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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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	25	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	26	<li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov	c6c98af	2007-04-29 18:02:48 +0000	[diff] [blame]	27	<li><a href="#aliasstructure">Aliases</a>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	28	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	29	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	30	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	31	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	32	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	33	</ol>
				34	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	35	<li><a href="#typesystem">Type System</a>
				36	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	37	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	38	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	39	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	40	<li><a href="#t_floating">Floating Point Types</a></li>
				41	<li><a href="#t_void">Void Type</a></li>
				42	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	43	</ol>
				44	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	45	<li><a href="#t_derived">Derived Types</a>
				46	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	47	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	48	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	49	<li><a href="#t_function">Function Type</a></li>
				50	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	51	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	52	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	53	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	54	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	55	</ol>
				56	</li>
				57	</ol>
				58	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	59	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	60	<ol>
				61	<li><a href="#simpleconstants">Simple Constants</a>
				62	<li><a href="#aggregateconstants">Aggregate Constants</a>
				63	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				64	<li><a href="#undefvalues">Undefined Values</a>
				65	<li><a href="#constantexprs">Constant Expressions</a>
				66	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	67	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	68	<li><a href="#othervalues">Other Values</a>
				69	<ol>
				70	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				71	</ol>
				72	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	73	<li><a href="#instref">Instruction Reference</a>
				74	<ol>
				75	<li><a href="#terminators">Terminator Instructions</a>
				76	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	77	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				78	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	79	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				80	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	82	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	83	</ol>
				84	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	85	<li><a href="#binaryops">Binary Operations</a>
				86	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	87	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				88	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				89	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	90	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				91	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				92	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	93	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				94	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				95	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	96	</ol>
				97	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	98	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				99	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	100	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				101	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				102	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	103	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	104	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	106	</ol>
				107	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	108	<li><a href="#vectorops">Vector Operations</a>
				109	<ol>
				110	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				111	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				112	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	113	</ol>
				114	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	115	<li><a href="#aggregateops">Aggregate Operations</a>
				116	<ol>
				117	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				118	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				119	</ol>
				120	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	121	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	122	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	123	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				124	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				125	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	126	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				127	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				128	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	129	</ol>
				130	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	131	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	132	<ol>
				133	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	138	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	142	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	144	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	145	</ol>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	146	<li><a href="#otherops">Other Operations</a>
				147	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	148	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				149	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	150	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				151	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	152	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	153	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	154	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	155	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	156	<li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	157	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	158	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	159	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	162	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	163	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				164	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	165	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				166	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				167	<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]	168	</ol>
				169	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	170	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				171	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	172	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				173	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				174	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	175	</ol>
				176	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	177	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				178	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	179	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				180	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				181	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				182	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				183	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				184	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				185	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	186	</ol>
				187	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	188	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				189	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	190	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				191	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				192	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				194	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	195	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	198	</ol>
				199	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	200	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	201	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	202	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	203	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				204	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				205	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	206	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				207	<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]	208	</ol>
				209	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	210	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	211	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	212	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	213	<ol>
				214	<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]	215	</ol>
				216	</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	217	<li><a href="#int_atomics">Atomic intrinsics</a>
				218	<ol>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	219	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	220	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	221	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	222	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				223	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				224	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				225	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				226	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				227	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				228	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				229	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				230	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				231	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	232	</ol>
				233	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	234	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	235	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	236	<li><a href="#int_var_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	237	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	238	<li><a href="#int_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	239	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	240	<li><a href="#int_trap">
				241	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	242	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	243	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	244	</ol>
				245	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	246	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	247
				248	<div class="doc_author">
				249	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				250	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	251	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	252
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	253	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	254	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				255	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	256
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	257	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	258	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	259	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	260	type safety, low-level operations, flexibility, and the capability of
				261	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	262	representation used throughout all phases of the LLVM compilation
				263	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	264	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	265
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	266	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	267	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				268	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	269
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	270	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	272	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	273	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]	274	representation (suitable for fast loading by a Just-In-Time compiler),
				275	and as a human readable assembly language representation. This allows
				276	LLVM to provide a powerful intermediate representation for efficient
				277	compiler transformations and analysis, while providing a natural means
				278	to debug and visualize the transformations. The three different forms
				279	of LLVM are all equivalent. This document describes the human readable
				280	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	281
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	282	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	283	while being expressive, typed, and extensible at the same time. It
				284	aims to be a "universal IR" of sorts, by being at a low enough level
				285	that high-level ideas may be cleanly mapped to it (similar to how
				286	microprocessors are "universal IR's", allowing many source languages to
				287	be mapped to them). By providing type information, LLVM can be used as
				288	the target of optimizations: for example, through pointer analysis, it
				289	can be proven that a C automatic variable is never accessed outside of
				290	the current function... allowing it to be promoted to a simple SSA
				291	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	292
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	293	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	294
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	295	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	296	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	297
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	298	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	299
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	300	<p>It is important to note that this document describes 'well formed'
				301	LLVM assembly language. There is a difference between what the parser
				302	accepts and what is considered 'well formed'. For example, the
				303	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	304
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	305	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	306	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	307	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	308	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	309	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	310
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	311	<p>...because the definition of <tt>%x</tt> does not dominate all of
				312	its uses. The LLVM infrastructure provides a verification pass that may
				313	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]	314	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	315	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	316	by the verifier pass indicate bugs in transformation passes or input to
				317	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	318	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	320	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	321
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	322	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	323	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	324	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	326	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	327
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	328	<p>LLVM identifiers come in two basic types: global and local. Global
				329	identifiers (functions, global variables) begin with the @ character. Local
				330	identifiers (register names, types) begin with the % character. Additionally,
				331	there are three different formats for identifiers, for different purposes:
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	332
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	333	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	334	<li>Named values are represented as a string of characters with their prefix.
				335	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				336	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]	337	Identifiers which require other characters in their names can be surrounded
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	338	with quotes. In this way, anything except a <tt>"</tt> character can
				339	be used in a named value.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	340
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	341	<li>Unnamed values are represented as an unsigned numeric value with their
				342	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	343
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	344	<li>Constants, which are described in a <a href="#constants">section about
				345	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	346	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	347
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	348	<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]	349	don't need to worry about name clashes with reserved words, and the set of
				350	reserved words may be expanded in the future without penalty. Additionally,
				351	unnamed identifiers allow a compiler to quickly come up with a temporary
				352	variable without having to avoid symbol table conflicts.</p>
				353
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	354	<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]	355	languages. There are keywords for different opcodes
				356	('<tt><a href="#i_add">add</a></tt>',
				357	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				358	'<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]	359	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]	360	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	361	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	362
				363	<p>Here is an example of LLVM code to multiply the integer variable
				364	'<tt>%X</tt>' by 8:</p>
				365
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	366	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	367
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	368	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	369	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	370	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	371	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	372	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	373
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	374	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	375
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	376	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	377	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	378	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	379	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	380	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	381
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>And the hard 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	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				387	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				388	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	390	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	392	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				393	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	394
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	395	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	396
				397	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				398	line.</li>
				399
				400	<li>Unnamed temporaries are created when the result of a computation is not
				401	assigned to a named value.</li>
				402
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	403	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	404
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	405	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	406
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	407	<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]	408	demonstrating instructions, we will follow an instruction with a comment that
				409	defines the type and name of value produced. Comments are shown in italic
				410	text.</p>
				411
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	412	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	413
				414	<!-- *********************************************************************** -->
				415	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				416	<!-- *********************************************************************** -->
				417
				418	<!-- ======================================================================= -->
				419	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				420	</div>
				421
				422	<div class="doc_text">
				423
				424	<p>LLVM programs are composed of "Module"s, each of which is a
				425	translation unit of the input programs. Each module consists of
				426	functions, global variables, and symbol table entries. Modules may be
				427	combined together with the LLVM linker, which merges function (and
				428	global variable) definitions, resolves forward declarations, and merges
				429	symbol table entries. Here is an example of the "hello world" module:</p>
				430
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	431	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	432	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	433	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				434	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]	435
				436	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	437	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	438
				439	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	440	define i32 @main() { <i>; i32()* </i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	441	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	442	%cast210 = <a
Chris Lattner	6c0955b	2007-06-12 17:01:15 +0000	[diff] [blame]	443	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]	444
				445	<i>; Call puts function to write out the string to stdout...</i>
				446	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	447	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	449	href="#i_ret">ret</a> i32 0<br>}<br>
				450	</pre>
				451	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	452
				453	<p>This example is made up of a <a href="#globalvars">global variable</a>
				454	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				455	function, and a <a href="#functionstructure">function definition</a>
				456	for "<tt>main</tt>".</p>
				457
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	458	<p>In general, a module is made up of a list of global values,
				459	where both functions and global variables are global values. Global values are
				460	represented by a pointer to a memory location (in this case, a pointer to an
				461	array of char, and a pointer to a function), and have one of the following <a
				462	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	463
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	464	</div>
				465
				466	<!-- ======================================================================= -->
				467	<div class="doc_subsection">
				468	<a name="linkage">Linkage Types</a>
				469	</div>
				470
				471	<div class="doc_text">
				472
				473	<p>
				474	All Global Variables and Functions have one of the following types of linkage:
				475	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	476
				477	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	478
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	479	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	480
				481	<dd>Global values with internal linkage are only directly accessible by
				482	objects in the current module. In particular, linking code into a module with
				483	an internal global value may cause the internal to be renamed as necessary to
				484	avoid collisions. Because the symbol is internal to the module, all
				485	references can be updated. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	486	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	487	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	488
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	489	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	490
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	491	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				492	the same name when linkage occurs. This is typically used to implement
				493	inline functions, templates, or other code which must be generated in each
				494	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				495	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	496	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	497
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	498	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				499
				500	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				501	linkage, except that unreferenced <tt>common</tt> globals may not be
				502	discarded. This is used for globals that may be emitted in multiple
				503	translation units, but that are not guaranteed to be emitted into every
				504	translation unit that uses them. One example of this is tentative
				505	definitions in C, such as "<tt>int X;</tt>" at global scope.
				506	</dd>
				507
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	508	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	509
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	510	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				511	that some targets may choose to emit different assembly sequences for them
				512	for target-dependent reasons. This is used for globals that are declared
				513	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	514	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	515
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	516	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	517
				518	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				519	pointer to array type. When two global variables with appending linkage are
				520	linked together, the two global arrays are appended together. This is the
				521	LLVM, typesafe, equivalent of having the system linker append together
				522	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	523	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	524
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	525	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	526	<dd>The semantics of this linkage follow the ELF object file model: the
				527	symbol is weak until linked, if not linked, the symbol becomes null instead
				528	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	529	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	530
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	531	<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]	532
				533	<dd>If none of the above identifiers are used, the global is externally
				534	visible, meaning that it participates in linkage and can be used to resolve
				535	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	536	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	537	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	538
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	539	<p>
				540	The next two types of linkage are targeted for Microsoft Windows platform
				541	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	542	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	543	</p>
				544
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	545	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	546	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				547
				548	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				549	or variable via a global pointer to a pointer that is set up by the DLL
				550	exporting the symbol. On Microsoft Windows targets, the pointer name is
				551	formed by combining <code>_imp__</code> and the function or variable name.
				552	</dd>
				553
				554	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				555
				556	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				557	pointer to a pointer in a DLL, so that it can be referenced with the
				558	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				559	name is formed by combining <code>_imp__</code> and the function or variable
				560	name.
				561	</dd>
				562
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	563	</dl>
				564
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	565	<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	566	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				567	variable and was linked with this one, one of the two would be renamed,
				568	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				569	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	570	outside of the current module.</p>
				571	<p>It is illegal for a function <i>declaration</i>
				572	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	573	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	574	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				575	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	576	</div>
				577
				578	<!-- ======================================================================= -->
				579	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	580	<a name="callingconv">Calling Conventions</a>
				581	</div>
				582
				583	<div class="doc_text">
				584
				585	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				586	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				587	specified for the call. The calling convention of any pair of dynamic
				588	caller/callee must match, or the behavior of the program is undefined. The
				589	following calling conventions are supported by LLVM, and more may be added in
				590	the future:</p>
				591
				592	<dl>
				593	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				594
				595	<dd>This calling convention (the default if no other calling convention is
				596	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	597	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	598	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	599	</dd>
				600
				601	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				602
				603	<dd>This calling convention attempts to make calls as fast as possible
				604	(e.g. by passing things in registers). This calling convention allows the
				605	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]	606	without having to conform to an externally specified ABI (Application Binary
				607	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	608	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				609	supported. This calling convention does not support varargs and requires the
				610	prototype of all callees to exactly match the prototype of the function
				611	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	612	</dd>
				613
				614	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				615
				616	<dd>This calling convention attempts to make code in the caller as efficient
				617	as possible under the assumption that the call is not commonly executed. As
				618	such, these calls often preserve all registers so that the call does not break
				619	any live ranges in the caller side. This calling convention does not support
				620	varargs and requires the prototype of all callees to exactly match the
				621	prototype of the function definition.
				622	</dd>
				623
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	624	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	625
				626	<dd>Any calling convention may be specified by number, allowing
				627	target-specific calling conventions to be used. Target specific calling
				628	conventions start at 64.
				629	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	630	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	631
				632	<p>More calling conventions can be added/defined on an as-needed basis, to
				633	support pascal conventions or any other well-known target-independent
				634	convention.</p>
				635
				636	</div>
				637
				638	<!-- ======================================================================= -->
				639	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	640	<a name="visibility">Visibility Styles</a>
				641	</div>
				642
				643	<div class="doc_text">
				644
				645	<p>
				646	All Global Variables and Functions have one of the following visibility styles:
				647	</p>
				648
				649	<dl>
				650	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				651
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	652	<dd>On targets that use the ELF object file format, default visibility means
				653	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	654	modules and, in shared libraries, means that the declared entity may be
				655	overridden. On Darwin, default visibility means that the declaration is
				656	visible to other modules. Default visibility corresponds to "external
				657	linkage" in the language.
				658	</dd>
				659
				660	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				661
				662	<dd>Two declarations of an object with hidden visibility refer to the same
				663	object if they are in the same shared object. Usually, hidden visibility
				664	indicates that the symbol will not be placed into the dynamic symbol table,
				665	so no other module (executable or shared library) can reference it
				666	directly.
				667	</dd>
				668
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	669	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				670
				671	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				672	the dynamic symbol table, but that references within the defining module will
				673	bind to the local symbol. That is, the symbol cannot be overridden by another
				674	module.
				675	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	676	</dl>
				677
				678	</div>
				679
				680	<!-- ======================================================================= -->
				681	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	682	<a name="globalvars">Global Variables</a>
				683	</div>
				684
				685	<div class="doc_text">
				686
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	687	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	688	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	689	an explicit section to be placed in, and may have an optional explicit alignment
				690	specified. A variable may be defined as "thread_local", which means that it
				691	will not be shared by threads (each thread will have a separated copy of the
				692	variable). A variable may be defined as a global "constant," which indicates
				693	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]	694	optimization, allowing the global data to be placed in the read-only section of
				695	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	696	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]	697
				698	<p>
				699	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				700	constant, even if the final definition of the global is not. This capability
				701	can be used to enable slightly better optimization of the program, but requires
				702	the language definition to guarantee that optimizations based on the
				703	'constantness' are valid for the translation units that do not include the
				704	definition.
