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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>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	156	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	157	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	158	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	159	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	160	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				163	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	164	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				165	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				166	<li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	167	</ol>
				168	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	169	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				170	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	171	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				172	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				173	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	174	</ol>
				175	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	176	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				177	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	178	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				179	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				180	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				181	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				182	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				183	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				184	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	185	</ol>
				186	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	187	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				188	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	189	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				190	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				191	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				192	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	194	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	197	</ol>
				198	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	199	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	200	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	201	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	202	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				203	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				204	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	205	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				206	<li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	207	</ol>
				208	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	209	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	210	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	211	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	212	<ol>
				213	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	214	</ol>
				215	</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	216	<li><a href="#int_atomics">Atomic intrinsics</a>
				217	<ol>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	218	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	219	<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]	220	<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]	221	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				222	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				223	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				224	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				225	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				226	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				227	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				228	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				229	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				230	<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]	231	</ol>
				232	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	233	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	234	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	235	<li><a href="#int_var_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	236	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	237	<li><a href="#int_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	238	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	239	<li><a href="#int_trap">
				240	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	241	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	242	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	243	</ol>
				244	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	245	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	246
				247	<div class="doc_author">
				248	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				249	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	250	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	251
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	252	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	253	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				254	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	255
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	256	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	257	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	258	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	259	type safety, low-level operations, flexibility, and the capability of
				260	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	261	representation used throughout all phases of the LLVM compilation
				262	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	263	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	264
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	265	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	266	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				267	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	268
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	269	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	270
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	271	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	272	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]	273	representation (suitable for fast loading by a Just-In-Time compiler),
				274	and as a human readable assembly language representation. This allows
				275	LLVM to provide a powerful intermediate representation for efficient
				276	compiler transformations and analysis, while providing a natural means
				277	to debug and visualize the transformations. The three different forms
				278	of LLVM are all equivalent. This document describes the human readable
				279	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	280
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	281	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	282	while being expressive, typed, and extensible at the same time. It
				283	aims to be a "universal IR" of sorts, by being at a low enough level
				284	that high-level ideas may be cleanly mapped to it (similar to how
				285	microprocessors are "universal IR's", allowing many source languages to
				286	be mapped to them). By providing type information, LLVM can be used as
				287	the target of optimizations: for example, through pointer analysis, it
				288	can be proven that a C automatic variable is never accessed outside of
				289	the current function... allowing it to be promoted to a simple SSA
				290	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	291
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	292	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	293
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	294	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	295	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	296
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	297	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	298
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	299	<p>It is important to note that this document describes 'well formed'
				300	LLVM assembly language. There is a difference between what the parser
				301	accepts and what is considered 'well formed'. For example, the
				302	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	303
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	304	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	305	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	306	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	307	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	308	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	310	<p>...because the definition of <tt>%x</tt> does not dominate all of
				311	its uses. The LLVM infrastructure provides a verification pass that may
				312	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]	313	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	314	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	315	by the verifier pass indicate bugs in transformation passes or input to
				316	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	317	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	319	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	320
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	321	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	322	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	323	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	324
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	325	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	326
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	327	<p>LLVM identifiers come in two basic types: global and local. Global
				328	identifiers (functions, global variables) begin with the @ character. Local
				329	identifiers (register names, types) begin with the % character. Additionally,
				330	there are three different formats for identifiers, for different purposes:
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	331
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	332	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	333	<li>Named values are represented as a string of characters with their prefix.
				334	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				335	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]	336	Identifiers which require other characters in their names can be surrounded
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	337	with quotes. In this way, anything except a <tt>"</tt> character can
				338	be used in a named value.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	339
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	340	<li>Unnamed values are represented as an unsigned numeric value with their
				341	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	342
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	343	<li>Constants, which are described in a <a href="#constants">section about
				344	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	345	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	346
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	347	<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]	348	don't need to worry about name clashes with reserved words, and the set of
				349	reserved words may be expanded in the future without penalty. Additionally,
				350	unnamed identifiers allow a compiler to quickly come up with a temporary
				351	variable without having to avoid symbol table conflicts.</p>
				352
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	353	<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]	354	languages. There are keywords for different opcodes
				355	('<tt><a href="#i_add">add</a></tt>',
				356	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				357	'<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]	358	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]	359	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	360	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	361
				362	<p>Here is an example of LLVM code to multiply the integer variable
				363	'<tt>%X</tt>' by 8:</p>
				364
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	365	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	366
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	367	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	368	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	369	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	370	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	371	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	372
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	373	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	374
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	375	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	376	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	377	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	378	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	379	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	380
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	381	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	382
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	383	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	384	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	385	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				386	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				387	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	388	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	389	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	390
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	391	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				392	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	394	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395
				396	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				397	line.</li>
				398
				399	<li>Unnamed temporaries are created when the result of a computation is not
				400	assigned to a named value.</li>
				401
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	402	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	403
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	404	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	405
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	406	<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]	407	demonstrating instructions, we will follow an instruction with a comment that
				408	defines the type and name of value produced. Comments are shown in italic
				409	text.</p>
				410
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	411	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	412
				413	<!-- *********************************************************************** -->
				414	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				415	<!-- *********************************************************************** -->
				416
				417	<!-- ======================================================================= -->
				418	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				419	</div>
				420
				421	<div class="doc_text">
				422
				423	<p>LLVM programs are composed of "Module"s, each of which is a
				424	translation unit of the input programs. Each module consists of
				425	functions, global variables, and symbol table entries. Modules may be
				426	combined together with the LLVM linker, which merges function (and
				427	global variable) definitions, resolves forward declarations, and merges
				428	symbol table entries. Here is an example of the "hello world" module:</p>
				429
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	430	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	431	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	432	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				433	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]	434
				435	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	436	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	437
				438	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	439	define i32 @main() { <i>; i32()* </i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	440	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	441	%cast210 = <a
Chris Lattner	6c0955b	2007-06-12 17:01:15 +0000	[diff] [blame]	442	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]	443
				444	<i>; Call puts function to write out the string to stdout...</i>
				445	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	446	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	447	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	448	href="#i_ret">ret</a> i32 0<br>}<br>
				449	</pre>
				450	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	451
				452	<p>This example is made up of a <a href="#globalvars">global variable</a>
				453	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				454	function, and a <a href="#functionstructure">function definition</a>
				455	for "<tt>main</tt>".</p>
				456
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	457	<p>In general, a module is made up of a list of global values,
				458	where both functions and global variables are global values. Global values are
				459	represented by a pointer to a memory location (in this case, a pointer to an
				460	array of char, and a pointer to a function), and have one of the following <a
				461	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	462
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	463	</div>
				464
				465	<!-- ======================================================================= -->
				466	<div class="doc_subsection">
				467	<a name="linkage">Linkage Types</a>
				468	</div>
				469
				470	<div class="doc_text">
				471
				472	<p>
				473	All Global Variables and Functions have one of the following types of linkage:
				474	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	475
				476	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	477
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	478	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	479
				480	<dd>Global values with internal linkage are only directly accessible by
				481	objects in the current module. In particular, linking code into a module with
				482	an internal global value may cause the internal to be renamed as necessary to
				483	avoid collisions. Because the symbol is internal to the module, all
				484	references can be updated. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	485	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	486	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	487
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	488	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	489
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	490	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				491	the same name when linkage occurs. This is typically used to implement
				492	inline functions, templates, or other code which must be generated in each
				493	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				494	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	495	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	496
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	497	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				498
				499	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				500	linkage, except that unreferenced <tt>common</tt> globals may not be
				501	discarded. This is used for globals that may be emitted in multiple
				502	translation units, but that are not guaranteed to be emitted into every
				503	translation unit that uses them. One example of this is tentative
				504	definitions in C, such as "<tt>int X;</tt>" at global scope.
				505	</dd>
				506
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	507	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	508
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	509	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				510	that some targets may choose to emit different assembly sequences for them
				511	for target-dependent reasons. This is used for globals that are declared
				512	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	513	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	514
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	515	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	516
				517	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				518	pointer to array type. When two global variables with appending linkage are
				519	linked together, the two global arrays are appended together. This is the
				520	LLVM, typesafe, equivalent of having the system linker append together
				521	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	522	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	523
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	524	<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]	525	<dd>The semantics of this linkage follow the ELF object file model: the
				526	symbol is weak until linked, if not linked, the symbol becomes null instead
				527	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	528	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	529
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	530	<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]	531
				532	<dd>If none of the above identifiers are used, the global is externally
				533	visible, meaning that it participates in linkage and can be used to resolve
				534	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	535	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	536	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	537
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	538	<p>
				539	The next two types of linkage are targeted for Microsoft Windows platform
				540	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	541	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	542	</p>
				543
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	544	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	545	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				546
				547	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				548	or variable via a global pointer to a pointer that is set up by the DLL
				549	exporting the symbol. On Microsoft Windows targets, the pointer name is
				550	formed by combining <code>_imp__</code> and the function or variable name.
				551	</dd>
				552
				553	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				554
				555	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				556	pointer to a pointer in a DLL, so that it can be referenced with the
				557	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				558	name is formed by combining <code>_imp__</code> and the function or variable
				559	name.
				560	</dd>
				561
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	562	</dl>
				563
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	564	<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]	565	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				566	variable and was linked with this one, one of the two would be renamed,
				567	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				568	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	569	outside of the current module.</p>
				570	<p>It is illegal for a function <i>declaration</i>
				571	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	572	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	573	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				574	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	575	</div>
				576
				577	<!-- ======================================================================= -->
				578	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	579	<a name="callingconv">Calling Conventions</a>
				580	</div>
				581
				582	<div class="doc_text">
				583
				584	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				585	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				586	specified for the call. The calling convention of any pair of dynamic
				587	caller/callee must match, or the behavior of the program is undefined. The
				588	following calling conventions are supported by LLVM, and more may be added in
				589	the future:</p>
				590
				591	<dl>
				592	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				593
				594	<dd>This calling convention (the default if no other calling convention is
				595	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	596	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	597	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	598	</dd>
				599
				600	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				601
				602	<dd>This calling convention attempts to make calls as fast as possible
				603	(e.g. by passing things in registers). This calling convention allows the
				604	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]	605	without having to conform to an externally specified ABI (Application Binary
				606	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	607	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				608	supported. This calling convention does not support varargs and requires the
				609	prototype of all callees to exactly match the prototype of the function
				610	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	611	</dd>
				612
				613	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				614
				615	<dd>This calling convention attempts to make code in the caller as efficient
				616	as possible under the assumption that the call is not commonly executed. As
				617	such, these calls often preserve all registers so that the call does not break
				618	any live ranges in the caller side. This calling convention does not support
				619	varargs and requires the prototype of all callees to exactly match the
				620	prototype of the function definition.
				621	</dd>
				622
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	623	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	624
				625	<dd>Any calling convention may be specified by number, allowing
				626	target-specific calling conventions to be used. Target specific calling
				627	conventions start at 64.
				628	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	629	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	630
				631	<p>More calling conventions can be added/defined on an as-needed basis, to
				632	support pascal conventions or any other well-known target-independent
				633	convention.</p>
				634
				635	</div>
				636
				637	<!-- ======================================================================= -->
				638	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	639	<a name="visibility">Visibility Styles</a>
				640	</div>
				641
				642	<div class="doc_text">
				643
				644	<p>
				645	All Global Variables and Functions have one of the following visibility styles:
				646	</p>
				647
				648	<dl>
				649	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				650
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	651	<dd>On targets that use the ELF object file format, default visibility means
				652	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	653	modules and, in shared libraries, means that the declared entity may be
				654	overridden. On Darwin, default visibility means that the declaration is
				655	visible to other modules. Default visibility corresponds to "external
				656	linkage" in the language.
				657	</dd>
				658
				659	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				660
				661	<dd>Two declarations of an object with hidden visibility refer to the same
				662	object if they are in the same shared object. Usually, hidden visibility
				663	indicates that the symbol will not be placed into the dynamic symbol table,
				664	so no other module (executable or shared library) can reference it
				665	directly.
				666	</dd>
				667
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	668	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				669
				670	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				671	the dynamic symbol table, but that references within the defining module will
				672	bind to the local symbol. That is, the symbol cannot be overridden by another
				673	module.
				674	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	675	</dl>
				676
				677	</div>
				678
				679	<!-- ======================================================================= -->
				680	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	681	<a name="globalvars">Global Variables</a>
				682	</div>
				683
				684	<div class="doc_text">
				685
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	686	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	687	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	688	an explicit section to be placed in, and may have an optional explicit alignment
				689	specified. A variable may be defined as "thread_local", which means that it
				690	will not be shared by threads (each thread will have a separated copy of the
				691	variable). A variable may be defined as a global "constant," which indicates
				692	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]	693	optimization, allowing the global data to be placed in the read-only section of
				694	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	695	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]	696
				697	<p>
				698	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				699	constant, even if the final definition of the global is not. This capability
				700	can be used to enable slightly better optimization of the program, but requires
				701	the language definition to guarantee that optimizations based on the
				702	'constantness' are valid for the translation units that do not include the
				703	definition.
