1345	<p>The integer type is a very simple derived type that simply specifies an
				1346	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1347	2^23-1 (about 8 million) can be specified.</p>
				1348
				1349	<h5>Syntax:</h5>
				1350
				1351	<pre>
				1352	iN
				1353	</pre>
				1354
				1355	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1356	value.</p>
				1357
				1358	<h5>Examples:</h5>
				1359	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1360	<tbody>
				1361	<tr>
				1362	<td><tt>i1</tt></td>
				1363	<td>a single-bit integer.</td>
				1364	</tr><tr>
				1365	<td><tt>i32</tt></td>
				1366	<td>a 32-bit integer.</td>
				1367	</tr><tr>
				1368	<td><tt>i1942652</tt></td>
				1369	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1370	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1371	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1372	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1373
				1374	<p>Note that the code generator does not yet support large integer types
				1375	to be used as function return types. The specific limit on how large a
				1376	return type the code generator can currently handle is target-dependent;
				1377	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1378	targets.</p>
				1379
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1380	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1381
				1382	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1383	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1384
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1385	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1386
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1387	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1388
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1389	<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]	1390	sequentially in memory. The array type requires a size (number of
				1391	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1392
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1393	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1394
				1395	<pre>
				1396	[<# elements> x <elementtype>]
				1397	</pre>
				1398
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1399	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1400	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1401
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1402	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1403	<table class="layout">
				1404	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1405	<td class="left"><tt>[40 x i32]</tt></td>
				1406	<td class="left">Array of 40 32-bit integer values.</td>
				1407	</tr>
				1408	<tr class="layout">
				1409	<td class="left"><tt>[41 x i32]</tt></td>
				1410	<td class="left">Array of 41 32-bit integer values.</td>
				1411	</tr>
				1412	<tr class="layout">
				1413	<td class="left"><tt>[4 x i8]</tt></td>
				1414	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1415	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1416	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1417	<p>Here are some examples of multidimensional arrays:</p>
				1418	<table class="layout">
				1419	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1420	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1421	<td class="left">3x4 array of 32-bit integer values.</td>
				1422	</tr>
				1423	<tr class="layout">
				1424	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1425	<td class="left">12x10 array of single precision floating point values.</td>
				1426	</tr>
				1427	<tr class="layout">
				1428	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1429	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1430	</tr>
				1431	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1432
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1433	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1434	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]	1435	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1436	As a special case, however, zero length arrays are recognized to be variable
				1437	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1438	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1439
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1440	<p>Note that the code generator does not yet support large aggregate types
				1441	to be used as function return types. The specific limit on how large an
				1442	aggregate return type the code generator can currently handle is
				1443	target-dependent, and also dependent on the aggregate element types.</p>
				1444
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1445	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1446
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1447	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1448	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1449	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1450
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1451	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1452
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1453	<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]	1454	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]	1455	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]	1456	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]	1457	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1458
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1459	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1460
				1461	<pre>
				1462	<returntype list> (<parameter list>)
				1463	</pre>
				1464
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1465	<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]	1466	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1467	which indicates that the function takes a variable number of arguments.
				1468	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1469	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1470	'<tt><returntype list></tt>' is a comma-separated list of
				1471	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1472
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1473	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1474	<table class="layout">
				1475	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1476	<td class="left"><tt>i32 (i32)</tt></td>
				1477	<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]	1478	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1479	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1480	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1481	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1482	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1483	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1484	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1485	<tt>float</tt>.
				1486	</td>
				1487	</tr><tr class="layout">
				1488	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1489	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1490	<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]	1491	which returns an integer. This is the signature for <tt>printf</tt> in
				1492	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1493	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1494	</tr><tr class="layout">
				1495	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1496	<td class="left">A function taking an <tt>i32</tt>, returning two
				1497	<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]	1498	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1499	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1500	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1501
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1502	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1503	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1504	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1505	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1506	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1507	<p>The structure type is used to represent a collection of data members
				1508	together in memory. The packing of the field types is defined to match
				1509	the ABI of the underlying processor. The elements of a structure may
				1510	be any type that has a size.</p>
				1511	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1512	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1513	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1514	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1515	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1516	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1517	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1518	<table class="layout">
				1519	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1520	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1521	<td class="left">A triple of three <tt>i32</tt> values</td>
				1522	</tr><tr class="layout">
				1523	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1524	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1525	second element is a <a href="#t_pointer">pointer</a> to a
				1526	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1527	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1528	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1529	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1530
				1531	<p>Note that the code generator does not yet support large aggregate types
				1532	to be used as function return types. The specific limit on how large an
				1533	aggregate return type the code generator can currently handle is
				1534	target-dependent, and also dependent on the aggregate element types.</p>
				1535
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1536	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1537
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1538	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1539	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1540	</div>
				1541	<div class="doc_text">
				1542	<h5>Overview:</h5>
				1543	<p>The packed structure type is used to represent a collection of data members
				1544	together in memory. There is no padding between fields. Further, the alignment
				1545	of a packed structure is 1 byte. The elements of a packed structure may
				1546	be any type that has a size.</p>
				1547	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1548	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1549	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1550	instruction.</p>
				1551	<h5>Syntax:</h5>
				1552	<pre> < { <type list> } > <br></pre>
				1553	<h5>Examples:</h5>
				1554	<table class="layout">
				1555	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1556	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1557	<td class="left">A triple of three <tt>i32</tt> values</td>
				1558	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1559	<td class="left">
				1560	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1561	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1562	second element is a <a href="#t_pointer">pointer</a> to a
				1563	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1564	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1565	</tr>
				1566	</table>
				1567	</div>
				1568
				1569	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1570	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1571	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1572	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1573	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1574	reference to another object, which must live in memory. Pointer types may have
				1575	an optional address space attribute defining the target-specific numbered
				1576	address space where the pointed-to object resides. The default address space is
				1577	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1578
				1579	<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]	1580	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]	1581
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1582	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1583	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1584	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1585	<table class="layout">
				1586	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1587	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1588	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1589	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1590	</tr>
				1591	<tr class="layout">
				1592	<td class="left"><tt>i32 (i32 ) </tt></td>
				1593	<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]	1594	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]	1595	<tt>i32</tt>.</td>
				1596	</tr>
				1597	<tr class="layout">
				1598	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1599	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1600	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1601	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1602	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1603	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1604
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1605	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1606	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1607	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1608
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1609	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1610
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1611	<p>A vector type is a simple derived type that represents a vector
				1612	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1613	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1614	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1615	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1616	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1617	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1618
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1619	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1620
				1621	<pre>
				1622	< <# elements> x <elementtype> >
				1623	</pre>
				1624
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1625	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1626	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1627
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1628	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1629
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1630	<table class="layout">
				1631	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1632	<td class="left"><tt><4 x i32></tt></td>
				1633	<td class="left">Vector of 4 32-bit integer values.</td>
				1634	</tr>
				1635	<tr class="layout">
				1636	<td class="left"><tt><8 x float></tt></td>
				1637	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1638	</tr>
				1639	<tr class="layout">
				1640	<td class="left"><tt><2 x i64></tt></td>
				1641	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1642	</tr>
				1643	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1644
				1645	<p>Note that the code generator does not yet support large vector types
				1646	to be used as function return types. The specific limit on how large a
				1647	vector return type codegen can currently handle is target-dependent;
				1648	currently it's often a few times longer than a hardware vector register.</p>
				1649
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1650	</div>
				1651
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1652	<!-- _______________________________________________________________________ -->
				1653	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1654	<div class="doc_text">
				1655
				1656	<h5>Overview:</h5>
				1657
				1658	<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]	1659	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]	1660	In LLVM, opaque types can eventually be resolved to any type (not just a
				1661	structure type).</p>
				1662
				1663	<h5>Syntax:</h5>
				1664
				1665	<pre>
				1666	opaque
				1667	</pre>
				1668
				1669	<h5>Examples:</h5>
				1670
				1671	<table class="layout">
				1672	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1673	<td class="left"><tt>opaque</tt></td>
				1674	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1675	</tr>
				1676	</table>
				1677	</div>
				1678
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1679	<!-- ======================================================================= -->
				1680	<div class="doc_subsection">
				1681	<a name="t_uprefs">Type Up-references</a>
				1682	</div>
				1683
				1684	<div class="doc_text">
				1685	<h5>Overview:</h5>
				1686	<p>
				1687	An "up reference" allows you to refer to a lexically enclosing type without
				1688	requiring it to have a name. For instance, a structure declaration may contain a
				1689	pointer to any of the types it is lexically a member of. Example of up
				1690	references (with their equivalent as named type declarations) include:</p>
				1691
				1692	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1693	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1694	{ \2 }* %y = type { %y }*
				1695	\1* %z = type %z*
				1696	</pre>
				1697
				1698	<p>
				1699	An up reference is needed by the asmprinter for printing out cyclic types when
				1700	there is no declared name for a type in the cycle. Because the asmprinter does
				1701	not want to print out an infinite type string, it needs a syntax to handle
				1702	recursive types that have no names (all names are optional in llvm IR).
				1703	</p>
				1704
				1705	<h5>Syntax:</h5>
				1706	<pre>
				1707	\<level>
				1708	</pre>
				1709
				1710	<p>
				1711	The level is the count of the lexical type that is being referred to.
				1712	</p>
				1713
				1714	<h5>Examples:</h5>
				1715
				1716	<table class="layout">
				1717	<tr class="layout">
				1718	<td class="left"><tt>\1*</tt></td>
				1719	<td class="left">Self-referential pointer.</td>
				1720	</tr>
				1721	<tr class="layout">
				1722	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1723	<td class="left">Recursive structure where the upref refers to the out-most
				1724	structure.</td>
				1725	</tr>
				1726	</table>
				1727	</div>
				1728
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1729
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1730	<!-- *********************************************************************** -->
				1731	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1732	<!-- *********************************************************************** -->
				1733
				1734	<div class="doc_text">
				1735
				1736	<p>LLVM has several different basic types of constants. This section describes
				1737	them all and their syntax.</p>
				1738
				1739	</div>
				1740
				1741	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1742	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1743
				1744	<div class="doc_text">
				1745
				1746	<dl>
				1747	<dt><b>Boolean constants</b></dt>
				1748
				1749	<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]	1750	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1751	</dd>
				1752
				1753	<dt><b>Integer constants</b></dt>
				1754
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1755	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1756	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1757	integer types.
				1758	</dd>
				1759
				1760	<dt><b>Floating point constants</b></dt>
				1761
				1762	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1763	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1764	notation (see below). The assembler requires the exact decimal value of
				1765	a floating-point constant. For example, the assembler accepts 1.25 but
				1766	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1767	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]	1768
				1769	<dt><b>Null pointer constants</b></dt>
				1770
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1771	<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]	1772	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1773
				1774	</dl>
				1775
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1776	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1777	of floating point constants. For example, the form '<tt>double
				1778	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1779	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]	1780	(and the only time that they are generated by the disassembler) is when a
				1781	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]	1782	decimal floating point number in a reasonable number of digits. For example,
				1783	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1784	special values are represented in their IEEE hexadecimal format so that
				1785	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]	1786	<p>When using the hexadecimal form, constants of types float and double are
				1787	represented using the 16-digit form shown above (which matches the IEEE754
				1788	representation for double); float values must, however, be exactly representable
				1789	as IEE754 single precision.
				1790	Hexadecimal format is always used for long
				1791	double, and there are three forms of long double. The 80-bit
				1792	format used by x86 is represented as <tt>0xK</tt>
				1793	followed by 20 hexadecimal digits.
				1794	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1795	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1796	format is represented
				1797	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1798	target uses this format. Long doubles will only work if they match
				1799	the long double format on your target. All hexadecimal formats are big-endian
				1800	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1801	</div>
				1802
				1803	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1804	<div class="doc_subsection">
				1805	<a name="aggregateconstants"> <!-- old anchor -->
				1806	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1807	</div>
				1808
				1809	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1810	<p>Complex constants are a (potentially recursive) combination of simple
				1811	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1812
				1813	<dl>
				1814	<dt><b>Structure constants</b></dt>
				1815
				1816	<dd>Structure constants are represented with notation similar to structure
				1817	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1818	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1819	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]	1820	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]	1821	types of elements must match those specified by the type.
				1822	</dd>
				1823
				1824	<dt><b>Array constants</b></dt>
				1825
				1826	<dd>Array constants are represented with notation similar to array type
				1827	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1828	(<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]	1829	constants must have <a href="#t_array">array type</a>, and the number and
				1830	types of elements must match those specified by the type.
				1831	</dd>
				1832
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1833	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1834
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1835	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1836	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1837	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1838	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1839	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]	1840	match those specified by the type.
				1841	</dd>
				1842
				1843	<dt><b>Zero initialization</b></dt>
				1844
				1845	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1846	value to zero of <em>any</em> type, including scalar and aggregate types.
				1847	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]	1848	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1849	initializers.
				1850	</dd>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame^]	1851
				1852	<dt><b>Metadata node</b></dt>
				1853
				1854	<dd>A metadata node is a structure-like constant with the type of an empty
				1855	struct. For example: "<tt>{ } !{ i32 0, { } !"test" }</tt>". Unlike other
				1856	constants that are meant to be interpreted as part of the instruction stream,
				1857	metadata is a place to attach additional information such as debug info.
				1858	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1859	</dl>
				1860
				1861	</div>
				1862
				1863	<!-- ======================================================================= -->
				1864	<div class="doc_subsection">
				1865	<a name="globalconstants">Global Variable and Function Addresses</a>
				1866	</div>
				1867
				1868	<div class="doc_text">
				1869
				1870	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1871	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1872	constants. These constants are explicitly referenced when the <a
				1873	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]	1874	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1875	file:</p>
				1876
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1877	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1878	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1879	@X = global i32 17
				1880	@Y = global i32 42
				1881	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1882	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1883	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1884
				1885	</div>
				1886
				1887	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1888	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1889	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1890	<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]	1891	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]	1892	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1893
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1894	<p>Undefined values indicate to the compiler that the program is well defined
				1895	no matter what value is used, giving the compiler more freedom to optimize.
				1896	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1897	</div>
				1898
				1899	<!-- ======================================================================= -->
				1900	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1901	</div>
				1902
				1903	<div class="doc_text">
				1904
				1905	<p>Constant expressions are used to allow expressions involving other constants
				1906	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1907	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]	1908	that does not have side effects (e.g. load and call are not supported). The
				1909	following is the syntax for constant expressions:</p>
				1910
				1911	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1912	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1913	<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]	1914	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1915
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1916	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1917	<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]	1918	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]	1919
				1920	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1921	<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]	1922	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]	1923
				1924	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1925	<dd>Truncate a floating point constant to another floating point type. The
				1926	size of CST must be larger than the size of TYPE. Both types must be
				1927	floating point.</dd>
				1928
				1929	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1930	<dd>Floating point extend a constant to another type. The size of CST must be
				1931	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1932
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1933	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1934	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1935	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1936	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1937	of the same number of elements. If the value won't fit in the integer type,
				1938	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1939
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1940	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1941	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1942	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1943	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1944	of the same number of elements. If the value won't fit in the integer type,
				1945	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1946
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1947	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1948	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1949	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1950	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1951	of the same number of elements. If the value won't fit in the floating point
				1952	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1953
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1954	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1955	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1956	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1957	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1958	of the same number of elements. If the value won't fit in the floating point
				1959	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1960
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1961	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1962	<dd>Convert a pointer typed constant to the corresponding integer constant
				1963	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1964	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1965
				1966	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1967	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1968	pointer type. CST must be of integer type. The CST value is zero extended,
				1969	truncated, or unchanged to make it fit in a pointer size. This one is
				1970	<i>really</i> dangerous!</dd>
				1971
				1972	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	1973	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				1974	are the same as those for the <a href="#i_bitcast">bitcast
				1975	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1976
				1977	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1978
				1979	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1980	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1981	instruction, the index list may have zero or more indexes, which are required
				1982	to make sense for the type of "CSTPTR".</dd>
				1983
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1984	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1985
				1986	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1987	constants.</dd>
				1988
				1989	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1990	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1991
				1992	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1993	<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]	1994
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1995	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1996	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1997
				1998	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1999	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2000
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2001	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2002
				2003	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2004	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2005
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2006	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2007
				2008	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2009	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2010
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2011
				2012	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2013
				2014	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2015	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2016
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2017	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2018
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2019	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2020	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]	2021	binary</a> operations. The constraints on operands are the same as those for
				2022	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2023	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2024	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2025	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2026
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame^]	2027	<!-- ======================================================================= -->
				2028	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2029	</div>
				2030
				2031	<div class="doc_text">
				2032
				2033	<p>Embedded metadata provides a way to attach arbitrary data to the
				2034	instruction stream without affecting the behaviour of the program. There are
				2035	two metadata primitives, strings and nodes. All metadata has the type of an
				2036	empty struct and is identified in syntax by a preceding exclamation point
				2037	('<tt>!</tt>').