				705	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	706
				707	<p>As SSA values, global variables define pointer values that are in
				708	scope (i.e. they dominate) all basic blocks in the program. Global
				709	variables always define a pointer to their "content" type because they
				710	describe a region of memory, and all memory objects in LLVM are
				711	accessed through pointers.</p>
				712
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	713	<p>A global variable may be declared to reside in a target-specifc numbered
				714	address space. For targets that support them, address spaces may affect how
				715	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	716	the variable. The default address space is zero. The address space qualifier
				717	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	718
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	719	<p>LLVM allows an explicit section to be specified for globals. If the target
				720	supports it, it will emit globals to the section specified.</p>
				721
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	722	<p>An explicit alignment may be specified for a global. If not present, or if
				723	the alignment is set to zero, the alignment of the global is set by the target
				724	to whatever it feels convenient. If an explicit alignment is specified, the
				725	global is forced to have at least that much alignment. All alignments must be
				726	a power of 2.</p>
				727
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	728	<p>For example, the following defines a global in a numbered address space with
				729	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	730
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	731	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	732	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	733	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	734	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	735	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	736
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	737	</div>
				738
				739
				740	<!-- ======================================================================= -->
				741	<div class="doc_subsection">
				742	<a name="functionstructure">Functions</a>
				743	</div>
				744
				745	<div class="doc_text">
				746
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	747	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				748	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	749	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	750	<a href="#callingconv">calling convention</a>, a return type, an optional
				751	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				752	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	753	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	754	optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	755	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]	756
				757	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				758	optional <a href="#linkage">linkage type</a>, an optional
				759	<a href="#visibility">visibility style</a>, an optional
				760	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	761	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	762	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]	763	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	764
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	765	<p>A function definition contains a list of basic blocks, forming the CFG
				766	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	767	the function. Each basic block may optionally start with a label (giving the
				768	basic block a symbol table entry), contains a list of instructions, and ends
				769	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				770	function return).</p>
				771
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	772	<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]	773	executed on entrance to the function, and it is not allowed to have predecessor
				774	basic blocks (i.e. there can not be any branches to the entry block of a
				775	function). Because the block can have no predecessors, it also cannot have any
				776	<a href="#i_phi">PHI nodes</a>.</p>
				777
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	778	<p>LLVM allows an explicit section to be specified for functions. If the target
				779	supports it, it will emit functions to the section specified.</p>
				780
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	781	<p>An explicit alignment may be specified for a function. If not present, or if
				782	the alignment is set to zero, the alignment of the function is set by the target
				783	to whatever it feels convenient. If an explicit alignment is specified, the
				784	function is forced to have at least that much alignment. All alignments must be
				785	a power of 2.</p>
				786
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	787	</div>
				788
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	789
				790	<!-- ======================================================================= -->
				791	<div class="doc_subsection">
				792	<a name="aliasstructure">Aliases</a>
				793	</div>
				794	<div class="doc_text">
				795	<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]	796	function, global variable, another alias or bitcast of global value). Aliases
				797	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	798	optional <a href="#visibility">visibility style</a>.</p>
				799
				800	<h5>Syntax:</h5>
				801
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	802	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	803	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	804	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	805	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	806	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	807
				808	</div>
				809
				810
				811
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	812	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	813	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				814	<div class="doc_text">
				815	<p>The return type and each parameter of a function type may have a set of
				816	<i>parameter attributes</i> associated with them. Parameter attributes are
				817	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	818	a function. Parameter attributes are considered to be part of the function,
				819	not of the function type, so functions with different parameter attributes
				820	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	821
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	822	<p>Parameter attributes are simple keywords that follow the type specified. If
				823	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	824	example:</p>
				825
				826	<div class="doc_code">
				827	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	828	declare i32 @printf(i8* noalias , ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	829	declare i32 @atoi(i8 zeroext)
				830	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	831	</pre>
				832	</div>
				833
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	834	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				835	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	836
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	837	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	838	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	839	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	840	<dd>This indicates to the code generator that the parameter or return value
				841	should be zero-extended to a 32-bit value by the caller (for a parameter)
				842	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	843
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	844	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	845	<dd>This indicates to the code generator that the parameter or return value
				846	should be sign-extended to a 32-bit value by the caller (for a parameter)
				847	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	848
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	849	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	850	<dd>This indicates that this parameter or return value should be treated
				851	in a special target-dependent fashion during while emitting code for a
				852	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]	853	to memory, though some targets use it to distinguish between two different
				854	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	855
				856	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	857	<dd>This indicates that the pointer parameter should really be passed by
				858	value to the function. The attribute implies that a hidden copy of the
				859	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]	860	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]	861	pointer arguments. It is generally used to pass structs and arrays by
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	862	value, but is also valid on pointers to scalars.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	863
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	864	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	865	<dd>This indicates that the pointer parameter specifies the address of a
				866	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]	867	This pointer must be guaranteed by the caller to be valid: loads and stores
				868	to the structure may be assumed by the callee to not to trap. This may only
				869	be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	870
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	871	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	872	<dd>This indicates that the parameter does not alias any global or any other
				873	parameter. The caller is responsible for ensuring that this is the case,
				874	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	875
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	876	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	877	<dd>This indicates that the pointer parameter can be excised using the
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	878	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	879	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	880
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	881	</div>
				882
				883	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	884	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	885	<a name="gc">Garbage Collector Names</a>
				886	</div>
				887
				888	<div class="doc_text">
				889	<p>Each function may specify a garbage collector name, which is simply a
				890	string.</p>
				891
				892	<div class="doc_code"><pre
				893	>define void @f() gc "name" { ...</pre></div>
				894
				895	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				896	collector which will cause the compiler to alter its output in order to support
				897	the named garbage collection algorithm.</p>
				898	</div>
				899
				900	<!-- ======================================================================= -->
				901	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	902	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	903	</div>
				904
				905	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	906
				907	<p>Function attributes are set to communicate additional information about
				908	a function. Function attributes are considered to be part of the function,
				909	not of the function type, so functions with different parameter attributes
				910	can have the same function type.</p>
				911
				912	<p>Function attributes are simple keywords that follow the type specified. If
				913	multiple attributes are needed, they are space separated. For
				914	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	915
				916	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	917	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	918	define void @f() noinline { ... }
				919	define void @f() alwaysinline { ... }
				920	define void @f() alwaysinline optsize { ... }
				921	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	922	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	923	</div>
				924
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	925	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	926	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	927	<dd>This attribute indicates that the inliner should attempt to inline this
				928	function into callers whenever possible, ignoring any active inlining size
				929	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	930
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	931	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	932	<dd>This attribute indicates that the inliner should never inline this function
				933	in any situation. This attribute may not be used together with
				934	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	935
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	936	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	937	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	938	make choices that keep the code size of this function low, and otherwise do
				939	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	940
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	941	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	942	<dd>This function attribute indicates that the function never returns normally.
				943	This produces undefined behavior at runtime if the function ever does
				944	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	945
				946	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	947	<dd>This function attribute indicates that the function never returns with an
				948	unwind or exceptional control flow. If the function does unwind, its runtime
				949	behavior is undefined.</dd>
				950
				951	<dt><tt>readnone</tt></dt>
				952	<dd>This attribute indicates that the function computes its result (or its
				953	thrown exception) based strictly on its arguments. It does not read any global
				954	mutable state (e.g. memory, control registers, etc) visible to caller functions.
				955	Furthermore, <tt>readnone</tt> functions never change any state visible to their
				956	caller.
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	957
				958	<dt><tt>readonly</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	959	<dd>This function attribute indicates that the function has no side-effects on
				960	the calling function, but that it depends on state (memory state, control
				961	register state, etc) that may be set in the caller. A readonly function always
				962	returns the same value (or throws the same exception) whenever it is called with
				963	a particular set of arguments and global state.</dd>
				964
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	965	</dl>
				966
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	967	</div>
				968
				969	<!-- ======================================================================= -->
				970	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	971	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	972	</div>
				973
				974	<div class="doc_text">
				975	<p>
				976	Modules may contain "module-level inline asm" blocks, which corresponds to the
				977	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				978	LLVM and treated as a single unit, but may be separated in the .ll file if
				979	desired. The syntax is very simple:
				980	</p>
				981
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	982	<div class="doc_code">
				983	<pre>
				984	module asm "inline asm code goes here"
				985	module asm "more can go here"
				986	</pre>
				987	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	988
				989	<p>The strings can contain any character by escaping non-printable characters.
				990	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				991	for the number.
				992	</p>
				993
				994	<p>
				995	The inline asm code is simply printed to the machine code .s file when
				996	assembly code is generated.
				997	</p>
				998	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	999
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1000	<!-- ======================================================================= -->
				1001	<div class="doc_subsection">
				1002	<a name="datalayout">Data Layout</a>
				1003	</div>
				1004
				1005	<div class="doc_text">
				1006	<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]	1007	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1008	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1009	<p>The <i>layout specification</i> consists of a list of specifications
				1010	separated by the minus sign character ('-'). Each specification starts with a
				1011	letter and may include other information after the letter to define some
				1012	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1013	<dl>
				1014	<dt><tt>E</tt></dt>
				1015	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1016	bits with the most significance have the lowest address location.</dd>
				1017	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1018	<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]	1019	the bits with the least significance have the lowest address location.</dd>
				1020	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1021	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1022	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1023	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1024	too.</dd>
				1025	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1026	<dd>This specifies the alignment for an integer type of a given bit
				1027	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1028	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1029	<dd>This specifies the alignment for a vector type of a given bit
				1030	<i>size</i>.</dd>
				1031	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1032	<dd>This specifies the alignment for a floating point type of a given bit
				1033	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1034	(double).</dd>
				1035	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1036	<dd>This specifies the alignment for an aggregate type of a given bit
				1037	<i>size</i>.</dd>
				1038	</dl>
				1039	<p>When constructing the data layout for a given target, LLVM starts with a
				1040	default set of specifications which are then (possibly) overriden by the
				1041	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1042	are given in this list:</p>
				1043	<ul>
				1044	<li><tt>E</tt> - big endian</li>
				1045	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1046	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1047	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1048	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1049	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1050	<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]	1051	alignment of 64-bits</li>
				1052	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1053	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1054	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1055	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1056	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1057	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1058	<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1059	following rules:
				1060	<ol>
				1061	<li>If the type sought is an exact match for one of the specifications, that
				1062	specification is used.</li>
				1063	<li>If no match is found, and the type sought is an integer type, then the
				1064	smallest integer type that is larger than the bitwidth of the sought type is
				1065	used. If none of the specifications are larger than the bitwidth then the the
				1066	largest integer type is used. For example, given the default specifications
				1067	above, the i7 type will use the alignment of i8 (next largest) while both
				1068	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1069	<li>If no match is found, and the type sought is a vector type, then the
				1070	largest vector type that is smaller than the sought vector type will be used
				1071	as a fall back. This happens because <128 x double> can be implemented in
				1072	terms of 64 <2 x double>, for example.</li>
				1073	</ol>
				1074	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1075
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1076	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1077	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1078	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1079
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1080	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1081
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1082	<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]	1083	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1084	optimizations to be performed on the intermediate representation directly,
				1085	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1086	extra analyses on the side before the transformation. A strong type
				1087	system makes it easier to read the generated code and enables novel
				1088	analyses and transformations that are not feasible to perform on normal
				1089	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1090
				1091	</div>
				1092
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1093	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1094	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1095	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1096	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1097	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1098	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1099
				1100	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1101	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1102	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1103	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1104	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1105	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1106	</tr>
				1107	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1108	<td><a href="#t_floating">floating point</a></td>
				1109	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1110	</tr>
				1111	<tr>
				1112	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1113	<td><a href="#t_integer">integer</a>,
				1114	<a href="#t_floating">floating point</a>,
				1115	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1116	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1117	<a href="#t_struct">structure</a>,
				1118	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1119	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1120	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1121	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1122	<tr>
				1123	<td><a href="#t_primitive">primitive</a></td>
				1124	<td><a href="#t_label">label</a>,
				1125	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1126	<a href="#t_floating">floating point</a>.</td>
				1127	</tr>
				1128	<tr>
				1129	<td><a href="#t_derived">derived</a></td>
				1130	<td><a href="#t_integer">integer</a>,
				1131	<a href="#t_array">array</a>,
				1132	<a href="#t_function">function</a>,
				1133	<a href="#t_pointer">pointer</a>,
				1134	<a href="#t_struct">structure</a>,
				1135	<a href="#t_pstruct">packed structure</a>,
				1136	<a href="#t_vector">vector</a>,
				1137	<a href="#t_opaque">opaque</a>.
				1138	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1139	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1140	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1141
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1142	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1143	most important. Values of these types are the only ones which can be
				1144	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1145	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1146	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1147
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1148	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1149	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1150
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1151	<div class="doc_text">
				1152	<p>The primitive types are the fundamental building blocks of the LLVM
				1153	system.</p>
				1154
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1155	</div>
				1156
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1157	<!-- _______________________________________________________________________ -->
				1158	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1159
				1160	<div class="doc_text">
				1161	<table>
				1162	<tbody>
				1163	<tr><th>Type</th><th>Description</th></tr>
				1164	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1165	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1166	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1167	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1168	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1169	</tbody>
				1170	</table>
				1171	</div>
				1172
				1173	<!-- _______________________________________________________________________ -->
				1174	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1175
				1176	<div class="doc_text">
				1177	<h5>Overview:</h5>
				1178	<p>The void type does not represent any value and has no size.</p>
				1179
				1180	<h5>Syntax:</h5>
				1181
				1182	<pre>
				1183	void
				1184	</pre>
				1185	</div>
				1186
				1187	<!-- _______________________________________________________________________ -->
				1188	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1189
				1190	<div class="doc_text">
				1191	<h5>Overview:</h5>
				1192	<p>The label type represents code labels.</p>
				1193
				1194	<h5>Syntax:</h5>
				1195
				1196	<pre>
				1197	label
				1198	</pre>
				1199	</div>
				1200
				1201
				1202	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1203	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1204
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1205	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1206
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1207	<p>The real power in LLVM comes from the derived types in the system.
				1208	This is what allows a programmer to represent arrays, functions,
				1209	pointers, and other useful types. Note that these derived types may be
				1210	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]	1211
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1212	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1213
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1214	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1215	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1216
				1217	<div class="doc_text">
				1218
				1219	<h5>Overview:</h5>
				1220	<p>The integer type is a very simple derived type that simply specifies an
				1221	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1222	2^23-1 (about 8 million) can be specified.</p>
				1223
				1224	<h5>Syntax:</h5>
				1225
				1226	<pre>
				1227	iN
				1228	</pre>
				1229
				1230	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1231	value.</p>
				1232
				1233	<h5>Examples:</h5>
				1234	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1235	<tbody>
				1236	<tr>
				1237	<td><tt>i1</tt></td>
				1238	<td>a single-bit integer.</td>
				1239	</tr><tr>
				1240	<td><tt>i32</tt></td>
				1241	<td>a 32-bit integer.</td>
				1242	</tr><tr>
				1243	<td><tt>i1942652</tt></td>
				1244	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1245	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1246	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1247	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1248	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1249
				1250	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1251	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1252
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1253	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1254
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1255	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1256
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1257	<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]	1258	sequentially in memory. The array type requires a size (number of
				1259	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1260
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1261	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1262
				1263	<pre>
				1264	[<# elements> x <elementtype>]
				1265	</pre>
				1266
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1267	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1268	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1269
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1270	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1271	<table class="layout">
				1272	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1273	<td class="left"><tt>[40 x i32]</tt></td>
				1274	<td class="left">Array of 40 32-bit integer values.</td>
				1275	</tr>
				1276	<tr class="layout">
				1277	<td class="left"><tt>[41 x i32]</tt></td>
				1278	<td class="left">Array of 41 32-bit integer values.</td>
				1279	</tr>
				1280	<tr class="layout">
				1281	<td class="left"><tt>[4 x i8]</tt></td>
				1282	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1283	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1284	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1285	<p>Here are some examples of multidimensional arrays:</p>
				1286	<table class="layout">
				1287	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1288	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1289	<td class="left">3x4 array of 32-bit integer values.</td>
				1290	</tr>
				1291	<tr class="layout">
				1292	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1293	<td class="left">12x10 array of single precision floating point values.</td>
				1294	</tr>
				1295	<tr class="layout">
				1296	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1297	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1298	</tr>
				1299	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1300
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1301	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1302	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]	1303	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1304	As a special case, however, zero length arrays are recognized to be variable
				1305	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1306	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1307
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1308	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1309
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1310	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1311	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1312	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1313
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1314	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1315
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1316	<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]	1317	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]	1318	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]	1319	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]	1320	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1321
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1322	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1323
				1324	<pre>
				1325	<returntype list> (<parameter list>)
				1326	</pre>
				1327
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1328	<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]	1329	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1330	which indicates that the function takes a variable number of arguments.
				1331	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1332	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1333	'<tt><returntype list></tt>' is a comma-separated list of
				1334	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1335
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1336	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1337	<table class="layout">
				1338	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1339	<td class="left"><tt>i32 (i32)</tt></td>
				1340	<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]	1341	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1342	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1343	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1344	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1345	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1346	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1347	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1348	<tt>float</tt>.
				1349	</td>
				1350	</tr><tr class="layout">
				1351	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1352	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1353	<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]	1354	which returns an integer. This is the signature for <tt>printf</tt> in
				1355	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1356	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1357	</tr><tr class="layout">
				1358	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1359	<td class="left">A function taking an <tt>i32></tt>, returning two
				1360	<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]	1361	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1362	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1363	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1364
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1365	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1366	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1367	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1368	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1369	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1370	<p>The structure type is used to represent a collection of data members
				1371	together in memory. The packing of the field types is defined to match
				1372	the ABI of the underlying processor. The elements of a structure may
				1373	be any type that has a size.</p>
				1374	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1375	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1376	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1377	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1378	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1379	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1380	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1381	<table class="layout">
				1382	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1383	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1384	<td class="left">A triple of three <tt>i32</tt> values</td>
				1385	</tr><tr class="layout">
				1386	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1387	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1388	second element is a <a href="#t_pointer">pointer</a> to a
				1389	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1390	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1391	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1392	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1393	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1394
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1395	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1396	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1397	</div>
				1398	<div class="doc_text">
				1399	<h5>Overview:</h5>
				1400	<p>The packed structure type is used to represent a collection of data members
				1401	together in memory. There is no padding between fields. Further, the alignment
				1402	of a packed structure is 1 byte. The elements of a packed structure may
				1403	be any type that has a size.</p>
				1404	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1405	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1406	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1407	instruction.</p>
				1408	<h5>Syntax:</h5>
				1409	<pre> < { <type list> } > <br></pre>
				1410	<h5>Examples:</h5>
				1411	<table class="layout">
				1412	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1413	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1414	<td class="left">A triple of three <tt>i32</tt> values</td>
				1415	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1416	<td class="left">
				1417	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1418	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1419	second element is a <a href="#t_pointer">pointer</a> to a
				1420	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1421	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1422	</tr>
				1423	</table>
				1424	</div>
				1425
				1426	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1427	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1428	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1429	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1430	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1431	reference to another object, which must live in memory. Pointer types may have
				1432	an optional address space attribute defining the target-specific numbered
				1433	address space where the pointed-to object resides. The default address space is
				1434	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1435	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1436	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1437	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1438	<table class="layout">
				1439	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1440	<td class="left"><tt>[4x i32]*</tt></td>
				1441	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1442	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1443	</tr>
				1444	<tr class="layout">
				1445	<td class="left"><tt>i32 (i32 ) </tt></td>
				1446	<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]	1447	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]	1448	<tt>i32</tt>.</td>
				1449	</tr>
				1450	<tr class="layout">
				1451	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1452	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1453	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1454	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1455	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1456	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1457
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1458	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1459	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1460	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1461
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1462	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1463
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1464	<p>A vector type is a simple derived type that represents a vector
				1465	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1466	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1467	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1468	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1469	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1470	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1471
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1472	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1473
				1474	<pre>
				1475	< <# elements> x <elementtype> >
				1476	</pre>
				1477
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1478	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1479	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1480
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1481	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1482
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1483	<table class="layout">
				1484	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1485	<td class="left"><tt><4 x i32></tt></td>
				1486	<td class="left">Vector of 4 32-bit integer values.</td>
				1487	</tr>
				1488	<tr class="layout">
				1489	<td class="left"><tt><8 x float></tt></td>
				1490	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1491	</tr>
				1492	<tr class="layout">
				1493	<td class="left"><tt><2 x i64></tt></td>
				1494	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1495	</tr>
				1496	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1497	</div>
				1498
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1499	<!-- _______________________________________________________________________ -->
				1500	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1501	<div class="doc_text">
				1502
				1503	<h5>Overview:</h5>
				1504
				1505	<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]	1506	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]	1507	In LLVM, opaque types can eventually be resolved to any type (not just a
				1508	structure type).</p>
				1509
				1510	<h5>Syntax:</h5>
				1511
				1512	<pre>
				1513	opaque
				1514	</pre>
				1515
				1516	<h5>Examples:</h5>
				1517
				1518	<table class="layout">
				1519	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1520	<td class="left"><tt>opaque</tt></td>
				1521	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1522	</tr>
				1523	</table>
				1524	</div>
				1525
				1526
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1527	<!-- *********************************************************************** -->
				1528	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1529	<!-- *********************************************************************** -->
				1530
				1531	<div class="doc_text">
				1532
				1533	<p>LLVM has several different basic types of constants. This section describes
				1534	them all and their syntax.</p>
				1535
				1536	</div>
				1537
				1538	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1539	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1540
				1541	<div class="doc_text">
				1542
				1543	<dl>
				1544	<dt><b>Boolean constants</b></dt>
				1545
				1546	<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]	1547	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1548	</dd>
				1549
				1550	<dt><b>Integer constants</b></dt>
				1551
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1552	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1553	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1554	integer types.