				704	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	705
				706	<p>As SSA values, global variables define pointer values that are in
				707	scope (i.e. they dominate) all basic blocks in the program. Global
				708	variables always define a pointer to their "content" type because they
				709	describe a region of memory, and all memory objects in LLVM are
				710	accessed through pointers.</p>
				711
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	712	<p>A global variable may be declared to reside in a target-specifc numbered
				713	address space. For targets that support them, address spaces may affect how
				714	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	715	the variable. The default address space is zero. The address space qualifier
				716	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	717
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	718	<p>LLVM allows an explicit section to be specified for globals. If the target
				719	supports it, it will emit globals to the section specified.</p>
				720
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	721	<p>An explicit alignment may be specified for a global. If not present, or if
				722	the alignment is set to zero, the alignment of the global is set by the target
				723	to whatever it feels convenient. If an explicit alignment is specified, the
				724	global is forced to have at least that much alignment. All alignments must be
				725	a power of 2.</p>
				726
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	727	<p>For example, the following defines a global in a numbered address space with
				728	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	729
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	730	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	731	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	732	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	733	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	734	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	735
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	736	</div>
				737
				738
				739	<!-- ======================================================================= -->
				740	<div class="doc_subsection">
				741	<a name="functionstructure">Functions</a>
				742	</div>
				743
				744	<div class="doc_text">
				745
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	746	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				747	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	748	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	749	<a href="#callingconv">calling convention</a>, a return type, an optional
				750	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				751	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	752	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	753	optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	754	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]	755
				756	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				757	optional <a href="#linkage">linkage type</a>, an optional
				758	<a href="#visibility">visibility style</a>, an optional
				759	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	760	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	761	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]	762	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	763
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	764	<p>A function definition contains a list of basic blocks, forming the CFG
				765	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	766	the function. Each basic block may optionally start with a label (giving the
				767	basic block a symbol table entry), contains a list of instructions, and ends
				768	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				769	function return).</p>
				770
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	771	<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]	772	executed on entrance to the function, and it is not allowed to have predecessor
				773	basic blocks (i.e. there can not be any branches to the entry block of a
				774	function). Because the block can have no predecessors, it also cannot have any
				775	<a href="#i_phi">PHI nodes</a>.</p>
				776
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	777	<p>LLVM allows an explicit section to be specified for functions. If the target
				778	supports it, it will emit functions to the section specified.</p>
				779
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	780	<p>An explicit alignment may be specified for a function. If not present, or if
				781	the alignment is set to zero, the alignment of the function is set by the target
				782	to whatever it feels convenient. If an explicit alignment is specified, the
				783	function is forced to have at least that much alignment. All alignments must be
				784	a power of 2.</p>
				785
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	786	</div>
				787
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	788
				789	<!-- ======================================================================= -->
				790	<div class="doc_subsection">
				791	<a name="aliasstructure">Aliases</a>
				792	</div>
				793	<div class="doc_text">
				794	<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]	795	function, global variable, another alias or bitcast of global value). Aliases
				796	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	797	optional <a href="#visibility">visibility style</a>.</p>
				798
				799	<h5>Syntax:</h5>
				800
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	801	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	802	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	803	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	804	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	805	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	806
				807	</div>
				808
				809
				810
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	811	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	812	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				813	<div class="doc_text">
				814	<p>The return type and each parameter of a function type may have a set of
				815	<i>parameter attributes</i> associated with them. Parameter attributes are
				816	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	817	a function. Parameter attributes are considered to be part of the function,
				818	not of the function type, so functions with different parameter attributes
				819	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	820
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	821	<p>Parameter attributes are simple keywords that follow the type specified. If
				822	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	823	example:</p>
				824
				825	<div class="doc_code">
				826	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	827	declare i32 @printf(i8* noalias , ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	828	declare i32 @atoi(i8 zeroext)
				829	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	830	</pre>
				831	</div>
				832
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	833	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				834	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	835
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	836	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	837	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	838	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	839	<dd>This indicates to the code generator that the parameter or return value
				840	should be zero-extended to a 32-bit value by the caller (for a parameter)
				841	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	842
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	843	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	844	<dd>This indicates to the code generator that the parameter or return value
				845	should be sign-extended to a 32-bit value by the caller (for a parameter)
				846	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	847
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	848	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	849	<dd>This indicates that this parameter or return value should be treated
				850	in a special target-dependent fashion during while emitting code for a
				851	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]	852	to memory, though some targets use it to distinguish between two different
				853	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	854
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame^]	855	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	856	<dd>This indicates that the pointer parameter should really be passed by
				857	value to the function. The attribute implies that a hidden copy of the
				858	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]	859	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]	860	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame^]	861	value, but is also valid on pointers to scalars. The copy is considered to
				862	belong to the caller not the callee (for example,
				863	<tt><a href="#readonly">readonly</a></tt> functions should not write to
				864	<tt>byval</tt> parameters).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	865
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	866	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	867	<dd>This indicates that the pointer parameter specifies the address of a
				868	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]	869	This pointer must be guaranteed by the caller to be valid: loads and stores
				870	to the structure may be assumed by the callee to not to trap. This may only
				871	be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	872
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	873	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	874	<dd>This indicates that the parameter does not alias any global or any other
				875	parameter. The caller is responsible for ensuring that this is the case,
				876	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	877
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	878	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	879	<dd>This indicates that the pointer parameter can be excised using the
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	880	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	881	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	882
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	883	</div>
				884
				885	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	886	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	887	<a name="gc">Garbage Collector Names</a>
				888	</div>
				889
				890	<div class="doc_text">
				891	<p>Each function may specify a garbage collector name, which is simply a
				892	string.</p>
				893
				894	<div class="doc_code"><pre
				895	>define void @f() gc "name" { ...</pre></div>
				896
				897	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				898	collector which will cause the compiler to alter its output in order to support
				899	the named garbage collection algorithm.</p>
				900	</div>
				901
				902	<!-- ======================================================================= -->
				903	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	904	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	905	</div>
				906
				907	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	908
				909	<p>Function attributes are set to communicate additional information about
				910	a function. Function attributes are considered to be part of the function,
				911	not of the function type, so functions with different parameter attributes
				912	can have the same function type.</p>
				913
				914	<p>Function attributes are simple keywords that follow the type specified. If
				915	multiple attributes are needed, they are space separated. For
				916	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	917
				918	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	919	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	920	define void @f() noinline { ... }
				921	define void @f() alwaysinline { ... }
				922	define void @f() alwaysinline optsize { ... }
				923	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	924	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	925	</div>
				926
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	927	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	928	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	929	<dd>This attribute indicates that the inliner should attempt to inline this
				930	function into callers whenever possible, ignoring any active inlining size
				931	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	932
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	933	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	934	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	935	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	936	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	937
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	938	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	939	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	940	make choices that keep the code size of this function low, and otherwise do
				941	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	942
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	943	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	944	<dd>This function attribute indicates that the function never returns normally.
				945	This produces undefined behavior at runtime if the function ever does
				946	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	947
				948	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	949	<dd>This function attribute indicates that the function never returns with an
				950	unwind or exceptional control flow. If the function does unwind, its runtime
				951	behavior is undefined.</dd>
				952
				953	<dt><tt>readnone</tt></dt>
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame^]	954	<dd>This attribute indicates that the function computes its result (or the
				955	exception it throws) based strictly on its arguments, without dereferencing any
				956	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				957	registers, etc) visible to caller functions. It does not write through any
				958	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
				959	never changes any state visible to callers.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	960
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame^]	961	<dt><tt><a name="readonly">readonly</a></tt></dt>
				962	<dd>This attribute indicates that the function does not write through any
				963	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				964	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				965	caller functions. It may dereference pointer arguments and read state that may
				966	be set in the caller. A readonly function always returns the same value (or
				967	throws the same exception) when called with the same set of arguments and global
				968	state.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	969	</dl>
				970
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	971	</div>
				972
				973	<!-- ======================================================================= -->
				974	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	975	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	976	</div>
				977
				978	<div class="doc_text">
				979	<p>
				980	Modules may contain "module-level inline asm" blocks, which corresponds to the
				981	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				982	LLVM and treated as a single unit, but may be separated in the .ll file if
				983	desired. The syntax is very simple:
				984	</p>
				985
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	986	<div class="doc_code">
				987	<pre>
				988	module asm "inline asm code goes here"
				989	module asm "more can go here"
				990	</pre>
				991	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	992
				993	<p>The strings can contain any character by escaping non-printable characters.
				994	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				995	for the number.
				996	</p>
				997
				998	<p>
				999	The inline asm code is simply printed to the machine code .s file when
				1000	assembly code is generated.
				1001	</p>
				1002	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1003
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1004	<!-- ======================================================================= -->
				1005	<div class="doc_subsection">
				1006	<a name="datalayout">Data Layout</a>
				1007	</div>
				1008
				1009	<div class="doc_text">
				1010	<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]	1011	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1012	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1013	<p>The <i>layout specification</i> consists of a list of specifications
				1014	separated by the minus sign character ('-'). Each specification starts with a
				1015	letter and may include other information after the letter to define some
				1016	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1017	<dl>
				1018	<dt><tt>E</tt></dt>
				1019	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1020	bits with the most significance have the lowest address location.</dd>
				1021	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1022	<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]	1023	the bits with the least significance have the lowest address location.</dd>
				1024	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1025	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1026	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1027	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1028	too.</dd>
				1029	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1030	<dd>This specifies the alignment for an integer type of a given bit
				1031	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1032	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1033	<dd>This specifies the alignment for a vector type of a given bit
				1034	<i>size</i>.</dd>
				1035	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1036	<dd>This specifies the alignment for a floating point type of a given bit
				1037	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1038	(double).</dd>
				1039	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1040	<dd>This specifies the alignment for an aggregate type of a given bit
				1041	<i>size</i>.</dd>
				1042	</dl>
				1043	<p>When constructing the data layout for a given target, LLVM starts with a
				1044	default set of specifications which are then (possibly) overriden by the
				1045	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1046	are given in this list:</p>
				1047	<ul>
				1048	<li><tt>E</tt> - big endian</li>
				1049	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1050	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1051	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1052	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1053	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1054	<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]	1055	alignment of 64-bits</li>
				1056	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1057	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1058	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1059	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1060	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1061	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1062	<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]	1063	following rules:
				1064	<ol>
				1065	<li>If the type sought is an exact match for one of the specifications, that
				1066	specification is used.</li>
				1067	<li>If no match is found, and the type sought is an integer type, then the
				1068	smallest integer type that is larger than the bitwidth of the sought type is
				1069	used. If none of the specifications are larger than the bitwidth then the the
				1070	largest integer type is used. For example, given the default specifications
				1071	above, the i7 type will use the alignment of i8 (next largest) while both
				1072	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1073	<li>If no match is found, and the type sought is a vector type, then the
				1074	largest vector type that is smaller than the sought vector type will be used
				1075	as a fall back. This happens because <128 x double> can be implemented in
				1076	terms of 64 <2 x double>, for example.</li>
				1077	</ol>
				1078	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1079
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1080	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1081	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1082	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1083
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1084	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1085
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1086	<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]	1087	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1088	optimizations to be performed on the intermediate representation directly,
				1089	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1090	extra analyses on the side before the transformation. A strong type
				1091	system makes it easier to read the generated code and enables novel
				1092	analyses and transformations that are not feasible to perform on normal
				1093	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1094
				1095	</div>
				1096
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1097	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1098	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1099	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1100	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1101	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1102	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1103
				1104	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1105	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1106	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1107	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1108	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1109	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1110	</tr>
				1111	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1112	<td><a href="#t_floating">floating point</a></td>
				1113	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1114	</tr>
				1115	<tr>
				1116	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1117	<td><a href="#t_integer">integer</a>,
				1118	<a href="#t_floating">floating point</a>,
				1119	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1120	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1121	<a href="#t_struct">structure</a>,
				1122	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1123	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1124	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1125	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1126	<tr>
				1127	<td><a href="#t_primitive">primitive</a></td>
				1128	<td><a href="#t_label">label</a>,
				1129	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1130	<a href="#t_floating">floating point</a>.</td>
				1131	</tr>
				1132	<tr>
				1133	<td><a href="#t_derived">derived</a></td>
				1134	<td><a href="#t_integer">integer</a>,
				1135	<a href="#t_array">array</a>,
				1136	<a href="#t_function">function</a>,
				1137	<a href="#t_pointer">pointer</a>,
				1138	<a href="#t_struct">structure</a>,
				1139	<a href="#t_pstruct">packed structure</a>,
				1140	<a href="#t_vector">vector</a>,
				1141	<a href="#t_opaque">opaque</a>.
				1142	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1143	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1144	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1145
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1146	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1147	most important. Values of these types are the only ones which can be
				1148	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1149	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1150	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1151
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1152	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1153	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1154
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1155	<div class="doc_text">
				1156	<p>The primitive types are the fundamental building blocks of the LLVM
				1157	system.</p>
				1158
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1159	</div>
				1160
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1161	<!-- _______________________________________________________________________ -->
				1162	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1163
				1164	<div class="doc_text">
				1165	<table>
				1166	<tbody>
				1167	<tr><th>Type</th><th>Description</th></tr>
				1168	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1169	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1170	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1171	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1172	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1173	</tbody>
				1174	</table>
				1175	</div>
				1176
				1177	<!-- _______________________________________________________________________ -->
				1178	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1179
				1180	<div class="doc_text">
				1181	<h5>Overview:</h5>
				1182	<p>The void type does not represent any value and has no size.</p>
				1183
				1184	<h5>Syntax:</h5>
				1185
				1186	<pre>
				1187	void
				1188	</pre>
				1189	</div>
				1190
				1191	<!-- _______________________________________________________________________ -->
				1192	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1193
				1194	<div class="doc_text">
				1195	<h5>Overview:</h5>
				1196	<p>The label type represents code labels.</p>
				1197
				1198	<h5>Syntax:</h5>
				1199
				1200	<pre>
				1201	label
				1202	</pre>
				1203	</div>
				1204
				1205
				1206	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1207	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1208
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1209	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1210
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1211	<p>The real power in LLVM comes from the derived types in the system.
				1212	This is what allows a programmer to represent arrays, functions,
				1213	pointers, and other useful types. Note that these derived types may be
				1214	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]	1215
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1216	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1217
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1218	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1219	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1220
				1221	<div class="doc_text">
				1222
				1223	<h5>Overview:</h5>
				1224	<p>The integer type is a very simple derived type that simply specifies an
				1225	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1226	2^23-1 (about 8 million) can be specified.</p>
				1227
				1228	<h5>Syntax:</h5>
				1229
				1230	<pre>
				1231	iN
				1232	</pre>
				1233
				1234	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1235	value.</p>
				1236
				1237	<h5>Examples:</h5>
				1238	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1239	<tbody>
				1240	<tr>
				1241	<td><tt>i1</tt></td>
				1242	<td>a single-bit integer.</td>
				1243	</tr><tr>
				1244	<td><tt>i32</tt></td>
				1245	<td>a 32-bit integer.</td>
				1246	</tr><tr>
				1247	<td><tt>i1942652</tt></td>
				1248	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1249	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1250	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1251	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1252	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1253
				1254	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1255	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
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	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1258
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1259	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1260
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1261	<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]	1262	sequentially in memory. The array type requires a size (number of
				1263	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1264
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1265	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1266
				1267	<pre>
				1268	[<# elements> x <elementtype>]
				1269	</pre>
				1270
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1271	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1272	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1273
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1274	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1275	<table class="layout">
				1276	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1277	<td class="left"><tt>[40 x i32]</tt></td>
				1278	<td class="left">Array of 40 32-bit integer values.</td>
				1279	</tr>
				1280	<tr class="layout">
				1281	<td class="left"><tt>[41 x i32]</tt></td>
				1282	<td class="left">Array of 41 32-bit integer values.</td>
				1283	</tr>
				1284	<tr class="layout">
				1285	<td class="left"><tt>[4 x i8]</tt></td>
				1286	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1287	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1288	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1289	<p>Here are some examples of multidimensional arrays:</p>
				1290	<table class="layout">
				1291	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1292	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1293	<td class="left">3x4 array of 32-bit integer values.</td>
				1294	</tr>
				1295	<tr class="layout">
				1296	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1297	<td class="left">12x10 array of single precision floating point values.</td>
				1298	</tr>
				1299	<tr class="layout">
				1300	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1301	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1302	</tr>
				1303	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1304
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1305	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1306	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]	1307	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1308	As a special case, however, zero length arrays are recognized to be variable
				1309	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1310	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1311
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1312	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1313
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1314	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1315	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1316	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1317
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1318	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1319
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1320	<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]	1321	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]	1322	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]	1323	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]	1324	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1325
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1326	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1327
				1328	<pre>
				1329	<returntype list> (<parameter list>)
				1330	</pre>
				1331
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1332	<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]	1333	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1334	which indicates that the function takes a variable number of arguments.