				2038	</p>
				2039
				2040	<p>A metadata string is a string surrounded by double quotes. It can contain
				2041	any character by escaping non-printable characters with "\xx" where "xx" is
				2042	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2043	</p>
				2044
				2045	<p>Metadata nodes are represented with notation similar to structure constants
				2046	(a comma separated list of elements, surrounded by braces and preceeded by an
				2047	exclamation point). For example: "<tt>!{ { } !"test\00", i32 10}</tt>".
				2048	</p>
				2049
				2050	<p>Optimizations may rely on metadata to provide additional information about
				2051	the program that isn't available in the instructions, or that isn't easily
				2052	computable. Similarly, the code generator may expect a certain metadata format
				2053	to be used to express debugging information.</p>
				2054	</div>
				2055
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2056	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2057	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2058	<!-- *********************************************************************** -->
				2059
				2060	<!-- ======================================================================= -->
				2061	<div class="doc_subsection">
				2062	<a name="inlineasm">Inline Assembler Expressions</a>
				2063	</div>
				2064
				2065	<div class="doc_text">
				2066
				2067	<p>
				2068	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2069	Module-Level Inline Assembly</a>) through the use of a special value. This
				2070	value represents the inline assembler as a string (containing the instructions
				2071	to emit), a list of operand constraints (stored as a string), and a flag that
				2072	indicates whether or not the inline asm expression has side effects. An example
				2073	inline assembler expression is:
				2074	</p>
				2075
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2076	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2077	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2078	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2079	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2080	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2081
				2082	<p>
				2083	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2084	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2085	</p>
				2086
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2087	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2088	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2089	%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]	2090	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2091	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2092
				2093	<p>
				2094	Inline asms with side effects not visible in the constraint list must be marked
				2095	as having side effects. This is done through the use of the
				2096	'<tt>sideeffect</tt>' keyword, like so:
				2097	</p>
				2098
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2099	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2100	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2101	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2102	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2103	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2104
				2105	<p>TODO: The format of the asm and constraints string still need to be
				2106	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]	2107	need to be documented). This is probably best done by reference to another
				2108	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2109	</p>
				2110
				2111	</div>
				2112
				2113	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2114	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2115	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2116
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2117	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2118
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2119	<p>The LLVM instruction set consists of several different
				2120	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2121	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2122	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2123	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2124	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2125
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2126	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2127
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2128	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2129	<div class="doc_subsection"> <a name="terminators">Terminator
				2130	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2131
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2132	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2133
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2134	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2135	basic block in a program ends with a "Terminator" instruction, which
				2136	indicates which block should be executed after the current block is
				2137	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2138	value: they produce control flow, not values (the one exception being
				2139	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2140	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2141	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2142	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2143	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2144	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2145	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2146
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2147	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2148
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2149	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2150	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2151	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2152	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2153	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2154	<pre>
				2155	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]	2156	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2157	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2158
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2159	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2160
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2161	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2162	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2163	<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]	2164	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]	2165	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2166
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2167	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2168
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2169	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2170	the return value. The type of the return value must be a
				2171	'<a href="#t_firstclass">first class</a>' type.</p>
				2172
				2173	<p>A function is not <a href="#wellformed">well formed</a> if
				2174	it it has a non-void return type and contains a '<tt>ret</tt>'
				2175	instruction with no return value or a return value with a type that
				2176	does not match its type, or if it has a void return type and contains
				2177	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2178
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2179	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2180
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2181	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2182	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]	2183	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2184	the instruction after the call. If the caller was an "<a
				2185	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2186	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2187	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]	2188	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2189
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2190	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2191
				2192	<pre>
				2193	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2194	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2195	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]	2196	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2197
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2198	<p>Note that the code generator does not yet fully support large
				2199	return values. The specific sizes that are currently supported are
				2200	dependent on the target. For integers, on 32-bit targets the limit
				2201	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2202	For aggregate types, the current limits are dependent on the element
				2203	types; for example targets are often limited to 2 total integer
				2204	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2205
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2206	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2207	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2208	<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]	2209	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2210	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2211	<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]	2212	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2213	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2214	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2215	transfer to a different basic block in the current function. There are
				2216	two forms of this instruction, corresponding to a conditional branch
				2217	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2218	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2219	<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]	2220	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2221	unconditional form of the '<tt>br</tt>' instruction takes a single
				2222	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2223	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2224	<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]	2225	argument is evaluated. If the value is <tt>true</tt>, control flows
				2226	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2227	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2228	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2229	<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]	2230	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]	2231	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2232	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2233	<div class="doc_subsubsection">
				2234	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2235	</div>
				2236
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2237	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2238	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2239
				2240	<pre>
				2241	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2242	</pre>
				2243
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2244	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2245
				2246	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2247	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2248	instruction, allowing a branch to occur to one of many possible
				2249	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2250
				2251
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2252	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2253
				2254	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2255	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2256	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2257	table is not allowed to contain duplicate constant entries.</p>
				2258
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2259	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2260
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2261	<p>The <tt>switch</tt> instruction specifies a table of values and
				2262	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2263	table is searched for the given value. If the value is found, control flow is
				2264	transfered to the corresponding destination; otherwise, control flow is
				2265	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2266
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2267	<h5>Implementation:</h5>
				2268
				2269	<p>Depending on properties of the target machine and the particular
				2270	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2271	ways. For example, it could be generated as a series of chained conditional
				2272	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2273
				2274	<h5>Example:</h5>
				2275
				2276	<pre>
				2277	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2278	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2279	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2280
				2281	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2282	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2283
				2284	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2285	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2286	i32 1, label %onone
				2287	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2288	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2289	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2290
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2291	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2292	<div class="doc_subsubsection">
				2293	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2294	</div>
				2295
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2296	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2297
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2298	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2299
				2300	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2301	<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]	2302	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2303	</pre>
				2304
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2305	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2306
				2307	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2308	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2309	'<tt>normal</tt>' label or the
				2310	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2311	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2312	"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]	2313	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2314	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2315
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2316	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2317
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2318	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2319
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2320	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2321	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2322	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2323	convention</a> the call should use. If none is specified, the call defaults
				2324	to using C calling conventions.
				2325	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2326
				2327	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2328	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2329	and '<tt>inreg</tt>' attributes are valid here.</li>
				2330
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2331	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2332	function value being invoked. In most cases, this is a direct function
				2333	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2334	an arbitrary pointer to function value.
				2335	</li>
				2336
				2337	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2338	function to be invoked. </li>
				2339
				2340	<li>'<tt>function args</tt>': argument list whose types match the function
				2341	signature argument types. If the function signature indicates the function
				2342	accepts a variable number of arguments, the extra arguments can be
				2343	specified. </li>
				2344
				2345	<li>'<tt>normal label</tt>': the label reached when the called function
				2346	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2347
				2348	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2349	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2350
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2351	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2352	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2353	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2354	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2355
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2356	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2357
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2358	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2359	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2360	difference is that it establishes an association with a label, which is used by
				2361	the runtime library to unwind the stack.</p>
				2362
				2363	<p>This instruction is used in languages with destructors to ensure that proper
				2364	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2365	exception. Additionally, this is important for implementation of
				2366	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2367
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2368	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2369	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2370	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2371	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2372	%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]	2373	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2374	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2375	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2376
				2377
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2378	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2379
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2380	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2381	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2382
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2383	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2384
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2385	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2386	<pre>
				2387	unwind
				2388	</pre>
				2389
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2390	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2391
				2392	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2393	at the first callee in the dynamic call stack which used an <a
				2394	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2395	primarily used to implement exception handling.</p>
				2396
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2397	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2398
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2399	<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]	2400	immediately halt. The dynamic call stack is then searched for the first <a
				2401	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2402	execution continues at the "exceptional" destination block specified by the
				2403	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2404	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2405	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2406
				2407	<!-- _______________________________________________________________________ -->
				2408
				2409	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2410	Instruction</a> </div>
				2411
				2412	<div class="doc_text">
				2413
				2414	<h5>Syntax:</h5>
				2415	<pre>
				2416	unreachable
				2417	</pre>
				2418
				2419	<h5>Overview:</h5>
				2420
				2421	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2422	instruction is used to inform the optimizer that a particular portion of the
				2423	code is not reachable. This can be used to indicate that the code after a
				2424	no-return function cannot be reached, and other facts.</p>
				2425
				2426	<h5>Semantics:</h5>
				2427
				2428	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2429	</div>
				2430
				2431
				2432
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2433	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2434	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2435	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2436	<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]	2437	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]	2438	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2439	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]	2440	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2441	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2442	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2443	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2444	<div class="doc_subsubsection">
				2445	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2446	</div>
				2447
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2448	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2449
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2450	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2451
				2452	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2453	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2454	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2455
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2456	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2457
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2458	<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]	2459
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2460	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2461
				2462	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2463	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2464	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2465	types.</p>
				2466
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2467	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2468
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2469	<p>The value produced is the integer or floating point sum of the two
				2470	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2471
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2472	<p>If an integer sum has unsigned overflow, the result returned is the
				2473	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2474	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2475
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2476	<p>Because LLVM integers use a two's complement representation, this
				2477	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2478
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2479	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2480
				2481	<pre>
				2482	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2483	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2484	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2485	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2486	<div class="doc_subsubsection">
				2487	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2488	</div>
				2489
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2490	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2491
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2492	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2493
				2494	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2495	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2496	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2497
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2498	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2499
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2500	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2501	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2502
				2503	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2504	'<tt>neg</tt>' instruction present in most other intermediate
				2505	representations.</p>
				2506
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2507	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2508
				2509	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2510	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2511	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2512	types.</p>
				2513
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2514	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2515
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2516	<p>The value produced is the integer or floating point difference of
				2517	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2518
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2519	<p>If an integer difference has unsigned overflow, the result returned is the
				2520	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2521	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2522
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2523	<p>Because LLVM integers use a two's complement representation, this
				2524	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2525
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2526	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2527	<pre>
				2528	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2529	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2530	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2531	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2532
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2533	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2534	<div class="doc_subsubsection">
				2535	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2536	</div>
				2537
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2538	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2539
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2540	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2541	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2542	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2543	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2544	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2545	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2546
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2547	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2548
				2549	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2550	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2551	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2552	types.</p>
				2553
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2554	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2555
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2556	<p>The value produced is the integer or floating point product of the
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2557	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2558
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2559	<p>If the result of an integer multiplication has unsigned overflow,
				2560	the result returned is the mathematical result modulo
				2561	2<sup>n</sup>, where n is the bit width of the result.</p>
				2562	<p>Because LLVM integers use a two's complement representation, and the
				2563	result is the same width as the operands, this instruction returns the
				2564	correct result for both signed and unsigned integers. If a full product
				2565	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2566	should be sign-extended or zero-extended as appropriate to the
				2567	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2568	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2569	<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]	2570	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2571	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2572
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2573	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2574	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2575	</a></div>
				2576	<div class="doc_text">
				2577	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2578	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2579	</pre>
				2580	<h5>Overview:</h5>
				2581	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2582	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2583
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2584	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2585
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2586	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2587	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2588	values. Both arguments must have identical types.</p>
				2589
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2590	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2591
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2592	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2593	<p>Note that unsigned integer division and signed integer division are distinct
				2594	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2595	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2596	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2597	<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]	2598	</pre>
				2599	</div>
				2600	<!-- _______________________________________________________________________ -->
				2601	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2602	</a> </div>
				2603	<div class="doc_text">
				2604	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2605	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2606	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2607	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2608
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2609	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2610
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2611	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2612	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2613
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2614	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2615
				2616	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2617	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2618	values. Both arguments must have identical types.</p>
				2619
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2620	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2621	<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]	2622	<p>Note that signed integer division and unsigned integer division are distinct
				2623	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2624	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2625	undefined behavior; this is a rare case, but can occur, for example,
				2626	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2627	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2628	<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]	2629	</pre>
				2630	</div>
				2631	<!-- _______________________________________________________________________ -->
				2632	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2633	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2634	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2635	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2636	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2637	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2638	</pre>
				2639	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2640
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2641	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2642	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2643
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2644	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2645
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2646	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2647	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2648	of floating point values. Both arguments must have identical types.</p>
				2649
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2650	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2651
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2652	<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]	2653
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2654	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2655
				2656	<pre>
				2657	<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]	2658	</pre>
				2659	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2660
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2661	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2662	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2663	</div>
				2664	<div class="doc_text">
				2665	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2666	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2667	</pre>
				2668	<h5>Overview:</h5>
				2669	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2670	unsigned division of its two arguments.</p>
				2671	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2672	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2673	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2674	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2675	<h5>Semantics:</h5>
				2676	<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]	2677	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2678	<p>Note that unsigned integer remainder and signed integer remainder are
				2679	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2680	<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]	2681	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2682	<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]	2683	</pre>
				2684
				2685	</div>
				2686	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2687	<div class="doc_subsubsection">
				2688	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2689	</div>
				2690
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2691	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2692
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2693	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2694
				2695	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2696	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2697	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2698
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2699	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2700
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2701	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2702	signed division of its two operands. This instruction can also take
				2703	<a href="#t_vector">vector</a> versions of the values in which case
				2704	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2705
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2706	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2707
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2708	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2709	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2710	values. Both arguments must have identical types.</p>
				2711
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2712	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2713
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2714	<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]	2715	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2716	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]	2717	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2718	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]	2719	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]	2720	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2721	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2722	<p>Note that signed integer remainder and unsigned integer remainder are
				2723	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2724	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2725	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2726	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2727	(The remainder doesn't actually overflow, but this rule lets srem be
				2728	implemented using instructions that return both the result of the division
				2729	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2730	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2731	<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]	2732	</pre>
				2733
				2734	</div>
				2735	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2736	<div class="doc_subsubsection">
				2737	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2738
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2739	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2740
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2741	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2742	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2743	</pre>
				2744	<h5>Overview:</h5>
				2745	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2746	division of its two operands.</p>
				2747	<h5>Arguments:</h5>
				2748	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2749	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2750	of floating point values. Both arguments must have identical types.</p>
				2751
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2752	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2753
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2754	<p>This instruction returns the <i>remainder</i> of a division.