				1555	</dd>
				1556
				1557	<dt><b>Floating point constants</b></dt>
				1558
				1559	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1560	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1561	notation (see below). The assembler requires the exact decimal value of
				1562	a floating-point constant. For example, the assembler accepts 1.25 but
				1563	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1564	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]	1565
				1566	<dt><b>Null pointer constants</b></dt>
				1567
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1568	<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]	1569	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1570
				1571	</dl>
				1572
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1573	<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1574	of floating point constants. For example, the form '<tt>double
				1575	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1576	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]	1577	(and the only time that they are generated by the disassembler) is when a
				1578	floating point constant must be emitted but it cannot be represented as a
				1579	decimal floating point number. For example, NaN's, infinities, and other
				1580	special values are represented in their IEEE hexadecimal format so that
				1581	assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1582
				1583	</div>
				1584
				1585	<!-- ======================================================================= -->
				1586	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1587	</div>
				1588
				1589	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1590	<p>Aggregate constants arise from aggregation of simple constants
				1591	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1592
				1593	<dl>
				1594	<dt><b>Structure constants</b></dt>
				1595
				1596	<dd>Structure constants are represented with notation similar to structure
				1597	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1598	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1599	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]	1600	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]	1601	types of elements must match those specified by the type.
				1602	</dd>
				1603
				1604	<dt><b>Array constants</b></dt>
				1605
				1606	<dd>Array constants are represented with notation similar to array type
				1607	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1608	(<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]	1609	constants must have <a href="#t_array">array type</a>, and the number and
				1610	types of elements must match those specified by the type.
				1611	</dd>
				1612
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1613	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1614
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1615	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1616	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1617	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1618	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1619	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]	1620	match those specified by the type.
				1621	</dd>
				1622
				1623	<dt><b>Zero initialization</b></dt>
				1624
				1625	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1626	value to zero of <em>any</em> type, including scalar and aggregate types.
				1627	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]	1628	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1629	initializers.
				1630	</dd>
				1631	</dl>
				1632
				1633	</div>
				1634
				1635	<!-- ======================================================================= -->
				1636	<div class="doc_subsection">
				1637	<a name="globalconstants">Global Variable and Function Addresses</a>
				1638	</div>
				1639
				1640	<div class="doc_text">
				1641
				1642	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1643	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1644	constants. These constants are explicitly referenced when the <a
				1645	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]	1646	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1647	file:</p>
				1648
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1649	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1650	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1651	@X = global i32 17
				1652	@Y = global i32 42
				1653	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1654	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1655	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1656
				1657	</div>
				1658
				1659	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1660	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1661	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1662	<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]	1663	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]	1664	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1665
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1666	<p>Undefined values indicate to the compiler that the program is well defined
				1667	no matter what value is used, giving the compiler more freedom to optimize.
				1668	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1669	</div>
				1670
				1671	<!-- ======================================================================= -->
				1672	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1673	</div>
				1674
				1675	<div class="doc_text">
				1676
				1677	<p>Constant expressions are used to allow expressions involving other constants
				1678	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1679	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]	1680	that does not have side effects (e.g. load and call are not supported). The
				1681	following is the syntax for constant expressions:</p>
				1682
				1683	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1684	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1685	<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]	1686	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1687
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1688	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1689	<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]	1690	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]	1691
				1692	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1693	<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]	1694	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]	1695
				1696	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1697	<dd>Truncate a floating point constant to another floating point type. The
				1698	size of CST must be larger than the size of TYPE. Both types must be
				1699	floating point.</dd>
				1700
				1701	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1702	<dd>Floating point extend a constant to another type. The size of CST must be
				1703	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1704
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1705	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1706	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1707	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1708	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1709	of the same number of elements. If the value won't fit in the integer type,
				1710	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1711
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1712	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1713	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1714	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1715	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1716	of the same number of elements. If the value won't fit in the integer type,
				1717	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1718
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1719	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1720	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1721	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1722	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1723	of the same number of elements. If the value won't fit in the floating point
				1724	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1725
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1726	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1727	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1728	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1729	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1730	of the same number of elements. If the value won't fit in the floating point
				1731	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1732
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1733	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1734	<dd>Convert a pointer typed constant to the corresponding integer constant
				1735	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1736	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1737
				1738	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1739	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1740	pointer type. CST must be of integer type. The CST value is zero extended,
				1741	truncated, or unchanged to make it fit in a pointer size. This one is
				1742	<i>really</i> dangerous!</dd>
				1743
				1744	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1745	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1746	identical (same number of bits). The conversion is done as if the CST value
				1747	was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1748	with this operator, just the type. This can be used for conversion of
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1749	vector types to any other type, as long as they have the same bit width. For
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	1750	pointers it is only valid to cast to another pointer type. It is not valid
				1751	to bitcast to or from an aggregate type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1752	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1753
				1754	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1755
				1756	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1757	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1758	instruction, the index list may have zero or more indexes, which are required
				1759	to make sense for the type of "CSTPTR".</dd>
				1760
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1761	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1762
				1763	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1764	constants.</dd>
				1765
				1766	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1767	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1768
				1769	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1770	<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]	1771
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1772	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1773	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1774
				1775	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1776	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1777
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1778	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1779
				1780	<dd>Perform the <a href="#i_extractelement">extractelement
				1781	operation</a> on constants.
				1782
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1783	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1784
				1785	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1786	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1787
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1788
				1789	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1790
				1791	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1792	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1793
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1794	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1795
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1796	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1797	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]	1798	binary</a> operations. The constraints on operands are the same as those for
				1799	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1800	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1801	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1802	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1803
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1804	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1805	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1806	<!-- *********************************************************************** -->
				1807
				1808	<!-- ======================================================================= -->
				1809	<div class="doc_subsection">
				1810	<a name="inlineasm">Inline Assembler Expressions</a>
				1811	</div>
				1812
				1813	<div class="doc_text">
				1814
				1815	<p>
				1816	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1817	Module-Level Inline Assembly</a>) through the use of a special value. This
				1818	value represents the inline assembler as a string (containing the instructions
				1819	to emit), a list of operand constraints (stored as a string), and a flag that
				1820	indicates whether or not the inline asm expression has side effects. An example
				1821	inline assembler expression is:
				1822	</p>
				1823
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1824	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1825	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1826	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1827	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1828	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1829
				1830	<p>
				1831	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1832	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1833	</p>
				1834
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1835	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1836	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1837	%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]	1838	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1839	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1840
				1841	<p>
				1842	Inline asms with side effects not visible in the constraint list must be marked
				1843	as having side effects. This is done through the use of the
				1844	'<tt>sideeffect</tt>' keyword, like so:
				1845	</p>
				1846
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1847	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1848	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1849	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1850	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1851	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1852
				1853	<p>TODO: The format of the asm and constraints string still need to be
				1854	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^]	1855	need to be documented). This is probably best done by reference to another
				1856	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1857	</p>
				1858
				1859	</div>
				1860
				1861	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1862	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1863	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1864
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1865	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1866
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1867	<p>The LLVM instruction set consists of several different
				1868	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1869	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1870	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1871	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1872	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1873
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1874	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1875
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1876	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1877	<div class="doc_subsection"> <a name="terminators">Terminator
				1878	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1879
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1880	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1881
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1882	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1883	basic block in a program ends with a "Terminator" instruction, which
				1884	indicates which block should be executed after the current block is
				1885	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1886	value: they produce control flow, not values (the one exception being
				1887	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1888	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1889	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1890	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1891	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1892	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1893	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1894
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1895	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1896
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1897	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1898	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1899	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1900	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1901	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1902	<pre> ret <type> <value> <i>; Return a value from a non-void function</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1903	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1904	ret <type> <value>, <type> <value> <i>; Return two values from a non-void function </i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1905	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1906
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1907	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1908
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1909	<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1910	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1911	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1912	returns value(s) and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1913	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1914
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1915	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1916
				1917	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1918	The type of each return value must be a '<a href="#t_firstclass">first
				1919	class</a>' type. Note that a function is not <a href="#wellformed">well
				1920	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1921	function that returns values that do not match the return type of the
				1922	function.</p>
				1923
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1924	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1925
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1926	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1927	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]	1928	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1929	the instruction after the call. If the caller was an "<a
				1930	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1931	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1932	returns a value, that value shall set the call or invoke instruction's
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1933	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1934	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1935	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1936
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1937	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1938
				1939	<pre>
				1940	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1941	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1942	ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1943	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1944	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1945	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1946	<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]	1947	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1948	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1949	<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]	1950	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1951	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1952	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1953	transfer to a different basic block in the current function. There are
				1954	two forms of this instruction, corresponding to a conditional branch
				1955	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1956	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1957	<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]	1958	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1959	unconditional form of the '<tt>br</tt>' instruction takes a single
				1960	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1961	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1962	<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]	1963	argument is evaluated. If the value is <tt>true</tt>, control flows
				1964	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1965	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1966	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1967	<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]	1968	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]	1969	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1970	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1971	<div class="doc_subsubsection">
				1972	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1973	</div>
				1974
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1975	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1976	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1977
				1978	<pre>
				1979	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1980	</pre>
				1981
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1982	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1983
				1984	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1985	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1986	instruction, allowing a branch to occur to one of many possible
				1987	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1988
				1989
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1990	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1991
				1992	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1993	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1994	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1995	table is not allowed to contain duplicate constant entries.</p>
				1996
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1997	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1998
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1999	<p>The <tt>switch</tt> instruction specifies a table of values and
				2000	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2001	table is searched for the given value. If the value is found, control flow is
				2002	transfered to the corresponding destination; otherwise, control flow is
				2003	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2004
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2005	<h5>Implementation:</h5>
				2006
				2007	<p>Depending on properties of the target machine and the particular
				2008	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2009	ways. For example, it could be generated as a series of chained conditional
				2010	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2011
				2012	<h5>Example:</h5>
				2013
				2014	<pre>
				2015	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2016	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2017	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2018
				2019	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2020	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2021
				2022	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2023	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2024	i32 1, label %onone
				2025	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2026	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2027	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2028
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2029	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2030	<div class="doc_subsubsection">
				2031	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2032	</div>
				2033
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2034	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2035
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2036	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2037
				2038	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2039	<result> = invoke [<a href="#callingconv">cconv</a>] <ptr to function ty> <function ptr val>(<function args>)
Chris Lattner	76b8a33	2006-05-14 18:23:06 +0000	[diff] [blame]	2040	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2041	</pre>
				2042
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2043	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2044
				2045	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2046	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2047	'<tt>normal</tt>' label or the
				2048	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2049	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2050	"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]	2051	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	2052	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	2053	returns multiple values then individual return values are only accessible through
				2054	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2055
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2056	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2057
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2058	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2059
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2060	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2061	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2062	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2063	convention</a> the call should use. If none is specified, the call defaults
				2064	to using C calling conventions.
				2065	</li>
				2066	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2067	function value being invoked. In most cases, this is a direct function
				2068	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2069	an arbitrary pointer to function value.
				2070	</li>
				2071
				2072	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2073	function to be invoked. </li>
				2074
				2075	<li>'<tt>function args</tt>': argument list whose types match the function
				2076	signature argument types. If the function signature indicates the function
				2077	accepts a variable number of arguments, the extra arguments can be
				2078	specified. </li>
				2079
				2080	<li>'<tt>normal label</tt>': the label reached when the called function
				2081	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2082
				2083	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2084	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2085
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2086	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2087
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2088	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2089
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2090	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2091	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2092	difference is that it establishes an association with a label, which is used by
				2093	the runtime library to unwind the stack.</p>
				2094
				2095	<p>This instruction is used in languages with destructors to ensure that proper
				2096	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2097	exception. Additionally, this is important for implementation of
				2098	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2099
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2100	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2101	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2102	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2103	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2104	%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]	2105	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2106	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2107	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2108
				2109
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2110	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2111
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2112	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2113	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2114
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2115	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2116
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2117	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2118	<pre>
				2119	unwind
				2120	</pre>
				2121
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2122	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2123
				2124	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2125	at the first callee in the dynamic call stack which used an <a
				2126	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2127	primarily used to implement exception handling.</p>
				2128
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2129	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2130
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2131	<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]	2132	immediately halt. The dynamic call stack is then searched for the first <a
				2133	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2134	execution continues at the "exceptional" destination block specified by the
				2135	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2136	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2137	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2138
				2139	<!-- _______________________________________________________________________ -->
				2140
				2141	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2142	Instruction</a> </div>
				2143
				2144	<div class="doc_text">
				2145
				2146	<h5>Syntax:</h5>
				2147	<pre>
				2148	unreachable
				2149	</pre>
				2150
				2151	<h5>Overview:</h5>
				2152
				2153	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2154	instruction is used to inform the optimizer that a particular portion of the
				2155	code is not reachable. This can be used to indicate that the code after a
				2156	no-return function cannot be reached, and other facts.</p>
				2157
				2158	<h5>Semantics:</h5>
				2159
				2160	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2161	</div>
				2162
				2163
				2164
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2165	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2166	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2167	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2168	<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]	2169	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]	2170	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2171	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]	2172	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2173	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2174	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2175	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2176	<div class="doc_subsubsection">
				2177	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2178	</div>
				2179
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2180	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2181
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2182	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2183
				2184	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2185	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2186	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2187
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2188	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2189
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2190	<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]	2191
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2192	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2193
				2194	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2195	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2196	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2197	types.</p>
				2198
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2199	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2200
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2201	<p>The value produced is the integer or floating point sum of the two
				2202	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2203
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2204	<p>If an integer sum has unsigned overflow, the result returned is the
				2205	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2206	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2207
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2208	<p>Because LLVM integers use a two's complement representation, this
				2209	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2210
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2211	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2212
				2213	<pre>
				2214	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2215	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2216	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2217	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2218	<div class="doc_subsubsection">
				2219	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2220	</div>
				2221
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2222	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2223
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2224	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2225
				2226	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2227	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2228	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2229
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2230	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2231
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2232	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2233	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2234
				2235	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2236	'<tt>neg</tt>' instruction present in most other intermediate
				2237	representations.</p>
				2238
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2239	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2240
				2241	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2242	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2243	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2244	types.</p>
				2245
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2246	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2247
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2248	<p>The value produced is the integer or floating point difference of
				2249	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2250
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2251	<p>If an integer difference has unsigned overflow, the result returned is the
				2252	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2253	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2254
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2255	<p>Because LLVM integers use a two's complement representation, this
				2256	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2257
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2258	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2259	<pre>
				2260	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2261	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2262	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2263	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2264
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2265	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2266	<div class="doc_subsubsection">
				2267	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2268	</div>
				2269
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2270	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2271
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2272	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2273	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2274	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2275	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2276	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2277	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2278
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2279	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2280
				2281	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2282	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2283	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2284	types.</p>
				2285
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2286	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2287
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2288	<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]	2289	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2290
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2291	<p>If the result of an integer multiplication has unsigned overflow,
				2292	the result returned is the mathematical result modulo
				2293	2<sup>n</sup>, where n is the bit width of the result.</p>
				2294	<p>Because LLVM integers use a two's complement representation, and the
				2295	result is the same width as the operands, this instruction returns the
				2296	correct result for both signed and unsigned integers. If a full product
				2297	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2298	should be sign-extended or zero-extended as appropriate to the
				2299	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2300	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2301	<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]	2302	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2303	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2304
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2305	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2306	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2307	</a></div>
				2308	<div class="doc_text">
				2309	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2310	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2311	</pre>
				2312	<h5>Overview:</h5>
				2313	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2314	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2315
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2316	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2317
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2318	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2319	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2320	values. Both arguments must have identical types.</p>
				2321
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2322	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2323
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2324	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2325	<p>Note that unsigned integer division and signed integer division are distinct
				2326	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2327	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2328	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2329	<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]	2330	</pre>
				2331	</div>
				2332	<!-- _______________________________________________________________________ -->
				2333	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2334	</a> </div>
				2335	<div class="doc_text">
				2336	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2337	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2338	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2339	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2340
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2341	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2342
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2343	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2344	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2345
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2346	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2347
				2348	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2349	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2350	values. Both arguments must have identical types.</p>
				2351
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2352	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2353	<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]	2354	<p>Note that signed integer division and unsigned integer division are distinct
				2355	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2356	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2357	undefined behavior; this is a rare case, but can occur, for example,
				2358	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2359	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2360	<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]	2361	</pre>
				2362	</div>
				2363	<!-- _______________________________________________________________________ -->
				2364	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2365	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2366	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2367	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2368	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2369	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2370	</pre>
				2371	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2372
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2373	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2374	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2375
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2376	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2377
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2378	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2379	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2380	of floating point values. Both arguments must have identical types.</p>
				2381
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2382	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2383
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2384	<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]	2385
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2386	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2387
				2388	<pre>
				2389	<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]	2390	</pre>
				2391	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2392
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2393	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2394	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2395	</div>
				2396	<div class="doc_text">
				2397	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2398	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2399	</pre>
				2400	<h5>Overview:</h5>
				2401	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2402	unsigned division of its two arguments.</p>
				2403	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2404	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2405	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2406	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2407	<h5>Semantics:</h5>
				2408	<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]	2409	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2410	<p>Note that unsigned integer remainder and signed integer remainder are
				2411	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2412	<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]	2413	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2414	<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]	2415	</pre>
				2416
				2417	</div>
				2418	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2419	<div class="doc_subsubsection">
				2420	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2421	</div>
				2422
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2423	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2424
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2425	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2426
				2427	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2428	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2429	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2430
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2431	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2432
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2433	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2434	signed division of its two operands. This instruction can also take
				2435	<a href="#t_vector">vector</a> versions of the values in which case
				2436	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2437
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2438	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2439
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2440	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2441	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2442	values. Both arguments must have identical types.</p>
				2443
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2444	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2445
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2446	<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]	2447	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2448	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]	2449	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2450	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]	2451	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]	2452	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2453	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2454	<p>Note that signed integer remainder and unsigned integer remainder are
				2455	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2456	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2457	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2458	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2459	(The remainder doesn't actually overflow, but this rule lets srem be
				2460	implemented using instructions that return both the result of the division
				2461	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2462	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2463	<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]	2464	</pre>
				2465
				2466	</div>
				2467	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2468	<div class="doc_subsubsection">
				2469	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2470
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2471	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2472
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2473	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2474	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2475	</pre>
				2476	<h5>Overview:</h5>
				2477	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2478	division of its two operands.</p>
				2479	<h5>Arguments:</h5>
				2480	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2481	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2482	of floating point values. Both arguments must have identical types.</p>
				2483
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2484	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2485
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2486	<p>This instruction returns the <i>remainder</i> of a division.