				1335	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1336	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1337	'<tt><returntype list></tt>' is a comma-separated list of
				1338	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1339
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1340	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1341	<table class="layout">
				1342	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1343	<td class="left"><tt>i32 (i32)</tt></td>
				1344	<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]	1345	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1346	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1347	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1348	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1349	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1350	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1351	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1352	<tt>float</tt>.
				1353	</td>
				1354	</tr><tr class="layout">
				1355	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1356	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1357	<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]	1358	which returns an integer. This is the signature for <tt>printf</tt> in
				1359	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1360	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1361	</tr><tr class="layout">
				1362	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1363	<td class="left">A function taking an <tt>i32></tt>, returning two
				1364	<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]	1365	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1366	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1367	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1368
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1369	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1370	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1371	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1372	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1373	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1374	<p>The structure type is used to represent a collection of data members
				1375	together in memory. The packing of the field types is defined to match
				1376	the ABI of the underlying processor. The elements of a structure may
				1377	be any type that has a size.</p>
				1378	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1379	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1380	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1381	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1382	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1383	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1384	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1385	<table class="layout">
				1386	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1387	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1388	<td class="left">A triple of three <tt>i32</tt> values</td>
				1389	</tr><tr class="layout">
				1390	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1391	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1392	second element is a <a href="#t_pointer">pointer</a> to a
				1393	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1394	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1395	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1396	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1397	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1398
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1399	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1400	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1401	</div>
				1402	<div class="doc_text">
				1403	<h5>Overview:</h5>
				1404	<p>The packed structure type is used to represent a collection of data members
				1405	together in memory. There is no padding between fields. Further, the alignment
				1406	of a packed structure is 1 byte. The elements of a packed structure may
				1407	be any type that has a size.</p>
				1408	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1409	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1410	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1411	instruction.</p>
				1412	<h5>Syntax:</h5>
				1413	<pre> < { <type list> } > <br></pre>
				1414	<h5>Examples:</h5>
				1415	<table class="layout">
				1416	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1417	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1418	<td class="left">A triple of three <tt>i32</tt> values</td>
				1419	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1420	<td class="left">
				1421	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1422	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1423	second element is a <a href="#t_pointer">pointer</a> to a
				1424	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1425	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1426	</tr>
				1427	</table>
				1428	</div>
				1429
				1430	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1431	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1432	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1433	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1434	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1435	reference to another object, which must live in memory. Pointer types may have
				1436	an optional address space attribute defining the target-specific numbered
				1437	address space where the pointed-to object resides. The default address space is
				1438	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1439	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1440	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1441	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1442	<table class="layout">
				1443	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1444	<td class="left"><tt>[4x i32]*</tt></td>
				1445	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1446	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1447	</tr>
				1448	<tr class="layout">
				1449	<td class="left"><tt>i32 (i32 ) </tt></td>
				1450	<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]	1451	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]	1452	<tt>i32</tt>.</td>
				1453	</tr>
				1454	<tr class="layout">
				1455	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1456	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1457	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1458	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1459	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1460	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1461
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1462	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1463	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1464	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1465
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1466	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1467
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1468	<p>A vector type is a simple derived type that represents a vector
				1469	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1470	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1471	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1472	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1473	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1474	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1475
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1476	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1477
				1478	<pre>
				1479	< <# elements> x <elementtype> >
				1480	</pre>
				1481
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1482	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1483	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1484
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1485	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1486
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1487	<table class="layout">
				1488	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1489	<td class="left"><tt><4 x i32></tt></td>
				1490	<td class="left">Vector of 4 32-bit integer values.</td>
				1491	</tr>
				1492	<tr class="layout">
				1493	<td class="left"><tt><8 x float></tt></td>
				1494	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1495	</tr>
				1496	<tr class="layout">
				1497	<td class="left"><tt><2 x i64></tt></td>
				1498	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1499	</tr>
				1500	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1501	</div>
				1502
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1503	<!-- _______________________________________________________________________ -->
				1504	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1505	<div class="doc_text">
				1506
				1507	<h5>Overview:</h5>
				1508
				1509	<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]	1510	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]	1511	In LLVM, opaque types can eventually be resolved to any type (not just a
				1512	structure type).</p>
				1513
				1514	<h5>Syntax:</h5>
				1515
				1516	<pre>
				1517	opaque
				1518	</pre>
				1519
				1520	<h5>Examples:</h5>
				1521
				1522	<table class="layout">
				1523	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1524	<td class="left"><tt>opaque</tt></td>
				1525	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1526	</tr>
				1527	</table>
				1528	</div>
				1529
				1530
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1531	<!-- *********************************************************************** -->
				1532	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1533	<!-- *********************************************************************** -->
				1534
				1535	<div class="doc_text">
				1536
				1537	<p>LLVM has several different basic types of constants. This section describes
				1538	them all and their syntax.</p>
				1539
				1540	</div>
				1541
				1542	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1543	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1544
				1545	<div class="doc_text">
				1546
				1547	<dl>
				1548	<dt><b>Boolean constants</b></dt>
				1549
				1550	<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]	1551	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1552	</dd>
				1553
				1554	<dt><b>Integer constants</b></dt>
				1555
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1556	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1557	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1558	integer types.
				1559	</dd>
				1560
				1561	<dt><b>Floating point constants</b></dt>
				1562
				1563	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1564	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1565	notation (see below). The assembler requires the exact decimal value of
				1566	a floating-point constant. For example, the assembler accepts 1.25 but
				1567	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1568	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]	1569
				1570	<dt><b>Null pointer constants</b></dt>
				1571
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1572	<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]	1573	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1574
				1575	</dl>
				1576
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1577	<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]	1578	of floating point constants. For example, the form '<tt>double
				1579	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1580	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]	1581	(and the only time that they are generated by the disassembler) is when a
				1582	floating point constant must be emitted but it cannot be represented as a
				1583	decimal floating point number. For example, NaN's, infinities, and other
				1584	special values are represented in their IEEE hexadecimal format so that
				1585	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]	1586
				1587	</div>
				1588
				1589	<!-- ======================================================================= -->
				1590	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1591	</div>
				1592
				1593	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1594	<p>Aggregate constants arise from aggregation of simple constants
				1595	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1596
				1597	<dl>
				1598	<dt><b>Structure constants</b></dt>
				1599
				1600	<dd>Structure constants are represented with notation similar to structure
				1601	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1602	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1603	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]	1604	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]	1605	types of elements must match those specified by the type.
				1606	</dd>
				1607
				1608	<dt><b>Array constants</b></dt>
				1609
				1610	<dd>Array constants are represented with notation similar to array type
				1611	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1612	(<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]	1613	constants must have <a href="#t_array">array type</a>, and the number and
				1614	types of elements must match those specified by the type.
				1615	</dd>
				1616
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1617	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1618
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1619	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1620	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1621	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1622	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1623	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]	1624	match those specified by the type.
				1625	</dd>
				1626
				1627	<dt><b>Zero initialization</b></dt>
				1628
				1629	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1630	value to zero of <em>any</em> type, including scalar and aggregate types.
				1631	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]	1632	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1633	initializers.
				1634	</dd>
				1635	</dl>
				1636
				1637	</div>
				1638
				1639	<!-- ======================================================================= -->
				1640	<div class="doc_subsection">
				1641	<a name="globalconstants">Global Variable and Function Addresses</a>
				1642	</div>
				1643
				1644	<div class="doc_text">
				1645
				1646	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1647	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1648	constants. These constants are explicitly referenced when the <a
				1649	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]	1650	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1651	file:</p>
				1652
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1653	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1654	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1655	@X = global i32 17
				1656	@Y = global i32 42
				1657	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1658	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1659	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1660
				1661	</div>
				1662
				1663	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1664	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1665	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1666	<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]	1667	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]	1668	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1669
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1670	<p>Undefined values indicate to the compiler that the program is well defined
				1671	no matter what value is used, giving the compiler more freedom to optimize.
				1672	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1673	</div>
				1674
				1675	<!-- ======================================================================= -->
				1676	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1677	</div>
				1678
				1679	<div class="doc_text">
				1680
				1681	<p>Constant expressions are used to allow expressions involving other constants
				1682	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1683	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]	1684	that does not have side effects (e.g. load and call are not supported). The
				1685	following is the syntax for constant expressions:</p>
				1686
				1687	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1688	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1689	<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]	1690	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1691
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1692	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1693	<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]	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>sext ( CST to TYPE )</tt></b></dt>
				1697	<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]	1698	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]	1699
				1700	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1701	<dd>Truncate a floating point constant to another floating point type. The
				1702	size of CST must be larger than the size of TYPE. Both types must be
				1703	floating point.</dd>
				1704
				1705	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1706	<dd>Floating point extend a constant to another type. The size of CST must be
				1707	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1708
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1709	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1710	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1711	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1712	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1713	of the same number of elements. If the value won't fit in the integer type,
				1714	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1715
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1716	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1717	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1718	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1719	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1720	of the same number of elements. If the value won't fit in the integer type,
				1721	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1722
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1723	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1724	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1725	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1726	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1727	of the same number of elements. If the value won't fit in the floating point
				1728	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1729
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1730	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1731	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1732	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1733	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1734	of the same number of elements. If the value won't fit in the floating point
				1735	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1736
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1737	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1738	<dd>Convert a pointer typed constant to the corresponding integer constant
				1739	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1740	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1741
				1742	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1743	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1744	pointer type. CST must be of integer type. The CST value is zero extended,
				1745	truncated, or unchanged to make it fit in a pointer size. This one is
				1746	<i>really</i> dangerous!</dd>
				1747
				1748	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1749	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1750	identical (same number of bits). The conversion is done as if the CST value
				1751	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]	1752	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]	1753	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]	1754	pointers it is only valid to cast to another pointer type. It is not valid
				1755	to bitcast to or from an aggregate type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1756	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1757
				1758	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1759
				1760	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1761	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1762	instruction, the index list may have zero or more indexes, which are required
				1763	to make sense for the type of "CSTPTR".</dd>
				1764
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1765	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1766
				1767	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1768	constants.</dd>
				1769
				1770	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1771	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1772
				1773	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1774	<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]	1775
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1776	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1777	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1778
				1779	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1780	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1781
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1782	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1783
				1784	<dd>Perform the <a href="#i_extractelement">extractelement
				1785	operation</a> on constants.
				1786
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1787	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1788
				1789	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1790	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1791
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1792
				1793	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1794
				1795	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1796	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1797
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1798	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1799
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1800	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1801	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]	1802	binary</a> operations. The constraints on operands are the same as those for
				1803	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1804	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1805	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1806	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1807
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1808	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1809	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1810	<!-- *********************************************************************** -->
				1811
				1812	<!-- ======================================================================= -->
				1813	<div class="doc_subsection">
				1814	<a name="inlineasm">Inline Assembler Expressions</a>
				1815	</div>
				1816
				1817	<div class="doc_text">
				1818
				1819	<p>
				1820	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1821	Module-Level Inline Assembly</a>) through the use of a special value. This
				1822	value represents the inline assembler as a string (containing the instructions
				1823	to emit), a list of operand constraints (stored as a string), and a flag that
				1824	indicates whether or not the inline asm expression has side effects. An example
				1825	inline assembler expression is:
				1826	</p>
				1827
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1828	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1829	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1830	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1831	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1832	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1833
				1834	<p>
				1835	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1836	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1837	</p>
				1838
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1839	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1840	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1841	%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]	1842	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1843	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1844
				1845	<p>
				1846	Inline asms with side effects not visible in the constraint list must be marked
				1847	as having side effects. This is done through the use of the
				1848	'<tt>sideeffect</tt>' keyword, like so:
				1849	</p>
				1850
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1851	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1852	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1853	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1854	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1855	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1856
				1857	<p>TODO: The format of the asm and constraints string still need to be
				1858	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]	1859	need to be documented). This is probably best done by reference to another
				1860	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1861	</p>
				1862
				1863	</div>
				1864
				1865	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1866	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1867	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1868
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1869	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1870
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1871	<p>The LLVM instruction set consists of several different
				1872	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1873	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1874	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1875	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1876	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1877
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1878	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1879
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1880	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1881	<div class="doc_subsection"> <a name="terminators">Terminator
				1882	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1883
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1884	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1885
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1886	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1887	basic block in a program ends with a "Terminator" instruction, which
				1888	indicates which block should be executed after the current block is
				1889	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1890	value: they produce control flow, not values (the one exception being
				1891	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1892	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1893	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1894	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1895	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1896	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1897	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1898
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1899	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1900
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1901	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1902	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1903	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1904	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1905	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1906	<pre>
				1907	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]	1908	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1909	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1910
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1911	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1912
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1913	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				1914	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1915	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1916	returns a value and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1917	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1918
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1919	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1920
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1921	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				1922	the return value. The type of the return value must be a
				1923	'<a href="#t_firstclass">first class</a>' type.</p>
				1924
				1925	<p>A function is not <a href="#wellformed">well formed</a> if
				1926	it it has a non-void return type and contains a '<tt>ret</tt>'
				1927	instruction with no return value or a return value with a type that
				1928	does not match its type, or if it has a void return type and contains
				1929	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1930
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1931	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1932
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1933	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1934	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]	1935	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1936	the instruction after the call. If the caller was an "<a
				1937	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1938	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1939	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1940	return value.