				2755	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2756
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2757	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2758
				2759	<pre>
				2760	<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]	2761	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2762	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2763
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2764	<!-- ======================================================================= -->
				2765	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2766	Operations</a> </div>
				2767	<div class="doc_text">
				2768	<p>Bitwise binary operators are used to do various forms of
				2769	bit-twiddling in a program. They are generally very efficient
				2770	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2771	instructions. They require two operands of the same type, execute an operation on them,
				2772	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]	2773	</div>
				2774
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2775	<!-- _______________________________________________________________________ -->
				2776	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2777	Instruction</a> </div>
				2778	<div class="doc_text">
				2779	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2780	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2781	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2782
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2783	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2784
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2785	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2786	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2787
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2788	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2789
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2790	<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]	2791	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]	2792	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2793
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2794	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2795
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2796	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2797	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]	2798	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2799	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2800	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2801
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2802	<h5>Example:</h5><pre>
				2803	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2804	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2805	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2806	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2807	<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]	2808	</pre>
				2809	</div>
				2810	<!-- _______________________________________________________________________ -->
				2811	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2812	Instruction</a> </div>
				2813	<div class="doc_text">
				2814	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2815	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2816	</pre>
				2817
				2818	<h5>Overview:</h5>
				2819	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2820	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]	2821
				2822	<h5>Arguments:</h5>
				2823	<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]	2824	<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]	2825	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2826
				2827	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2828
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2829	<p>This instruction always performs a logical shift right operation. The most
				2830	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]	2831	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]	2832	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2833	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2834	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2835
				2836	<h5>Example:</h5>
				2837	<pre>
				2838	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2839	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2840	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2841	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2842	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2843	<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]	2844	</pre>
				2845	</div>
				2846
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2847	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2848	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2849	Instruction</a> </div>
				2850	<div class="doc_text">
				2851
				2852	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2853	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2854	</pre>
				2855
				2856	<h5>Overview:</h5>
				2857	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2858	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]	2859
				2860	<h5>Arguments:</h5>
				2861	<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]	2862	<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]	2863	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2864
				2865	<h5>Semantics:</h5>
				2866	<p>This instruction always performs an arithmetic shift right operation,
				2867	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]	2868	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]	2869	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				2870	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2871	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2872
				2873	<h5>Example:</h5>
				2874	<pre>
				2875	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2876	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2877	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2878	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2879	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2880	<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]	2881	</pre>
				2882	</div>
				2883
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2884	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2885	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2886	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2887
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2888	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2889
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2890	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2891
				2892	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2893	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2894	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2895
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2896	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2897
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2898	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2899	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2900
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2901	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2902
				2903	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2904	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2905	values. Both arguments must have identical types.</p>
				2906
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2907	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2908	<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]	2909	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2910	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2911	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2912	<tbody>
				2913	<tr>
				2914	<td>In0</td>
				2915	<td>In1</td>
				2916	<td>Out</td>
				2917	</tr>
				2918	<tr>
				2919	<td>0</td>
				2920	<td>0</td>
				2921	<td>0</td>
				2922	</tr>
				2923	<tr>
				2924	<td>0</td>
				2925	<td>1</td>
				2926	<td>0</td>
				2927	</tr>
				2928	<tr>
				2929	<td>1</td>
				2930	<td>0</td>
				2931	<td>0</td>
				2932	</tr>
				2933	<tr>
				2934	<td>1</td>
				2935	<td>1</td>
				2936	<td>1</td>
				2937	</tr>
				2938	</tbody>
				2939	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2940	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2941	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2942	<pre>
				2943	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2944	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2945	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2946	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2947	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2948	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2949	<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]	2950	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2951	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2952	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2953	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2954	<h5>Overview:</h5>
				2955	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2956	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2957	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2958
				2959	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2960	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2961	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2962	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2963	<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]	2964	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2965	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2966	<table border="1" cellspacing="0" cellpadding="4">
				2967	<tbody>
				2968	<tr>
				2969	<td>In0</td>
				2970	<td>In1</td>
				2971	<td>Out</td>
				2972	</tr>
				2973	<tr>
				2974	<td>0</td>
				2975	<td>0</td>
				2976	<td>0</td>
				2977	</tr>
				2978	<tr>
				2979	<td>0</td>
				2980	<td>1</td>
				2981	<td>1</td>
				2982	</tr>
				2983	<tr>
				2984	<td>1</td>
				2985	<td>0</td>
				2986	<td>1</td>
				2987	</tr>
				2988	<tr>
				2989	<td>1</td>
				2990	<td>1</td>
				2991	<td>1</td>
				2992	</tr>
				2993	</tbody>
				2994	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2995	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2996	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2997	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2998	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2999	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3000	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3001	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3002	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3003	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3004	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3005	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3006	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3007	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3008	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3009	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3010	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3011	or of its two operands. The <tt>xor</tt> is used to implement the
				3012	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3013	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3014	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3015	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3016	values. Both arguments must have identical types.</p>
				3017
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3018	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3019
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3020	<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]	3021	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3022	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3023	<table border="1" cellspacing="0" cellpadding="4">
				3024	<tbody>
				3025	<tr>
				3026	<td>In0</td>
				3027	<td>In1</td>
				3028	<td>Out</td>
				3029	</tr>
				3030	<tr>
				3031	<td>0</td>
				3032	<td>0</td>
				3033	<td>0</td>
				3034	</tr>
				3035	<tr>
				3036	<td>0</td>
				3037	<td>1</td>
				3038	<td>1</td>
				3039	</tr>
				3040	<tr>
				3041	<td>1</td>
				3042	<td>0</td>
				3043	<td>1</td>
				3044	</tr>
				3045	<tr>
				3046	<td>1</td>
				3047	<td>1</td>
				3048	<td>0</td>
				3049	</tr>
				3050	</tbody>
				3051	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3052	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3053	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3054	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3055	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3056	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3057	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3058	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3059	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3060	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3061
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3062	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3063	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3064	<a name="vectorops">Vector Operations</a>
				3065	</div>
				3066
				3067	<div class="doc_text">
				3068
				3069	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3070	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3071	vector-specific operations needed to process vectors effectively. While LLVM
				3072	does directly support these vector operations, many sophisticated algorithms
				3073	will want to use target-specific intrinsics to take full advantage of a specific
				3074	target.</p>
				3075
				3076	</div>
				3077
				3078	<!-- _______________________________________________________________________ -->
				3079	<div class="doc_subsubsection">
				3080	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3081	</div>
				3082
				3083	<div class="doc_text">
				3084
				3085	<h5>Syntax:</h5>
				3086
				3087	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3088	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3089	</pre>
				3090
				3091	<h5>Overview:</h5>
				3092
				3093	<p>
				3094	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3095	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3096	</p>
				3097
				3098
				3099	<h5>Arguments:</h5>
				3100
				3101	<p>
				3102	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3103	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]	3104	an index indicating the position from which to extract the element.
				3105	The index may be a variable.</p>
				3106
				3107	<h5>Semantics:</h5>
				3108
				3109	<p>
				3110	The result is a scalar of the same type as the element type of
				3111	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3112	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3113	results are undefined.
				3114	</p>
				3115
				3116	<h5>Example:</h5>
				3117
				3118	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3119	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3120	</pre>
				3121	</div>
				3122
				3123
				3124	<!-- _______________________________________________________________________ -->
				3125	<div class="doc_subsubsection">
				3126	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3127	</div>
				3128
				3129	<div class="doc_text">
				3130
				3131	<h5>Syntax:</h5>
				3132
				3133	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3134	<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]	3135	</pre>
				3136
				3137	<h5>Overview:</h5>
				3138
				3139	<p>
				3140	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3141	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3142	</p>
				3143
				3144
				3145	<h5>Arguments:</h5>
				3146
				3147	<p>
				3148	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3149	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]	3150	scalar value whose type must equal the element type of the first
				3151	operand. The third operand is an index indicating the position at
				3152	which to insert the value. The index may be a variable.</p>
				3153
				3154	<h5>Semantics:</h5>
				3155
				3156	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3157	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]	3158	element values are those of <tt>val</tt> except at position
				3159	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3160	exceeds the length of <tt>val</tt>, the results are undefined.
				3161	</p>
				3162
				3163	<h5>Example:</h5>
				3164
				3165	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3166	%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]	3167	</pre>
				3168	</div>
				3169
				3170	<!-- _______________________________________________________________________ -->
				3171	<div class="doc_subsubsection">
				3172	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3173	</div>
				3174
				3175	<div class="doc_text">
				3176
				3177	<h5>Syntax:</h5>
				3178
				3179	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3180	<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]	3181	</pre>
				3182
				3183	<h5>Overview:</h5>
				3184
				3185	<p>
				3186	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3187	from two input vectors, returning a vector with the same element type as
				3188	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3189	</p>
				3190
				3191	<h5>Arguments:</h5>
				3192
				3193	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3194	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3195	with types that match each other. The third argument is a shuffle mask whose
				3196	element type is always 'i32'. The result of the instruction is a vector whose
				3197	length is the same as the shuffle mask and whose element type is the same as
				3198	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3199	</p>
				3200
				3201	<p>
				3202	The shuffle mask operand is required to be a constant vector with either
				3203	constant integer or undef values.
				3204	</p>
				3205
				3206	<h5>Semantics:</h5>
				3207
				3208	<p>
				3209	The elements of the two input vectors are numbered from left to right across
				3210	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]	3211	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]	3212	gets. The element selector may be undef (meaning "don't care") and the second
				3213	operand may be undef if performing a shuffle from only one vector.
				3214	</p>
				3215
				3216	<h5>Example:</h5>
				3217
				3218	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3219	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3220	<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]	3221	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3222	<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]	3223	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3224	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3225	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3226	<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]	3227	</pre>
				3228	</div>
				3229
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3230
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3231	<!-- ======================================================================= -->
				3232	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3233	<a name="aggregateops">Aggregate Operations</a>
				3234	</div>
				3235
				3236	<div class="doc_text">
				3237
				3238	<p>LLVM supports several instructions for working with aggregate values.
				3239	</p>
				3240
				3241	</div>
				3242
				3243	<!-- _______________________________________________________________________ -->
				3244	<div class="doc_subsubsection">
				3245	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3246	</div>
				3247
				3248	<div class="doc_text">
				3249
				3250	<h5>Syntax:</h5>
				3251
				3252	<pre>
				3253	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3254	</pre>
				3255
				3256	<h5>Overview:</h5>
				3257
				3258	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3259	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3260	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3261	</p>
				3262
				3263
				3264	<h5>Arguments:</h5>
				3265
				3266	<p>
				3267	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3268	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]	3269	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3270	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3271	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3272	</p>
				3273
				3274	<h5>Semantics:</h5>
				3275
				3276	<p>
				3277	The result is the value at the position in the aggregate specified by
				3278	the index operands.
				3279	</p>
				3280
				3281	<h5>Example:</h5>
				3282
				3283	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3284	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3285	</pre>
				3286	</div>
				3287
				3288
				3289	<!-- _______________________________________________________________________ -->
				3290	<div class="doc_subsubsection">
				3291	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3292	</div>
				3293
				3294	<div class="doc_text">
				3295
				3296	<h5>Syntax:</h5>
				3297
				3298	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3299	<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]	3300	</pre>
				3301
				3302	<h5>Overview:</h5>
				3303
				3304	<p>
				3305	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3306	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3307	</p>
				3308
				3309
				3310	<h5>Arguments:</h5>
				3311
				3312	<p>
				3313	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3314	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3315	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3316	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3317	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]	3318	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3319	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3320	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]	3321	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3322	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3323
				3324	<h5>Semantics:</h5>
				3325
				3326	<p>
				3327	The result is an aggregate of the same type as <tt>val</tt>. Its
				3328	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]	3329	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3330	</p>
				3331
				3332	<h5>Example:</h5>
				3333
				3334	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3335	%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]	3336	</pre>
				3337	</div>
				3338
				3339
				3340	<!-- ======================================================================= -->
				3341	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3342	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3343	</div>
				3344
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3345	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3346
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3347	<p>A key design point of an SSA-based representation is how it
				3348	represents memory. In LLVM, no memory locations are in SSA form, which
				3349	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3350	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3351
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3352	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3353
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3354	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3355	<div class="doc_subsubsection">
				3356	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3357	</div>
				3358
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3359	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3360
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3361	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3362
				3363	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3364	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3365	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3366
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3367	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3368
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3369	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3370	heap and returns a pointer to it. The object is always allocated in the generic
				3371	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3372
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3373	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3374
				3375	<p>The '<tt>malloc</tt>' instruction allocates
				3376	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3377	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]	3378	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3379	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3380	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3381	be aligned to at least that boundary. If not specified, or if zero, the target can
				3382	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3383
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3384	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3385
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3386	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3387
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3388	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3389	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]	3390	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3391
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3392	<h5>Example:</h5>
				3393
				3394	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3395	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3396
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3397	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3398	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3399	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3400	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3401	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3402	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3403
				3404	<p>Note that the code generator does not yet respect the
				3405	alignment value.</p>
				3406
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3407	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3408
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3409	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3410	<div class="doc_subsubsection">
				3411	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3412	</div>
				3413
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3414	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3415
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3416	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3417
				3418	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3419	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3420	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3421
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3422	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3423
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3424	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3425	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3426
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3427	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3428
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3429	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3430	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3431	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3432
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3433	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3434
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3435	<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]	3436	after this instruction executes. If the pointer is null, the operation
				3437	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3438
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3439	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3440
				3441	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3442	%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]	3443	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3444	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3445	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3446
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3447	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3448	<div class="doc_subsubsection">
				3449	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3450	</div>
				3451
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3452	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3453
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3454	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3455
				3456	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3457	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3458	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3459
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3460	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3461
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3462	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3463	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3464	returns to its caller. The object is always allocated in the generic address
				3465	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3466
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3467	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3468
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3469	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3470	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3471	appropriate type to the program. If "NumElements" is specified, it is the
				3472	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3473	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3474	to be aligned to at least that boundary. If not specified, or if zero, the target
				3475	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3476
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3477	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3478
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3479	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3480
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3481	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3482	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3483	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3484	instruction is commonly used to represent automatic variables that must
				3485	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]	3486	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]	3487	instructions), the memory is reclaimed. Allocating zero bytes
				3488	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3489
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3490	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3491
				3492	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3493	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3494	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3495	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3496	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3497	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3498	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3499
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3500	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3501	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3502	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3503	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3504	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3505	<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]	3506	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3507	<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]	3508	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3509	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3510	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3511	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]	3512	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]	3513	the number or order of execution of this <tt>load</tt> with other
				3514	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3515	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3516	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3517	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3518	(that is, the alignment of the memory address). A value of 0 or an
				3519	omitted "align" argument means that the operation has the preferential
				3520	alignment for the target. It is the responsibility of the code emitter
				3521	to ensure that the alignment information is correct. Overestimating
				3522	the alignment results in an undefined behavior. Underestimating the
				3523	alignment may produce less efficient code. An alignment of 1 is always
				3524	safe.
				3525	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3526	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3527	<p>The location of memory pointed to is loaded. If the value being loaded
				3528	is of scalar type then the number of bytes read does not exceed the minimum
				3529	number of bytes needed to hold all bits of the type. For example, loading an
				3530	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3531	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3532	is undefined if the value was not originally written using a store of the
				3533	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3534	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3535	<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]	3536	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3537	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3538	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3539	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3540	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3541	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3542	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3543	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3544	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3545	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3546	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3547	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3548	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3549	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3550	<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]	3551	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3552	<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]	3553	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]	3554	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3555	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3556	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]	3557	optimizer is not allowed to modify the number or order of execution of
				3558	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3559	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3560	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3561	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3562	(that is, the alignment of the memory address). A value of 0 or an
				3563	omitted "align" argument means that the operation has the preferential
				3564	alignment for the target. It is the responsibility of the code emitter
				3565	to ensure that the alignment information is correct. Overestimating
				3566	the alignment results in an undefined behavior. Underestimating the
				3567	alignment may produce less efficient code. An alignment of 1 is always
				3568	safe.
				3569	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3570	<h5>Semantics:</h5>
				3571	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3572	at the location specified by the '<tt><pointer></tt>' operand.
				3573	If '<tt><value></tt>' is of scalar type then the number of bytes
				3574	written does not exceed the minimum number of bytes needed to hold all
				3575	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3576	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3577	size that is not an integral number of bytes, it is unspecified what
				3578	happens to the extra bits that do not belong to the type, but they will
				3579	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3580	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3581	<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]	3582	store i32 3, i32* %ptr <i>; yields {void}</i>
				3583	%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]	3584	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3585	</div>
				3586
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3587	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3588	<div class="doc_subsubsection">
				3589	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3590	</div>
				3591
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3592	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3593	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3594	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3595	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3596	</pre>
				3597
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3598	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3599
				3600	<p>
				3601	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]	3602	subelement of an aggregate data structure. It performs address calculation only
				3603	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3604
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3605	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3606
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3607	<p>The first argument is always a pointer, and forms the basis of the
				3608	calculation. The remaining arguments are indices, that indicate which of the
				3609	elements of the aggregate object are indexed. The interpretation of each index
				3610	is dependent on the type being indexed into. The first index always indexes the
				3611	pointer value given as the first argument, the second index indexes a value of
				3612	the type pointed to (not necessarily the value directly pointed to, since the
				3613	first index can be non-zero), etc. The first type indexed into must be a pointer
				3614	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3615	types being indexed into can never be pointers, since that would require loading
				3616	the pointer before continuing calculation.</p>
				3617
				3618	<p>The type of each index argument depends on the type it is indexing into.