				2487	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2488
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2489	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2490
				2491	<pre>
				2492	<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]	2493	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2494	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2495
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2496	<!-- ======================================================================= -->
				2497	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2498	Operations</a> </div>
				2499	<div class="doc_text">
				2500	<p>Bitwise binary operators are used to do various forms of
				2501	bit-twiddling in a program. They are generally very efficient
				2502	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2503	instructions. They require two operands of the same type, execute an operation on them,
				2504	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]	2505	</div>
				2506
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2507	<!-- _______________________________________________________________________ -->
				2508	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2509	Instruction</a> </div>
				2510	<div class="doc_text">
				2511	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2512	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2513	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2514
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2515	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2516
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2517	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2518	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2519
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2520	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2521
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2522	<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]	2523	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]	2524	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2525
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2526	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2527
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2528	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2529	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2530	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2531
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2532	<h5>Example:</h5><pre>
				2533	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2534	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2535	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2536	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2537	</pre>
				2538	</div>
				2539	<!-- _______________________________________________________________________ -->
				2540	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2541	Instruction</a> </div>
				2542	<div class="doc_text">
				2543	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2544	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2545	</pre>
				2546
				2547	<h5>Overview:</h5>
				2548	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2549	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]	2550
				2551	<h5>Arguments:</h5>
				2552	<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]	2553	<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]	2554	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2555
				2556	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2557
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2558	<p>This instruction always performs a logical shift right operation. The most
				2559	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]	2560	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2561	the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2562
				2563	<h5>Example:</h5>
				2564	<pre>
				2565	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2566	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2567	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2568	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2569	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2570	</pre>
				2571	</div>
				2572
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2573	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2574	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2575	Instruction</a> </div>
				2576	<div class="doc_text">
				2577
				2578	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2579	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2580	</pre>
				2581
				2582	<h5>Overview:</h5>
				2583	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2584	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]	2585
				2586	<h5>Arguments:</h5>
				2587	<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]	2588	<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]	2589	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2590
				2591	<h5>Semantics:</h5>
				2592	<p>This instruction always performs an arithmetic shift right operation,
				2593	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]	2594	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2595	larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2596	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2597
				2598	<h5>Example:</h5>
				2599	<pre>
				2600	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2601	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2602	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2603	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2604	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2605	</pre>
				2606	</div>
				2607
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2608	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2609	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2610	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2611
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2612	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2613
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2614	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2615
				2616	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2617	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2618	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2619
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2620	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2621
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2622	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2623	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2624
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2625	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2626
				2627	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2628	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2629	values. Both arguments must have identical types.</p>
				2630
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2631	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2632	<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]	2633	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2634	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2635	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2636	<tbody>
				2637	<tr>
				2638	<td>In0</td>
				2639	<td>In1</td>
				2640	<td>Out</td>
				2641	</tr>
				2642	<tr>
				2643	<td>0</td>
				2644	<td>0</td>
				2645	<td>0</td>
				2646	</tr>
				2647	<tr>
				2648	<td>0</td>
				2649	<td>1</td>
				2650	<td>0</td>
				2651	</tr>
				2652	<tr>
				2653	<td>1</td>
				2654	<td>0</td>
				2655	<td>0</td>
				2656	</tr>
				2657	<tr>
				2658	<td>1</td>
				2659	<td>1</td>
				2660	<td>1</td>
				2661	</tr>
				2662	</tbody>
				2663	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2664	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2665	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2666	<pre>
				2667	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2668	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2669	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2670	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2671	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2672	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2673	<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]	2674	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2675	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2676	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2677	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2678	<h5>Overview:</h5>
				2679	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2680	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2681	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2682
				2683	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2684	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2685	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2686	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2687	<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]	2688	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2689	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2690	<table border="1" cellspacing="0" cellpadding="4">
				2691	<tbody>
				2692	<tr>
				2693	<td>In0</td>
				2694	<td>In1</td>
				2695	<td>Out</td>
				2696	</tr>
				2697	<tr>
				2698	<td>0</td>
				2699	<td>0</td>
				2700	<td>0</td>
				2701	</tr>
				2702	<tr>
				2703	<td>0</td>
				2704	<td>1</td>
				2705	<td>1</td>
				2706	</tr>
				2707	<tr>
				2708	<td>1</td>
				2709	<td>0</td>
				2710	<td>1</td>
				2711	</tr>
				2712	<tr>
				2713	<td>1</td>
				2714	<td>1</td>
				2715	<td>1</td>
				2716	</tr>
				2717	</tbody>
				2718	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2719	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2720	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2721	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2722	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2723	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2724	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2725	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2726	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2727	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2728	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2729	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2730	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2731	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2732	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2733	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2734	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2735	or of its two operands. The <tt>xor</tt> is used to implement the
				2736	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2737	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2738	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2739	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2740	values. Both arguments must have identical types.</p>
				2741
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2742	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2743
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2744	<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]	2745	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2746	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2747	<table border="1" cellspacing="0" cellpadding="4">
				2748	<tbody>
				2749	<tr>
				2750	<td>In0</td>
				2751	<td>In1</td>
				2752	<td>Out</td>
				2753	</tr>
				2754	<tr>
				2755	<td>0</td>
				2756	<td>0</td>
				2757	<td>0</td>
				2758	</tr>
				2759	<tr>
				2760	<td>0</td>
				2761	<td>1</td>
				2762	<td>1</td>
				2763	</tr>
				2764	<tr>
				2765	<td>1</td>
				2766	<td>0</td>
				2767	<td>1</td>
				2768	</tr>
				2769	<tr>
				2770	<td>1</td>
				2771	<td>1</td>
				2772	<td>0</td>
				2773	</tr>
				2774	</tbody>
				2775	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2776	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2777	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2778	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2779	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2780	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2781	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2782	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2783	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2784	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2785
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2786	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2787	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2788	<a name="vectorops">Vector Operations</a>
				2789	</div>
				2790
				2791	<div class="doc_text">
				2792
				2793	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2794	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2795	vector-specific operations needed to process vectors effectively. While LLVM
				2796	does directly support these vector operations, many sophisticated algorithms
				2797	will want to use target-specific intrinsics to take full advantage of a specific
				2798	target.</p>
				2799
				2800	</div>
				2801
				2802	<!-- _______________________________________________________________________ -->
				2803	<div class="doc_subsubsection">
				2804	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2805	</div>
				2806
				2807	<div class="doc_text">
				2808
				2809	<h5>Syntax:</h5>
				2810
				2811	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2812	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2813	</pre>
				2814
				2815	<h5>Overview:</h5>
				2816
				2817	<p>
				2818	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2819	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2820	</p>
				2821
				2822
				2823	<h5>Arguments:</h5>
				2824
				2825	<p>
				2826	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2827	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]	2828	an index indicating the position from which to extract the element.
				2829	The index may be a variable.</p>
				2830
				2831	<h5>Semantics:</h5>
				2832
				2833	<p>
				2834	The result is a scalar of the same type as the element type of
				2835	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2836	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2837	results are undefined.
				2838	</p>
				2839
				2840	<h5>Example:</h5>
				2841
				2842	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2843	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2844	</pre>
				2845	</div>
				2846
				2847
				2848	<!-- _______________________________________________________________________ -->
				2849	<div class="doc_subsubsection">
				2850	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2851	</div>
				2852
				2853	<div class="doc_text">
				2854
				2855	<h5>Syntax:</h5>
				2856
				2857	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2858	<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]	2859	</pre>
				2860
				2861	<h5>Overview:</h5>
				2862
				2863	<p>
				2864	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2865	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2866	</p>
				2867
				2868
				2869	<h5>Arguments:</h5>
				2870
				2871	<p>
				2872	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2873	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]	2874	scalar value whose type must equal the element type of the first
				2875	operand. The third operand is an index indicating the position at
				2876	which to insert the value. The index may be a variable.</p>
				2877
				2878	<h5>Semantics:</h5>
				2879
				2880	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2881	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]	2882	element values are those of <tt>val</tt> except at position
				2883	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2884	exceeds the length of <tt>val</tt>, the results are undefined.
				2885	</p>
				2886
				2887	<h5>Example:</h5>
				2888
				2889	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2890	%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]	2891	</pre>
				2892	</div>
				2893
				2894	<!-- _______________________________________________________________________ -->
				2895	<div class="doc_subsubsection">
				2896	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2897	</div>
				2898
				2899	<div class="doc_text">
				2900
				2901	<h5>Syntax:</h5>
				2902
				2903	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2904	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2905	</pre>
				2906
				2907	<h5>Overview:</h5>
				2908
				2909	<p>
				2910	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2911	from two input vectors, returning a vector of the same type.
				2912	</p>
				2913
				2914	<h5>Arguments:</h5>
				2915
				2916	<p>
				2917	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2918	with types that match each other and types that match the result of the
				2919	instruction. The third argument is a shuffle mask, which has the same number
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2920	of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2921	</p>
				2922
				2923	<p>
				2924	The shuffle mask operand is required to be a constant vector with either
				2925	constant integer or undef values.
				2926	</p>
				2927
				2928	<h5>Semantics:</h5>
				2929
				2930	<p>
				2931	The elements of the two input vectors are numbered from left to right across
				2932	both of the vectors. The shuffle mask operand specifies, for each element of
				2933	the result vector, which element of the two input registers the result element
				2934	gets. The element selector may be undef (meaning "don't care") and the second
				2935	operand may be undef if performing a shuffle from only one vector.
				2936	</p>
				2937
				2938	<h5>Example:</h5>
				2939
				2940	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2941	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2942	<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]	2943	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2944	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2945	</pre>
				2946	</div>
				2947
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2948
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2949	<!-- ======================================================================= -->
				2950	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2951	<a name="aggregateops">Aggregate Operations</a>
				2952	</div>
				2953
				2954	<div class="doc_text">
				2955
				2956	<p>LLVM supports several instructions for working with aggregate values.
				2957	</p>
				2958
				2959	</div>
				2960
				2961	<!-- _______________________________________________________________________ -->
				2962	<div class="doc_subsubsection">
				2963	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2964	</div>
				2965
				2966	<div class="doc_text">
				2967
				2968	<h5>Syntax:</h5>
				2969
				2970	<pre>
				2971	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2972	</pre>
				2973
				2974	<h5>Overview:</h5>
				2975
				2976	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2977	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2978	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2979	</p>
				2980
				2981
				2982	<h5>Arguments:</h5>
				2983
				2984	<p>
				2985	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2986	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]	2987	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2988	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2989	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2990	</p>
				2991
				2992	<h5>Semantics:</h5>
				2993
				2994	<p>
				2995	The result is the value at the position in the aggregate specified by
				2996	the index operands.
				2997	</p>
				2998
				2999	<h5>Example:</h5>
				3000
				3001	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3002	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3003	</pre>
				3004	</div>
				3005
				3006
				3007	<!-- _______________________________________________________________________ -->
				3008	<div class="doc_subsubsection">
				3009	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3010	</div>
				3011
				3012	<div class="doc_text">
				3013
				3014	<h5>Syntax:</h5>
				3015
				3016	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3017	<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]	3018	</pre>
				3019
				3020	<h5>Overview:</h5>
				3021
				3022	<p>
				3023	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3024	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3025	</p>
				3026
				3027
				3028	<h5>Arguments:</h5>
				3029
				3030	<p>
				3031	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3032	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3033	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3034	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3035	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]	3036	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3037	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3038	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]	3039	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3040
				3041	<h5>Semantics:</h5>
				3042
				3043	<p>
				3044	The result is an aggregate of the same type as <tt>val</tt>. Its
				3045	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]	3046	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3047	</p>
				3048
				3049	<h5>Example:</h5>
				3050
				3051	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3052	%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]	3053	</pre>
				3054	</div>
				3055
				3056
				3057	<!-- ======================================================================= -->
				3058	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3059	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3060	</div>
				3061
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3062	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3063
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3064	<p>A key design point of an SSA-based representation is how it
				3065	represents memory. In LLVM, no memory locations are in SSA form, which
				3066	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3067	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3068
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3069	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3070
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3071	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3072	<div class="doc_subsubsection">
				3073	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3074	</div>
				3075
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3076	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3077
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3078	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3079
				3080	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3081	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3082	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3083
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3084	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3085
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3086	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3087	heap and returns a pointer to it. The object is always allocated in the generic
				3088	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3089
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3090	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3091
				3092	<p>The '<tt>malloc</tt>' instruction allocates
				3093	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3094	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]	3095	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3096	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3097	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]	3098	be aligned to at least that boundary. If not specified, or if zero, the target can
				3099	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3100
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3101	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3102
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3103	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3104
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3105	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3106	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3107	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3108
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3109	<h5>Example:</h5>
				3110
				3111	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3112	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3113
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3114	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3115	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3116	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3117	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3118	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3119	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3120	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3121
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3122	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3123	<div class="doc_subsubsection">
				3124	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3125	</div>
				3126
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3127	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3128
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3129	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3130
				3131	<pre>
				3132	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3133	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3134
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3135	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3136
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3137	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3138	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3139
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3140	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3141
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3142	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3143	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3144	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3145
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3146	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3147
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3148	<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]	3149	after this instruction executes. If the pointer is null, the operation
				3150	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3151
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3152	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3153
				3154	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3155	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3156	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3157	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3158	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3159
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3160	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3161	<div class="doc_subsubsection">
				3162	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3163	</div>
				3164
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3165	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3166
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3167	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3168
				3169	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3170	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3171	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3172
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3173	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3174
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3175	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3176	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3177	returns to its caller. The object is always allocated in the generic address
				3178	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3179
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3180	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3181
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3182	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3183	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3184	appropriate type to the program. If "NumElements" is specified, it is the
				3185	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3186	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]	3187	to be aligned to at least that boundary. If not specified, or if zero, the target
				3188	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3189
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3190	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3191
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3192	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3193
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3194	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3195	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3196	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3197	instruction is commonly used to represent automatic variables that must
				3198	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]	3199	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]	3200	instructions), the memory is reclaimed. Allocating zero bytes
				3201	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3202
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3203	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3204
				3205	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3206	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3207	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3208	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3209	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3210	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3211	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3212
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3213	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3214	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3215	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3216	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3217	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3218	<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]	3219	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3220	<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]	3221	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3222	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3223	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3224	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]	3225	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]	3226	the number or order of execution of this <tt>load</tt> with other
				3227	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3228	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3229	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3230	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3231	(that is, the alignment of the memory address). A value of 0 or an
				3232	omitted "align" argument means that the operation has the preferential
				3233	alignment for the target. It is the responsibility of the code emitter
				3234	to ensure that the alignment information is correct. Overestimating
				3235	the alignment results in an undefined behavior. Underestimating the
				3236	alignment may produce less efficient code. An alignment of 1 is always
				3237	safe.
				3238	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3239	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3240	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3241	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3242	<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]	3243	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3244	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3245	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3246	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3247	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3248	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3249	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3250	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3251	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3252	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3253	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3254	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3255	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3256	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3257	<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]	3258	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3259	<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]	3260	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]	3261	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3262	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3263	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]	3264	optimizer is not allowed to modify the number or order of execution of
				3265	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3266	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3267	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3268	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3269	(that is, the alignment of the memory address). A value of 0 or an
				3270	omitted "align" argument means that the operation has the preferential
				3271	alignment for the target. It is the responsibility of the code emitter
				3272	to ensure that the alignment information is correct. Overestimating
				3273	the alignment results in an undefined behavior. Underestimating the
				3274	alignment may produce less efficient code. An alignment of 1 is always
				3275	safe.