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1941
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1942	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1943
				1944	<pre>
				1945	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1946	ret void <i>; Return from a void function</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1947	ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1948	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1949	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1950	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1951	<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]	1952	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1953	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1954	<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]	1955	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1956	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1957	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1958	transfer to a different basic block in the current function. There are
				1959	two forms of this instruction, corresponding to a conditional branch
				1960	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1961	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1962	<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]	1963	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1964	unconditional form of the '<tt>br</tt>' instruction takes a single
				1965	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1966	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1967	<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]	1968	argument is evaluated. If the value is <tt>true</tt>, control flows
				1969	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1970	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1971	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1972	<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]	1973	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]	1974	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1975	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1976	<div class="doc_subsubsection">
				1977	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1978	</div>
				1979
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1980	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1981	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1982
				1983	<pre>
				1984	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1985	</pre>
				1986
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1987	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1988
				1989	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1990	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1991	instruction, allowing a branch to occur to one of many possible
				1992	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1993
				1994
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1995	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1996
				1997	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1998	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1999	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2000	table is not allowed to contain duplicate constant entries.</p>
				2001
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2002	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2003
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2004	<p>The <tt>switch</tt> instruction specifies a table of values and
				2005	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2006	table is searched for the given value. If the value is found, control flow is
				2007	transfered to the corresponding destination; otherwise, control flow is
				2008	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2009
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2010	<h5>Implementation:</h5>
				2011
				2012	<p>Depending on properties of the target machine and the particular
				2013	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2014	ways. For example, it could be generated as a series of chained conditional
				2015	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2016
				2017	<h5>Example:</h5>
				2018
				2019	<pre>
				2020	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2021	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2022	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2023
				2024	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2025	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2026
				2027	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2028	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2029	i32 1, label %onone
				2030	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2031	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2032	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2033
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2034	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2035	<div class="doc_subsubsection">
				2036	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2037	</div>
				2038
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2039	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2040
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2041	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2042
				2043	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2044	<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]	2045	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2046	</pre>
				2047
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2048	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2049
				2050	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2051	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2052	'<tt>normal</tt>' label or the
				2053	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2054	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2055	"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]	2056	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2057	continued at the dynamically nearest "exception" label.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2058
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2059	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2060
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2061	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2062
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2063	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2064	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2065	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2066	convention</a> the call should use. If none is specified, the call defaults
				2067	to using C calling conventions.
				2068	</li>
				2069	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2070	function value being invoked. In most cases, this is a direct function
				2071	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2072	an arbitrary pointer to function value.
				2073	</li>
				2074
				2075	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2076	function to be invoked. </li>
				2077
				2078	<li>'<tt>function args</tt>': argument list whose types match the function
				2079	signature argument types. If the function signature indicates the function
				2080	accepts a variable number of arguments, the extra arguments can be
				2081	specified. </li>
				2082
				2083	<li>'<tt>normal label</tt>': the label reached when the called function
				2084	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2085
				2086	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2087	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2088
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2089	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2090
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2091	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2092
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2093	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2094	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2095	difference is that it establishes an association with a label, which is used by
				2096	the runtime library to unwind the stack.</p>
				2097
				2098	<p>This instruction is used in languages with destructors to ensure that proper
				2099	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2100	exception. Additionally, this is important for implementation of
				2101	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2102
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2103	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2104	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2105	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2106	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2107	%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]	2108	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2109	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2110	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2111
				2112
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2113	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2114
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2115	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2116	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2117
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2118	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2119
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2120	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2121	<pre>
				2122	unwind
				2123	</pre>
				2124
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2125	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2126
				2127	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2128	at the first callee in the dynamic call stack which used an <a
				2129	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2130	primarily used to implement exception handling.</p>
				2131
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2132	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2133
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2134	<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]	2135	immediately halt. The dynamic call stack is then searched for the first <a
				2136	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2137	execution continues at the "exceptional" destination block specified by the
				2138	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2139	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2140	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2141
				2142	<!-- _______________________________________________________________________ -->
				2143
				2144	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2145	Instruction</a> </div>
				2146
				2147	<div class="doc_text">
				2148
				2149	<h5>Syntax:</h5>
				2150	<pre>
				2151	unreachable
				2152	</pre>
				2153
				2154	<h5>Overview:</h5>
				2155
				2156	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2157	instruction is used to inform the optimizer that a particular portion of the
				2158	code is not reachable. This can be used to indicate that the code after a
				2159	no-return function cannot be reached, and other facts.</p>
				2160
				2161	<h5>Semantics:</h5>
				2162
				2163	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2164	</div>
				2165
				2166
				2167
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2168	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2169	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2170	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2171	<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]	2172	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]	2173	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2174	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]	2175	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2176	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2177	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2178	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2179	<div class="doc_subsubsection">
				2180	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2181	</div>
				2182
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2183	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2184
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2185	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2186
				2187	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2188	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2189	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2190
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2191	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2192
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2193	<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]	2194
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2195	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2196
				2197	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2198	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2199	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2200	types.</p>
				2201
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2202	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2203
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2204	<p>The value produced is the integer or floating point sum of the two
				2205	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2206
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2207	<p>If an integer sum has unsigned overflow, the result returned is the
				2208	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2209	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2210
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2211	<p>Because LLVM integers use a two's complement representation, this
				2212	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2213
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2214	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2215
				2216	<pre>
				2217	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2218	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2219	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2220	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2221	<div class="doc_subsubsection">
				2222	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2223	</div>
				2224
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2225	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2226
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2227	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2228
				2229	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2230	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2231	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2232
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2233	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2234
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2235	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2236	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2237
				2238	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2239	'<tt>neg</tt>' instruction present in most other intermediate
				2240	representations.</p>
				2241
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2242	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2243
				2244	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2245	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2246	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2247	types.</p>
				2248
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2249	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2250
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2251	<p>The value produced is the integer or floating point difference of
				2252	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2253
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2254	<p>If an integer difference has unsigned overflow, the result returned is the
				2255	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2256	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2257
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2258	<p>Because LLVM integers use a two's complement representation, this
				2259	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2260
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2261	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2262	<pre>
				2263	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2264	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2265	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2266	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2267
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2268	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2269	<div class="doc_subsubsection">
				2270	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2271	</div>
				2272
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2273	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2274
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2275	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2276	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2277	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2278	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2279	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2280	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2281
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2282	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2283
				2284	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2285	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2286	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2287	types.</p>
				2288
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2289	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2290
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2291	<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]	2292	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2293
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2294	<p>If the result of an integer multiplication has unsigned overflow,
				2295	the result returned is the mathematical result modulo
				2296	2<sup>n</sup>, where n is the bit width of the result.</p>
				2297	<p>Because LLVM integers use a two's complement representation, and the
				2298	result is the same width as the operands, this instruction returns the
				2299	correct result for both signed and unsigned integers. If a full product
				2300	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2301	should be sign-extended or zero-extended as appropriate to the
				2302	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2303	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2304	<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]	2305	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2306	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2307
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2308	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2309	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2310	</a></div>
				2311	<div class="doc_text">
				2312	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2313	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2314	</pre>
				2315	<h5>Overview:</h5>
				2316	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2317	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2318
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2319	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2320
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2321	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2322	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2323	values. Both arguments must have identical types.</p>
				2324
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2325	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2326
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2327	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2328	<p>Note that unsigned integer division and signed integer division are distinct
				2329	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2330	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2331	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2332	<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]	2333	</pre>
				2334	</div>
				2335	<!-- _______________________________________________________________________ -->
				2336	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2337	</a> </div>
				2338	<div class="doc_text">
				2339	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2340	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2341	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2342	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2343
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2344	<h5>Overview:</h5>
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	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2347	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2348
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2349	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2350
				2351	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2352	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2353	values. Both arguments must have identical types.</p>
				2354
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2355	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2356	<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]	2357	<p>Note that signed integer division and unsigned integer division are distinct
				2358	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2359	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2360	undefined behavior; this is a rare case, but can occur, for example,
				2361	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2362	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2363	<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]	2364	</pre>
				2365	</div>
				2366	<!-- _______________________________________________________________________ -->
				2367	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2368	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2369	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2370	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2371	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2372	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2373	</pre>
				2374	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2375
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2376	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2377	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2378
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2379	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2380
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2381	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2382	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2383	of floating point values. Both arguments must have identical types.</p>
				2384
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2385	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2386
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2387	<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]	2388
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2389	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2390
				2391	<pre>
				2392	<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]	2393	</pre>
				2394	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2395
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2396	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2397	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2398	</div>
				2399	<div class="doc_text">
				2400	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2401	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2402	</pre>
				2403	<h5>Overview:</h5>
				2404	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2405	unsigned division of its two arguments.</p>
				2406	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2407	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2408	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2409	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2410	<h5>Semantics:</h5>
				2411	<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]	2412	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2413	<p>Note that unsigned integer remainder and signed integer remainder are
				2414	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2415	<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]	2416	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2417	<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]	2418	</pre>
				2419
				2420	</div>
				2421	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2422	<div class="doc_subsubsection">
				2423	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2424	</div>
				2425
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2426	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2427
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2428	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2429
				2430	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2431	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2432	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2433
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2434	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2435
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2436	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2437	signed division of its two operands. This instruction can also take
				2438	<a href="#t_vector">vector</a> versions of the values in which case
				2439	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2440
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2441	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2442
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2443	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2444	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2445	values. Both arguments must have identical types.</p>
				2446
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2447	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2448
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2449	<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]	2450	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2451	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]	2452	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2453	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]	2454	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]	2455	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2456	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2457	<p>Note that signed integer remainder and unsigned integer remainder are
				2458	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2459	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2460	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2461	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2462	(The remainder doesn't actually overflow, but this rule lets srem be
				2463	implemented using instructions that return both the result of the division
				2464	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2465	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2466	<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]	2467	</pre>
				2468
				2469	</div>
				2470	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2471	<div class="doc_subsubsection">
				2472	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2473
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2474	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2475
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2476	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2477	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2478	</pre>
				2479	<h5>Overview:</h5>
				2480	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2481	division of its two operands.</p>
				2482	<h5>Arguments:</h5>
				2483	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2484	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2485	of floating point values. Both arguments must have identical types.</p>
				2486
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2487	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2488
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2489	<p>This instruction returns the <i>remainder</i> of a division.
				2490	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2491
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2492	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2493
				2494	<pre>
				2495	<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]	2496	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2497	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2498
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2499	<!-- ======================================================================= -->
				2500	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2501	Operations</a> </div>
				2502	<div class="doc_text">
				2503	<p>Bitwise binary operators are used to do various forms of
				2504	bit-twiddling in a program. They are generally very efficient
				2505	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2506	instructions. They require two operands of the same type, execute an operation on them,
				2507	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]	2508	</div>
				2509
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2510	<!-- _______________________________________________________________________ -->
				2511	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2512	Instruction</a> </div>
				2513	<div class="doc_text">
				2514	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2515	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2516	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2517
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2518	<h5>Overview:</h5>
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	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2521	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2522
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2523	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2524
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2525	<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]	2526	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]	2527	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2528
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2529	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2530
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2531	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2532	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2533	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]	2534
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2535	<h5>Example:</h5><pre>
				2536	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2537	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2538	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2539	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2540	</pre>
				2541	</div>
				2542	<!-- _______________________________________________________________________ -->
				2543	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2544	Instruction</a> </div>
				2545	<div class="doc_text">
				2546	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2547	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2548	</pre>
				2549
				2550	<h5>Overview:</h5>
				2551	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2552	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]	2553
				2554	<h5>Arguments:</h5>
				2555	<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]	2556	<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]	2557	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2558
				2559	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2560
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2561	<p>This instruction always performs a logical shift right operation. The most
				2562	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]	2563	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2564	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]	2565
				2566	<h5>Example:</h5>
				2567	<pre>
				2568	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2569	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2570	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2571	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2572	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2573	</pre>
				2574	</div>
				2575
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2576	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2577	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2578	Instruction</a> </div>
				2579	<div class="doc_text">
				2580
				2581	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2582	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2583	</pre>
				2584
				2585	<h5>Overview:</h5>
				2586	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2587	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]	2588
				2589	<h5>Arguments:</h5>
				2590	<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]	2591	<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]	2592	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2593
				2594	<h5>Semantics:</h5>
				2595	<p>This instruction always performs an arithmetic shift right operation,
				2596	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]	2597	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2598	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]	2599	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2600
				2601	<h5>Example:</h5>
				2602	<pre>
				2603	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2604	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2605	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2606	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2607	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2608	</pre>
				2609	</div>
				2610
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2611	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2612	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2613	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2614
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2615	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2616
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2617	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2618
				2619	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2620	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2621	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2622
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2623	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2624
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2625	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2626	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2627
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2628	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2629
				2630	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2631	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2632	values. Both arguments must have identical types.</p>
				2633
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2634	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2635	<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]	2636	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2637	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2638	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2639	<tbody>
				2640	<tr>
				2641	<td>In0</td>
				2642	<td>In1</td>
				2643	<td>Out</td>
				2644	</tr>
				2645	<tr>
				2646	<td>0</td>
				2647	<td>0</td>
				2648	<td>0</td>
				2649	</tr>
				2650	<tr>
				2651	<td>0</td>
				2652	<td>1</td>
				2653	<td>0</td>
				2654	</tr>
				2655	<tr>
				2656	<td>1</td>
				2657	<td>0</td>
				2658	<td>0</td>
				2659	</tr>
				2660	<tr>
				2661	<td>1</td>
				2662	<td>1</td>
				2663	<td>1</td>
				2664	</tr>
				2665	</tbody>
				2666	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2667	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2668	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2669	<pre>
				2670	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2671	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2672	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2673	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2674	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2675	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2676	<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]	2677	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2678	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2679	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2680	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2681	<h5>Overview:</h5>
				2682	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2683	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2684	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2685
				2686	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2687	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2688	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2689	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2690	<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]	2691	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2692	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2693	<table border="1" cellspacing="0" cellpadding="4">
				2694	<tbody>
				2695	<tr>
				2696	<td>In0</td>
				2697	<td>In1</td>
				2698	<td>Out</td>
				2699	</tr>
				2700	<tr>
				2701	<td>0</td>
				2702	<td>0</td>
				2703	<td>0</td>
				2704	</tr>
				2705	<tr>
				2706	<td>0</td>
				2707	<td>1</td>
				2708	<td>1</td>
				2709	</tr>
				2710	<tr>
				2711	<td>1</td>
				2712	<td>0</td>
				2713	<td>1</td>
				2714	</tr>
				2715	<tr>
				2716	<td>1</td>
				2717	<td>1</td>
				2718	<td>1</td>
				2719	</tr>
				2720	</tbody>
				2721	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2722	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2723	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2724	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2725	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2726	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2727	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2728	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2729	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2730	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2731	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2732	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2733	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2734	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2735	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2736	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2737	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2738	or of its two operands. The <tt>xor</tt> is used to implement the
				2739	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2740	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2741	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2742	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2743	values. Both arguments must have identical types.</p>
				2744
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2745	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2746
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2747	<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]	2748	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2749	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2750	<table border="1" cellspacing="0" cellpadding="4">
				2751	<tbody>
				2752	<tr>
				2753	<td>In0</td>
				2754	<td>In1</td>
				2755	<td>Out</td>
				2756	</tr>
				2757	<tr>
				2758	<td>0</td>
				2759	<td>0</td>
				2760	<td>0</td>
				2761	</tr>
				2762	<tr>
				2763	<td>0</td>
				2764	<td>1</td>
				2765	<td>1</td>
				2766	</tr>
				2767	<tr>
				2768	<td>1</td>
				2769	<td>0</td>
				2770	<td>1</td>
				2771	</tr>
				2772	<tr>
				2773	<td>1</td>
				2774	<td>1</td>
				2775	<td>0</td>
				2776	</tr>
				2777	</tbody>
				2778	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2779	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2780	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2781	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2782	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2783	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2784	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2785	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2786	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2787	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2788
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2789	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2790	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2791	<a name="vectorops">Vector Operations</a>
				2792	</div>
				2793
				2794	<div class="doc_text">
				2795
				2796	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2797	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2798	vector-specific operations needed to process vectors effectively. While LLVM
				2799	does directly support these vector operations, many sophisticated algorithms
				2800	will want to use target-specific intrinsics to take full advantage of a specific
				2801	target.</p>
				2802
				2803	</div>
				2804
				2805	<!-- _______________________________________________________________________ -->
				2806	<div class="doc_subsubsection">
				2807	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2808	</div>
				2809
				2810	<div class="doc_text">
				2811
				2812	<h5>Syntax:</h5>
				2813
				2814	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2815	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2816	</pre>
				2817
				2818	<h5>Overview:</h5>
				2819
				2820	<p>
				2821	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2822	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2823	</p>
				2824
				2825
				2826	<h5>Arguments:</h5>
				2827
				2828	<p>
				2829	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2830	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]	2831	an index indicating the position from which to extract the element.