				3619	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3620	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
				3621	only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
				3622	will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3623
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3624	<p>For example, let's consider a C code fragment and how it gets
				3625	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3626
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3627	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3628	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3629	struct RT {
				3630	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3631	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3632	char C;
				3633	};
				3634	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3635	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3636	double Y;
				3637	struct RT Z;
				3638	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3639
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3640	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3641	return &s[1].Z.B[5][13];
				3642	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3643	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3644	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3645
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3646	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3647
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3648	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3649	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3650	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3651	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3652
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3653	define i32* %foo(%ST* %s) {
				3654	entry:
				3655	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3656	ret i32* %reg
				3657	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3658	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3659	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3660
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3661	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3662
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3663	<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]	3664	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]	3665	}</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]	3666	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3667	i8 }</tt>' type, another structure. The third index indexes into the second
				3668	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]	3669	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3670	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3671	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]	3672
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3673	<p>Note that it is perfectly legal to index partially through a
				3674	structure, returning a pointer to an inner element. Because of this,
				3675	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3676
				3677	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3678	define i32* %foo(%ST* %s) {
				3679	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3680	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3681	%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]	3682	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3683	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3684	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3685	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3686	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3687
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3688	<p>Note that it is undefined to access an array out of bounds: array
				3689	and pointer indexes must always be within the defined bounds of the
				3690	array type when accessed with an instruction that dereferences the
				3691	pointer (e.g. a load or store instruction). The one exception for
				3692	this rule is zero length arrays. These arrays are defined to be
				3693	accessible as variable length arrays, which requires access beyond the
				3694	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3695
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3696	<p>The getelementptr instruction is often confusing. For some more insight
				3697	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3698	FAQ</a>.</p>
				3699
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3700	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3701
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3702	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3703	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3704	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3705	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3706	%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]	3707	<i>; yields i8*:eptr</i>
				3708	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3709	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3710	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3711
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3712	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3713	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3714	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3715	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3716	<p>The instructions in this category are the conversion instructions (casting)
				3717	which all take a single operand and a type. They perform various bit conversions
				3718	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3719	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3720
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3721	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3722	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3723	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3724	</div>
				3725	<div class="doc_text">
				3726
				3727	<h5>Syntax:</h5>
				3728	<pre>
				3729	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3730	</pre>
				3731
				3732	<h5>Overview:</h5>
				3733	<p>
				3734	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3735	</p>
				3736
				3737	<h5>Arguments:</h5>
				3738	<p>
				3739	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3740	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]	3741	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]	3742	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3743	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3744
				3745	<h5>Semantics:</h5>
				3746	<p>
				3747	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]	3748	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3749	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3750	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3751
				3752	<h5>Example:</h5>
				3753	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3754	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3755	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3756	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3757	</pre>
				3758	</div>
				3759
				3760	<!-- _______________________________________________________________________ -->
				3761	<div class="doc_subsubsection">
				3762	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3763	</div>
				3764	<div class="doc_text">
				3765
				3766	<h5>Syntax:</h5>
				3767	<pre>
				3768	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3769	</pre>
				3770
				3771	<h5>Overview:</h5>
				3772	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3773	<tt>ty2</tt>.</p>
				3774
				3775
				3776	<h5>Arguments:</h5>
				3777	<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]	3778	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3779	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]	3780	<tt>value</tt> must be smaller than the bit size of the destination type,
				3781	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3782
				3783	<h5>Semantics:</h5>
				3784	<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]	3785	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]	3786
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3787	<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]	3788
				3789	<h5>Example:</h5>
				3790	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3791	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3792	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3793	</pre>
				3794	</div>
				3795
				3796	<!-- _______________________________________________________________________ -->
				3797	<div class="doc_subsubsection">
				3798	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3799	</div>
				3800	<div class="doc_text">
				3801
				3802	<h5>Syntax:</h5>
				3803	<pre>
				3804	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3805	</pre>
				3806
				3807	<h5>Overview:</h5>
				3808	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3809
				3810	<h5>Arguments:</h5>
				3811	<p>
				3812	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]	3813	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3814	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]	3815	<tt>value</tt> must be smaller than the bit size of the destination type,
				3816	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3817
				3818	<h5>Semantics:</h5>
				3819	<p>
				3820	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3821	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]	3822	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3823
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3824	<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]	3825
				3826	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3827	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3828	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3829	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3830	</pre>
				3831	</div>
				3832
				3833	<!-- _______________________________________________________________________ -->
				3834	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3835	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3836	</div>
				3837
				3838	<div class="doc_text">
				3839
				3840	<h5>Syntax:</h5>
				3841
				3842	<pre>
				3843	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3844	</pre>
				3845
				3846	<h5>Overview:</h5>
				3847	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3848	<tt>ty2</tt>.</p>
				3849
				3850
				3851	<h5>Arguments:</h5>
				3852	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3853	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3854	cast it to. The size of <tt>value</tt> must be larger than the size of
				3855	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3856	<i>no-op cast</i>.</p>
				3857
				3858	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3859	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3860	<a href="#t_floating">floating point</a> type to a smaller
				3861	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3862	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3863
				3864	<h5>Example:</h5>
				3865	<pre>
				3866	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3867	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3868	</pre>
				3869	</div>
				3870
				3871	<!-- _______________________________________________________________________ -->
				3872	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3873	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3874	</div>
				3875	<div class="doc_text">
				3876
				3877	<h5>Syntax:</h5>
				3878	<pre>
				3879	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3880	</pre>
				3881
				3882	<h5>Overview:</h5>
				3883	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3884	floating point value.</p>
				3885
				3886	<h5>Arguments:</h5>
				3887	<p>The '<tt>fpext</tt>' instruction takes a
				3888	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3889	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3890	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3891
				3892	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3893	<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]	3894	<a href="#t_floating">floating point</a> type to a larger
				3895	<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]	3896	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]	3897	<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]	3898
				3899	<h5>Example:</h5>
				3900	<pre>
				3901	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3902	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3903	</pre>
				3904	</div>
				3905
				3906	<!-- _______________________________________________________________________ -->
				3907	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3908	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3909	</div>
				3910	<div class="doc_text">
				3911
				3912	<h5>Syntax:</h5>
				3913	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3914	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3915	</pre>
				3916
				3917	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3918	<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]	3919	unsigned integer equivalent of type <tt>ty2</tt>.
				3920	</p>
				3921
				3922	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3923	<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]	3924	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3925	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3926	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3927	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]	3928
				3929	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3930	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3931	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3932	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3933	the results are undefined.</p>
				3934
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3935	<h5>Example:</h5>
				3936	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3937	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3938	%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]	3939	%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]	3940	</pre>
				3941	</div>
				3942
				3943	<!-- _______________________________________________________________________ -->
				3944	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3945	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3946	</div>
				3947	<div class="doc_text">
				3948
				3949	<h5>Syntax:</h5>
				3950	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3951	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3952	</pre>
				3953
				3954	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3955	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3956	<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]	3957	</p>
				3958
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3959	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3960	<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]	3961	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3962	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3963	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3964	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]	3965
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3966	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3967	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3968	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3969	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3970	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3971
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3972	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3973	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3974	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3975	%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]	3976	%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]	3977	</pre>
				3978	</div>
				3979
				3980	<!-- _______________________________________________________________________ -->
				3981	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3982	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3983	</div>
				3984	<div class="doc_text">
				3985
				3986	<h5>Syntax:</h5>
				3987	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3988	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3989	</pre>
				3990
				3991	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3992	<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]	3993	integer and converts that value to the <tt>ty2</tt> type.</p>
				3994
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3995	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3996	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3997	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3998	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3999	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4000	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]	4001
				4002	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4003	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4004	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4005	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]	4006
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4007	<h5>Example:</h5>
				4008	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4009	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4010	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4011	</pre>
				4012	</div>
				4013
				4014	<!-- _______________________________________________________________________ -->
				4015	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4016	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4017	</div>
				4018	<div class="doc_text">
				4019
				4020	<h5>Syntax:</h5>
				4021	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4022	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4023	</pre>
				4024
				4025	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4026	<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]	4027	integer and converts that value to the <tt>ty2</tt> type.</p>
				4028
				4029	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4030	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4031	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4032	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4033	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4034	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]	4035
				4036	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4037	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4038	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4039	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]	4040
				4041	<h5>Example:</h5>
				4042	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4043	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4044	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4045	</pre>
				4046	</div>
				4047
				4048	<!-- _______________________________________________________________________ -->
				4049	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4050	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4051	</div>
				4052	<div class="doc_text">
				4053
				4054	<h5>Syntax:</h5>
				4055	<pre>
				4056	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4057	</pre>
				4058
				4059	<h5>Overview:</h5>
				4060	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4061	the integer type <tt>ty2</tt>.</p>
				4062
				4063	<h5>Arguments:</h5>
				4064	<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]	4065	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]	4066	<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]	4067
				4068	<h5>Semantics:</h5>
				4069	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4070	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4071	truncating or zero extending that value to the size of the integer type. If
				4072	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4073	<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]	4074	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4075	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4076
				4077	<h5>Example:</h5>
				4078	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4079	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4080	%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]	4081	</pre>
				4082	</div>
				4083
				4084	<!-- _______________________________________________________________________ -->
				4085	<div class="doc_subsubsection">
				4086	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4087	</div>
				4088	<div class="doc_text">
				4089
				4090	<h5>Syntax:</h5>
				4091	<pre>
				4092	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4093	</pre>
				4094
				4095	<h5>Overview:</h5>
				4096	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4097	a pointer type, <tt>ty2</tt>.</p>
				4098
				4099	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4100	<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]	4101	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]	4102	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4103
				4104	<h5>Semantics:</h5>
				4105	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4106	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4107	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4108	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4109	the size of a pointer then a zero extension is done. If they are the same size,
				4110	nothing is done (<i>no-op cast</i>).</p>
				4111
				4112	<h5>Example:</h5>
				4113	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4114	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4115	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4116	%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]	4117	</pre>
				4118	</div>
				4119
				4120	<!-- _______________________________________________________________________ -->
				4121	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4122	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4123	</div>
				4124	<div class="doc_text">
				4125
				4126	<h5>Syntax:</h5>
				4127	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4128	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4129	</pre>
				4130
				4131	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4132
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4133	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4134	<tt>ty2</tt> without changing any bits.</p>
				4135
				4136	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4137
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4138	<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]	4139	a non-aggregate first class value, and a type to cast it to, which must also be
				4140	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4141	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4142	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]	4143	type is a pointer, the destination type must also be a pointer. This
				4144	instruction supports bitwise conversion of vectors to integers and to vectors
				4145	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4146
				4147	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4148	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4149	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4150	this conversion. The conversion is done as if the <tt>value</tt> had been
				4151	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4152	converted to other pointer types with this instruction. To convert pointers to
				4153	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4154	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4155
				4156	<h5>Example:</h5>
				4157	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4158	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4159	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4160	%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]	4161	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4162	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4163
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4164	<!-- ======================================================================= -->
				4165	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4166	<div class="doc_text">
				4167	<p>The instructions in this category are the "miscellaneous"
				4168	instructions, which defy better classification.</p>
				4169	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4170
				4171	<!-- _______________________________________________________________________ -->
				4172	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4173	</div>
				4174	<div class="doc_text">
				4175	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4176	<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]	4177	</pre>
				4178	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4179	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4180	a vector of boolean values based on comparison
				4181	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4182	<h5>Arguments:</h5>
				4183	<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]	4184	the condition code indicating the kind of comparison to perform. It is not
				4185	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4186	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4187	<ol>
				4188	<li><tt>eq</tt>: equal</li>
				4189	<li><tt>ne</tt>: not equal </li>
				4190	<li><tt>ugt</tt>: unsigned greater than</li>
				4191	<li><tt>uge</tt>: unsigned greater or equal</li>
				4192	<li><tt>ult</tt>: unsigned less than</li>
				4193	<li><tt>ule</tt>: unsigned less or equal</li>
				4194	<li><tt>sgt</tt>: signed greater than</li>
				4195	<li><tt>sge</tt>: signed greater or equal</li>
				4196	<li><tt>slt</tt>: signed less than</li>
				4197	<li><tt>sle</tt>: signed less or equal</li>
				4198	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4199	<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]	4200	<a href="#t_pointer">pointer</a>
				4201	or integer <a href="#t_vector">vector</a> typed.
				4202	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4203	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4204	<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]	4205	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4206	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]	4207	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4208	<ol>
				4209	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4210	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4211	</li>
				4212	<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]	4213	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4214	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4215	<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]	4216	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4217	<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]	4218	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4219	<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]	4220	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4221	<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]	4222	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4223	<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]	4224	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4225	<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]	4226	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4227	<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]	4228	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4229	<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]	4230	</ol>
				4231	<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]	4232	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4233	<p>If the operands are integer vectors, then they are compared
				4234	element by element. The result is an <tt>i1</tt> vector with
				4235	the same number of elements as the values being compared.
				4236	Otherwise, the result is an <tt>i1</tt>.
				4237	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4238
				4239	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4240	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4241	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4242	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4243	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4244	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4245	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4246	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4247
				4248	<p>Note that the code generator does not yet support vector types with
				4249	the <tt>icmp</tt> instruction.</p>
				4250
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4251	</div>
				4252
				4253	<!-- _______________________________________________________________________ -->
				4254	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4255	</div>
				4256	<div class="doc_text">
				4257	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4258	<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]	4259	</pre>
				4260	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4261	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4262	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4263	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4264	<p>
				4265	If the operands are floating point scalars, then the result
				4266	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4267	</p>
				4268	<p>If the operands are floating point vectors, then the result type
				4269	is a vector of boolean with the same number of elements as the
				4270	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4271	<h5>Arguments:</h5>
				4272	<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]	4273	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]	4274	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4275	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4276	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4277	<li><tt>oeq</tt>: ordered and equal</li>
				4278	<li><tt>ogt</tt>: ordered and greater than </li>
				4279	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4280	<li><tt>olt</tt>: ordered and less than </li>
				4281	<li><tt>ole</tt>: ordered and less than or equal</li>
				4282	<li><tt>one</tt>: ordered and not equal</li>
				4283	<li><tt>ord</tt>: ordered (no nans)</li>
				4284	<li><tt>ueq</tt>: unordered or equal</li>
				4285	<li><tt>ugt</tt>: unordered or greater than </li>
				4286	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4287	<li><tt>ult</tt>: unordered or less than </li>
				4288	<li><tt>ule</tt>: unordered or less than or equal</li>
				4289	<li><tt>une</tt>: unordered or not equal</li>
				4290	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4291	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4292	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4293	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4294	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4295	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4296	either a <a href="#t_floating">floating point</a> type
				4297	or a <a href="#t_vector">vector</a> of floating point type.
				4298	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4299	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4300	<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]	4301	according to the condition code given as <tt>cond</tt>.
				4302	If the operands are vectors, then the vectors are compared
				4303	element by element.