				3276	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3277	<h5>Semantics:</h5>
				3278	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3279	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3280	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3281	<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]	3282	store i32 3, i32* %ptr <i>; yields {void}</i>
				3283	%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]	3284	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3285	</div>
				3286
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3287	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3288	<div class="doc_subsubsection">
				3289	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3290	</div>
				3291
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3292	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3293	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3294	<pre>
				3295	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3296	</pre>
				3297
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3298	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3299
				3300	<p>
				3301	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3302	subelement of an aggregate data structure.</p>
				3303
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3304	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3305
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3306	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3307	elements of the aggregate object to index to. The actual types of the arguments
				3308	provided depend on the type of the first pointer argument. The
				3309	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3310	levels of a structure or to a specific index in an array. When indexing into a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3311	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3312	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3313	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3314
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3315	<p>For example, let's consider a C code fragment and how it gets
				3316	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3317
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3318	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3319	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3320	struct RT {
				3321	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3322	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3323	char C;
				3324	};
				3325	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3326	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3327	double Y;
				3328	struct RT Z;
				3329	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3330
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3331	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3332	return &s[1].Z.B[5][13];
				3333	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3334	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3335	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3336
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3337	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3338
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3339	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3340	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3341	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3342	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3343
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3344	define i32* %foo(%ST* %s) {
				3345	entry:
				3346	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3347	ret i32* %reg
				3348	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3349	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3350	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3351
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3352	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3353
				3354	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3355	on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3356	and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer	42ddd84	2006-12-03 16:53:48 +0000	[diff] [blame]	3357	<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3358	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3359	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3360
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3361	<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]	3362	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]	3363	}</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]	3364	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3365	i8 }</tt>' type, another structure. The third index indexes into the second
				3366	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]	3367	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3368	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3369	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]	3370
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3371	<p>Note that it is perfectly legal to index partially through a
				3372	structure, returning a pointer to an inner element. Because of this,
				3373	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3374
				3375	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3376	define i32* %foo(%ST* %s) {
				3377	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3378	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3379	%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]	3380	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3381	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3382	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3383	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3384	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3385
				3386	<p>Note that it is undefined to access an array out of bounds: array and
				3387	pointer indexes must always be within the defined bounds of the array type.
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3388	The one exception for this rule is zero length arrays. These arrays are
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3389	defined to be accessible as variable length arrays, which requires access
				3390	beyond the zero'th element.</p>
				3391
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3392	<p>The getelementptr instruction is often confusing. For some more insight
				3393	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3394	FAQ</a>.</p>
				3395
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3396	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3397
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3398	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3399	<i>; yields [12 x i8]*:aptr</i>
				3400	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3401	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3402	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3403
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3404	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3405	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3406	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3407	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3408	<p>The instructions in this category are the conversion instructions (casting)
				3409	which all take a single operand and a type. They perform various bit conversions
				3410	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3411	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3412
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3413	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3414	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3415	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3416	</div>
				3417	<div class="doc_text">
				3418
				3419	<h5>Syntax:</h5>
				3420	<pre>
				3421	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3422	</pre>
				3423
				3424	<h5>Overview:</h5>
				3425	<p>
				3426	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3427	</p>
				3428
				3429	<h5>Arguments:</h5>
				3430	<p>
				3431	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3432	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]	3433	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]	3434	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3435	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3436
				3437	<h5>Semantics:</h5>
				3438	<p>
				3439	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]	3440	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3441	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3442	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3443
				3444	<h5>Example:</h5>
				3445	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3446	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3447	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3448	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3449	</pre>
				3450	</div>
				3451
				3452	<!-- _______________________________________________________________________ -->
				3453	<div class="doc_subsubsection">
				3454	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3455	</div>
				3456	<div class="doc_text">
				3457
				3458	<h5>Syntax:</h5>
				3459	<pre>
				3460	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3461	</pre>
				3462
				3463	<h5>Overview:</h5>
				3464	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3465	<tt>ty2</tt>.</p>
				3466
				3467
				3468	<h5>Arguments:</h5>
				3469	<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]	3470	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3471	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]	3472	<tt>value</tt> must be smaller than the bit size of the destination type,
				3473	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3474
				3475	<h5>Semantics:</h5>
				3476	<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]	3477	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]	3478
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3479	<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]	3480
				3481	<h5>Example:</h5>
				3482	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3483	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3484	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3485	</pre>
				3486	</div>
				3487
				3488	<!-- _______________________________________________________________________ -->
				3489	<div class="doc_subsubsection">
				3490	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3491	</div>
				3492	<div class="doc_text">
				3493
				3494	<h5>Syntax:</h5>
				3495	<pre>
				3496	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3497	</pre>
				3498
				3499	<h5>Overview:</h5>
				3500	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3501
				3502	<h5>Arguments:</h5>
				3503	<p>
				3504	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]	3505	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3506	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]	3507	<tt>value</tt> must be smaller than the bit size of the destination type,
				3508	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3509
				3510	<h5>Semantics:</h5>
				3511	<p>
				3512	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3513	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]	3514	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3515
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3516	<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]	3517
				3518	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3519	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3520	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3521	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3522	</pre>
				3523	</div>
				3524
				3525	<!-- _______________________________________________________________________ -->
				3526	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3527	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3528	</div>
				3529
				3530	<div class="doc_text">
				3531
				3532	<h5>Syntax:</h5>
				3533
				3534	<pre>
				3535	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3536	</pre>
				3537
				3538	<h5>Overview:</h5>
				3539	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3540	<tt>ty2</tt>.</p>
				3541
				3542
				3543	<h5>Arguments:</h5>
				3544	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3545	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3546	cast it to. The size of <tt>value</tt> must be larger than the size of
				3547	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3548	<i>no-op cast</i>.</p>
				3549
				3550	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3551	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3552	<a href="#t_floating">floating point</a> type to a smaller
				3553	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3554	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3555
				3556	<h5>Example:</h5>
				3557	<pre>
				3558	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3559	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3560	</pre>
				3561	</div>
				3562
				3563	<!-- _______________________________________________________________________ -->
				3564	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3565	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3566	</div>
				3567	<div class="doc_text">
				3568
				3569	<h5>Syntax:</h5>
				3570	<pre>
				3571	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3572	</pre>
				3573
				3574	<h5>Overview:</h5>
				3575	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3576	floating point value.</p>
				3577
				3578	<h5>Arguments:</h5>
				3579	<p>The '<tt>fpext</tt>' instruction takes a
				3580	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3581	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3582	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3583
				3584	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3585	<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]	3586	<a href="#t_floating">floating point</a> type to a larger
				3587	<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]	3588	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]	3589	<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]	3590
				3591	<h5>Example:</h5>
				3592	<pre>
				3593	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3594	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3595	</pre>
				3596	</div>
				3597
				3598	<!-- _______________________________________________________________________ -->
				3599	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3600	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3601	</div>
				3602	<div class="doc_text">
				3603
				3604	<h5>Syntax:</h5>
				3605	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3606	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3607	</pre>
				3608
				3609	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3610	<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]	3611	unsigned integer equivalent of type <tt>ty2</tt>.
				3612	</p>
				3613
				3614	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3615	<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]	3616	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3617	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3618	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3619	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]	3620
				3621	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3622	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3623	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3624	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3625	the results are undefined.</p>
				3626
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3627	<h5>Example:</h5>
				3628	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3629	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3630	%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]	3631	%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]	3632	</pre>
				3633	</div>
				3634
				3635	<!-- _______________________________________________________________________ -->
				3636	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3637	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3638	</div>
				3639	<div class="doc_text">
				3640
				3641	<h5>Syntax:</h5>
				3642	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3643	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3644	</pre>
				3645
				3646	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3647	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3648	<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]	3649	</p>
				3650
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3651	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3652	<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]	3653	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3654	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3655	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3656	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]	3657
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3658	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3659	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3660	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3661	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3662	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3663
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3664	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3665	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3666	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3667	%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]	3668	%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]	3669	</pre>
				3670	</div>
				3671
				3672	<!-- _______________________________________________________________________ -->
				3673	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3674	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3675	</div>
				3676	<div class="doc_text">
				3677
				3678	<h5>Syntax:</h5>
				3679	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3680	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3681	</pre>
				3682
				3683	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3684	<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]	3685	integer and converts that value to the <tt>ty2</tt> type.</p>
				3686
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3687	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3688	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3689	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3690	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3691	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3692	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]	3693
				3694	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3695	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3696	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3697	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]	3698
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3699	<h5>Example:</h5>
				3700	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3701	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3702	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3703	</pre>
				3704	</div>
				3705
				3706	<!-- _______________________________________________________________________ -->
				3707	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3708	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3709	</div>
				3710	<div class="doc_text">
				3711
				3712	<h5>Syntax:</h5>
				3713	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3714	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3715	</pre>
				3716
				3717	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3718	<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]	3719	integer and converts that value to the <tt>ty2</tt> type.</p>
				3720
				3721	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3722	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3723	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3724	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3725	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3726	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]	3727
				3728	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3729	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3730	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3731	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]	3732
				3733	<h5>Example:</h5>
				3734	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3735	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3736	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3737	</pre>
				3738	</div>
				3739
				3740	<!-- _______________________________________________________________________ -->
				3741	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3742	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3743	</div>
				3744	<div class="doc_text">
				3745
				3746	<h5>Syntax:</h5>
				3747	<pre>
				3748	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3749	</pre>
				3750
				3751	<h5>Overview:</h5>
				3752	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3753	the integer type <tt>ty2</tt>.</p>
				3754
				3755	<h5>Arguments:</h5>
				3756	<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]	3757	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3758	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3759
				3760	<h5>Semantics:</h5>
				3761	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3762	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3763	truncating or zero extending that value to the size of the integer type. If
				3764	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3765	<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]	3766	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3767	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3768
				3769	<h5>Example:</h5>
				3770	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3771	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3772	%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]	3773	</pre>
				3774	</div>
				3775
				3776	<!-- _______________________________________________________________________ -->
				3777	<div class="doc_subsubsection">
				3778	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3779	</div>
				3780	<div class="doc_text">
				3781
				3782	<h5>Syntax:</h5>
				3783	<pre>
				3784	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3785	</pre>
				3786
				3787	<h5>Overview:</h5>
				3788	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3789	a pointer type, <tt>ty2</tt>.</p>
				3790
				3791	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3792	<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]	3793	value to cast, and a type to cast it to, which must be a
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	3794	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3795
				3796	<h5>Semantics:</h5>
				3797	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3798	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3799	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3800	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3801	the size of a pointer then a zero extension is done. If they are the same size,
				3802	nothing is done (<i>no-op cast</i>).</p>
				3803
				3804	<h5>Example:</h5>
				3805	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3806	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3807	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3808	%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]	3809	</pre>
				3810	</div>
				3811
				3812	<!-- _______________________________________________________________________ -->
				3813	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3814	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3815	</div>
				3816	<div class="doc_text">
				3817
				3818	<h5>Syntax:</h5>
				3819	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3820	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3821	</pre>
				3822
				3823	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3824
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3825	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3826	<tt>ty2</tt> without changing any bits.</p>
				3827
				3828	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3829
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3830	<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]	3831	a non-aggregate first class value, and a type to cast it to, which must also be
				3832	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3833	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	3834	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]	3835	type is a pointer, the destination type must also be a pointer. This
				3836	instruction supports bitwise conversion of vectors to integers and to vectors
				3837	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3838
				3839	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3840	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3841	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3842	this conversion. The conversion is done as if the <tt>value</tt> had been
				3843	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3844	converted to other pointer types with this instruction. To convert pointers to
				3845	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3846	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3847
				3848	<h5>Example:</h5>
				3849	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3850	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3851	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3852	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3853	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3854	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3855
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3856	<!-- ======================================================================= -->
				3857	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3858	<div class="doc_text">
				3859	<p>The instructions in this category are the "miscellaneous"
				3860	instructions, which defy better classification.</p>
				3861	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3862
				3863	<!-- _______________________________________________________________________ -->
				3864	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3865	</div>
				3866	<div class="doc_text">
				3867	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3868	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3869	</pre>
				3870	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3871	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3872	a vector of boolean values based on comparison
				3873	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3874	<h5>Arguments:</h5>
				3875	<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]	3876	the condition code indicating the kind of comparison to perform. It is not
				3877	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3878	<ol>
				3879	<li><tt>eq</tt>: equal</li>
				3880	<li><tt>ne</tt>: not equal </li>
				3881	<li><tt>ugt</tt>: unsigned greater than</li>
				3882	<li><tt>uge</tt>: unsigned greater or equal</li>
				3883	<li><tt>ult</tt>: unsigned less than</li>
				3884	<li><tt>ule</tt>: unsigned less or equal</li>
				3885	<li><tt>sgt</tt>: signed greater than</li>
				3886	<li><tt>sge</tt>: signed greater or equal</li>
				3887	<li><tt>slt</tt>: signed less than</li>
				3888	<li><tt>sle</tt>: signed less or equal</li>
				3889	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3890	<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]	3891	<a href="#t_pointer">pointer</a>
				3892	or integer <a href="#t_vector">vector</a> typed.
				3893	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3894	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3895	<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]	3896	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3897	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3898	<ol>
				3899	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3900	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3901	</li>
				3902	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3903	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3904	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3905	<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]	3906	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3907	<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]	3908	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3909	<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]	3910	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3911	<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]	3912	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3913	<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]	3914	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3915	<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]	3916	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3917	<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]	3918	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3919	<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]	3920	</ol>
				3921	<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]	3922	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3923	<p>If the operands are integer vectors, then they are compared
				3924	element by element. The result is an <tt>i1</tt> vector with
				3925	the same number of elements as the values being compared.
				3926	Otherwise, the result is an <tt>i1</tt>.
				3927	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3928
				3929	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3930	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3931	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3932	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3933	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3934	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3935	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3936	</pre>
				3937	</div>
				3938
				3939	<!-- _______________________________________________________________________ -->
				3940	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3941	</div>
				3942	<div class="doc_text">
				3943	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3944	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3945	</pre>
				3946	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3947	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3948	or vector of boolean values based on comparison
				3949	of its operands.
				3950	<p>
				3951	If the operands are floating point scalars, then the result
				3952	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3953	</p>
				3954	<p>If the operands are floating point vectors, then the result type
				3955	is a vector of boolean with the same number of elements as the
				3956	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3957	<h5>Arguments:</h5>
				3958	<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]	3959	the condition code indicating the kind of comparison to perform. It is not
				3960	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3961	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3962	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3963	<li><tt>oeq</tt>: ordered and equal</li>
				3964	<li><tt>ogt</tt>: ordered and greater than </li>
				3965	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3966	<li><tt>olt</tt>: ordered and less than </li>
				3967	<li><tt>ole</tt>: ordered and less than or equal</li>
				3968	<li><tt>one</tt>: ordered and not equal</li>
				3969	<li><tt>ord</tt>: ordered (no nans)</li>
				3970	<li><tt>ueq</tt>: unordered or equal</li>
				3971	<li><tt>ugt</tt>: unordered or greater than </li>
				3972	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3973	<li><tt>ult</tt>: unordered or less than </li>
				3974	<li><tt>ule</tt>: unordered or less than or equal</li>
				3975	<li><tt>une</tt>: unordered or not equal</li>
				3976	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3977	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3978	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3979	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3980	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3981	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				3982	either a <a href="#t_floating">floating point</a> type
				3983	or a <a href="#t_vector">vector</a> of floating point type.
				3984	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3985	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3986	<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]	3987	according to the condition code given as <tt>cond</tt>.
				3988	If the operands are vectors, then the vectors are compared
				3989	element by element.
				3990	Each comparison performed
				3991	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3992	<ol>
				3993	<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]	3994	<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]	3995	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3996	<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]	3997	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3998	<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]	3999	<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]	4000	<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]	4001	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4002	<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]	4003	<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]	4004	<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]	4005	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4006	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4007	<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]	4008	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4009	<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]	4010	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4011	<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]	4012	<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]	4013	<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]	4014	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4015	<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]	4016	<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]	4017	<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]	4018	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4019	<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]	4020	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4021	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4022
				4023	<h5>Example:</h5>
				4024	<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]	4025	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4026	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4027	<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]	4028	</pre>
				4029	</div>
				4030
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4031	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4032	<div class="doc_subsubsection">
				4033	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4034	</div>
				4035	<div class="doc_text">
				4036	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4037	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4038	</pre>
				4039	<h5>Overview:</h5>
				4040	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4041	element-wise comparison of its two integer vector operands.</p>
				4042	<h5>Arguments:</h5>
				4043	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4044	the condition code indicating the kind of comparison to perform. It is not
				4045	a value, just a keyword. The possible condition code are:
				4046	<ol>
				4047	<li><tt>eq</tt>: equal</li>
				4048	<li><tt>ne</tt>: not equal </li>
				4049	<li><tt>ugt</tt>: unsigned greater than</li>
				4050	<li><tt>uge</tt>: unsigned greater or equal</li>
				4051	<li><tt>ult</tt>: unsigned less than</li>
				4052	<li><tt>ule</tt>: unsigned less or equal</li>
				4053	<li><tt>sgt</tt>: signed greater than</li>
				4054	<li><tt>sge</tt>: signed greater or equal</li>
				4055	<li><tt>slt</tt>: signed less than</li>
				4056	<li><tt>sle</tt>: signed less or equal</li>
				4057	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4058	<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]	4059	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4060	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4061	<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]	4062	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4063	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4064	identical type as the values being compared. The most significant bit in each
				4065	element is 1 if the element-wise comparison evaluates to true, and is 0
				4066	otherwise. All other bits of the result are undefined. The condition codes
				4067	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4068	instruction</a>.