				2832	The index may be a variable.</p>
				2833
				2834	<h5>Semantics:</h5>
				2835
				2836	<p>
				2837	The result is a scalar of the same type as the element type of
				2838	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2839	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2840	results are undefined.
				2841	</p>
				2842
				2843	<h5>Example:</h5>
				2844
				2845	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2846	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2847	</pre>
				2848	</div>
				2849
				2850
				2851	<!-- _______________________________________________________________________ -->
				2852	<div class="doc_subsubsection">
				2853	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2854	</div>
				2855
				2856	<div class="doc_text">
				2857
				2858	<h5>Syntax:</h5>
				2859
				2860	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2861	<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]	2862	</pre>
				2863
				2864	<h5>Overview:</h5>
				2865
				2866	<p>
				2867	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2868	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2869	</p>
				2870
				2871
				2872	<h5>Arguments:</h5>
				2873
				2874	<p>
				2875	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2876	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]	2877	scalar value whose type must equal the element type of the first
				2878	operand. The third operand is an index indicating the position at
				2879	which to insert the value. The index may be a variable.</p>
				2880
				2881	<h5>Semantics:</h5>
				2882
				2883	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2884	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]	2885	element values are those of <tt>val</tt> except at position
				2886	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2887	exceeds the length of <tt>val</tt>, the results are undefined.
				2888	</p>
				2889
				2890	<h5>Example:</h5>
				2891
				2892	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2893	%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]	2894	</pre>
				2895	</div>
				2896
				2897	<!-- _______________________________________________________________________ -->
				2898	<div class="doc_subsubsection">
				2899	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2900	</div>
				2901
				2902	<div class="doc_text">
				2903
				2904	<h5>Syntax:</h5>
				2905
				2906	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2907	<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]	2908	</pre>
				2909
				2910	<h5>Overview:</h5>
				2911
				2912	<p>
				2913	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2914	from two input vectors, returning a vector of the same type.
				2915	</p>
				2916
				2917	<h5>Arguments:</h5>
				2918
				2919	<p>
				2920	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2921	with types that match each other and types that match the result of the
				2922	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]	2923	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]	2924	</p>
				2925
				2926	<p>
				2927	The shuffle mask operand is required to be a constant vector with either
				2928	constant integer or undef values.
				2929	</p>
				2930
				2931	<h5>Semantics:</h5>
				2932
				2933	<p>
				2934	The elements of the two input vectors are numbered from left to right across
				2935	both of the vectors. The shuffle mask operand specifies, for each element of
				2936	the result vector, which element of the two input registers the result element
				2937	gets. The element selector may be undef (meaning "don't care") and the second
				2938	operand may be undef if performing a shuffle from only one vector.
				2939	</p>
				2940
				2941	<h5>Example:</h5>
				2942
				2943	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2944	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2945	<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]	2946	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2947	<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]	2948	</pre>
				2949	</div>
				2950
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2951
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2952	<!-- ======================================================================= -->
				2953	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2954	<a name="aggregateops">Aggregate Operations</a>
				2955	</div>
				2956
				2957	<div class="doc_text">
				2958
				2959	<p>LLVM supports several instructions for working with aggregate values.
				2960	</p>
				2961
				2962	</div>
				2963
				2964	<!-- _______________________________________________________________________ -->
				2965	<div class="doc_subsubsection">
				2966	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2967	</div>
				2968
				2969	<div class="doc_text">
				2970
				2971	<h5>Syntax:</h5>
				2972
				2973	<pre>
				2974	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2975	</pre>
				2976
				2977	<h5>Overview:</h5>
				2978
				2979	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2980	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2981	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2982	</p>
				2983
				2984
				2985	<h5>Arguments:</h5>
				2986
				2987	<p>
				2988	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2989	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]	2990	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2991	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2992	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2993	</p>
				2994
				2995	<h5>Semantics:</h5>
				2996
				2997	<p>
				2998	The result is the value at the position in the aggregate specified by
				2999	the index operands.
				3000	</p>
				3001
				3002	<h5>Example:</h5>
				3003
				3004	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3005	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3006	</pre>
				3007	</div>
				3008
				3009
				3010	<!-- _______________________________________________________________________ -->
				3011	<div class="doc_subsubsection">
				3012	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3013	</div>
				3014
				3015	<div class="doc_text">
				3016
				3017	<h5>Syntax:</h5>
				3018
				3019	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3020	<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]	3021	</pre>
				3022
				3023	<h5>Overview:</h5>
				3024
				3025	<p>
				3026	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3027	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3028	</p>
				3029
				3030
				3031	<h5>Arguments:</h5>
				3032
				3033	<p>
				3034	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3035	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3036	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3037	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3038	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]	3039	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3040	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3041	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]	3042	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3043
				3044	<h5>Semantics:</h5>
				3045
				3046	<p>
				3047	The result is an aggregate of the same type as <tt>val</tt>. Its
				3048	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]	3049	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3050	</p>
				3051
				3052	<h5>Example:</h5>
				3053
				3054	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3055	%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]	3056	</pre>
				3057	</div>
				3058
				3059
				3060	<!-- ======================================================================= -->
				3061	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3062	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3063	</div>
				3064
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3065	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3066
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3067	<p>A key design point of an SSA-based representation is how it
				3068	represents memory. In LLVM, no memory locations are in SSA form, which
				3069	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3070	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3071
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3072	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3073
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3074	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3075	<div class="doc_subsubsection">
				3076	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3077	</div>
				3078
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3079	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3080
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3081	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3082
				3083	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3084	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3085	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3086
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3087	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3088
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3089	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3090	heap and returns a pointer to it. The object is always allocated in the generic
				3091	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3092
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3093	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3094
				3095	<p>The '<tt>malloc</tt>' instruction allocates
				3096	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3097	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]	3098	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3099	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3100	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]	3101	be aligned to at least that boundary. If not specified, or if zero, the target can
				3102	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3103
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3104	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3105
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3106	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3107
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3108	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3109	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3110	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3111
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3112	<h5>Example:</h5>
				3113
				3114	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3115	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3116
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3117	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3118	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3119	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3120	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3121	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3122	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3123	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3124
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3125	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3126	<div class="doc_subsubsection">
				3127	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3128	</div>
				3129
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3130	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3131
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3132	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3133
				3134	<pre>
				3135	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3136	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3137
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3138	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3139
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3140	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3141	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3142
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3143	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3144
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3145	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3146	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3147	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3148
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3149	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3150
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3151	<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]	3152	after this instruction executes. If the pointer is null, the operation
				3153	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3154
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3155	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3156
				3157	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3158	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3159	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3160	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3161	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3162
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3163	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3164	<div class="doc_subsubsection">
				3165	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3166	</div>
				3167
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3168	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3169
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3170	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3171
				3172	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3173	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3174	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3175
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3176	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3177
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3178	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3179	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3180	returns to its caller. The object is always allocated in the generic address
				3181	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3182
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3183	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3184
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3185	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3186	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3187	appropriate type to the program. If "NumElements" is specified, it is the
				3188	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3189	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]	3190	to be aligned to at least that boundary. If not specified, or if zero, the target
				3191	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3192
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3193	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3194
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3195	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3196
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3197	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3198	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3199	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3200	instruction is commonly used to represent automatic variables that must
				3201	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]	3202	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]	3203	instructions), the memory is reclaimed. Allocating zero bytes
				3204	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3205
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3206	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3207
				3208	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3209	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3210	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3211	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3212	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3213	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3214	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3215
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3216	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3217	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3218	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3219	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3220	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3221	<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]	3222	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3223	<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]	3224	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3225	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3226	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3227	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]	3228	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]	3229	the number or order of execution of this <tt>load</tt> with other
				3230	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3231	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3232	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3233	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3234	(that is, the alignment of the memory address). A value of 0 or an
				3235	omitted "align" argument means that the operation has the preferential
				3236	alignment for the target. It is the responsibility of the code emitter
				3237	to ensure that the alignment information is correct. Overestimating
				3238	the alignment results in an undefined behavior. Underestimating the
				3239	alignment may produce less efficient code. An alignment of 1 is always
				3240	safe.
				3241	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3242	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3243	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3244	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3245	<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]	3246	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3247	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3248	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3249	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3250	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3251	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3252	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3253	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3254	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3255	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3256	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3257	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3258	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3259	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3260	<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]	3261	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3262	<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]	3263	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]	3264	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3265	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3266	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]	3267	optimizer is not allowed to modify the number or order of execution of
				3268	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3269	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3270	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3271	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3272	(that is, the alignment of the memory address). A value of 0 or an
				3273	omitted "align" argument means that the operation has the preferential
				3274	alignment for the target. It is the responsibility of the code emitter
				3275	to ensure that the alignment information is correct. Overestimating
				3276	the alignment results in an undefined behavior. Underestimating the
				3277	alignment may produce less efficient code. An alignment of 1 is always
				3278	safe.