				4304	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4305	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]	4306	<ol>
				4307	<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]	4308	<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]	4309	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4310	<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]	4311	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4312	<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]	4313	<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]	4314	<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]	4315	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4316	<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]	4317	<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]	4318	<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]	4319	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4320	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4321	<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]	4322	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4323	<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]	4324	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4325	<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]	4326	<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]	4327	<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]	4328	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4329	<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]	4330	<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]	4331	<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]	4332	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4333	<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]	4334	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4335	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4336
				4337	<h5>Example:</h5>
				4338	<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]	4339	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4340	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4341	<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]	4342	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4343
				4344	<p>Note that the code generator does not yet support vector types with
				4345	the <tt>fcmp</tt> instruction.</p>
				4346
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4347	</div>
				4348
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4349	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4350	<div class="doc_subsubsection">
				4351	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4352	</div>
				4353	<div class="doc_text">
				4354	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4355	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4356	</pre>
				4357	<h5>Overview:</h5>
				4358	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4359	element-wise comparison of its two integer vector operands.</p>
				4360	<h5>Arguments:</h5>
				4361	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4362	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]	4363	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4364	<ol>
				4365	<li><tt>eq</tt>: equal</li>
				4366	<li><tt>ne</tt>: not equal </li>
				4367	<li><tt>ugt</tt>: unsigned greater than</li>
				4368	<li><tt>uge</tt>: unsigned greater or equal</li>
				4369	<li><tt>ult</tt>: unsigned less than</li>
				4370	<li><tt>ule</tt>: unsigned less or equal</li>
				4371	<li><tt>sgt</tt>: signed greater than</li>
				4372	<li><tt>sge</tt>: signed greater or equal</li>
				4373	<li><tt>slt</tt>: signed less than</li>
				4374	<li><tt>sle</tt>: signed less or equal</li>
				4375	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4376	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4377	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4378	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4379	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4380	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4381	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4382	identical type as the values being compared. The most significant bit in each
				4383	element is 1 if the element-wise comparison evaluates to true, and is 0
				4384	otherwise. All other bits of the result are undefined. The condition codes
				4385	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4386	instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4387
				4388	<h5>Example:</h5>
				4389	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4390	<result> = vicmp eq <2 x i32> < i32 4, i32 0>, < i32 5, i32 0> <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4391	<result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4392	</pre>
				4393	</div>
				4394
				4395	<!-- _______________________________________________________________________ -->
				4396	<div class="doc_subsubsection">
				4397	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4398	</div>
				4399	<div class="doc_text">
				4400	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4401	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4402	<h5>Overview:</h5>
				4403	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4404	element-wise comparison of its two floating point vector operands. The output
				4405	elements have the same width as the input elements.</p>
				4406	<h5>Arguments:</h5>
				4407	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4408	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]	4409	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4410	<ol>
				4411	<li><tt>false</tt>: no comparison, always returns false</li>
				4412	<li><tt>oeq</tt>: ordered and equal</li>
				4413	<li><tt>ogt</tt>: ordered and greater than </li>
				4414	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4415	<li><tt>olt</tt>: ordered and less than </li>
				4416	<li><tt>ole</tt>: ordered and less than or equal</li>
				4417	<li><tt>one</tt>: ordered and not equal</li>
				4418	<li><tt>ord</tt>: ordered (no nans)</li>
				4419	<li><tt>ueq</tt>: unordered or equal</li>
				4420	<li><tt>ugt</tt>: unordered or greater than </li>
				4421	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4422	<li><tt>ult</tt>: unordered or less than </li>
				4423	<li><tt>ule</tt>: unordered or less than or equal</li>
				4424	<li><tt>une</tt>: unordered or not equal</li>
				4425	<li><tt>uno</tt>: unordered (either nans)</li>
				4426	<li><tt>true</tt>: no comparison, always returns true</li>
				4427	</ol>
				4428	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4429	<a href="#t_floating">floating point</a> typed. They must also be identical
				4430	types.</p>
				4431	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4432	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4433	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4434	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4435	an identical number of elements as the values being compared, and each element
				4436	having identical with to the width of the floating point elements. The most
				4437	significant bit in each element is 1 if the element-wise comparison evaluates to
				4438	true, and is 0 otherwise. All other bits of the result are undefined. The
				4439	condition codes are evaluated identically to the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4440	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4441
				4442	<h5>Example:</h5>
				4443	<pre>
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	4444	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4445	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4446
				4447	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4448	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4449	</pre>
				4450	</div>
				4451
				4452	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4453	<div class="doc_subsubsection">
				4454	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4455	</div>
				4456
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4457	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4458
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4459	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4460
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4461	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4462	<h5>Overview:</h5>
				4463	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4464	the SSA graph representing the function.</p>
				4465	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4466
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4467	<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]	4468	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4469	as arguments, with one pair for each predecessor basic block of the
				4470	current block. Only values of <a href="#t_firstclass">first class</a>
				4471	type may be used as the value arguments to the PHI node. Only labels
				4472	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4473
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4474	<p>There must be no non-phi instructions between the start of a basic
				4475	block and the PHI instructions: i.e. PHI instructions must be first in
				4476	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4477
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4478	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4479
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4480	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4481	specified by the pair corresponding to the predecessor basic block that executed
				4482	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4483
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4484	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4485	<pre>
				4486	Loop: ; Infinite loop that counts from 0 on up...
				4487	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4488	%nextindvar = add i32 %indvar, 1
				4489	br label %Loop
				4490	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4491	</div>
				4492
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4493	<!-- _______________________________________________________________________ -->
				4494	<div class="doc_subsubsection">
				4495	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4496	</div>
				4497
				4498	<div class="doc_text">
				4499
				4500	<h5>Syntax:</h5>
				4501
				4502	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4503	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4504
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4505	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4506	</pre>
				4507
				4508	<h5>Overview:</h5>
				4509
				4510	<p>
				4511	The '<tt>select</tt>' instruction is used to choose one value based on a
				4512	condition, without branching.
				4513	</p>
				4514
				4515
				4516	<h5>Arguments:</h5>
				4517
				4518	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4519	The '<tt>select</tt>' instruction requires an 'i1' value or
				4520	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4521	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]	4522	type. If the val1/val2 are vectors and
				4523	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4524	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4525	</p>
				4526
				4527	<h5>Semantics:</h5>
				4528
				4529	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4530	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]	4531	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4532	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4533	<p>
				4534	If the condition is a vector of i1, then the value arguments must
				4535	be vectors of the same size, and the selection is done element
				4536	by element.
				4537	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4538
				4539	<h5>Example:</h5>
				4540
				4541	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4542	%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]	4543	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4544
				4545	<p>Note that the code generator does not yet support conditions
				4546	with vector type.</p>
				4547
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4548	</div>
				4549
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4550
				4551	<!-- _______________________________________________________________________ -->
				4552	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4553	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4554	</div>
				4555
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4556	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4557
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4558	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4559	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4560	<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]	4561	</pre>
				4562
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4563	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4564
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4565	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4566
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4567	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4568
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4569	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4570
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4571	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4572	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4573	<p>The optional "tail" marker indicates whether the callee function accesses
				4574	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]	4575	function call is eligible for tail call optimization. Note that calls may
				4576	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4577	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4578	</li>
				4579	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4580	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4581	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]	4582	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4583	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4584
				4585	<li>
				4586	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4587	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4588	and '<tt>inreg</tt>' attributes are valid here.</p>
				4589	</li>
				4590
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4591	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4592	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4593	the type of the return value. Functions that return no value are marked
				4594	<tt><a href="#t_void">void</a></tt>.</p>
				4595	</li>
				4596	<li>
				4597	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4598	value being invoked. The argument types must match the types implied by
				4599	this signature. This type can be omitted if the function is not varargs
				4600	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]	4601	</li>
				4602	<li>
				4603	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4604	be invoked. In most cases, this is a direct function invocation, but
				4605	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]	4606	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4607	</li>
				4608	<li>
				4609	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4610	function signature argument types. All arguments must be of
				4611	<a href="#t_firstclass">first class</a> type. If the function signature
				4612	indicates the function accepts a variable number of arguments, the extra
				4613	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4614	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4615	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4616	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4617	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4618	'<tt>readnone</tt>' attributes are valid here.</p>
				4619	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4620	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4621
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4622	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4623
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4624	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4625	transfer to a specified function, with its incoming arguments bound to
				4626	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4627	instruction in the called function, control flow continues with the
				4628	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4629	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4630
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4631	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4632
				4633	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4634	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4635	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4636	%X = tail call i32 @foo() <i>; yields i32</i>
				4637	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4638	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4639
				4640	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4641	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4642	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4643	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4644	%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]	4645	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4646	</pre>
				4647
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4648	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4649
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4650	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4651	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4652	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4653	</div>
				4654
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4655	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4656
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4657	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4658
				4659	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4660	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4661	</pre>
				4662
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4663	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4664
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4665	<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]	4666	the "variable argument" area of a function call. It is used to implement the
				4667	<tt>va_arg</tt> macro in C.</p>
				4668
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4669	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4670
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4671	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4672	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4673	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]	4674	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4675
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4676	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4677
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4678	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4679	type from the specified <tt>va_list</tt> and causes the
				4680	<tt>va_list</tt> to point to the next argument. For more information,
				4681	see the variable argument handling <a href="#int_varargs">Intrinsic
				4682	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4683
				4684	<p>It is legal for this instruction to be called in a function which does not
				4685	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4686	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4687
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4688	<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]	4689	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4690	argument.</p>
				4691
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4692	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4693
				4694	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4695
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4696	<p>Note that the code generator does not yet fully support va_arg
				4697	on many targets. Also, it does not currently support va_arg with
				4698	aggregate types on any target.</p>
				4699
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4700	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4701
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4702	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4703	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4704	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4705
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4706	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4707
				4708	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4709	well known names and semantics and are required to follow certain restrictions.
				4710	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4711	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]	4712	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]	4713
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4714	<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]	4715	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4716	begin with this prefix. Intrinsic functions must always be external functions:
				4717	you cannot define the body of intrinsic functions. Intrinsic functions may
				4718	only be used in call or invoke instructions: it is illegal to take the address
				4719	of an intrinsic function. Additionally, because intrinsic functions are part
				4720	of the LLVM language, it is required if any are added that they be documented
				4721	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4722
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4723	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4724	a family of functions that perform the same operation but on different data
				4725	types. Because LLVM can represent over 8 million different integer types,
				4726	overloading is used commonly to allow an intrinsic function to operate on any
				4727	integer type. One or more of the argument types or the result type can be
				4728	overloaded to accept any integer type. Argument types may also be defined as
				4729	exactly matching a previous argument's type or the result type. This allows an
				4730	intrinsic function which accepts multiple arguments, but needs all of them to
				4731	be of the same type, to only be overloaded with respect to a single argument or
				4732	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4733
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4734	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4735	encoded into its function name, each preceded by a period. Only those types
				4736	which are overloaded result in a name suffix. Arguments whose type is matched
				4737	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4738	take an integer of any width and returns an integer of exactly the same integer
				4739	width. This leads to a family of functions such as
				4740	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4741	Only one type, the return type, is overloaded, and only one type suffix is
				4742	required. Because the argument's type is matched against the return type, it
				4743	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4744
				4745	<p>To learn how to add an intrinsic function, please see the
				4746	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4747	</p>
				4748
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4749	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4750
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4751	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4752	<div class="doc_subsection">
				4753	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4754	</div>
				4755
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4756	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4757
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4758	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4759	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]	4760	intrinsic functions. These functions are related to the similarly
				4761	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4762
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4763	<p>All of these functions operate on arguments that use a
				4764	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4765	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4766	transformations should be prepared to handle these functions regardless of
				4767	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4768
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4769	<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]	4770	instruction and the variable argument handling intrinsic functions are
				4771	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4772
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4773	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4774	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4775	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4776	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4777	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4778	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4779	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4780
				4781	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4782	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4783
				4784	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4785	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4786	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4787	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4788	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4789
				4790	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4791	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4792	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4793	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4794
				4795	declare void @llvm.va_start(i8*)
				4796	declare void @llvm.va_copy(i8, i8)
				4797	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4798	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4799	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4800
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4801	</div>
				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_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4805	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4806	</div>
				4807
				4808
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4809	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4810	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4811	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4812	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4813	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4814	<tt>*<arglist></tt> for subsequent use by <tt><a
				4815	href="#i_va_arg">va_arg</a></tt>.</p>
				4816
				4817	<h5>Arguments:</h5>
				4818
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4819	<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]	4820
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4821	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4822
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4823	<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]	4824	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4825	<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]	4826	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4827	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]	4828	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]	4829
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4830	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4831
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4832	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4833	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4834	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4835	</div>
				4836
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4837	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4838	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4839	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4840	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4841
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4842	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4843	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]	4844	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]	4845
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4846	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4847
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4848	<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]	4849
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4850	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4851
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4852	<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]	4853	macro available in C. In a target-dependent way, it destroys the
				4854	<tt>va_list</tt> element to which the argument points. Calls to <a
				4855	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4856	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4857	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4858
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4859	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4860
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4861	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4862	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4863	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4864	</div>
				4865
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4866	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4867
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4868	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4869
				4870	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4871	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4872	</pre>
				4873
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4874	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4875
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4876	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4877	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4878
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4879	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4880
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4881	<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]	4882	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]	4883
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4884
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4885	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4886
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4887	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4888	macro available in C. In a target-dependent way, it copies the source
				4889	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4890	intrinsic is necessary because the <tt><a href="#int_va_start">
				4891	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4892	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4893
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4894	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4895
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4896	<!-- ======================================================================= -->
				4897	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4898	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4899	</div>
				4900
				4901	<div class="doc_text">
				4902
				4903	<p>
				4904	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4905	Collection</a> (GC) requires the implementation and generation of these
				4906	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4907	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]	4908	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4909	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]	4910	Front-ends for type-safe garbage collected languages should generate these
				4911	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4912	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4913	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4914
				4915	<p>The garbage collection intrinsics only operate on objects in the generic
				4916	address space (address space zero).</p>
				4917
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4918	</div>
				4919
				4920	<!-- _______________________________________________________________________ -->
				4921	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4922	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4923	</div>
				4924
				4925	<div class="doc_text">
				4926
				4927	<h5>Syntax:</h5>
				4928
				4929	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4930	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4931	</pre>
				4932
				4933	<h5>Overview:</h5>
				4934
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4935	<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]	4936	the code generator, and allows some metadata to be associated with it.</p>
				4937
				4938	<h5>Arguments:</h5>
				4939
				4940	<p>The first argument specifies the address of a stack object that contains the
				4941	root pointer. The second pointer (which must be either a constant or a global
				4942	value address) contains the meta-data to be associated with the root.</p>
				4943
				4944	<h5>Semantics:</h5>
				4945
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4946	<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]	4947	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4948	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4949	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4950	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4951
				4952	</div>
				4953
				4954
				4955	<!-- _______________________________________________________________________ -->
				4956	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4957	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4958	</div>
				4959
				4960	<div class="doc_text">
				4961
				4962	<h5>Syntax:</h5>
				4963
				4964	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4965	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4966	</pre>
				4967
				4968	<h5>Overview:</h5>
				4969
				4970	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4971	locations, allowing garbage collector implementations that require read
				4972	barriers.</p>
				4973
				4974	<h5>Arguments:</h5>
				4975
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4976	<p>The second argument is the address to read from, which should be an address
				4977	allocated from the garbage collector. The first object is a pointer to the
				4978	start of the referenced object, if needed by the language runtime (otherwise
				4979	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4980
				4981	<h5>Semantics:</h5>
				4982
				4983	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4984	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4985	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4986	may only be used in a function which <a href="#gc">specifies a GC
				4987	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4988
				4989	</div>
				4990
				4991
				4992	<!-- _______________________________________________________________________ -->
				4993	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4994	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4995	</div>
				4996
				4997	<div class="doc_text">
				4998
				4999	<h5>Syntax:</h5>
				5000
				5001	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5002	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5003	</pre>
				5004
				5005	<h5>Overview:</h5>
				5006
				5007	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5008	locations, allowing garbage collector implementations that require write
				5009	barriers (such as generational or reference counting collectors).</p>
				5010
				5011	<h5>Arguments:</h5>
				5012
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5013	<p>The first argument is the reference to store, the second is the start of the
				5014	object to store it to, and the third is the address of the field of Obj to
				5015	store to. If the runtime does not require a pointer to the object, Obj may be
				5016	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5017
				5018	<h5>Semantics:</h5>
				5019
				5020	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5021	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5022	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5023	may only be used in a function which <a href="#gc">specifies a GC
				5024	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5025
				5026	</div>
				5027
				5028
				5029
				5030	<!-- ======================================================================= -->
				5031	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5032	<a name="int_codegen">Code Generator Intrinsics</a>
				5033	</div>
				5034
				5035	<div class="doc_text">
				5036	<p>
				5037	These intrinsics are provided by LLVM to expose special features that may only
				5038	be implemented with code generator support.