				4069
				4070	<h5>Example:</h5>
				4071	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4072	<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>
				4073	<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]	4074	</pre>
				4075	</div>
				4076
				4077	<!-- _______________________________________________________________________ -->
				4078	<div class="doc_subsubsection">
				4079	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4080	</div>
				4081	<div class="doc_text">
				4082	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4083	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4084	<h5>Overview:</h5>
				4085	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4086	element-wise comparison of its two floating point vector operands. The output
				4087	elements have the same width as the input elements.</p>
				4088	<h5>Arguments:</h5>
				4089	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4090	the condition code indicating the kind of comparison to perform. It is not
				4091	a value, just a keyword. The possible condition code are:
				4092	<ol>
				4093	<li><tt>false</tt>: no comparison, always returns false</li>
				4094	<li><tt>oeq</tt>: ordered and equal</li>
				4095	<li><tt>ogt</tt>: ordered and greater than </li>
				4096	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4097	<li><tt>olt</tt>: ordered and less than </li>
				4098	<li><tt>ole</tt>: ordered and less than or equal</li>
				4099	<li><tt>one</tt>: ordered and not equal</li>
				4100	<li><tt>ord</tt>: ordered (no nans)</li>
				4101	<li><tt>ueq</tt>: unordered or equal</li>
				4102	<li><tt>ugt</tt>: unordered or greater than </li>
				4103	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4104	<li><tt>ult</tt>: unordered or less than </li>
				4105	<li><tt>ule</tt>: unordered or less than or equal</li>
				4106	<li><tt>une</tt>: unordered or not equal</li>
				4107	<li><tt>uno</tt>: unordered (either nans)</li>
				4108	<li><tt>true</tt>: no comparison, always returns true</li>
				4109	</ol>
				4110	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4111	<a href="#t_floating">floating point</a> typed. They must also be identical
				4112	types.</p>
				4113	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4114	<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]	4115	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4116	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4117	an identical number of elements as the values being compared, and each element
				4118	having identical with to the width of the floating point elements. The most
				4119	significant bit in each element is 1 if the element-wise comparison evaluates to
				4120	true, and is 0 otherwise. All other bits of the result are undefined. The
				4121	condition codes are evaluated identically to the
				4122	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4123
				4124	<h5>Example:</h5>
				4125	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4126	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 > <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4127	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2> <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4128	</pre>
				4129	</div>
				4130
				4131	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4132	<div class="doc_subsubsection">
				4133	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4134	</div>
				4135
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4136	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4137
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4138	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4139
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4140	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4141	<h5>Overview:</h5>
				4142	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4143	the SSA graph representing the function.</p>
				4144	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4145
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4146	<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]	4147	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4148	as arguments, with one pair for each predecessor basic block of the
				4149	current block. Only values of <a href="#t_firstclass">first class</a>
				4150	type may be used as the value arguments to the PHI node. Only labels
				4151	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4152
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4153	<p>There must be no non-phi instructions between the start of a basic
				4154	block and the PHI instructions: i.e. PHI instructions must be first in
				4155	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4156
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4157	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4158
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4159	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4160	specified by the pair corresponding to the predecessor basic block that executed
				4161	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4162
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4163	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4164	<pre>
				4165	Loop: ; Infinite loop that counts from 0 on up...
				4166	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4167	%nextindvar = add i32 %indvar, 1
				4168	br label %Loop
				4169	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4170	</div>
				4171
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4172	<!-- _______________________________________________________________________ -->
				4173	<div class="doc_subsubsection">
				4174	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4175	</div>
				4176
				4177	<div class="doc_text">
				4178
				4179	<h5>Syntax:</h5>
				4180
				4181	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4182	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4183
				4184	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4185	</pre>
				4186
				4187	<h5>Overview:</h5>
				4188
				4189	<p>
				4190	The '<tt>select</tt>' instruction is used to choose one value based on a
				4191	condition, without branching.
				4192	</p>
				4193
				4194
				4195	<h5>Arguments:</h5>
				4196
				4197	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4198	The '<tt>select</tt>' instruction requires an 'i1' value or
				4199	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4200	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]	4201	type. If the val1/val2 are vectors and
				4202	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4203	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4204	</p>
				4205
				4206	<h5>Semantics:</h5>
				4207
				4208	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4209	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]	4210	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4211	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4212	<p>
				4213	If the condition is a vector of i1, then the value arguments must
				4214	be vectors of the same size, and the selection is done element
				4215	by element.
				4216	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4217
				4218	<h5>Example:</h5>
				4219
				4220	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4221	%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]	4222	</pre>
				4223	</div>
				4224
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4225
				4226	<!-- _______________________________________________________________________ -->
				4227	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4228	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4229	</div>
				4230
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4231	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4232
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4233	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4234	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4235	<result> = [tail] call [<a href="#callingconv">cconv</a>] <ty> [<fnty>*] <fnptrval>(<param list>)
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4236	</pre>
				4237
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4238	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4239
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4240	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4241
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4242	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4243
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4244	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4245
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4246	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4247	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4248	<p>The optional "tail" marker indicates whether the callee function accesses
				4249	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]	4250	function call is eligible for tail call optimization. Note that calls may
				4251	be marked "tail" even if they do not occur before a <a
				4252	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4253	</li>
				4254	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4255	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4256	convention</a> the call should use. If none is specified, the call defaults
				4257	to using C calling conventions.
				4258	</li>
				4259	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4260	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4261	the type of the return value. Functions that return no value are marked
				4262	<tt><a href="#t_void">void</a></tt>.</p>
				4263	</li>
				4264	<li>
				4265	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4266	value being invoked. The argument types must match the types implied by
				4267	this signature. This type can be omitted if the function is not varargs
				4268	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]	4269	</li>
				4270	<li>
				4271	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4272	be invoked. In most cases, this is a direct function invocation, but
				4273	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]	4274	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4275	</li>
				4276	<li>
				4277	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4278	function signature argument types. All arguments must be of
				4279	<a href="#t_firstclass">first class</a> type. If the function signature
				4280	indicates the function accepts a variable number of arguments, the extra
				4281	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4282	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4283	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4284
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4285	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4286
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4287	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4288	transfer to a specified function, with its incoming arguments bound to
				4289	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4290	instruction in the called function, control flow continues with the
				4291	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4292	function is bound to the result argument. If the callee returns multiple
				4293	values then the return values of the function are only accessible through
				4294	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4295
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4296	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4297
				4298	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4299	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4300	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4301	%X = tail call i32 @foo() <i>; yields i32</i>
				4302	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4303	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4304
				4305	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4306	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4307	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4308	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4309	</pre>
				4310
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4311	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4312
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4313	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4314	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4315	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4316	</div>
				4317
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4318	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4319
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4320	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4321
				4322	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4323	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4324	</pre>
				4325
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4326	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4327
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4328	<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]	4329	the "variable argument" area of a function call. It is used to implement the
				4330	<tt>va_arg</tt> macro in C.</p>
				4331
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4332	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4333
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4334	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4335	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4336	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]	4337	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4338
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4339	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4340
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4341	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4342	type from the specified <tt>va_list</tt> and causes the
				4343	<tt>va_list</tt> to point to the next argument. For more information,
				4344	see the variable argument handling <a href="#int_varargs">Intrinsic
				4345	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4346
				4347	<p>It is legal for this instruction to be called in a function which does not
				4348	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4349	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4350
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4351	<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]	4352	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4353	argument.</p>
				4354
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4355	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4356
				4357	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4358
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4359	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4360
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4361	<!-- _______________________________________________________________________ -->
				4362	<div class="doc_subsubsection">
				4363	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4364	</div>
				4365
				4366	<div class="doc_text">
				4367
				4368	<h5>Syntax:</h5>
				4369	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4370	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4371	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4372
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4373	<h5>Overview:</h5>
				4374
				4375	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4376	from a '<tt><a href="#i_call">call</a></tt>'
				4377	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4378	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4379
				4380	<h5>Arguments:</h5>
				4381
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4382	<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner	1c406d7	2008-04-23 04:06:52 +0000	[diff] [blame]	4383	first argument, or an undef value. The value must have <a
				4384	href="#t_struct">structure type</a>. The second argument is a constant
				4385	unsigned index value which must be in range for the number of values returned
				4386	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4387
				4388	<h5>Semantics:</h5>
				4389
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4390	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4391	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4392
				4393	<h5>Example:</h5>
				4394
				4395	<pre>
				4396	%struct.A = type { i32, i8 }
				4397
				4398	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4399	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4400	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4401	add i32 %gr, 42
				4402	add i8 %gr1, 41
				4403	</pre>
				4404
				4405	</div>
				4406
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4407	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4408	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4409	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4410
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4411	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4412
				4413	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4414	well known names and semantics and are required to follow certain restrictions.
				4415	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4416	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]	4417	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]	4418
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4419	<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]	4420	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4421	begin with this prefix. Intrinsic functions must always be external functions:
				4422	you cannot define the body of intrinsic functions. Intrinsic functions may
				4423	only be used in call or invoke instructions: it is illegal to take the address
				4424	of an intrinsic function. Additionally, because intrinsic functions are part
				4425	of the LLVM language, it is required if any are added that they be documented
				4426	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4427
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4428	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4429	a family of functions that perform the same operation but on different data
				4430	types. Because LLVM can represent over 8 million different integer types,
				4431	overloading is used commonly to allow an intrinsic function to operate on any
				4432	integer type. One or more of the argument types or the result type can be
				4433	overloaded to accept any integer type. Argument types may also be defined as
				4434	exactly matching a previous argument's type or the result type. This allows an
				4435	intrinsic function which accepts multiple arguments, but needs all of them to
				4436	be of the same type, to only be overloaded with respect to a single argument or
				4437	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4438
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4439	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4440	encoded into its function name, each preceded by a period. Only those types
				4441	which are overloaded result in a name suffix. Arguments whose type is matched
				4442	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4443	take an integer of any width and returns an integer of exactly the same integer
				4444	width. This leads to a family of functions such as
				4445	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4446	Only one type, the return type, is overloaded, and only one type suffix is
				4447	required. Because the argument's type is matched against the return type, it
				4448	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4449
				4450	<p>To learn how to add an intrinsic function, please see the
				4451	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4452	</p>
				4453
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4454	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4455
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4456	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4457	<div class="doc_subsection">
				4458	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4459	</div>
				4460
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4461	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4462
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4463	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4464	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]	4465	intrinsic functions. These functions are related to the similarly
				4466	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4467
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4468	<p>All of these functions operate on arguments that use a
				4469	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4470	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4471	transformations should be prepared to handle these functions regardless of
				4472	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4473
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4474	<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]	4475	instruction and the variable argument handling intrinsic functions are
				4476	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4477
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4478	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4479	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4480	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4481	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4482	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4483	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4484	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4485
				4486	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4487	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4488
				4489	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4490	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4491	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4492	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4493	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4494
				4495	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4496	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4497	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4498	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4499
				4500	declare void @llvm.va_start(i8*)
				4501	declare void @llvm.va_copy(i8, i8)
				4502	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4503	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4504	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4505
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4506	</div>
				4507
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4508	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4509	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4510	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4511	</div>
				4512
				4513
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4514	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4515	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4516	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4517	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4518	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4519	<tt>*<arglist></tt> for subsequent use by <tt><a
				4520	href="#i_va_arg">va_arg</a></tt>.</p>
				4521
				4522	<h5>Arguments:</h5>
				4523
				4524	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4525
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4526	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4527
				4528	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4529	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4530	<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]	4531	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4532	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]	4533	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]	4534
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4535	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4536
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4537	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4538	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4539	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4540	</div>
				4541
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4542	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4543	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4544	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4545	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4546
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4547	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4548	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]	4549	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]	4550
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4551	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4552
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4553	<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]	4554
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4555	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4556
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4557	<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]	4558	macro available in C. In a target-dependent way, it destroys the
				4559	<tt>va_list</tt> element to which the argument points. Calls to <a
				4560	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4561	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4562	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4563
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4564	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4565
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4566	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4567	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4568	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4569	</div>
				4570
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4571	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4572
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4573	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4574
				4575	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4576	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4577	</pre>
				4578
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4579	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4580
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4581	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4582	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4583
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4584	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4585
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4586	<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]	4587	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]	4588
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4589
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4590	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4591
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4592	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4593	macro available in C. In a target-dependent way, it copies the source
				4594	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4595	intrinsic is necessary because the <tt><a href="#int_va_start">
				4596	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4597	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4598
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4599	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4600
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4601	<!-- ======================================================================= -->
				4602	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4603	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4604	</div>
				4605
				4606	<div class="doc_text">
				4607
				4608	<p>
				4609	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4610	Collection</a> (GC) requires the implementation and generation of these
				4611	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4612	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]	4613	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4614	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]	4615	Front-ends for type-safe garbage collected languages should generate these
				4616	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4617	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4618	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4619
				4620	<p>The garbage collection intrinsics only operate on objects in the generic
				4621	address space (address space zero).</p>
				4622
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4623	</div>
				4624
				4625	<!-- _______________________________________________________________________ -->
				4626	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4627	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4628	</div>
				4629
				4630	<div class="doc_text">
				4631
				4632	<h5>Syntax:</h5>
				4633
				4634	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4635	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4636	</pre>
				4637
				4638	<h5>Overview:</h5>
				4639
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4640	<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]	4641	the code generator, and allows some metadata to be associated with it.</p>
				4642
				4643	<h5>Arguments:</h5>
				4644
				4645	<p>The first argument specifies the address of a stack object that contains the
				4646	root pointer. The second pointer (which must be either a constant or a global
				4647	value address) contains the meta-data to be associated with the root.</p>
				4648
				4649	<h5>Semantics:</h5>
				4650
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4651	<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]	4652	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4653	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4654	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4655	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4656
				4657	</div>
				4658
				4659
				4660	<!-- _______________________________________________________________________ -->
				4661	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4662	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4663	</div>
				4664
				4665	<div class="doc_text">
				4666
				4667	<h5>Syntax:</h5>
				4668
				4669	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4670	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4671	</pre>
				4672
				4673	<h5>Overview:</h5>
				4674
				4675	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4676	locations, allowing garbage collector implementations that require read
				4677	barriers.</p>
				4678
				4679	<h5>Arguments:</h5>
				4680
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4681	<p>The second argument is the address to read from, which should be an address
				4682	allocated from the garbage collector. The first object is a pointer to the
				4683	start of the referenced object, if needed by the language runtime (otherwise
				4684	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4685
				4686	<h5>Semantics:</h5>
				4687
				4688	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4689	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4690	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4691	may only be used in a function which <a href="#gc">specifies a GC
				4692	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4693
				4694	</div>
				4695
				4696
				4697	<!-- _______________________________________________________________________ -->
				4698	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4699	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4700	</div>
				4701
				4702	<div class="doc_text">
				4703
				4704	<h5>Syntax:</h5>
				4705
				4706	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4707	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4708	</pre>
				4709
				4710	<h5>Overview:</h5>
				4711
				4712	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4713	locations, allowing garbage collector implementations that require write
				4714	barriers (such as generational or reference counting collectors).</p>
				4715
				4716	<h5>Arguments:</h5>
				4717
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4718	<p>The first argument is the reference to store, the second is the start of the
				4719	object to store it to, and the third is the address of the field of Obj to
				4720	store to. If the runtime does not require a pointer to the object, Obj may be
				4721	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4722
				4723	<h5>Semantics:</h5>
				4724
				4725	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4726	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4727	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4728	may only be used in a function which <a href="#gc">specifies a GC
				4729	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4730
				4731	</div>
				4732
				4733
				4734
				4735	<!-- ======================================================================= -->
				4736	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4737	<a name="int_codegen">Code Generator Intrinsics</a>
				4738	</div>
				4739
				4740	<div class="doc_text">
				4741	<p>
				4742	These intrinsics are provided by LLVM to expose special features that may only
				4743	be implemented with code generator support.
				4744	</p>
				4745
				4746	</div>
				4747
				4748	<!-- _______________________________________________________________________ -->
				4749	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4750	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4751	</div>
				4752
				4753	<div class="doc_text">
				4754
				4755	<h5>Syntax:</h5>
				4756	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4757	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4758	</pre>
				4759
				4760	<h5>Overview:</h5>
				4761
				4762	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4763	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4764	target-specific value indicating the return address of the current function
				4765	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4766	</p>
				4767
				4768	<h5>Arguments:</h5>
				4769
				4770	<p>
				4771	The argument to this intrinsic indicates which function to return the address
				4772	for. Zero indicates the calling function, one indicates its caller, etc. The
				4773	argument is <b>required</b> to be a constant integer value.
				4774	</p>
				4775
				4776	<h5>Semantics:</h5>
				4777
				4778	<p>
				4779	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4780	the return address of the specified call frame, or zero if it cannot be
				4781	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4782	for arguments other than zero, so it should only be used for debugging purposes.
				4783	</p>
				4784
				4785	<p>
				4786	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4787	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]	4788	source-language caller.
				4789	</p>
				4790	</div>
				4791
				4792
				4793	<!-- _______________________________________________________________________ -->
				4794	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4795	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4796	</div>
				4797
				4798	<div class="doc_text">
				4799
				4800	<h5>Syntax:</h5>
				4801	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4802	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4803	</pre>
				4804
				4805	<h5>Overview:</h5>
				4806
				4807	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4808	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4809	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4810	</p>
				4811
				4812	<h5>Arguments:</h5>
				4813
				4814	<p>
				4815	The argument to this intrinsic indicates which function to return the frame
				4816	pointer for. Zero indicates the calling function, one indicates its caller,
				4817	etc. The argument is <b>required</b> to be a constant integer value.
				4818	</p>
				4819
				4820	<h5>Semantics:</h5>
				4821
				4822	<p>
				4823	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4824	the frame address of the specified call frame, or zero if it cannot be
				4825	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4826	for arguments other than zero, so it should only be used for debugging purposes.
				4827	</p>
				4828
				4829	<p>
				4830	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4831	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]	4832	source-language caller.
				4833	</p>
				4834	</div>
				4835
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4836	<!-- _______________________________________________________________________ -->
				4837	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4838	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4839	</div>
				4840
				4841	<div class="doc_text">
				4842
				4843	<h5>Syntax:</h5>
				4844	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4845	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4846	</pre>
				4847
				4848	<h5>Overview:</h5>
				4849
				4850	<p>
				4851	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]	4852	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4853	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4854	features like scoped automatic variable sized arrays in C99.
				4855	</p>
				4856
				4857	<h5>Semantics:</h5>
				4858
				4859	<p>
				4860	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]	4861	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4862	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4863	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4864	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4865	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4866	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4867	</p>
				4868
				4869	</div>
				4870
				4871	<!-- _______________________________________________________________________ -->
				4872	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4873	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4874	</div>
				4875
				4876	<div class="doc_text">
				4877
				4878	<h5>Syntax:</h5>
				4879	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4880	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4881	</pre>
				4882
				4883	<h5>Overview:</h5>
				4884
				4885	<p>
				4886	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4887	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]	4888	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4889	useful for implementing language features like scoped automatic variable sized
				4890	arrays in C99.