				3279	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3280	<h5>Semantics:</h5>
				3281	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3282	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3283	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3284	<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]	3285	store i32 3, i32* %ptr <i>; yields {void}</i>
				3286	%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]	3287	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3288	</div>
				3289
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3290	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3291	<div class="doc_subsubsection">
				3292	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3293	</div>
				3294
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3295	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3296	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3297	<pre>
				3298	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3299	</pre>
				3300
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3301	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3302
				3303	<p>
				3304	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3305	subelement of an aggregate data structure.</p>
				3306
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3307	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3308
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3309	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3310	elements of the aggregate object to index to. The actual types of the arguments
				3311	provided depend on the type of the first pointer argument. The
				3312	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3313	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]	3314	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3315	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3316	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3317
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3318	<p>For example, let's consider a C code fragment and how it gets
				3319	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3320
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3321	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3322	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3323	struct RT {
				3324	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3325	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3326	char C;
				3327	};
				3328	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3329	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3330	double Y;
				3331	struct RT Z;
				3332	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3333
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3334	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3335	return &s[1].Z.B[5][13];
				3336	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3337	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3338	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3339
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3340	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3341
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3342	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3343	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3344	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3345	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3346
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3347	define i32* %foo(%ST* %s) {
				3348	entry:
				3349	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3350	ret i32* %reg
				3351	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3352	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3353	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3354
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3355	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3356
				3357	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3358	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]	3359	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]	3360	<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]	3361	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3362	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3363
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3364	<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]	3365	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]	3366	}</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]	3367	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3368	i8 }</tt>' type, another structure. The third index indexes into the second
				3369	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]	3370	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3371	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3372	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]	3373
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3374	<p>Note that it is perfectly legal to index partially through a
				3375	structure, returning a pointer to an inner element. Because of this,
				3376	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3377
				3378	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3379	define i32* %foo(%ST* %s) {
				3380	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3381	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3382	%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]	3383	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3384	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3385	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3386	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3387	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3388
				3389	<p>Note that it is undefined to access an array out of bounds: array and
				3390	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]	3391	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]	3392	defined to be accessible as variable length arrays, which requires access
				3393	beyond the zero'th element.</p>
				3394
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3395	<p>The getelementptr instruction is often confusing. For some more insight
				3396	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3397	FAQ</a>.</p>
				3398
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3399	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3400
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3401	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3402	<i>; yields [12 x i8]*:aptr</i>
				3403	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3404	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3405	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3406
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3407	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3408	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3409	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3410	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3411	<p>The instructions in this category are the conversion instructions (casting)
				3412	which all take a single operand and a type. They perform various bit conversions
				3413	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3414	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3415
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3416	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3417	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3418	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3419	</div>
				3420	<div class="doc_text">
				3421
				3422	<h5>Syntax:</h5>
				3423	<pre>
				3424	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3425	</pre>
				3426
				3427	<h5>Overview:</h5>
				3428	<p>
				3429	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3430	</p>
				3431
				3432	<h5>Arguments:</h5>
				3433	<p>
				3434	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3435	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]	3436	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]	3437	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3438	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3439
				3440	<h5>Semantics:</h5>
				3441	<p>
				3442	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]	3443	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3444	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3445	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3446
				3447	<h5>Example:</h5>
				3448	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3449	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3450	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3451	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3452	</pre>
				3453	</div>
				3454
				3455	<!-- _______________________________________________________________________ -->
				3456	<div class="doc_subsubsection">
				3457	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3458	</div>
				3459	<div class="doc_text">
				3460
				3461	<h5>Syntax:</h5>
				3462	<pre>
				3463	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3464	</pre>
				3465
				3466	<h5>Overview:</h5>
				3467	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3468	<tt>ty2</tt>.</p>
				3469
				3470
				3471	<h5>Arguments:</h5>
				3472	<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]	3473	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3474	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]	3475	<tt>value</tt> must be smaller than the bit size of the destination type,
				3476	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3477
				3478	<h5>Semantics:</h5>
				3479	<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]	3480	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]	3481
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3482	<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]	3483
				3484	<h5>Example:</h5>
				3485	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3486	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3487	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3488	</pre>
				3489	</div>
				3490
				3491	<!-- _______________________________________________________________________ -->
				3492	<div class="doc_subsubsection">
				3493	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3494	</div>
				3495	<div class="doc_text">
				3496
				3497	<h5>Syntax:</h5>
				3498	<pre>
				3499	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3500	</pre>
				3501
				3502	<h5>Overview:</h5>
				3503	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3504
				3505	<h5>Arguments:</h5>
				3506	<p>
				3507	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]	3508	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3509	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]	3510	<tt>value</tt> must be smaller than the bit size of the destination type,
				3511	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3512
				3513	<h5>Semantics:</h5>
				3514	<p>
				3515	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3516	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]	3517	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3518
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3519	<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]	3520
				3521	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3522	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3523	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3524	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3525	</pre>
				3526	</div>
				3527
				3528	<!-- _______________________________________________________________________ -->
				3529	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3530	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3531	</div>
				3532
				3533	<div class="doc_text">
				3534
				3535	<h5>Syntax:</h5>
				3536
				3537	<pre>
				3538	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3539	</pre>
				3540
				3541	<h5>Overview:</h5>
				3542	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3543	<tt>ty2</tt>.</p>
				3544
				3545
				3546	<h5>Arguments:</h5>
				3547	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3548	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3549	cast it to. The size of <tt>value</tt> must be larger than the size of
				3550	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3551	<i>no-op cast</i>.</p>
				3552
				3553	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3554	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3555	<a href="#t_floating">floating point</a> type to a smaller
				3556	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3557	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3558
				3559	<h5>Example:</h5>
				3560	<pre>
				3561	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3562	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3563	</pre>
				3564	</div>
				3565
				3566	<!-- _______________________________________________________________________ -->
				3567	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3568	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3569	</div>
				3570	<div class="doc_text">
				3571
				3572	<h5>Syntax:</h5>
				3573	<pre>
				3574	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3575	</pre>
				3576
				3577	<h5>Overview:</h5>
				3578	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3579	floating point value.</p>
				3580
				3581	<h5>Arguments:</h5>
				3582	<p>The '<tt>fpext</tt>' instruction takes a
				3583	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3584	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3585	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3586
				3587	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3588	<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]	3589	<a href="#t_floating">floating point</a> type to a larger
				3590	<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]	3591	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]	3592	<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]	3593
				3594	<h5>Example:</h5>
				3595	<pre>
				3596	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3597	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3598	</pre>
				3599	</div>
				3600
				3601	<!-- _______________________________________________________________________ -->
				3602	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3603	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3604	</div>
				3605	<div class="doc_text">
				3606
				3607	<h5>Syntax:</h5>
				3608	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3609	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3610	</pre>
				3611
				3612	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3613	<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]	3614	unsigned integer equivalent of type <tt>ty2</tt>.
				3615	</p>
				3616
				3617	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3618	<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]	3619	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3620	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3621	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3622	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]	3623
				3624	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3625	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3626	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3627	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3628	the results are undefined.</p>
				3629
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3630	<h5>Example:</h5>
				3631	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3632	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3633	%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]	3634	%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]	3635	</pre>
				3636	</div>
				3637
				3638	<!-- _______________________________________________________________________ -->
				3639	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3640	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3641	</div>
				3642	<div class="doc_text">
				3643
				3644	<h5>Syntax:</h5>
				3645	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3646	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3647	</pre>
				3648
				3649	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3650	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3651	<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]	3652	</p>
				3653
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3654	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3655	<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]	3656	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3657	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3658	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3659	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]	3660
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3661	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3662	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3663	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3664	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3665	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3666
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3667	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3668	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3669	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3670	%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]	3671	%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]	3672	</pre>
				3673	</div>
				3674
				3675	<!-- _______________________________________________________________________ -->
				3676	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3677	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3678	</div>
				3679	<div class="doc_text">
				3680
				3681	<h5>Syntax:</h5>
				3682	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3683	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3684	</pre>
				3685
				3686	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3687	<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]	3688	integer and converts that value to the <tt>ty2</tt> type.</p>
				3689
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3690	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3691	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3692	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3693	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3694	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3695	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]	3696
				3697	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3698	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3699	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3700	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]	3701
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3702	<h5>Example:</h5>
				3703	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3704	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3705	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3706	</pre>
				3707	</div>
				3708
				3709	<!-- _______________________________________________________________________ -->
				3710	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3711	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3712	</div>
				3713	<div class="doc_text">
				3714
				3715	<h5>Syntax:</h5>
				3716	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3717	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3718	</pre>
				3719
				3720	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3721	<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]	3722	integer and converts that value to the <tt>ty2</tt> type.</p>
				3723
				3724	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3725	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3726	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3727	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3728	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3729	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]	3730
				3731	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3732	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3733	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3734	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]	3735
				3736	<h5>Example:</h5>
				3737	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3738	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3739	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3740	</pre>
				3741	</div>
				3742
				3743	<!-- _______________________________________________________________________ -->
				3744	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3745	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3746	</div>
				3747	<div class="doc_text">
				3748
				3749	<h5>Syntax:</h5>
				3750	<pre>
				3751	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3752	</pre>
				3753
				3754	<h5>Overview:</h5>
				3755	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3756	the integer type <tt>ty2</tt>.</p>
				3757
				3758	<h5>Arguments:</h5>
				3759	<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]	3760	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]	3761	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3762
				3763	<h5>Semantics:</h5>
				3764	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3765	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3766	truncating or zero extending that value to the size of the integer type. If
				3767	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3768	<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]	3769	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3770	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3771
				3772	<h5>Example:</h5>
				3773	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3774	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3775	%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]	3776	</pre>
				3777	</div>
				3778
				3779	<!-- _______________________________________________________________________ -->
				3780	<div class="doc_subsubsection">
				3781	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3782	</div>
				3783	<div class="doc_text">
				3784
				3785	<h5>Syntax:</h5>
				3786	<pre>
				3787	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3788	</pre>
				3789
				3790	<h5>Overview:</h5>
				3791	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3792	a pointer type, <tt>ty2</tt>.</p>
				3793
				3794	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3795	<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]	3796	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]	3797	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3798
				3799	<h5>Semantics:</h5>
				3800	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3801	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3802	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3803	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3804	the size of a pointer then a zero extension is done. If they are the same size,
				3805	nothing is done (<i>no-op cast</i>).</p>
				3806
				3807	<h5>Example:</h5>
				3808	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3809	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3810	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3811	%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]	3812	</pre>
				3813	</div>
				3814
				3815	<!-- _______________________________________________________________________ -->
				3816	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3817	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3818	</div>
				3819	<div class="doc_text">
				3820
				3821	<h5>Syntax:</h5>
				3822	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3823	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3824	</pre>
				3825
				3826	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3827
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3828	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3829	<tt>ty2</tt> without changing any bits.</p>
				3830
				3831	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3832
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3833	<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]	3834	a non-aggregate first class value, and a type to cast it to, which must also be
				3835	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3836	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	3837	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]	3838	type is a pointer, the destination type must also be a pointer. This
				3839	instruction supports bitwise conversion of vectors to integers and to vectors
				3840	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3841
				3842	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3843	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3844	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3845	this conversion. The conversion is done as if the <tt>value</tt> had been
				3846	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3847	converted to other pointer types with this instruction. To convert pointers to
				3848	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3849	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3850
				3851	<h5>Example:</h5>
				3852	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3853	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3854	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3855	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3856	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3857	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3858
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3859	<!-- ======================================================================= -->
				3860	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3861	<div class="doc_text">
				3862	<p>The instructions in this category are the "miscellaneous"
				3863	instructions, which defy better classification.</p>
				3864	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3865
				3866	<!-- _______________________________________________________________________ -->
				3867	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3868	</div>
				3869	<div class="doc_text">
				3870	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3871	<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]	3872	</pre>
				3873	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3874	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3875	a vector of boolean values based on comparison
				3876	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3877	<h5>Arguments:</h5>
				3878	<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]	3879	the condition code indicating the kind of comparison to perform. It is not
				3880	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3881	<ol>
				3882	<li><tt>eq</tt>: equal</li>
				3883	<li><tt>ne</tt>: not equal </li>
				3884	<li><tt>ugt</tt>: unsigned greater than</li>
				3885	<li><tt>uge</tt>: unsigned greater or equal</li>
				3886	<li><tt>ult</tt>: unsigned less than</li>
				3887	<li><tt>ule</tt>: unsigned less or equal</li>
				3888	<li><tt>sgt</tt>: signed greater than</li>
				3889	<li><tt>sge</tt>: signed greater or equal</li>
				3890	<li><tt>slt</tt>: signed less than</li>
				3891	<li><tt>sle</tt>: signed less or equal</li>
				3892	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3893	<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]	3894	<a href="#t_pointer">pointer</a>
				3895	or integer <a href="#t_vector">vector</a> typed.
				3896	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3897	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3898	<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]	3899	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3900	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]	3901	<ol>
				3902	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3903	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3904	</li>
				3905	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3906	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3907	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3908	<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]	3909	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3910	<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]	3911	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3912	<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]	3913	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3914	<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]	3915	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3916	<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]	3917	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3918	<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]	3919	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3920	<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]	3921	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3922	<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]	3923	</ol>
				3924	<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]	3925	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3926	<p>If the operands are integer vectors, then they are compared
				3927	element by element. The result is an <tt>i1</tt> vector with
				3928	the same number of elements as the values being compared.
				3929	Otherwise, the result is an <tt>i1</tt>.
				3930	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3931
				3932	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3933	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3934	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3935	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3936	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3937	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3938	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3939	</pre>
				3940	</div>
				3941
				3942	<!-- _______________________________________________________________________ -->
				3943	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3944	</div>
				3945	<div class="doc_text">
				3946	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3947	<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]	3948	</pre>
				3949	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3950	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3951	or vector of boolean values based on comparison
				3952	of its operands.
				3953	<p>
				3954	If the operands are floating point scalars, then the result
				3955	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3956	</p>
				3957	<p>If the operands are floating point vectors, then the result type
				3958	is a vector of boolean with the same number of elements as the
				3959	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3960	<h5>Arguments:</h5>
				3961	<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]	3962	the condition code indicating the kind of comparison to perform. It is not
				3963	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3964	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3965	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3966	<li><tt>oeq</tt>: ordered and equal</li>
				3967	<li><tt>ogt</tt>: ordered and greater than </li>
				3968	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3969	<li><tt>olt</tt>: ordered and less than </li>
				3970	<li><tt>ole</tt>: ordered and less than or equal</li>
				3971	<li><tt>one</tt>: ordered and not equal</li>
				3972	<li><tt>ord</tt>: ordered (no nans)</li>
				3973	<li><tt>ueq</tt>: unordered or equal</li>
				3974	<li><tt>ugt</tt>: unordered or greater than </li>
				3975	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3976	<li><tt>ult</tt>: unordered or less than </li>
				3977	<li><tt>ule</tt>: unordered or less than or equal</li>
				3978	<li><tt>une</tt>: unordered or not equal</li>
				3979	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3980	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3981	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3982	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3983	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3984	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				3985	either a <a href="#t_floating">floating point</a> type
				3986	or a <a href="#t_vector">vector</a> of floating point type.
				3987	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3988	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3989	<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]	3990	according to the condition code given as <tt>cond</tt>.
				3991	If the operands are vectors, then the vectors are compared
				3992	element by element.
				3993	Each comparison performed
				3994	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3995	<ol>
				3996	<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]	3997	<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]	3998	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3999	<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]	4000	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4001	<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]	4002	<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]	4003	<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]	4004	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4005	<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]	4006	<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]	4007	<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]	4008	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4009	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4010	<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]	4011	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4012	<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]	4013	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4014	<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]	4015	<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]	4016	<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]	4017	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4018	<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]	4019	<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]	4020	<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]	4021	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4022	<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]	4023	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4024	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4025
				4026	<h5>Example:</h5>
				4027	<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]	4028	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4029	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4030	<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]	4031	</pre>
				4032	</div>
				4033
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4034	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4035	<div class="doc_subsubsection">
				4036	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4037	</div>
				4038	<div class="doc_text">
				4039	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4040	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4041	</pre>
				4042	<h5>Overview:</h5>
				4043	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4044	element-wise comparison of its two integer vector operands.</p>
				4045	<h5>Arguments:</h5>
				4046	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4047	the condition code indicating the kind of comparison to perform. It is not
				4048	a value, just a keyword. The possible condition code are:
				4049	<ol>
				4050	<li><tt>eq</tt>: equal</li>
				4051	<li><tt>ne</tt>: not equal </li>
				4052	<li><tt>ugt</tt>: unsigned greater than</li>
				4053	<li><tt>uge</tt>: unsigned greater or equal</li>
				4054	<li><tt>ult</tt>: unsigned less than</li>
				4055	<li><tt>ule</tt>: unsigned less or equal</li>
				4056	<li><tt>sgt</tt>: signed greater than</li>
				4057	<li><tt>sge</tt>: signed greater or equal</li>
				4058	<li><tt>slt</tt>: signed less than</li>
				4059	<li><tt>sle</tt>: signed less or equal</li>
				4060	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4061	<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]	4062	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4063	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4064	<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]	4065	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4066	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4067	identical type as the values being compared. The most significant bit in each
				4068	element is 1 if the element-wise comparison evaluates to true, and is 0
				4069	otherwise. All other bits of the result are undefined. The condition codes
				4070	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4071	instruction</a>.