				5039	</p>
				5040
				5041	</div>
				5042
				5043	<!-- _______________________________________________________________________ -->
				5044	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5045	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5046	</div>
				5047
				5048	<div class="doc_text">
				5049
				5050	<h5>Syntax:</h5>
				5051	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5052	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5053	</pre>
				5054
				5055	<h5>Overview:</h5>
				5056
				5057	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5058	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5059	target-specific value indicating the return address of the current function
				5060	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5061	</p>
				5062
				5063	<h5>Arguments:</h5>
				5064
				5065	<p>
				5066	The argument to this intrinsic indicates which function to return the address
				5067	for. Zero indicates the calling function, one indicates its caller, etc. The
				5068	argument is <b>required</b> to be a constant integer value.
				5069	</p>
				5070
				5071	<h5>Semantics:</h5>
				5072
				5073	<p>
				5074	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5075	the return address of the specified call frame, or zero if it cannot be
				5076	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5077	for arguments other than zero, so it should only be used for debugging purposes.
				5078	</p>
				5079
				5080	<p>
				5081	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5082	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]	5083	source-language caller.
				5084	</p>
				5085	</div>
				5086
				5087
				5088	<!-- _______________________________________________________________________ -->
				5089	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5090	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5091	</div>
				5092
				5093	<div class="doc_text">
				5094
				5095	<h5>Syntax:</h5>
				5096	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5097	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5098	</pre>
				5099
				5100	<h5>Overview:</h5>
				5101
				5102	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5103	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5104	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5105	</p>
				5106
				5107	<h5>Arguments:</h5>
				5108
				5109	<p>
				5110	The argument to this intrinsic indicates which function to return the frame
				5111	pointer for. Zero indicates the calling function, one indicates its caller,
				5112	etc. The argument is <b>required</b> to be a constant integer value.
				5113	</p>
				5114
				5115	<h5>Semantics:</h5>
				5116
				5117	<p>
				5118	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5119	the frame address of the specified call frame, or zero if it cannot be
				5120	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5121	for arguments other than zero, so it should only be used for debugging purposes.
				5122	</p>
				5123
				5124	<p>
				5125	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5126	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]	5127	source-language caller.
				5128	</p>
				5129	</div>
				5130
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5131	<!-- _______________________________________________________________________ -->
				5132	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5133	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5134	</div>
				5135
				5136	<div class="doc_text">
				5137
				5138	<h5>Syntax:</h5>
				5139	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5140	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5141	</pre>
				5142
				5143	<h5>Overview:</h5>
				5144
				5145	<p>
				5146	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]	5147	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5148	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5149	features like scoped automatic variable sized arrays in C99.
				5150	</p>
				5151
				5152	<h5>Semantics:</h5>
				5153
				5154	<p>
				5155	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]	5156	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5157	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5158	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5159	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5160	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5161	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5162	</p>
				5163
				5164	</div>
				5165
				5166	<!-- _______________________________________________________________________ -->
				5167	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5168	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5169	</div>
				5170
				5171	<div class="doc_text">
				5172
				5173	<h5>Syntax:</h5>
				5174	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5175	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5176	</pre>
				5177
				5178	<h5>Overview:</h5>
				5179
				5180	<p>
				5181	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5182	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]	5183	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5184	useful for implementing language features like scoped automatic variable sized
				5185	arrays in C99.
				5186	</p>
				5187
				5188	<h5>Semantics:</h5>
				5189
				5190	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5191	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]	5192	</p>
				5193
				5194	</div>
				5195
				5196
				5197	<!-- _______________________________________________________________________ -->
				5198	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5199	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5200	</div>
				5201
				5202	<div class="doc_text">
				5203
				5204	<h5>Syntax:</h5>
				5205	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5206	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5207	</pre>
				5208
				5209	<h5>Overview:</h5>
				5210
				5211
				5212	<p>
				5213	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]	5214	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5215	no
				5216	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5217	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5218	</p>
				5219
				5220	<h5>Arguments:</h5>
				5221
				5222	<p>
				5223	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5224	determining if the fetch should be for a read (0) or write (1), and
				5225	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5226	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]	5227	<tt>locality</tt> arguments must be constant integers.
				5228	</p>
				5229
				5230	<h5>Semantics:</h5>
				5231
				5232	<p>
				5233	This intrinsic does not modify the behavior of the program. In particular,
				5234	prefetches cannot trap and do not produce a value. On targets that support this
				5235	intrinsic, the prefetch can provide hints to the processor cache for better
				5236	performance.
				5237	</p>
				5238
				5239	</div>
				5240
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5241	<!-- _______________________________________________________________________ -->
				5242	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5243	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5244	</div>
				5245
				5246	<div class="doc_text">
				5247
				5248	<h5>Syntax:</h5>
				5249	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5250	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5251	</pre>
				5252
				5253	<h5>Overview:</h5>
				5254
				5255
				5256	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5257	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]	5258	(PC) in a region of
				5259	code to simulators and other tools. The method is target specific, but it is
				5260	expected that the marker will use exported symbols to transmit the PC of the
				5261	marker.
				5262	The marker makes no guarantees that it will remain with any specific instruction
				5263	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]	5264	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5265	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5266	</p>
				5267
				5268	<h5>Arguments:</h5>
				5269
				5270	<p>
				5271	<tt>id</tt> is a numerical id identifying the marker.
				5272	</p>
				5273
				5274	<h5>Semantics:</h5>
				5275
				5276	<p>
				5277	This intrinsic does not modify the behavior of the program. Backends that do not
				5278	support this intrinisic may ignore it.
				5279	</p>
				5280
				5281	</div>
				5282
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5283	<!-- _______________________________________________________________________ -->
				5284	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5285	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5286	</div>
				5287
				5288	<div class="doc_text">
				5289
				5290	<h5>Syntax:</h5>
				5291	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5292	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5293	</pre>
				5294
				5295	<h5>Overview:</h5>
				5296
				5297
				5298	<p>
				5299	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5300	counter register (or similar low latency, high accuracy clocks) on those targets
				5301	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5302	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5303	should only be used for small timings.
				5304	</p>
				5305
				5306	<h5>Semantics:</h5>
				5307
				5308	<p>
				5309	When directly supported, reading the cycle counter should not modify any memory.
				5310	Implementations are allowed to either return a application specific value or a
				5311	system wide value. On backends without support, this is lowered to a constant 0.
				5312	</p>
				5313
				5314	</div>
				5315
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5316	<!-- ======================================================================= -->
				5317	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5318	<a name="int_libc">Standard C Library Intrinsics</a>
				5319	</div>
				5320
				5321	<div class="doc_text">
				5322	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5323	LLVM provides intrinsics for a few important standard C library functions.
				5324	These intrinsics allow source-language front-ends to pass information about the
				5325	alignment of the pointer arguments to the code generator, providing opportunity
				5326	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5327	</p>
				5328
				5329	</div>
				5330
				5331	<!-- _______________________________________________________________________ -->
				5332	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5333	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5334	</div>
				5335
				5336	<div class="doc_text">
				5337
				5338	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5339	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5340	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5341	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5342	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5343	i8 <len>, i32 <align>)
				5344	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5345	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5346	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5347	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5348	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5349	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5350	</pre>
				5351
				5352	<h5>Overview:</h5>
				5353
				5354	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5355	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]	5356	location to the destination location.
				5357	</p>
				5358
				5359	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5360	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5361	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5362	</p>
				5363
				5364	<h5>Arguments:</h5>
				5365
				5366	<p>
				5367	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]	5368	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5369	specifying the number of bytes to copy, and the fourth argument is the alignment
				5370	of the source and destination locations.
				5371	</p>
				5372
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5373	<p>
				5374	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]	5375	the caller guarantees that both the source and destination pointers are aligned
				5376	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5377	</p>
				5378
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5379	<h5>Semantics:</h5>
				5380
				5381	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5382	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]	5383	location to the destination location, which are not allowed to overlap. It
				5384	copies "len" bytes of memory over. If the argument is known to be aligned to
				5385	some boundary, this can be specified as the fourth argument, otherwise it should
				5386	be set to 0 or 1.
				5387	</p>
				5388	</div>
				5389
				5390
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5391	<!-- _______________________________________________________________________ -->
				5392	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5393	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5394	</div>
				5395
				5396	<div class="doc_text">
				5397
				5398	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5399	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5400	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5401	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5402	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5403	i8 <len>, i32 <align>)
				5404	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5405	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5406	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5407	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5408	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5409	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5410	</pre>
				5411
				5412	<h5>Overview:</h5>
				5413
				5414	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5415	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5416	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5417	'<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]	5418	</p>
				5419
				5420	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5421	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5422	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5423	</p>
				5424
				5425	<h5>Arguments:</h5>
				5426
				5427	<p>
				5428	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]	5429	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5430	specifying the number of bytes to copy, and the fourth argument is the alignment
				5431	of the source and destination locations.
				5432	</p>
				5433
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5434	<p>
				5435	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]	5436	the caller guarantees that the source and destination pointers are aligned to
				5437	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5438	</p>
				5439
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5440	<h5>Semantics:</h5>
				5441
				5442	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5443	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]	5444	location to the destination location, which may overlap. It
				5445	copies "len" bytes of memory over. If the argument is known to be aligned to
				5446	some boundary, this can be specified as the fourth argument, otherwise it should
				5447	be set to 0 or 1.
				5448	</p>
				5449	</div>
				5450
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5451
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5452	<!-- _______________________________________________________________________ -->
				5453	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5454	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5455	</div>
				5456
				5457	<div class="doc_text">
				5458
				5459	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5460	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5461	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5462	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5463	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5464	i8 <len>, i32 <align>)
				5465	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5466	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5467	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5468	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5469	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5470	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5471	</pre>
				5472
				5473	<h5>Overview:</h5>
				5474
				5475	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5476	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]	5477	byte value.
				5478	</p>
				5479
				5480	<p>
				5481	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5482	does not return a value, and takes an extra alignment argument.
				5483	</p>
				5484
				5485	<h5>Arguments:</h5>
				5486
				5487	<p>
				5488	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]	5489	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5490	argument specifying the number of bytes to fill, and the fourth argument is the
				5491	known alignment of destination location.
				5492	</p>
				5493
				5494	<p>
				5495	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]	5496	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5497	</p>
				5498
				5499	<h5>Semantics:</h5>
				5500
				5501	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5502	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5503	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5504	destination location. If the argument is known to be aligned to some boundary,
				5505	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5506	1.
				5507	</p>
				5508	</div>
				5509
				5510
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5511	<!-- _______________________________________________________________________ -->
				5512	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5513	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5514	</div>
				5515
				5516	<div class="doc_text">
				5517
				5518	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5519	<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]	5520	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]	5521	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5522	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5523	declare float @llvm.sqrt.f32(float %Val)
				5524	declare double @llvm.sqrt.f64(double %Val)
				5525	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5526	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5527	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5528	</pre>
				5529
				5530	<h5>Overview:</h5>
				5531
				5532	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5533	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]	5534	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]	5535	<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]	5536	negative numbers other than -0.0 (which allows for better optimization, because
				5537	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5538	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5539	</p>
				5540
				5541	<h5>Arguments:</h5>
				5542
				5543	<p>
				5544	The argument and return value are floating point numbers of the same type.
				5545	</p>
				5546
				5547	<h5>Semantics:</h5>
				5548
				5549	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5550	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]	5551	floating point number.
				5552	</p>
				5553	</div>
				5554
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5555	<!-- _______________________________________________________________________ -->
				5556	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5557	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5558	</div>
				5559
				5560	<div class="doc_text">
				5561
				5562	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5563	<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]	5564	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]	5565	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5566	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5567	declare float @llvm.powi.f32(float %Val, i32 %power)
				5568	declare double @llvm.powi.f64(double %Val, i32 %power)
				5569	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5570	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5571	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5572	</pre>
				5573
				5574	<h5>Overview:</h5>
				5575
				5576	<p>
				5577	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5578	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5579	multiplications is not defined. When a vector of floating point type is
				5580	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5581	</p>
				5582
				5583	<h5>Arguments:</h5>
				5584
				5585	<p>
				5586	The second argument is an integer power, and the first is a value to raise to
				5587	that power.
				5588	</p>
				5589
				5590	<h5>Semantics:</h5>
				5591
				5592	<p>
				5593	This function returns the first value raised to the second power with an
				5594	unspecified sequence of rounding operations.</p>
				5595	</div>
				5596
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5597	<!-- _______________________________________________________________________ -->
				5598	<div class="doc_subsubsection">
				5599	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5600	</div>
				5601
				5602	<div class="doc_text">
				5603
				5604	<h5>Syntax:</h5>
				5605	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5606	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]	5607	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5608	<pre>
				5609	declare float @llvm.sin.f32(float %Val)
				5610	declare double @llvm.sin.f64(double %Val)
				5611	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5612	declare fp128 @llvm.sin.f128(fp128 %Val)
				5613	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5614	</pre>
				5615
				5616	<h5>Overview:</h5>
				5617
				5618	<p>
				5619	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5620	</p>
				5621
				5622	<h5>Arguments:</h5>
				5623
				5624	<p>
				5625	The argument and return value are floating point numbers of the same type.
				5626	</p>
				5627
				5628	<h5>Semantics:</h5>
				5629
				5630	<p>
				5631	This function returns the sine of the specified operand, returning the
				5632	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]	5633	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5634	</div>
				5635
				5636	<!-- _______________________________________________________________________ -->
				5637	<div class="doc_subsubsection">
				5638	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5639	</div>
				5640
				5641	<div class="doc_text">
				5642
				5643	<h5>Syntax:</h5>
				5644	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5645	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]	5646	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5647	<pre>
				5648	declare float @llvm.cos.f32(float %Val)
				5649	declare double @llvm.cos.f64(double %Val)
				5650	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5651	declare fp128 @llvm.cos.f128(fp128 %Val)
				5652	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5653	</pre>
				5654
				5655	<h5>Overview:</h5>
				5656
				5657	<p>
				5658	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5659	</p>
				5660
				5661	<h5>Arguments:</h5>
				5662
				5663	<p>
				5664	The argument and return value are floating point numbers of the same type.
				5665	</p>
				5666
				5667	<h5>Semantics:</h5>
				5668
				5669	<p>
				5670	This function returns the cosine of the specified operand, returning the
				5671	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]	5672	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5673	</div>
				5674
				5675	<!-- _______________________________________________________________________ -->
				5676	<div class="doc_subsubsection">
				5677	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5678	</div>
				5679
				5680	<div class="doc_text">
				5681
				5682	<h5>Syntax:</h5>
				5683	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5684	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]	5685	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5686	<pre>
				5687	declare float @llvm.pow.f32(float %Val, float %Power)
				5688	declare double @llvm.pow.f64(double %Val, double %Power)
				5689	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5690	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5691	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5692	</pre>
				5693
				5694	<h5>Overview:</h5>
				5695
				5696	<p>
				5697	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5698	specified (positive or negative) power.
				5699	</p>
				5700
				5701	<h5>Arguments:</h5>
				5702
				5703	<p>
				5704	The second argument is a floating point power, and the first is a value to
				5705	raise to that power.
				5706	</p>
				5707
				5708	<h5>Semantics:</h5>
				5709
				5710	<p>
				5711	This function returns the first value raised to the second power,
				5712	returning the
				5713	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]	5714	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5715	</div>
				5716
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5717
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5718	<!-- ======================================================================= -->
				5719	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5720	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5721	</div>
				5722
				5723	<div class="doc_text">
				5724	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5725	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5726	These allow efficient code generation for some algorithms.