				4891	</p>
				4892
				4893	<h5>Semantics:</h5>
				4894
				4895	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4896	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]	4897	</p>
				4898
				4899	</div>
				4900
				4901
				4902	<!-- _______________________________________________________________________ -->
				4903	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4904	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4905	</div>
				4906
				4907	<div class="doc_text">
				4908
				4909	<h5>Syntax:</h5>
				4910	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4911	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4912	</pre>
				4913
				4914	<h5>Overview:</h5>
				4915
				4916
				4917	<p>
				4918	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]	4919	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4920	no
				4921	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4922	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4923	</p>
				4924
				4925	<h5>Arguments:</h5>
				4926
				4927	<p>
				4928	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4929	determining if the fetch should be for a read (0) or write (1), and
				4930	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4931	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]	4932	<tt>locality</tt> arguments must be constant integers.
				4933	</p>
				4934
				4935	<h5>Semantics:</h5>
				4936
				4937	<p>
				4938	This intrinsic does not modify the behavior of the program. In particular,
				4939	prefetches cannot trap and do not produce a value. On targets that support this
				4940	intrinsic, the prefetch can provide hints to the processor cache for better
				4941	performance.
				4942	</p>
				4943
				4944	</div>
				4945
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4946	<!-- _______________________________________________________________________ -->
				4947	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4948	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4949	</div>
				4950
				4951	<div class="doc_text">
				4952
				4953	<h5>Syntax:</h5>
				4954	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4955	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4956	</pre>
				4957
				4958	<h5>Overview:</h5>
				4959
				4960
				4961	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4962	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]	4963	(PC) in a region of
				4964	code to simulators and other tools. The method is target specific, but it is
				4965	expected that the marker will use exported symbols to transmit the PC of the
				4966	marker.
				4967	The marker makes no guarantees that it will remain with any specific instruction
				4968	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]	4969	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4970	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4971	</p>
				4972
				4973	<h5>Arguments:</h5>
				4974
				4975	<p>
				4976	<tt>id</tt> is a numerical id identifying the marker.
				4977	</p>
				4978
				4979	<h5>Semantics:</h5>
				4980
				4981	<p>
				4982	This intrinsic does not modify the behavior of the program. Backends that do not
				4983	support this intrinisic may ignore it.
				4984	</p>
				4985
				4986	</div>
				4987
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4988	<!-- _______________________________________________________________________ -->
				4989	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4990	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4991	</div>
				4992
				4993	<div class="doc_text">
				4994
				4995	<h5>Syntax:</h5>
				4996	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4997	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4998	</pre>
				4999
				5000	<h5>Overview:</h5>
				5001
				5002
				5003	<p>
				5004	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5005	counter register (or similar low latency, high accuracy clocks) on those targets
				5006	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5007	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5008	should only be used for small timings.
				5009	</p>
				5010
				5011	<h5>Semantics:</h5>
				5012
				5013	<p>
				5014	When directly supported, reading the cycle counter should not modify any memory.
				5015	Implementations are allowed to either return a application specific value or a
				5016	system wide value. On backends without support, this is lowered to a constant 0.
				5017	</p>
				5018
				5019	</div>
				5020
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5021	<!-- ======================================================================= -->
				5022	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5023	<a name="int_libc">Standard C Library Intrinsics</a>
				5024	</div>
				5025
				5026	<div class="doc_text">
				5027	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5028	LLVM provides intrinsics for a few important standard C library functions.
				5029	These intrinsics allow source-language front-ends to pass information about the
				5030	alignment of the pointer arguments to the code generator, providing opportunity
				5031	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5032	</p>
				5033
				5034	</div>
				5035
				5036	<!-- _______________________________________________________________________ -->
				5037	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5038	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5039	</div>
				5040
				5041	<div class="doc_text">
				5042
				5043	<h5>Syntax:</h5>
				5044	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5045	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5046	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5047	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5048	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5049	</pre>
				5050
				5051	<h5>Overview:</h5>
				5052
				5053	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5054	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]	5055	location to the destination location.
				5056	</p>
				5057
				5058	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5059	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5060	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5061	</p>
				5062
				5063	<h5>Arguments:</h5>
				5064
				5065	<p>
				5066	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]	5067	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5068	specifying the number of bytes to copy, and the fourth argument is the alignment
				5069	of the source and destination locations.
				5070	</p>
				5071
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5072	<p>
				5073	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]	5074	the caller guarantees that both the source and destination pointers are aligned
				5075	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5076	</p>
				5077
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5078	<h5>Semantics:</h5>
				5079
				5080	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5081	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]	5082	location to the destination location, which are not allowed to overlap. It
				5083	copies "len" bytes of memory over. If the argument is known to be aligned to
				5084	some boundary, this can be specified as the fourth argument, otherwise it should
				5085	be set to 0 or 1.
				5086	</p>
				5087	</div>
				5088
				5089
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5090	<!-- _______________________________________________________________________ -->
				5091	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5092	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5093	</div>
				5094
				5095	<div class="doc_text">
				5096
				5097	<h5>Syntax:</h5>
				5098	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5099	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5100	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5101	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5102	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5103	</pre>
				5104
				5105	<h5>Overview:</h5>
				5106
				5107	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5108	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5109	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5110	'<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]	5111	</p>
				5112
				5113	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5114	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5115	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5116	</p>
				5117
				5118	<h5>Arguments:</h5>
				5119
				5120	<p>
				5121	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]	5122	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5123	specifying the number of bytes to copy, and the fourth argument is the alignment
				5124	of the source and destination locations.
				5125	</p>
				5126
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5127	<p>
				5128	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]	5129	the caller guarantees that the source and destination pointers are aligned to
				5130	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5131	</p>
				5132
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5133	<h5>Semantics:</h5>
				5134
				5135	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5136	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]	5137	location to the destination location, which may overlap. It
				5138	copies "len" bytes of memory over. If the argument is known to be aligned to
				5139	some boundary, this can be specified as the fourth argument, otherwise it should
				5140	be set to 0 or 1.
				5141	</p>
				5142	</div>
				5143
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5144
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5145	<!-- _______________________________________________________________________ -->
				5146	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5147	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5148	</div>
				5149
				5150	<div class="doc_text">
				5151
				5152	<h5>Syntax:</h5>
				5153	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5154	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5155	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5156	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5157	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5158	</pre>
				5159
				5160	<h5>Overview:</h5>
				5161
				5162	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5163	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]	5164	byte value.
				5165	</p>
				5166
				5167	<p>
				5168	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5169	does not return a value, and takes an extra alignment argument.
				5170	</p>
				5171
				5172	<h5>Arguments:</h5>
				5173
				5174	<p>
				5175	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]	5176	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5177	argument specifying the number of bytes to fill, and the fourth argument is the
				5178	known alignment of destination location.
				5179	</p>
				5180
				5181	<p>
				5182	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]	5183	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5184	</p>
				5185
				5186	<h5>Semantics:</h5>
				5187
				5188	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5189	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5190	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5191	destination location. If the argument is known to be aligned to some boundary,
				5192	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5193	1.
				5194	</p>
				5195	</div>
				5196
				5197
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5198	<!-- _______________________________________________________________________ -->
				5199	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5200	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5201	</div>
				5202
				5203	<div class="doc_text">
				5204
				5205	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5206	<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]	5207	floating point or vector of floating point type. Not all targets support all
				5208	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5209	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5210	declare float @llvm.sqrt.f32(float %Val)
				5211	declare double @llvm.sqrt.f64(double %Val)
				5212	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5213	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5214	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5215	</pre>
				5216
				5217	<h5>Overview:</h5>
				5218
				5219	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5220	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]	5221	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]	5222	<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]	5223	negative numbers other than -0.0 (which allows for better optimization, because
				5224	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5225	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5226	</p>
				5227
				5228	<h5>Arguments:</h5>
				5229
				5230	<p>
				5231	The argument and return value are floating point numbers of the same type.
				5232	</p>
				5233
				5234	<h5>Semantics:</h5>
				5235
				5236	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5237	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]	5238	floating point number.
				5239	</p>
				5240	</div>
				5241
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5242	<!-- _______________________________________________________________________ -->
				5243	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5244	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5245	</div>
				5246
				5247	<div class="doc_text">
				5248
				5249	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5250	<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]	5251	floating point or vector of floating point type. Not all targets support all
				5252	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5253	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5254	declare float @llvm.powi.f32(float %Val, i32 %power)
				5255	declare double @llvm.powi.f64(double %Val, i32 %power)
				5256	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5257	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5258	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5259	</pre>
				5260
				5261	<h5>Overview:</h5>
				5262
				5263	<p>
				5264	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5265	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5266	multiplications is not defined. When a vector of floating point type is
				5267	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5268	</p>
				5269
				5270	<h5>Arguments:</h5>
				5271
				5272	<p>
				5273	The second argument is an integer power, and the first is a value to raise to
				5274	that power.
				5275	</p>
				5276
				5277	<h5>Semantics:</h5>
				5278
				5279	<p>
				5280	This function returns the first value raised to the second power with an
				5281	unspecified sequence of rounding operations.</p>
				5282	</div>
				5283
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5284	<!-- _______________________________________________________________________ -->
				5285	<div class="doc_subsubsection">
				5286	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5287	</div>
				5288
				5289	<div class="doc_text">
				5290
				5291	<h5>Syntax:</h5>
				5292	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5293	floating point or vector of floating point type. Not all targets support all
				5294	types however.
				5295	<pre>
				5296	declare float @llvm.sin.f32(float %Val)
				5297	declare double @llvm.sin.f64(double %Val)
				5298	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5299	declare fp128 @llvm.sin.f128(fp128 %Val)
				5300	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5301	</pre>
				5302
				5303	<h5>Overview:</h5>
				5304
				5305	<p>
				5306	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5307	</p>
				5308
				5309	<h5>Arguments:</h5>
				5310
				5311	<p>
				5312	The argument and return value are floating point numbers of the same type.
				5313	</p>
				5314
				5315	<h5>Semantics:</h5>
				5316
				5317	<p>
				5318	This function returns the sine of the specified operand, returning the
				5319	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]	5320	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5321	</div>
				5322
				5323	<!-- _______________________________________________________________________ -->
				5324	<div class="doc_subsubsection">
				5325	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5326	</div>
				5327
				5328	<div class="doc_text">
				5329
				5330	<h5>Syntax:</h5>
				5331	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5332	floating point or vector of floating point type. Not all targets support all
				5333	types however.
				5334	<pre>
				5335	declare float @llvm.cos.f32(float %Val)
				5336	declare double @llvm.cos.f64(double %Val)
				5337	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5338	declare fp128 @llvm.cos.f128(fp128 %Val)
				5339	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5340	</pre>
				5341
				5342	<h5>Overview:</h5>
				5343
				5344	<p>
				5345	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5346	</p>
				5347
				5348	<h5>Arguments:</h5>
				5349
				5350	<p>
				5351	The argument and return value are floating point numbers of the same type.
				5352	</p>
				5353
				5354	<h5>Semantics:</h5>
				5355
				5356	<p>
				5357	This function returns the cosine of the specified operand, returning the
				5358	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]	5359	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5360	</div>
				5361
				5362	<!-- _______________________________________________________________________ -->
				5363	<div class="doc_subsubsection">
				5364	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5365	</div>
				5366
				5367	<div class="doc_text">
				5368
				5369	<h5>Syntax:</h5>
				5370	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5371	floating point or vector of floating point type. Not all targets support all
				5372	types however.
				5373	<pre>
				5374	declare float @llvm.pow.f32(float %Val, float %Power)
				5375	declare double @llvm.pow.f64(double %Val, double %Power)
				5376	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5377	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5378	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5379	</pre>
				5380
				5381	<h5>Overview:</h5>
				5382
				5383	<p>
				5384	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5385	specified (positive or negative) power.
				5386	</p>
				5387
				5388	<h5>Arguments:</h5>
				5389
				5390	<p>
				5391	The second argument is a floating point power, and the first is a value to
				5392	raise to that power.
				5393	</p>
				5394
				5395	<h5>Semantics:</h5>
				5396
				5397	<p>
				5398	This function returns the first value raised to the second power,
				5399	returning the
				5400	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]	5401	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5402	</div>
				5403
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5404
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5405	<!-- ======================================================================= -->
				5406	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5407	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5408	</div>
				5409
				5410	<div class="doc_text">
				5411	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5412	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5413	These allow efficient code generation for some algorithms.
				5414	</p>
				5415
				5416	</div>
				5417
				5418	<!-- _______________________________________________________________________ -->
				5419	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5420	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5421	</div>
				5422
				5423	<div class="doc_text">
				5424
				5425	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5426	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5427	type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5428	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5429	declare i16 @llvm.bswap.i16(i16 <id>)
				5430	declare i32 @llvm.bswap.i32(i32 <id>)
				5431	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5432	</pre>
				5433
				5434	<h5>Overview:</h5>
				5435
				5436	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5437	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]	5438	values with an even number of bytes (positive multiple of 16 bits). These are
				5439	useful for performing operations on data that is not in the target's native
				5440	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5441	</p>
				5442
				5443	<h5>Semantics:</h5>
				5444
				5445	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5446	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]	5447	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5448	intrinsic returns an i32 value that has the four bytes of the input i32
				5449	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]	5450	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5451	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5452	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5453	</p>
				5454
				5455	</div>
				5456
				5457	<!-- _______________________________________________________________________ -->
				5458	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5459	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5460	</div>
				5461
				5462	<div class="doc_text">
				5463
				5464	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5465	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5466	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5467	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5468	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5469	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5470	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5471	declare i64 @llvm.ctpop.i64(i64 <src>)
				5472	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5473	</pre>
				5474
				5475	<h5>Overview:</h5>
				5476
				5477	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5478	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5479	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5480	</p>
				5481
				5482	<h5>Arguments:</h5>
				5483
				5484	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5485	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]	5486	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5487	</p>
				5488
				5489	<h5>Semantics:</h5>
				5490
				5491	<p>
				5492	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5493	</p>
				5494	</div>
				5495
				5496	<!-- _______________________________________________________________________ -->
				5497	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5498	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5499	</div>
				5500
				5501	<div class="doc_text">
				5502
				5503	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5504	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5505	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5506	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5507	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5508	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5509	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5510	declare i64 @llvm.ctlz.i64(i64 <src>)
				5511	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5512	</pre>
				5513
				5514	<h5>Overview:</h5>
				5515
				5516	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5517	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5518	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5519	</p>
				5520
				5521	<h5>Arguments:</h5>
				5522
				5523	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5524	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]	5525	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5526	</p>
				5527
				5528	<h5>Semantics:</h5>
				5529
				5530	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5531	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5532	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]	5533	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5534	</p>
				5535	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5536
				5537
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5538
				5539	<!-- _______________________________________________________________________ -->
				5540	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5541	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5542	</div>
				5543
				5544	<div class="doc_text">
				5545
				5546	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5547	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5548	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5549	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5550	declare i8 @llvm.cttz.i8 (i8 <src>)
				5551	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5552	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5553	declare i64 @llvm.cttz.i64(i64 <src>)
				5554	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5555	</pre>
				5556
				5557	<h5>Overview:</h5>
				5558
				5559	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5560	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5561	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5562	</p>
				5563
				5564	<h5>Arguments:</h5>
				5565
				5566	<p>
				5567	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]	5568	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5569	</p>
				5570
				5571	<h5>Semantics:</h5>
				5572
				5573	<p>
				5574	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5575	in a variable. If the src == 0 then the result is the size in bits of the type
				5576	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5577	</p>
				5578	</div>
				5579
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5580	<!-- _______________________________________________________________________ -->
				5581	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5582	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5583	</div>
				5584
				5585	<div class="doc_text">
				5586
				5587	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5588	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5589	on any integer bit width.
				5590	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5591	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5592	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5593	</pre>
				5594
				5595	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5596	<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]	5597	range of bits from an integer value and returns them in the same bit width as
				5598	the original value.</p>
				5599
				5600	<h5>Arguments:</h5>
				5601	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5602	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]	5603	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]	5604
				5605	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5606	<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]	5607	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5608	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5609	operates in forward mode.</p>
				5610	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5611	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]	5612	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5613	<ol>
				5614	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5615	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5616	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5617	to determine the number of bits to retain.</li>
				5618	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5619	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5620	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5621	<p>In reverse mode, a similar computation is made except that the bits are
				5622	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5623	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5624	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5625	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5626	</div>
				5627
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5628	<div class="doc_subsubsection">
				5629	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5630	</div>
				5631
				5632	<div class="doc_text">
				5633
				5634	<h5>Syntax:</h5>
				5635	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5636	on any integer bit width.
				5637	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5638	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5639	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]	5640	</pre>
				5641
				5642	<h5>Overview:</h5>
				5643	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5644	of bits in an integer value with another integer value. It returns the integer
				5645	with the replaced bits.</p>
				5646
				5647	<h5>Arguments:</h5>
				5648	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5649	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5650	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5651	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5652	type since they specify only a bit index.</p>
				5653
				5654	<h5>Semantics:</h5>
				5655	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5656	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5657	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5658	operates in forward mode.</p>
				5659	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5660	truncating it down to the size of the replacement area or zero extending it
				5661	up to that size.</p>
				5662	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5663	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5664	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5665	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5666	<p>In reverse mode, a similar computation is made except that the bits are
				5667	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5668	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5669	<h5>Examples:</h5>
				5670	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5671	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5672	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5673	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5674	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5675	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5676	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5677	</div>
				5678
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5679	<!-- ======================================================================= -->
				5680	<div class="doc_subsection">
				5681	<a name="int_debugger">Debugger Intrinsics</a>
				5682	</div>
				5683
				5684	<div class="doc_text">
				5685	<p>
				5686	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5687	are described in the <a
				5688	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5689	Debugging</a> document.