				4072
				4073	<h5>Example:</h5>
				4074	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4075	<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>
				4076	<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]	4077	</pre>
				4078	</div>
				4079
				4080	<!-- _______________________________________________________________________ -->
				4081	<div class="doc_subsubsection">
				4082	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4083	</div>
				4084	<div class="doc_text">
				4085	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4086	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4087	<h5>Overview:</h5>
				4088	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4089	element-wise comparison of its two floating point vector operands. The output
				4090	elements have the same width as the input elements.</p>
				4091	<h5>Arguments:</h5>
				4092	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4093	the condition code indicating the kind of comparison to perform. It is not
				4094	a value, just a keyword. The possible condition code are:
				4095	<ol>
				4096	<li><tt>false</tt>: no comparison, always returns false</li>
				4097	<li><tt>oeq</tt>: ordered and equal</li>
				4098	<li><tt>ogt</tt>: ordered and greater than </li>
				4099	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4100	<li><tt>olt</tt>: ordered and less than </li>
				4101	<li><tt>ole</tt>: ordered and less than or equal</li>
				4102	<li><tt>one</tt>: ordered and not equal</li>
				4103	<li><tt>ord</tt>: ordered (no nans)</li>
				4104	<li><tt>ueq</tt>: unordered or equal</li>
				4105	<li><tt>ugt</tt>: unordered or greater than </li>
				4106	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4107	<li><tt>ult</tt>: unordered or less than </li>
				4108	<li><tt>ule</tt>: unordered or less than or equal</li>
				4109	<li><tt>une</tt>: unordered or not equal</li>
				4110	<li><tt>uno</tt>: unordered (either nans)</li>
				4111	<li><tt>true</tt>: no comparison, always returns true</li>
				4112	</ol>
				4113	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4114	<a href="#t_floating">floating point</a> typed. They must also be identical
				4115	types.</p>
				4116	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4117	<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]	4118	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4119	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4120	an identical number of elements as the values being compared, and each element
				4121	having identical with to the width of the floating point elements. The most
				4122	significant bit in each element is 1 if the element-wise comparison evaluates to
				4123	true, and is 0 otherwise. All other bits of the result are undefined. The
				4124	condition codes are evaluated identically to the
				4125	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4126
				4127	<h5>Example:</h5>
				4128	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4129	<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>
				4130	<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]	4131	</pre>
				4132	</div>
				4133
				4134	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4135	<div class="doc_subsubsection">
				4136	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4137	</div>
				4138
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4139	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4140
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4141	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4142
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4143	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4144	<h5>Overview:</h5>
				4145	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4146	the SSA graph representing the function.</p>
				4147	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4148
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4149	<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]	4150	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4151	as arguments, with one pair for each predecessor basic block of the
				4152	current block. Only values of <a href="#t_firstclass">first class</a>
				4153	type may be used as the value arguments to the PHI node. Only labels
				4154	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4155
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4156	<p>There must be no non-phi instructions between the start of a basic
				4157	block and the PHI instructions: i.e. PHI instructions must be first in
				4158	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4159
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4160	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4161
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4162	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4163	specified by the pair corresponding to the predecessor basic block that executed
				4164	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4165
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4166	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4167	<pre>
				4168	Loop: ; Infinite loop that counts from 0 on up...
				4169	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4170	%nextindvar = add i32 %indvar, 1
				4171	br label %Loop
				4172	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4173	</div>
				4174
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4175	<!-- _______________________________________________________________________ -->
				4176	<div class="doc_subsubsection">
				4177	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4178	</div>
				4179
				4180	<div class="doc_text">
				4181
				4182	<h5>Syntax:</h5>
				4183
				4184	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4185	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4186
				4187	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4188	</pre>
				4189
				4190	<h5>Overview:</h5>
				4191
				4192	<p>
				4193	The '<tt>select</tt>' instruction is used to choose one value based on a
				4194	condition, without branching.
				4195	</p>
				4196
				4197
				4198	<h5>Arguments:</h5>
				4199
				4200	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4201	The '<tt>select</tt>' instruction requires an 'i1' value or
				4202	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4203	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]	4204	type. If the val1/val2 are vectors and
				4205	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4206	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4207	</p>
				4208
				4209	<h5>Semantics:</h5>
				4210
				4211	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4212	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]	4213	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4214	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4215	<p>
				4216	If the condition is a vector of i1, then the value arguments must
				4217	be vectors of the same size, and the selection is done element
				4218	by element.
				4219	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4220
				4221	<h5>Example:</h5>
				4222
				4223	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4224	%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]	4225	</pre>
				4226	</div>
				4227
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4228
				4229	<!-- _______________________________________________________________________ -->
				4230	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4231	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4232	</div>
				4233
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4234	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4235
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4236	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4237	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4238	<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]	4239	</pre>
				4240
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4241	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4242
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4243	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4244
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4245	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4246
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4247	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4248
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4249	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4250	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4251	<p>The optional "tail" marker indicates whether the callee function accesses
				4252	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]	4253	function call is eligible for tail call optimization. Note that calls may
				4254	be marked "tail" even if they do not occur before a <a
				4255	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4256	</li>
				4257	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4258	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4259	convention</a> the call should use. If none is specified, the call defaults
				4260	to using C calling conventions.
				4261	</li>
				4262	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4263	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4264	the type of the return value. Functions that return no value are marked
				4265	<tt><a href="#t_void">void</a></tt>.</p>
				4266	</li>
				4267	<li>
				4268	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4269	value being invoked. The argument types must match the types implied by
				4270	this signature. This type can be omitted if the function is not varargs
				4271	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]	4272	</li>
				4273	<li>
				4274	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4275	be invoked. In most cases, this is a direct function invocation, but
				4276	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]	4277	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4278	</li>
				4279	<li>
				4280	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4281	function signature argument types. All arguments must be of
				4282	<a href="#t_firstclass">first class</a> type. If the function signature
				4283	indicates the function accepts a variable number of arguments, the extra
				4284	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4285	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4286	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4287
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4288	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4289
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4290	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4291	transfer to a specified function, with its incoming arguments bound to
				4292	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4293	instruction in the called function, control flow continues with the
				4294	instruction after the function call, and the return value of the
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4295	function is bound to the result argument.
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4296
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4297	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4298
				4299	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4300	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4301	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4302	%X = tail call i32 @foo() <i>; yields i32</i>
				4303	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4304	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4305
				4306	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4307	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4308	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4309	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4310	</pre>
				4311
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4312	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4313
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4314	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4315	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4316	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4317	</div>
				4318
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4319	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4320
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4321	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4322
				4323	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4324	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4325	</pre>
				4326
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4327	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4328
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4329	<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]	4330	the "variable argument" area of a function call. It is used to implement the
				4331	<tt>va_arg</tt> macro in C.</p>
				4332
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4333	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4334
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4335	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4336	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4337	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]	4338	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4339
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4340	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4341
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4342	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4343	type from the specified <tt>va_list</tt> and causes the
				4344	<tt>va_list</tt> to point to the next argument. For more information,
				4345	see the variable argument handling <a href="#int_varargs">Intrinsic
				4346	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4347
				4348	<p>It is legal for this instruction to be called in a function which does not
				4349	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4350	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4351
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4352	<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]	4353	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4354	argument.</p>
				4355
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4356	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4357
				4358	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4359
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4360	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4361
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4362	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4363	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4364	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4365
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4366	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4367
				4368	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4369	well known names and semantics and are required to follow certain restrictions.
				4370	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4371	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]	4372	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]	4373
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4374	<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]	4375	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4376	begin with this prefix. Intrinsic functions must always be external functions:
				4377	you cannot define the body of intrinsic functions. Intrinsic functions may
				4378	only be used in call or invoke instructions: it is illegal to take the address
				4379	of an intrinsic function. Additionally, because intrinsic functions are part
				4380	of the LLVM language, it is required if any are added that they be documented
				4381	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4382
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4383	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4384	a family of functions that perform the same operation but on different data
				4385	types. Because LLVM can represent over 8 million different integer types,
				4386	overloading is used commonly to allow an intrinsic function to operate on any
				4387	integer type. One or more of the argument types or the result type can be
				4388	overloaded to accept any integer type. Argument types may also be defined as
				4389	exactly matching a previous argument's type or the result type. This allows an
				4390	intrinsic function which accepts multiple arguments, but needs all of them to
				4391	be of the same type, to only be overloaded with respect to a single argument or
				4392	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4393
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4394	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4395	encoded into its function name, each preceded by a period. Only those types
				4396	which are overloaded result in a name suffix. Arguments whose type is matched
				4397	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4398	take an integer of any width and returns an integer of exactly the same integer
				4399	width. This leads to a family of functions such as
				4400	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4401	Only one type, the return type, is overloaded, and only one type suffix is
				4402	required. Because the argument's type is matched against the return type, it
				4403	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4404
				4405	<p>To learn how to add an intrinsic function, please see the
				4406	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4407	</p>
				4408
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4409	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4410
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4411	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4412	<div class="doc_subsection">
				4413	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4414	</div>
				4415
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4416	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4417
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4418	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4419	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]	4420	intrinsic functions. These functions are related to the similarly
				4421	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4422
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4423	<p>All of these functions operate on arguments that use a
				4424	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4425	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4426	transformations should be prepared to handle these functions regardless of
				4427	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4428
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4429	<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]	4430	instruction and the variable argument handling intrinsic functions are
				4431	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4432
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4433	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4434	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4435	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4436	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4437	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4438	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4439	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4440
				4441	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4442	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4443
				4444	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4445	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4446	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4447	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4448	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4449
				4450	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4451	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4452	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4453	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4454
				4455	declare void @llvm.va_start(i8*)
				4456	declare void @llvm.va_copy(i8, i8)
				4457	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4458	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4459	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4460
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4461	</div>
				4462
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4463	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4464	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4465	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4466	</div>
				4467
				4468
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4469	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4470	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4471	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4472	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4473	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4474	<tt>*<arglist></tt> for subsequent use by <tt><a
				4475	href="#i_va_arg">va_arg</a></tt>.</p>
				4476
				4477	<h5>Arguments:</h5>
				4478
				4479	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4480
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4481	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4482
				4483	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4484	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4485	<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]	4486	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4487	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]	4488	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]	4489
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4490	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4491
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4492	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4493	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4494	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4495	</div>
				4496
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4497	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4498	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4499	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4500	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4501
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4502	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4503	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]	4504	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]	4505
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4506	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4507
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4508	<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]	4509
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4510	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4511
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4512	<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]	4513	macro available in C. In a target-dependent way, it destroys the
				4514	<tt>va_list</tt> element to which the argument points. Calls to <a
				4515	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4516	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4517	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4518
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4519	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4520
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4521	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4522	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4523	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4524	</div>
				4525
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4526	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4527
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4528	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4529
				4530	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4531	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4532	</pre>
				4533
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4534	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4535
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4536	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4537	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4538
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4539	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4540
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4541	<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]	4542	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]	4543
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4544
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4545	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4546
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4547	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4548	macro available in C. In a target-dependent way, it copies the source
				4549	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4550	intrinsic is necessary because the <tt><a href="#int_va_start">
				4551	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4552	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4553
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4554	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4555
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4556	<!-- ======================================================================= -->
				4557	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4558	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4559	</div>
				4560
				4561	<div class="doc_text">
				4562
				4563	<p>
				4564	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4565	Collection</a> (GC) requires the implementation and generation of these
				4566	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4567	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]	4568	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4569	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]	4570	Front-ends for type-safe garbage collected languages should generate these
				4571	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4572	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4573	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4574
				4575	<p>The garbage collection intrinsics only operate on objects in the generic
				4576	address space (address space zero).</p>
				4577
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4578	</div>
				4579
				4580	<!-- _______________________________________________________________________ -->
				4581	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4582	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4583	</div>
				4584
				4585	<div class="doc_text">
				4586
				4587	<h5>Syntax:</h5>
				4588
				4589	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4590	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4591	</pre>
				4592
				4593	<h5>Overview:</h5>
				4594
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4595	<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]	4596	the code generator, and allows some metadata to be associated with it.</p>
				4597
				4598	<h5>Arguments:</h5>
				4599
				4600	<p>The first argument specifies the address of a stack object that contains the
				4601	root pointer. The second pointer (which must be either a constant or a global
				4602	value address) contains the meta-data to be associated with the root.</p>
				4603
				4604	<h5>Semantics:</h5>
				4605
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4606	<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]	4607	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4608	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4609	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4610	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4611
				4612	</div>
				4613
				4614
				4615	<!-- _______________________________________________________________________ -->
				4616	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4617	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4618	</div>
				4619
				4620	<div class="doc_text">
				4621
				4622	<h5>Syntax:</h5>
				4623
				4624	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4625	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4626	</pre>
				4627
				4628	<h5>Overview:</h5>
				4629
				4630	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4631	locations, allowing garbage collector implementations that require read
				4632	barriers.</p>
				4633
				4634	<h5>Arguments:</h5>
				4635
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4636	<p>The second argument is the address to read from, which should be an address
				4637	allocated from the garbage collector. The first object is a pointer to the
				4638	start of the referenced object, if needed by the language runtime (otherwise
				4639	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4640
				4641	<h5>Semantics:</h5>
				4642
				4643	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4644	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4645	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4646	may only be used in a function which <a href="#gc">specifies a GC
				4647	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4648
				4649	</div>
				4650
				4651
				4652	<!-- _______________________________________________________________________ -->
				4653	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4654	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4655	</div>
				4656
				4657	<div class="doc_text">
				4658
				4659	<h5>Syntax:</h5>
				4660
				4661	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4662	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4663	</pre>
				4664
				4665	<h5>Overview:</h5>
				4666
				4667	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4668	locations, allowing garbage collector implementations that require write
				4669	barriers (such as generational or reference counting collectors).</p>
				4670
				4671	<h5>Arguments:</h5>
				4672
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4673	<p>The first argument is the reference to store, the second is the start of the
				4674	object to store it to, and the third is the address of the field of Obj to
				4675	store to. If the runtime does not require a pointer to the object, Obj may be
				4676	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4677
				4678	<h5>Semantics:</h5>
				4679
				4680	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4681	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4682	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4683	may only be used in a function which <a href="#gc">specifies a GC
				4684	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4685
				4686	</div>
				4687
				4688
				4689
				4690	<!-- ======================================================================= -->
				4691	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4692	<a name="int_codegen">Code Generator Intrinsics</a>
				4693	</div>
				4694
				4695	<div class="doc_text">
				4696	<p>
				4697	These intrinsics are provided by LLVM to expose special features that may only
				4698	be implemented with code generator support.