				5727	</p>
				5728
				5729	</div>
				5730
				5731	<!-- _______________________________________________________________________ -->
				5732	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5733	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5734	</div>
				5735
				5736	<div class="doc_text">
				5737
				5738	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5739	<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]	5740	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]	5741	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5742	declare i16 @llvm.bswap.i16(i16 <id>)
				5743	declare i32 @llvm.bswap.i32(i32 <id>)
				5744	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5745	</pre>
				5746
				5747	<h5>Overview:</h5>
				5748
				5749	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5750	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]	5751	values with an even number of bytes (positive multiple of 16 bits). These are
				5752	useful for performing operations on data that is not in the target's native
				5753	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5754	</p>
				5755
				5756	<h5>Semantics:</h5>
				5757
				5758	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5759	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]	5760	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5761	intrinsic returns an i32 value that has the four bytes of the input i32
				5762	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]	5763	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5764	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5765	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5766	</p>
				5767
				5768	</div>
				5769
				5770	<!-- _______________________________________________________________________ -->
				5771	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5772	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5773	</div>
				5774
				5775	<div class="doc_text">
				5776
				5777	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5778	<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]	5779	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5780	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5781	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5782	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5783	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5784	declare i64 @llvm.ctpop.i64(i64 <src>)
				5785	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5786	</pre>
				5787
				5788	<h5>Overview:</h5>
				5789
				5790	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5791	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5792	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5793	</p>
				5794
				5795	<h5>Arguments:</h5>
				5796
				5797	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5798	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]	5799	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5800	</p>
				5801
				5802	<h5>Semantics:</h5>
				5803
				5804	<p>
				5805	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5806	</p>
				5807	</div>
				5808
				5809	<!-- _______________________________________________________________________ -->
				5810	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5811	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5812	</div>
				5813
				5814	<div class="doc_text">
				5815
				5816	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5817	<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]	5818	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5819	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5820	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5821	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5822	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5823	declare i64 @llvm.ctlz.i64(i64 <src>)
				5824	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5825	</pre>
				5826
				5827	<h5>Overview:</h5>
				5828
				5829	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5830	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5831	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5832	</p>
				5833
				5834	<h5>Arguments:</h5>
				5835
				5836	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5837	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]	5838	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5839	</p>
				5840
				5841	<h5>Semantics:</h5>
				5842
				5843	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5844	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5845	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]	5846	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5847	</p>
				5848	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5849
				5850
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5851
				5852	<!-- _______________________________________________________________________ -->
				5853	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5854	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5855	</div>
				5856
				5857	<div class="doc_text">
				5858
				5859	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5860	<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]	5861	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5862	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5863	declare i8 @llvm.cttz.i8 (i8 <src>)
				5864	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5865	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5866	declare i64 @llvm.cttz.i64(i64 <src>)
				5867	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5868	</pre>
				5869
				5870	<h5>Overview:</h5>
				5871
				5872	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5873	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5874	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5875	</p>
				5876
				5877	<h5>Arguments:</h5>
				5878
				5879	<p>
				5880	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]	5881	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5882	</p>
				5883
				5884	<h5>Semantics:</h5>
				5885
				5886	<p>
				5887	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5888	in a variable. If the src == 0 then the result is the size in bits of the type
				5889	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5890	</p>
				5891	</div>
				5892
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5893	<!-- _______________________________________________________________________ -->
				5894	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5895	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5896	</div>
				5897
				5898	<div class="doc_text">
				5899
				5900	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5901	<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]	5902	on any integer bit width.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5903	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5904	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5905	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5906	</pre>
				5907
				5908	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5909	<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]	5910	range of bits from an integer value and returns them in the same bit width as
				5911	the original value.</p>
				5912
				5913	<h5>Arguments:</h5>
				5914	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5915	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]	5916	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]	5917
				5918	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5919	<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]	5920	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5921	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5922	operates in forward mode.</p>
				5923	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5924	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]	5925	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5926	<ol>
				5927	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5928	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5929	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5930	to determine the number of bits to retain.</li>
				5931	<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]	5932	<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]	5933	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5934	<p>In reverse mode, a similar computation is made except that the bits are
				5935	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5936	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5937	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5938	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5939	</div>
				5940
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5941	<div class="doc_subsubsection">
				5942	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5943	</div>
				5944
				5945	<div class="doc_text">
				5946
				5947	<h5>Syntax:</h5>
				5948	<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]	5949	on any integer bit width.</p>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5950	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5951	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5952	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]	5953	</pre>
				5954
				5955	<h5>Overview:</h5>
				5956	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5957	of bits in an integer value with another integer value. It returns the integer
				5958	with the replaced bits.</p>
				5959
				5960	<h5>Arguments:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5961	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				5962	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]	5963	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5964	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5965	type since they specify only a bit index.</p>
				5966
				5967	<h5>Semantics:</h5>
				5968	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5969	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5970	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5971	operates in forward mode.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5972
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5973	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5974	truncating it down to the size of the replacement area or zero extending it
				5975	up to that size.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5976
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5977	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5978	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5979	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]	5980	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5981
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5982	<p>In reverse mode, a similar computation is made except that the bits are
				5983	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]	5984	<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]	5985
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5986	<h5>Examples:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5987
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5988	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5989	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5990	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5991	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5992	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5993	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5994	</pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5995
				5996	</div>
				5997
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5998	<!-- ======================================================================= -->
				5999	<div class="doc_subsection">
				6000	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6001	</div>
				6002
				6003	<div class="doc_text">
				6004	<p>
				6005	LLVM provides intrinsics for some arithmetic with overflow operations.
				6006	</p>
				6007
				6008	</div>
				6009
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6010	<!-- _______________________________________________________________________ -->
				6011	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6012	<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]	6013	</div>
				6014
				6015	<div class="doc_text">
				6016
				6017	<h5>Syntax:</h5>
				6018
				6019	<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]	6020	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6021
				6022	<pre>
				6023	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6024	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6025	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6026	</pre>
				6027
				6028	<h5>Overview:</h5>
				6029
				6030	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6031	a signed addition of the two arguments, and indicate whether an overflow
				6032	occurred during the signed summation.</p>
				6033
				6034	<h5>Arguments:</h5>
				6035
				6036	<p>The arguments (%a and %b) and the first element of the result structure may
				6037	be of integer types of any bit width, but they must have the same bit width. The
				6038	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6039	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6040
				6041	<h5>Semantics:</h5>
				6042
				6043	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6044	a signed addition of the two variables. They return a structure — the
				6045	first element of which is the signed summation, and the second element of which
				6046	is a bit specifying if the signed summation resulted in an overflow.</p>
				6047
				6048	<h5>Examples:</h5>
				6049	<pre>
				6050	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6051	%sum = extractvalue {i32, i1} %res, 0
				6052	%obit = extractvalue {i32, i1} %res, 1
				6053	br i1 %obit, label %overflow, label %normal
				6054	</pre>
				6055
				6056	</div>
				6057
				6058	<!-- _______________________________________________________________________ -->
				6059	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6060	<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]	6061	</div>
				6062
				6063	<div class="doc_text">
				6064
				6065	<h5>Syntax:</h5>
				6066
				6067	<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]	6068	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6069
				6070	<pre>
				6071	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6072	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6073	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6074	</pre>
				6075
				6076	<h5>Overview:</h5>
				6077
				6078	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6079	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6080	during the unsigned summation.</p>
				6081
				6082	<h5>Arguments:</h5>
				6083
				6084	<p>The arguments (%a and %b) and the first element of the result structure may
				6085	be of integer types of any bit width, but they must have the same bit width. The
				6086	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6087	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6088
				6089	<h5>Semantics:</h5>
				6090
				6091	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6092	an unsigned addition of the two arguments. They return a structure — the
				6093	first element of which is the sum, and the second element of which is a bit
				6094	specifying if the unsigned summation resulted in a carry.</p>
				6095
				6096	<h5>Examples:</h5>
				6097	<pre>
				6098	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6099	%sum = extractvalue {i32, i1} %res, 0
				6100	%obit = extractvalue {i32, i1} %res, 1
				6101	br i1 %obit, label %carry, label %normal
				6102	</pre>
				6103
				6104	</div>
				6105
				6106	<!-- _______________________________________________________________________ -->
				6107	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6108	<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]	6109	</div>
				6110
				6111	<div class="doc_text">
				6112
				6113	<h5>Syntax:</h5>
				6114
				6115	<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]	6116	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6117
				6118	<pre>
				6119	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6120	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6121	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6122	</pre>
				6123
				6124	<h5>Overview:</h5>
				6125
				6126	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6127	a signed subtraction of the two arguments, and indicate whether an overflow
				6128	occurred during the signed subtraction.</p>
				6129
				6130	<h5>Arguments:</h5>
				6131
				6132	<p>The arguments (%a and %b) and the first element of the result structure may
				6133	be of integer types of any bit width, but they must have the same bit width. The
				6134	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6135	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6136
				6137	<h5>Semantics:</h5>
				6138
				6139	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6140	a signed subtraction of the two arguments. They return a structure — the
				6141	first element of which is the subtraction, and the second element of which is a bit
				6142	specifying if the signed subtraction resulted in an overflow.</p>
				6143
				6144	<h5>Examples:</h5>
				6145	<pre>
				6146	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6147	%sum = extractvalue {i32, i1} %res, 0
				6148	%obit = extractvalue {i32, i1} %res, 1
				6149	br i1 %obit, label %overflow, label %normal
				6150	</pre>
				6151
				6152	</div>
				6153
				6154	<!-- _______________________________________________________________________ -->
				6155	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6156	<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]	6157	</div>
				6158
				6159	<div class="doc_text">
				6160
				6161	<h5>Syntax:</h5>
				6162
				6163	<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]	6164	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6165
				6166	<pre>
				6167	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6168	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6169	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6170	</pre>
				6171
				6172	<h5>Overview:</h5>
				6173
				6174	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6175	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6176	occurred during the unsigned subtraction.</p>
				6177
				6178	<h5>Arguments:</h5>
				6179
				6180	<p>The arguments (%a and %b) and the first element of the result structure may
				6181	be of integer types of any bit width, but they must have the same bit width. The
				6182	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6183	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6184
				6185	<h5>Semantics:</h5>
				6186
				6187	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6188	an unsigned subtraction of the two arguments. They return a structure — the
				6189	first element of which is the subtraction, and the second element of which is a bit
				6190	specifying if the unsigned subtraction resulted in an overflow.</p>
				6191
				6192	<h5>Examples:</h5>
				6193	<pre>
				6194	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6195	%sum = extractvalue {i32, i1} %res, 0
				6196	%obit = extractvalue {i32, i1} %res, 1
				6197	br i1 %obit, label %overflow, label %normal
				6198	</pre>
				6199
				6200	</div>
				6201
				6202	<!-- _______________________________________________________________________ -->
				6203	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6204	<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]	6205	</div>
				6206
				6207	<div class="doc_text">
				6208
				6209	<h5>Syntax:</h5>
				6210
				6211	<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]	6212	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6213
				6214	<pre>
				6215	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6216	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6217	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6218	</pre>
				6219
				6220	<h5>Overview:</h5>
				6221
				6222	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6223	a signed multiplication of the two arguments, and indicate whether an overflow
				6224	occurred during the signed multiplication.</p>
				6225
				6226	<h5>Arguments:</h5>
				6227
				6228	<p>The arguments (%a and %b) and the first element of the result structure may
				6229	be of integer types of any bit width, but they must have the same bit width. The
				6230	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6231	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6232
				6233	<h5>Semantics:</h5>
				6234
				6235	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6236	a signed multiplication of the two arguments. They return a structure —
				6237	the first element of which is the multiplication, and the second element of
				6238	which is a bit specifying if the signed multiplication resulted in an
				6239	overflow.</p>
				6240
				6241	<h5>Examples:</h5>
				6242	<pre>
				6243	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6244	%sum = extractvalue {i32, i1} %res, 0
				6245	%obit = extractvalue {i32, i1} %res, 1
				6246	br i1 %obit, label %overflow, label %normal
				6247	</pre>
				6248
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6249	</div>
				6250
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6251	<!-- _______________________________________________________________________ -->
				6252	<div class="doc_subsubsection">
				6253	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6254	</div>
				6255
				6256	<div class="doc_text">
				6257
				6258	<h5>Syntax:</h5>
				6259
				6260	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6261	on any integer bit width.</p>
				6262
				6263	<pre>
				6264	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6265	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6266	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6267	</pre>
				6268
				6269	<h5>Overview:</h5>
				6270
				6271	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6272	actively being fixed, but it should not currently be used!</i></p>
				6273
				6274	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6275	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6276	occurred during the unsigned 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 unsigned
				6284	multiplication.</p>
				6285
				6286	<h5>Semantics:</h5>
				6287
				6288	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6289	an unsigned multiplication of the two arguments. They return a structure —
				6290	the first element of which is the multiplication, and the second element of
				6291	which is a bit specifying if the unsigned multiplication resulted in an
				6292	overflow.</p>
				6293
				6294	<h5>Examples:</h5>
				6295	<pre>
				6296	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6297	%sum = extractvalue {i32, i1} %res, 0
				6298	%obit = extractvalue {i32, i1} %res, 1
				6299	br i1 %obit, label %overflow, label %normal
				6300	</pre>
				6301
				6302	</div>
				6303
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6304	<!-- ======================================================================= -->
				6305	<div class="doc_subsection">
				6306	<a name="int_debugger">Debugger Intrinsics</a>
				6307	</div>
				6308
				6309	<div class="doc_text">
				6310	<p>
				6311	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6312	are described in the <a
				6313	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6314	Debugging</a> document.
				6315	</p>
				6316	</div>
				6317
				6318
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6319	<!-- ======================================================================= -->
				6320	<div class="doc_subsection">
				6321	<a name="int_eh">Exception Handling Intrinsics</a>
				6322	</div>
				6323
				6324	<div class="doc_text">
				6325	<p> The LLVM exception handling intrinsics (which all start with
				6326	<tt>llvm.eh.</tt> prefix), are described in the <a
				6327	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6328	Handling</a> document. </p>
				6329	</div>
				6330
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6331	<!-- ======================================================================= -->
				6332	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6333	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6334	</div>
				6335
				6336	<div class="doc_text">
				6337	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6338	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6339	the <tt>nest</tt> attribute, from a function. The result is a callable
				6340	function pointer lacking the nest parameter - the caller does not need
				6341	to provide a value for it. Instead, the value to use is stored in
				6342	advance in a "trampoline", a block of memory usually allocated
				6343	on the stack, which also contains code to splice the nest value into the
				6344	argument list. This is used to implement the GCC nested function address
				6345	extension.
				6346	</p>
				6347	<p>
				6348	For example, if the function is
				6349	<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]	6350	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]	6351	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6352	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6353	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6354	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6355	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6356	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6357	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6358	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]	6359	</div>
				6360
				6361	<!-- _______________________________________________________________________ -->
				6362	<div class="doc_subsubsection">
				6363	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6364	</div>
				6365	<div class="doc_text">
				6366	<h5>Syntax:</h5>
				6367	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6368	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6369	</pre>
				6370	<h5>Overview:</h5>
				6371	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6372	This fills the memory pointed to by <tt>tramp</tt> with code
				6373	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6374	</p>
				6375	<h5>Arguments:</h5>
				6376	<p>
				6377	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6378	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6379	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]	6380	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6381	currently provides no portable way of determining them, so a front-end that
				6382	generates this intrinsic needs to have some target-specific knowledge.
				6383	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]	6384	</p>
				6385	<h5>Semantics:</h5>
				6386	<p>
				6387	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]	6388	dependent code, turning it into a function. A pointer to this function is
				6389	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6390	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6391	before being called. The new function's signature is the same as that of
				6392	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6393	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6394	of pointer type. Calling the new function is equivalent to calling
				6395	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6396	missing <tt>nest</tt> argument. If, after calling
				6397	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6398	modified, then the effect of any later call to the returned function pointer is
				6399	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6400	</p>
				6401	</div>
				6402
				6403	<!-- ======================================================================= -->
				6404	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6405	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6406	</div>
				6407
				6408	<div class="doc_text">
				6409	<p>
				6410	These intrinsic functions expand the "universal IR" of LLVM to represent
				6411	hardware constructs for atomic operations and memory synchronization. This
				6412	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]	6413	is aimed at a low enough level to allow any programming models or APIs
				6414	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6415	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6416	hardware behavior. Just as hardware provides a "universal IR" for source
				6417	languages, it also provides a starting point for developing a "universal"
				6418	atomic operation and synchronization IR.