				5690	</p>
				5691	</div>
				5692
				5693
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5694	<!-- ======================================================================= -->
				5695	<div class="doc_subsection">
				5696	<a name="int_eh">Exception Handling Intrinsics</a>
				5697	</div>
				5698
				5699	<div class="doc_text">
				5700	<p> The LLVM exception handling intrinsics (which all start with
				5701	<tt>llvm.eh.</tt> prefix), are described in the <a
				5702	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5703	Handling</a> document. </p>
				5704	</div>
				5705
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5706	<!-- ======================================================================= -->
				5707	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5708	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5709	</div>
				5710
				5711	<div class="doc_text">
				5712	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5713	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5714	the <tt>nest</tt> attribute, from a function. The result is a callable
				5715	function pointer lacking the nest parameter - the caller does not need
				5716	to provide a value for it. Instead, the value to use is stored in
				5717	advance in a "trampoline", a block of memory usually allocated
				5718	on the stack, which also contains code to splice the nest value into the
				5719	argument list. This is used to implement the GCC nested function address
				5720	extension.
				5721	</p>
				5722	<p>
				5723	For example, if the function is
				5724	<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]	5725	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]	5726	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5727	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5728	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5729	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5730	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5731	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5732	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5733	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]	5734	</div>
				5735
				5736	<!-- _______________________________________________________________________ -->
				5737	<div class="doc_subsubsection">
				5738	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5739	</div>
				5740	<div class="doc_text">
				5741	<h5>Syntax:</h5>
				5742	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5743	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5744	</pre>
				5745	<h5>Overview:</h5>
				5746	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5747	This fills the memory pointed to by <tt>tramp</tt> with code
				5748	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5749	</p>
				5750	<h5>Arguments:</h5>
				5751	<p>
				5752	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5753	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5754	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]	5755	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5756	currently provides no portable way of determining them, so a front-end that
				5757	generates this intrinsic needs to have some target-specific knowledge.
				5758	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]	5759	</p>
				5760	<h5>Semantics:</h5>
				5761	<p>
				5762	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]	5763	dependent code, turning it into a function. A pointer to this function is
				5764	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5765	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5766	before being called. The new function's signature is the same as that of
				5767	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5768	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5769	of pointer type. Calling the new function is equivalent to calling
				5770	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5771	missing <tt>nest</tt> argument. If, after calling
				5772	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5773	modified, then the effect of any later call to the returned function pointer is
				5774	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5775	</p>
				5776	</div>
				5777
				5778	<!-- ======================================================================= -->
				5779	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5780	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5781	</div>
				5782
				5783	<div class="doc_text">
				5784	<p>
				5785	These intrinsic functions expand the "universal IR" of LLVM to represent
				5786	hardware constructs for atomic operations and memory synchronization. This
				5787	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]	5788	is aimed at a low enough level to allow any programming models or APIs
				5789	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5790	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5791	hardware behavior. Just as hardware provides a "universal IR" for source
				5792	languages, it also provides a starting point for developing a "universal"
				5793	atomic operation and synchronization IR.
				5794	</p>
				5795	<p>
				5796	These do <em>not</em> form an API such as high-level threading libraries,
				5797	software transaction memory systems, atomic primitives, and intrinsic
				5798	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5799	application libraries. The hardware interface provided by LLVM should allow
				5800	a clean implementation of all of these APIs and parallel programming models.
				5801	No one model or paradigm should be selected above others unless the hardware
				5802	itself ubiquitously does so.
				5803
				5804	</p>
				5805	</div>
				5806
				5807	<!-- _______________________________________________________________________ -->
				5808	<div class="doc_subsubsection">
				5809	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5810	</div>
				5811	<div class="doc_text">
				5812	<h5>Syntax:</h5>
				5813	<pre>
				5814	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5815	i1 <device> )
				5816
				5817	</pre>
				5818	<h5>Overview:</h5>
				5819	<p>
				5820	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5821	specific pairs of memory access types.
				5822	</p>
				5823	<h5>Arguments:</h5>
				5824	<p>
				5825	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5826	The first four arguments enables a specific barrier as listed below. The fith
				5827	argument specifies that the barrier applies to io or device or uncached memory.
				5828
				5829	</p>
				5830	<ul>
				5831	<li><tt>ll</tt>: load-load barrier</li>
				5832	<li><tt>ls</tt>: load-store barrier</li>
				5833	<li><tt>sl</tt>: store-load barrier</li>
				5834	<li><tt>ss</tt>: store-store barrier</li>
				5835	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5836	</ul>
				5837	<h5>Semantics:</h5>
				5838	<p>
				5839	This intrinsic causes the system to enforce some ordering constraints upon
				5840	the loads and stores of the program. This barrier does not indicate
				5841	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5842	which they occur. For any of the specified pairs of load and store operations
				5843	(f.ex. load-load, or store-load), all of the first operations preceding the
				5844	barrier will complete before any of the second operations succeeding the
				5845	barrier begin. Specifically the semantics for each pairing is as follows:
				5846	</p>
				5847	<ul>
				5848	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5849	after the barrier begins.</li>
				5850
				5851	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5852	store after the barrier begins.</li>
				5853	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5854	store after the barrier begins.</li>
				5855	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5856	load after the barrier begins.</li>
				5857	</ul>
				5858	<p>
				5859	These semantics are applied with a logical "and" behavior when more than one
				5860	is enabled in a single memory barrier intrinsic.
				5861	</p>
				5862	<p>
				5863	Backends may implement stronger barriers than those requested when they do not
				5864	support as fine grained a barrier as requested. Some architectures do not
				5865	need all types of barriers and on such architectures, these become noops.
				5866	</p>
				5867	<h5>Example:</h5>
				5868	<pre>
				5869	%ptr = malloc i32
				5870	store i32 4, %ptr
				5871
				5872	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5873	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5874	<i>; guarantee the above finishes</i>
				5875	store i32 8, %ptr <i>; before this begins</i>
				5876	</pre>
				5877	</div>
				5878
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5879	<!-- _______________________________________________________________________ -->
				5880	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5881	<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]	5882	</div>
				5883	<div class="doc_text">
				5884	<h5>Syntax:</h5>
				5885	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5886	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5887	any integer bit width and for different address spaces. Not all targets
				5888	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5889
				5890	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5891	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5892	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5893	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5894	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]	5895
				5896	</pre>
				5897	<h5>Overview:</h5>
				5898	<p>
				5899	This loads a value in memory and compares it to a given value. If they are
				5900	equal, it stores a new value into the memory.
				5901	</p>
				5902	<h5>Arguments:</h5>
				5903	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5904	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]	5905	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5906	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5907	this integer type. While any bit width integer may be used, targets may only
				5908	lower representations they support in hardware.
				5909
				5910	</p>
				5911	<h5>Semantics:</h5>
				5912	<p>
				5913	This entire intrinsic must be executed atomically. It first loads the value
				5914	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5915	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5916	loaded value is yielded in all cases. This provides the equivalent of an
				5917	atomic compare-and-swap operation within the SSA framework.
				5918	</p>
				5919	<h5>Examples:</h5>
				5920
				5921	<pre>
				5922	%ptr = malloc i32
				5923	store i32 4, %ptr
				5924
				5925	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5926	%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]	5927	<i>; yields {i32}:result1 = 4</i>
				5928	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5929	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5930
				5931	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5932	%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]	5933	<i>; yields {i32}:result2 = 8</i>
				5934	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5935
				5936	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5937	</pre>
				5938	</div>
				5939
				5940	<!-- _______________________________________________________________________ -->
				5941	<div class="doc_subsubsection">
				5942	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5943	</div>
				5944	<div class="doc_text">
				5945	<h5>Syntax:</h5>
				5946
				5947	<p>
				5948	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5949	integer bit width. Not all targets support all bit widths however.</p>
				5950	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5951	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5952	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5953	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5954	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5955
				5956	</pre>
				5957	<h5>Overview:</h5>
				5958	<p>
				5959	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5960	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5961	at <tt>ptr</tt>.
				5962	</p>
				5963	<h5>Arguments:</h5>
				5964
				5965	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5966	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5967	<tt>val</tt> argument and the result must be integers of the same bit width.
				5968	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5969	integer type. The targets may only lower integer representations they
				5970	support.
				5971	</p>
				5972	<h5>Semantics:</h5>
				5973	<p>
				5974	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5975	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5976	equivalent of an atomic swap operation within the SSA framework.
				5977
				5978	</p>
				5979	<h5>Examples:</h5>
				5980	<pre>
				5981	%ptr = malloc i32
				5982	store i32 4, %ptr
				5983
				5984	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5985	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5986	<i>; yields {i32}:result1 = 4</i>
				5987	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5988	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5989
				5990	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5991	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5992	<i>; yields {i32}:result2 = 8</i>
				5993
				5994	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5995	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5996	</pre>
				5997	</div>
				5998
				5999	<!-- _______________________________________________________________________ -->
				6000	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6001	<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]	6002
				6003	</div>
				6004	<div class="doc_text">
				6005	<h5>Syntax:</h5>
				6006	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6007	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]	6008	integer bit width. Not all targets support all bit widths however.</p>
				6009	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6010	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6011	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6012	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6013	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6014
				6015	</pre>
				6016	<h5>Overview:</h5>
				6017	<p>
				6018	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6019	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6020	</p>
				6021	<h5>Arguments:</h5>
				6022	<p>
				6023
				6024	The intrinsic takes two arguments, the first a pointer to an integer value
				6025	and the second an integer value. The result is also an integer value. These
				6026	integer types can have any bit width, but they must all have the same bit
				6027	width. The targets may only lower integer representations they support.
				6028	</p>
				6029	<h5>Semantics:</h5>
				6030	<p>
				6031	This intrinsic does a series of operations atomically. It first loads the
				6032	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6033	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6034	</p>
				6035
				6036	<h5>Examples:</h5>
				6037	<pre>
				6038	%ptr = malloc i32
				6039	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6040	%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]	6041	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6042	%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]	6043	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6044	%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]	6045	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6046	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6047	</pre>
				6048	</div>
				6049
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6050	<!-- _______________________________________________________________________ -->
				6051	<div class="doc_subsubsection">
				6052	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6053
				6054	</div>
				6055	<div class="doc_text">
				6056	<h5>Syntax:</h5>
				6057	<p>
				6058	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]	6059	any integer bit width and for different address spaces. Not all targets
				6060	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6061	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6062	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6063	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6064	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6065	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]	6066
				6067	</pre>
				6068	<h5>Overview:</h5>
				6069	<p>
				6070	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6071	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6072	</p>
				6073	<h5>Arguments:</h5>
				6074	<p>
				6075
				6076	The intrinsic takes two arguments, the first a pointer to an integer value
				6077	and the second an integer value. The result is also an integer value. These
				6078	integer types can have any bit width, but they must all have the same bit
				6079	width. The targets may only lower integer representations they support.
				6080	</p>
				6081	<h5>Semantics:</h5>
				6082	<p>
				6083	This intrinsic does a series of operations atomically. It first loads the
				6084	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6085	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6086	</p>
				6087
				6088	<h5>Examples:</h5>
				6089	<pre>
				6090	%ptr = malloc i32
				6091	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6092	%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]	6093	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6094	%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]	6095	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6096	%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]	6097	<i>; yields {i32}:result3 = 2</i>
				6098	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6099	</pre>
				6100	</div>
				6101
				6102	<!-- _______________________________________________________________________ -->
				6103	<div class="doc_subsubsection">
				6104	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6105	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6106	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6107	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6108
				6109	</div>
				6110	<div class="doc_text">
				6111	<h5>Syntax:</h5>
				6112	<p>
				6113	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6114	<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]	6115	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6116	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6117	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6118	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6119	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6120	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6121	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]	6122
				6123	</pre>
				6124
				6125	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6126	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6127	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6128	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6129	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]	6130
				6131	</pre>
				6132
				6133	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6134	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6135	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6136	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6137	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]	6138
				6139	</pre>
				6140
				6141	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6142	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6143	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6144	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6145	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]	6146
				6147	</pre>
				6148	<h5>Overview:</h5>
				6149	<p>
				6150	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6151	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6152	at <tt>ptr</tt>.
				6153	</p>
				6154	<h5>Arguments:</h5>
				6155	<p>
				6156
				6157	These intrinsics take two arguments, the first a pointer to an integer value
				6158	and the second an integer value. The result is also an integer value. These
				6159	integer types can have any bit width, but they must all have the same bit
				6160	width. The targets may only lower integer representations they support.
				6161	</p>
				6162	<h5>Semantics:</h5>
				6163	<p>
				6164	These intrinsics does a series of operations atomically. They first load the
				6165	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6166	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6167	value stored at <tt>ptr</tt>.
				6168	</p>
				6169
				6170	<h5>Examples:</h5>
				6171	<pre>
				6172	%ptr = malloc i32
				6173	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6174	%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]	6175	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6176	%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]	6177	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6178	%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]	6179	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6180	%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]	6181	<i>; yields {i32}:result3 = FF</i>
				6182	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6183	</pre>
				6184	</div>
				6185
				6186
				6187	<!-- _______________________________________________________________________ -->
				6188	<div class="doc_subsubsection">
				6189	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6190	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6191	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6192	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6193
				6194	</div>
				6195	<div class="doc_text">
				6196	<h5>Syntax:</h5>
				6197	<p>
				6198	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6199	<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]	6200	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6201	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6202	support all bit widths however.</p>
				6203	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6204	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6205	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6206	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6207	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]	6208
				6209	</pre>
				6210
				6211	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6212	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6213	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6214	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6215	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]	6216
				6217	</pre>
				6218
				6219	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6220	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6221	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6222	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6223	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]	6224
				6225	</pre>
				6226
				6227	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6228	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6229	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6230	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6231	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]	6232
				6233	</pre>
				6234	<h5>Overview:</h5>
				6235	<p>
				6236	These intrinsics takes the signed or unsigned minimum or maximum of
				6237	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6238	original value at <tt>ptr</tt>.
				6239	</p>
				6240	<h5>Arguments:</h5>
				6241	<p>
				6242
				6243	These intrinsics take two arguments, the first a pointer to an integer value
				6244	and the second an integer value. The result is also an integer value. These
				6245	integer types can have any bit width, but they must all have the same bit
				6246	width. The targets may only lower integer representations they support.
				6247	</p>
				6248	<h5>Semantics:</h5>
				6249	<p>
				6250	These intrinsics does a series of operations atomically. They first load the
				6251	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6252	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6253	the original value stored at <tt>ptr</tt>.
				6254	</p>
				6255
				6256	<h5>Examples:</h5>
				6257	<pre>
				6258	%ptr = malloc i32
				6259	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6260	%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]	6261	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6262	%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]	6263	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6264	%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]	6265	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6266	%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]	6267	<i>; yields {i32}:result3 = 8</i>
				6268	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6269	</pre>
				6270	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6271
				6272	<!-- ======================================================================= -->
				6273	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6274	<a name="int_general">General Intrinsics</a>
				6275	</div>
				6276
				6277	<div class="doc_text">
				6278	<p> This class of intrinsics is designed to be generic and has
				6279	no specific purpose. </p>
				6280	</div>
				6281
				6282	<!-- _______________________________________________________________________ -->
				6283	<div class="doc_subsubsection">
				6284	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6285	</div>
				6286
				6287	<div class="doc_text">
				6288
				6289	<h5>Syntax:</h5>
				6290	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6291	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]	6292	</pre>
				6293
				6294	<h5>Overview:</h5>
				6295
				6296	<p>
				6297	The '<tt>llvm.var.annotation</tt>' intrinsic
				6298	</p>
				6299
				6300	<h5>Arguments:</h5>
				6301
				6302	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6303	The first argument is a pointer to a value, the second is a pointer to a
				6304	global string, the third is a pointer to a global string which is the source
				6305	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6306	</p>
				6307
				6308	<h5>Semantics:</h5>
				6309
				6310	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6311	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6312	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]	6313	annotations. These have no other defined use, they are ignored by code
				6314	generation and optimization.
				6315	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6316	</div>
				6317
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6318	<!-- _______________________________________________________________________ -->
				6319	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6320	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6321	</div>
				6322
				6323	<div class="doc_text">
				6324
				6325	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6326	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6327	any integer bit width.
				6328	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6329	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6330	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6331	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6332	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6333	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6334	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]	6335	</pre>
				6336
				6337	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6338
				6339	<p>
				6340	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6341	</p>
				6342
				6343	<h5>Arguments:</h5>
				6344
				6345	<p>
				6346	The first argument is an integer value (result of some expression),
				6347	the second is a pointer to a global string, the third is a pointer to a global
				6348	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]	6349	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6350	</p>
				6351
				6352	<h5>Semantics:</h5>
				6353
				6354	<p>
				6355	This intrinsic allows annotations to be put on arbitrary expressions
				6356	with arbitrary strings. This can be useful for special purpose optimizations
				6357	that want to look for these annotations. These have no other defined use, they
				6358	are ignored by code generation and optimization.
				6359	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6360
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6361	<!-- _______________________________________________________________________ -->
				6362	<div class="doc_subsubsection">
				6363	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6364	</div>
				6365
				6366	<div class="doc_text">
				6367
				6368	<h5>Syntax:</h5>
				6369	<pre>
				6370	declare void @llvm.trap()
				6371	</pre>
				6372
				6373	<h5>Overview:</h5>
				6374
				6375	<p>
				6376	The '<tt>llvm.trap</tt>' intrinsic
				6377	</p>
				6378
				6379	<h5>Arguments:</h5>
				6380
				6381	<p>
				6382	None
				6383	</p>
				6384
				6385	<h5>Semantics:</h5>
				6386
				6387	<p>
				6388	This intrinsics is lowered to the target dependent trap instruction. If the
				6389	target does not have a trap instruction, this intrinsic will be lowered to the
				6390	call of the abort() function.
				6391	</p>
				6392	</div>
				6393
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6394	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6395	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6396	<address>
				6397	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6398	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6399	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6400	src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6401
				6402	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6403	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6404	Last modified: $Date$
				6405	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6406
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6407	</body>
				6408	</html>