				6419	</p>
				6420	<p>
				6421	These do <em>not</em> form an API such as high-level threading libraries,
				6422	software transaction memory systems, atomic primitives, and intrinsic
				6423	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6424	application libraries. The hardware interface provided by LLVM should allow
				6425	a clean implementation of all of these APIs and parallel programming models.
				6426	No one model or paradigm should be selected above others unless the hardware
				6427	itself ubiquitously does so.
				6428
				6429	</p>
				6430	</div>
				6431
				6432	<!-- _______________________________________________________________________ -->
				6433	<div class="doc_subsubsection">
				6434	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6435	</div>
				6436	<div class="doc_text">
				6437	<h5>Syntax:</h5>
				6438	<pre>
				6439	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6440	i1 <device> )
				6441
				6442	</pre>
				6443	<h5>Overview:</h5>
				6444	<p>
				6445	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6446	specific pairs of memory access types.
				6447	</p>
				6448	<h5>Arguments:</h5>
				6449	<p>
				6450	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6451	The first four arguments enables a specific barrier as listed below. The fith
				6452	argument specifies that the barrier applies to io or device or uncached memory.
				6453
				6454	</p>
				6455	<ul>
				6456	<li><tt>ll</tt>: load-load barrier</li>
				6457	<li><tt>ls</tt>: load-store barrier</li>
				6458	<li><tt>sl</tt>: store-load barrier</li>
				6459	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6460	<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]	6461	</ul>
				6462	<h5>Semantics:</h5>
				6463	<p>
				6464	This intrinsic causes the system to enforce some ordering constraints upon
				6465	the loads and stores of the program. This barrier does not indicate
				6466	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6467	which they occur. For any of the specified pairs of load and store operations
				6468	(f.ex. load-load, or store-load), all of the first operations preceding the
				6469	barrier will complete before any of the second operations succeeding the
				6470	barrier begin. Specifically the semantics for each pairing is as follows:
				6471	</p>
				6472	<ul>
				6473	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6474	after the barrier begins.</li>
				6475
				6476	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6477	store after the barrier begins.</li>
				6478	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6479	store after the barrier begins.</li>
				6480	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6481	load after the barrier begins.</li>
				6482	</ul>
				6483	<p>
				6484	These semantics are applied with a logical "and" behavior when more than one
				6485	is enabled in a single memory barrier intrinsic.
				6486	</p>
				6487	<p>
				6488	Backends may implement stronger barriers than those requested when they do not
				6489	support as fine grained a barrier as requested. Some architectures do not
				6490	need all types of barriers and on such architectures, these become noops.
				6491	</p>
				6492	<h5>Example:</h5>
				6493	<pre>
				6494	%ptr = malloc i32
				6495	store i32 4, %ptr
				6496
				6497	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6498	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6499	<i>; guarantee the above finishes</i>
				6500	store i32 8, %ptr <i>; before this begins</i>
				6501	</pre>
				6502	</div>
				6503
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6504	<!-- _______________________________________________________________________ -->
				6505	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6506	<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]	6507	</div>
				6508	<div class="doc_text">
				6509	<h5>Syntax:</h5>
				6510	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6511	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6512	any integer bit width and for different address spaces. Not all targets
				6513	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6514
				6515	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6516	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6517	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6518	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6519	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]	6520
				6521	</pre>
				6522	<h5>Overview:</h5>
				6523	<p>
				6524	This loads a value in memory and compares it to a given value. If they are
				6525	equal, it stores a new value into the memory.
				6526	</p>
				6527	<h5>Arguments:</h5>
				6528	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6529	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]	6530	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6531	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6532	this integer type. While any bit width integer may be used, targets may only
				6533	lower representations they support in hardware.
				6534
				6535	</p>
				6536	<h5>Semantics:</h5>
				6537	<p>
				6538	This entire intrinsic must be executed atomically. It first loads the value
				6539	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6540	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6541	loaded value is yielded in all cases. This provides the equivalent of an
				6542	atomic compare-and-swap operation within the SSA framework.
				6543	</p>
				6544	<h5>Examples:</h5>
				6545
				6546	<pre>
				6547	%ptr = malloc i32
				6548	store i32 4, %ptr
				6549
				6550	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6551	%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]	6552	<i>; yields {i32}:result1 = 4</i>
				6553	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6554	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6555
				6556	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6557	%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]	6558	<i>; yields {i32}:result2 = 8</i>
				6559	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6560
				6561	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6562	</pre>
				6563	</div>
				6564
				6565	<!-- _______________________________________________________________________ -->
				6566	<div class="doc_subsubsection">
				6567	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6568	</div>
				6569	<div class="doc_text">
				6570	<h5>Syntax:</h5>
				6571
				6572	<p>
				6573	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6574	integer bit width. Not all targets support all bit widths however.</p>
				6575	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6576	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6577	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6578	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6579	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6580
				6581	</pre>
				6582	<h5>Overview:</h5>
				6583	<p>
				6584	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6585	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6586	at <tt>ptr</tt>.
				6587	</p>
				6588	<h5>Arguments:</h5>
				6589
				6590	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6591	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6592	<tt>val</tt> argument and the result must be integers of the same bit width.
				6593	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6594	integer type. The targets may only lower integer representations they
				6595	support.
				6596	</p>
				6597	<h5>Semantics:</h5>
				6598	<p>
				6599	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6600	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6601	equivalent of an atomic swap operation within the SSA framework.
				6602
				6603	</p>
				6604	<h5>Examples:</h5>
				6605	<pre>
				6606	%ptr = malloc i32
				6607	store i32 4, %ptr
				6608
				6609	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6610	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6611	<i>; yields {i32}:result1 = 4</i>
				6612	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6613	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6614
				6615	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6616	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6617	<i>; yields {i32}:result2 = 8</i>
				6618
				6619	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6620	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6621	</pre>
				6622	</div>
				6623
				6624	<!-- _______________________________________________________________________ -->
				6625	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6626	<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]	6627
				6628	</div>
				6629	<div class="doc_text">
				6630	<h5>Syntax:</h5>
				6631	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6632	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]	6633	integer bit width. Not all targets support all bit widths however.</p>
				6634	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6635	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6636	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6637	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6638	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6639
				6640	</pre>
				6641	<h5>Overview:</h5>
				6642	<p>
				6643	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6644	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6645	</p>
				6646	<h5>Arguments:</h5>
				6647	<p>
				6648
				6649	The intrinsic takes two arguments, the first a pointer to an integer value
				6650	and the second an integer value. The result is also an integer value. These
				6651	integer types can have any bit width, but they must all have the same bit
				6652	width. The targets may only lower integer representations they support.
				6653	</p>
				6654	<h5>Semantics:</h5>
				6655	<p>
				6656	This intrinsic does a series of operations atomically. It first loads the
				6657	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6658	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6659	</p>
				6660
				6661	<h5>Examples:</h5>
				6662	<pre>
				6663	%ptr = malloc i32
				6664	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6665	%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]	6666	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6667	%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]	6668	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6669	%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]	6670	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6671	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6672	</pre>
				6673	</div>
				6674
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6675	<!-- _______________________________________________________________________ -->
				6676	<div class="doc_subsubsection">
				6677	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6678
				6679	</div>
				6680	<div class="doc_text">
				6681	<h5>Syntax:</h5>
				6682	<p>
				6683	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]	6684	any integer bit width and for different address spaces. Not all targets
				6685	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6686	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6687	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6688	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6689	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6690	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]	6691
				6692	</pre>
				6693	<h5>Overview:</h5>
				6694	<p>
				6695	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6696	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6697	</p>
				6698	<h5>Arguments:</h5>
				6699	<p>
				6700
				6701	The intrinsic takes two arguments, the first a pointer to an integer value
				6702	and the second an integer value. The result is also an integer value. These
				6703	integer types can have any bit width, but they must all have the same bit
				6704	width. The targets may only lower integer representations they support.
				6705	</p>
				6706	<h5>Semantics:</h5>
				6707	<p>
				6708	This intrinsic does a series of operations atomically. It first loads the
				6709	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6710	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6711	</p>
				6712
				6713	<h5>Examples:</h5>
				6714	<pre>
				6715	%ptr = malloc i32
				6716	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6717	%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]	6718	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6719	%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]	6720	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6721	%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]	6722	<i>; yields {i32}:result3 = 2</i>
				6723	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6724	</pre>
				6725	</div>
				6726
				6727	<!-- _______________________________________________________________________ -->
				6728	<div class="doc_subsubsection">
				6729	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6730	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6731	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6732	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6733
				6734	</div>
				6735	<div class="doc_text">
				6736	<h5>Syntax:</h5>
				6737	<p>
				6738	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6739	<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]	6740	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6741	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6742	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6743	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6744	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6745	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6746	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]	6747
				6748	</pre>
				6749
				6750	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6751	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6752	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6753	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6754	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]	6755
				6756	</pre>
				6757
				6758	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6759	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6760	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6761	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6762	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]	6763
				6764	</pre>
				6765
				6766	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6767	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6768	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6769	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6770	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]	6771
				6772	</pre>
				6773	<h5>Overview:</h5>
				6774	<p>
				6775	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6776	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6777	at <tt>ptr</tt>.
				6778	</p>
				6779	<h5>Arguments:</h5>
				6780	<p>
				6781
				6782	These intrinsics take two arguments, the first a pointer to an integer value
				6783	and the second an integer value. The result is also an integer value. These
				6784	integer types can have any bit width, but they must all have the same bit
				6785	width. The targets may only lower integer representations they support.
				6786	</p>
				6787	<h5>Semantics:</h5>
				6788	<p>
				6789	These intrinsics does a series of operations atomically. They first load the
				6790	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6791	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6792	value stored at <tt>ptr</tt>.
				6793	</p>
				6794
				6795	<h5>Examples:</h5>
				6796	<pre>
				6797	%ptr = malloc i32
				6798	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6799	%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]	6800	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6801	%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]	6802	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6803	%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]	6804	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6805	%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]	6806	<i>; yields {i32}:result3 = FF</i>
				6807	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6808	</pre>
				6809	</div>
				6810
				6811
				6812	<!-- _______________________________________________________________________ -->
				6813	<div class="doc_subsubsection">
				6814	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6815	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6816	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6817	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6818
				6819	</div>
				6820	<div class="doc_text">
				6821	<h5>Syntax:</h5>
				6822	<p>
				6823	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6824	<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]	6825	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6826	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6827	support all bit widths however.</p>
				6828	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6829	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6830	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6831	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6832	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]	6833
				6834	</pre>
				6835
				6836	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6837	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6838	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6839	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6840	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]	6841
				6842	</pre>
				6843
				6844	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6845	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6846	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6847	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6848	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]	6849
				6850	</pre>
				6851
				6852	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6853	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6854	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6855	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6856	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]	6857
				6858	</pre>
				6859	<h5>Overview:</h5>
				6860	<p>
				6861	These intrinsics takes the signed or unsigned minimum or maximum of
				6862	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6863	original value at <tt>ptr</tt>.
				6864	</p>
				6865	<h5>Arguments:</h5>
				6866	<p>
				6867
				6868	These intrinsics take two arguments, the first a pointer to an integer value
				6869	and the second an integer value. The result is also an integer value. These
				6870	integer types can have any bit width, but they must all have the same bit
				6871	width. The targets may only lower integer representations they support.
				6872	</p>
				6873	<h5>Semantics:</h5>
				6874	<p>
				6875	These intrinsics does a series of operations atomically. They first load the
				6876	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6877	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6878	the original value stored at <tt>ptr</tt>.
				6879	</p>
				6880
				6881	<h5>Examples:</h5>
				6882	<pre>
				6883	%ptr = malloc i32
				6884	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6885	%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]	6886	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6887	%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]	6888	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6889	%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]	6890	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6891	%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]	6892	<i>; yields {i32}:result3 = 8</i>
				6893	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6894	</pre>
				6895	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6896
				6897	<!-- ======================================================================= -->
				6898	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6899	<a name="int_general">General Intrinsics</a>
				6900	</div>
				6901
				6902	<div class="doc_text">
				6903	<p> This class of intrinsics is designed to be generic and has
				6904	no specific purpose. </p>
				6905	</div>
				6906
				6907	<!-- _______________________________________________________________________ -->
				6908	<div class="doc_subsubsection">
				6909	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6910	</div>
				6911
				6912	<div class="doc_text">
				6913
				6914	<h5>Syntax:</h5>
				6915	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6916	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]	6917	</pre>
				6918
				6919	<h5>Overview:</h5>
				6920
				6921	<p>
				6922	The '<tt>llvm.var.annotation</tt>' intrinsic
				6923	</p>
				6924
				6925	<h5>Arguments:</h5>
				6926
				6927	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6928	The first argument is a pointer to a value, the second is a pointer to a
				6929	global string, the third is a pointer to a global string which is the source
				6930	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6931	</p>
				6932
				6933	<h5>Semantics:</h5>
				6934
				6935	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6936	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6937	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]	6938	annotations. These have no other defined use, they are ignored by code
				6939	generation and optimization.
				6940	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6941	</div>
				6942
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6943	<!-- _______________________________________________________________________ -->
				6944	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6945	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6946	</div>
				6947
				6948	<div class="doc_text">
				6949
				6950	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6951	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6952	any integer bit width.
				6953	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6954	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6955	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6956	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6957	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6958	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6959	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]	6960	</pre>
				6961
				6962	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6963
				6964	<p>
				6965	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6966	</p>
				6967
				6968	<h5>Arguments:</h5>
				6969
				6970	<p>
				6971	The first argument is an integer value (result of some expression),
				6972	the second is a pointer to a global string, the third is a pointer to a global
				6973	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]	6974	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6975	</p>
				6976
				6977	<h5>Semantics:</h5>
				6978
				6979	<p>
				6980	This intrinsic allows annotations to be put on arbitrary expressions
				6981	with arbitrary strings. This can be useful for special purpose optimizations
				6982	that want to look for these annotations. These have no other defined use, they
				6983	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6984	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6985	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6986
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6987	<!-- _______________________________________________________________________ -->
				6988	<div class="doc_subsubsection">
				6989	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6990	</div>
				6991
				6992	<div class="doc_text">
				6993
				6994	<h5>Syntax:</h5>
				6995	<pre>
				6996	declare void @llvm.trap()
				6997	</pre>
				6998
				6999	<h5>Overview:</h5>
				7000
				7001	<p>
				7002	The '<tt>llvm.trap</tt>' intrinsic
				7003	</p>
				7004
				7005	<h5>Arguments:</h5>
				7006
				7007	<p>
				7008	None
				7009	</p>
				7010
				7011	<h5>Semantics:</h5>
				7012
				7013	<p>
				7014	This intrinsics is lowered to the target dependent trap instruction. If the
				7015	target does not have a trap instruction, this intrinsic will be lowered to the
				7016	call of the abort() function.
				7017	</p>
				7018	</div>
				7019
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7020	<!-- _______________________________________________________________________ -->
				7021	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	7022	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7023	</div>
				7024	<div class="doc_text">
				7025	<h5>Syntax:</h5>
				7026	<pre>
				7027	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7028
				7029	</pre>
				7030	<h5>Overview:</h5>
				7031	<p>
				7032	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7033	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7034	it is placed on the stack before local variables.
				7035	</p>
				7036	<h5>Arguments:</h5>
				7037	<p>
				7038	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7039	first argument is the value loaded from the stack guard
				7040	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7041	has enough space to hold the value of the guard.
				7042	</p>
				7043	<h5>Semantics:</h5>
				7044	<p>
				7045	This intrinsic causes the prologue/epilogue inserter to force the position of
				7046	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7047	stack. This is to ensure that if a local variable on the stack is overwritten,
				7048	it will destroy the value of the guard. When the function exits, the guard on
				7049	the stack is checked against the original guard. If they're different, then
				7050	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7051	</p>
				7052	</div>
				7053
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7054	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7055	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7056	<address>
				7057	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7058	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]	7059	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7060	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]	7061
				7062	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7063	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7064	Last modified: $Date$
				7065	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7066
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7067	</body>
				7068	</html>