				4699	</p>
				4700
				4701	</div>
				4702
				4703	<!-- _______________________________________________________________________ -->
				4704	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4705	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4706	</div>
				4707
				4708	<div class="doc_text">
				4709
				4710	<h5>Syntax:</h5>
				4711	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4712	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4713	</pre>
				4714
				4715	<h5>Overview:</h5>
				4716
				4717	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4718	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4719	target-specific value indicating the return address of the current function
				4720	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4721	</p>
				4722
				4723	<h5>Arguments:</h5>
				4724
				4725	<p>
				4726	The argument to this intrinsic indicates which function to return the address
				4727	for. Zero indicates the calling function, one indicates its caller, etc. The
				4728	argument is <b>required</b> to be a constant integer value.
				4729	</p>
				4730
				4731	<h5>Semantics:</h5>
				4732
				4733	<p>
				4734	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4735	the return address of the specified call frame, or zero if it cannot be
				4736	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4737	for arguments other than zero, so it should only be used for debugging purposes.
				4738	</p>
				4739
				4740	<p>
				4741	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4742	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]	4743	source-language caller.
				4744	</p>
				4745	</div>
				4746
				4747
				4748	<!-- _______________________________________________________________________ -->
				4749	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4750	<a name="int_frameaddress">'<tt>llvm.frameaddress</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>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4757	declare i8 *@llvm.frameaddress(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.frameaddress</tt>' intrinsic attempts to return the
				4764	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4765	</p>
				4766
				4767	<h5>Arguments:</h5>
				4768
				4769	<p>
				4770	The argument to this intrinsic indicates which function to return the frame
				4771	pointer for. Zero indicates the calling function, one indicates its caller,
				4772	etc. The argument is <b>required</b> to be a constant integer value.
				4773	</p>
				4774
				4775	<h5>Semantics:</h5>
				4776
				4777	<p>
				4778	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4779	the frame address of the specified call frame, or zero if it cannot be
				4780	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4781	for arguments other than zero, so it should only be used for debugging purposes.
				4782	</p>
				4783
				4784	<p>
				4785	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4786	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]	4787	source-language caller.
				4788	</p>
				4789	</div>
				4790
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4791	<!-- _______________________________________________________________________ -->
				4792	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4793	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4794	</div>
				4795
				4796	<div class="doc_text">
				4797
				4798	<h5>Syntax:</h5>
				4799	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4800	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4801	</pre>
				4802
				4803	<h5>Overview:</h5>
				4804
				4805	<p>
				4806	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]	4807	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4808	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4809	features like scoped automatic variable sized arrays in C99.
				4810	</p>
				4811
				4812	<h5>Semantics:</h5>
				4813
				4814	<p>
				4815	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]	4816	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4817	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4818	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4819	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4820	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4821	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4822	</p>
				4823
				4824	</div>
				4825
				4826	<!-- _______________________________________________________________________ -->
				4827	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4828	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4829	</div>
				4830
				4831	<div class="doc_text">
				4832
				4833	<h5>Syntax:</h5>
				4834	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4835	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4836	</pre>
				4837
				4838	<h5>Overview:</h5>
				4839
				4840	<p>
				4841	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4842	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]	4843	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4844	useful for implementing language features like scoped automatic variable sized
				4845	arrays in C99.
				4846	</p>
				4847
				4848	<h5>Semantics:</h5>
				4849
				4850	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4851	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]	4852	</p>
				4853
				4854	</div>
				4855
				4856
				4857	<!-- _______________________________________________________________________ -->
				4858	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4859	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4860	</div>
				4861
				4862	<div class="doc_text">
				4863
				4864	<h5>Syntax:</h5>
				4865	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4866	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4867	</pre>
				4868
				4869	<h5>Overview:</h5>
				4870
				4871
				4872	<p>
				4873	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]	4874	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4875	no
				4876	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4877	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4878	</p>
				4879
				4880	<h5>Arguments:</h5>
				4881
				4882	<p>
				4883	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4884	determining if the fetch should be for a read (0) or write (1), and
				4885	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4886	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]	4887	<tt>locality</tt> arguments must be constant integers.
				4888	</p>
				4889
				4890	<h5>Semantics:</h5>
				4891
				4892	<p>
				4893	This intrinsic does not modify the behavior of the program. In particular,
				4894	prefetches cannot trap and do not produce a value. On targets that support this
				4895	intrinsic, the prefetch can provide hints to the processor cache for better
				4896	performance.
				4897	</p>
				4898
				4899	</div>
				4900
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4901	<!-- _______________________________________________________________________ -->
				4902	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4903	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4904	</div>
				4905
				4906	<div class="doc_text">
				4907
				4908	<h5>Syntax:</h5>
				4909	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4910	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4911	</pre>
				4912
				4913	<h5>Overview:</h5>
				4914
				4915
				4916	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4917	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]	4918	(PC) in a region of
				4919	code to simulators and other tools. The method is target specific, but it is
				4920	expected that the marker will use exported symbols to transmit the PC of the
				4921	marker.
				4922	The marker makes no guarantees that it will remain with any specific instruction
				4923	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]	4924	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4925	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4926	</p>
				4927
				4928	<h5>Arguments:</h5>
				4929
				4930	<p>
				4931	<tt>id</tt> is a numerical id identifying the marker.
				4932	</p>
				4933
				4934	<h5>Semantics:</h5>
				4935
				4936	<p>
				4937	This intrinsic does not modify the behavior of the program. Backends that do not
				4938	support this intrinisic may ignore it.
				4939	</p>
				4940
				4941	</div>
				4942
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4943	<!-- _______________________________________________________________________ -->
				4944	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4945	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4946	</div>
				4947
				4948	<div class="doc_text">
				4949
				4950	<h5>Syntax:</h5>
				4951	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4952	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4953	</pre>
				4954
				4955	<h5>Overview:</h5>
				4956
				4957
				4958	<p>
				4959	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4960	counter register (or similar low latency, high accuracy clocks) on those targets
				4961	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4962	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4963	should only be used for small timings.
				4964	</p>
				4965
				4966	<h5>Semantics:</h5>
				4967
				4968	<p>
				4969	When directly supported, reading the cycle counter should not modify any memory.
				4970	Implementations are allowed to either return a application specific value or a
				4971	system wide value. On backends without support, this is lowered to a constant 0.
				4972	</p>
				4973
				4974	</div>
				4975
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4976	<!-- ======================================================================= -->
				4977	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4978	<a name="int_libc">Standard C Library Intrinsics</a>
				4979	</div>
				4980
				4981	<div class="doc_text">
				4982	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4983	LLVM provides intrinsics for a few important standard C library functions.
				4984	These intrinsics allow source-language front-ends to pass information about the
				4985	alignment of the pointer arguments to the code generator, providing opportunity
				4986	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4987	</p>
				4988
				4989	</div>
				4990
				4991	<!-- _______________________________________________________________________ -->
				4992	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4993	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4994	</div>
				4995
				4996	<div class="doc_text">
				4997
				4998	<h5>Syntax:</h5>
				4999	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5000	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5001	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5002	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5003	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5004	</pre>
				5005
				5006	<h5>Overview:</h5>
				5007
				5008	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5009	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]	5010	location to the destination location.
				5011	</p>
				5012
				5013	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5014	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5015	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5016	</p>
				5017
				5018	<h5>Arguments:</h5>
				5019
				5020	<p>
				5021	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]	5022	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5023	specifying the number of bytes to copy, and the fourth argument is the alignment
				5024	of the source and destination locations.
				5025	</p>
				5026
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5027	<p>
				5028	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]	5029	the caller guarantees that both the source and destination pointers are aligned
				5030	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5031	</p>
				5032
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5033	<h5>Semantics:</h5>
				5034
				5035	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5036	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]	5037	location to the destination location, which are not allowed to overlap. It
				5038	copies "len" bytes of memory over. If the argument is known to be aligned to
				5039	some boundary, this can be specified as the fourth argument, otherwise it should
				5040	be set to 0 or 1.
				5041	</p>
				5042	</div>
				5043
				5044
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5045	<!-- _______________________________________________________________________ -->
				5046	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5047	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5048	</div>
				5049
				5050	<div class="doc_text">
				5051
				5052	<h5>Syntax:</h5>
				5053	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5054	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5055	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5056	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5057	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5058	</pre>
				5059
				5060	<h5>Overview:</h5>
				5061
				5062	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5063	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5064	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5065	'<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]	5066	</p>
				5067
				5068	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5069	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5070	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5071	</p>
				5072
				5073	<h5>Arguments:</h5>
				5074
				5075	<p>
				5076	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]	5077	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5078	specifying the number of bytes to copy, and the fourth argument is the alignment
				5079	of the source and destination locations.
				5080	</p>
				5081
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5082	<p>
				5083	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]	5084	the caller guarantees that the source and destination pointers are aligned to
				5085	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5086	</p>
				5087
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5088	<h5>Semantics:</h5>
				5089
				5090	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5091	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]	5092	location to the destination location, which may overlap. It
				5093	copies "len" bytes of memory over. If the argument is known to be aligned to
				5094	some boundary, this can be specified as the fourth argument, otherwise it should
				5095	be set to 0 or 1.
				5096	</p>
				5097	</div>
				5098
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5099
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5100	<!-- _______________________________________________________________________ -->
				5101	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5102	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5103	</div>
				5104
				5105	<div class="doc_text">
				5106
				5107	<h5>Syntax:</h5>
				5108	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5109	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5110	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5111	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5112	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5113	</pre>
				5114
				5115	<h5>Overview:</h5>
				5116
				5117	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5118	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]	5119	byte value.
				5120	</p>
				5121
				5122	<p>
				5123	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5124	does not return a value, and takes an extra alignment argument.
				5125	</p>
				5126
				5127	<h5>Arguments:</h5>
				5128
				5129	<p>
				5130	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]	5131	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5132	argument specifying the number of bytes to fill, and the fourth argument is the
				5133	known alignment of destination location.
				5134	</p>
				5135
				5136	<p>
				5137	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]	5138	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5139	</p>
				5140
				5141	<h5>Semantics:</h5>
				5142
				5143	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5144	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5145	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5146	destination location. If the argument is known to be aligned to some boundary,
				5147	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5148	1.
				5149	</p>
				5150	</div>
				5151
				5152
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5153	<!-- _______________________________________________________________________ -->
				5154	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5155	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5156	</div>
				5157
				5158	<div class="doc_text">
				5159
				5160	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5161	<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]	5162	floating point or vector of floating point type. Not all targets support all
				5163	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5164	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5165	declare float @llvm.sqrt.f32(float %Val)
				5166	declare double @llvm.sqrt.f64(double %Val)
				5167	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5168	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5169	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5170	</pre>
				5171
				5172	<h5>Overview:</h5>
				5173
				5174	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5175	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]	5176	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]	5177	<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]	5178	negative numbers other than -0.0 (which allows for better optimization, because
				5179	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5180	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5181	</p>
				5182
				5183	<h5>Arguments:</h5>
				5184
				5185	<p>
				5186	The argument and return value are floating point numbers of the same type.
				5187	</p>
				5188
				5189	<h5>Semantics:</h5>
				5190
				5191	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5192	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]	5193	floating point number.
				5194	</p>
				5195	</div>
				5196
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5197	<!-- _______________________________________________________________________ -->
				5198	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5199	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5200	</div>
				5201
				5202	<div class="doc_text">
				5203
				5204	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5205	<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]	5206	floating point or vector of floating point type. Not all targets support all
				5207	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5208	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5209	declare float @llvm.powi.f32(float %Val, i32 %power)
				5210	declare double @llvm.powi.f64(double %Val, i32 %power)
				5211	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5212	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5213	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5214	</pre>
				5215
				5216	<h5>Overview:</h5>
				5217
				5218	<p>
				5219	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5220	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5221	multiplications is not defined. When a vector of floating point type is
				5222	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5223	</p>
				5224
				5225	<h5>Arguments:</h5>
				5226
				5227	<p>
				5228	The second argument is an integer power, and the first is a value to raise to
				5229	that power.
				5230	</p>
				5231
				5232	<h5>Semantics:</h5>
				5233
				5234	<p>
				5235	This function returns the first value raised to the second power with an
				5236	unspecified sequence of rounding operations.</p>
				5237	</div>
				5238
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5239	<!-- _______________________________________________________________________ -->
				5240	<div class="doc_subsubsection">
				5241	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5242	</div>
				5243
				5244	<div class="doc_text">
				5245
				5246	<h5>Syntax:</h5>
				5247	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5248	floating point or vector of floating point type. Not all targets support all
				5249	types however.
				5250	<pre>
				5251	declare float @llvm.sin.f32(float %Val)
				5252	declare double @llvm.sin.f64(double %Val)
				5253	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5254	declare fp128 @llvm.sin.f128(fp128 %Val)
				5255	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5256	</pre>
				5257
				5258	<h5>Overview:</h5>
				5259
				5260	<p>
				5261	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5262	</p>
				5263
				5264	<h5>Arguments:</h5>
				5265
				5266	<p>
				5267	The argument and return value are floating point numbers of the same type.
				5268	</p>
				5269
				5270	<h5>Semantics:</h5>
				5271
				5272	<p>
				5273	This function returns the sine of the specified operand, returning the
				5274	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]	5275	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5276	</div>
				5277
				5278	<!-- _______________________________________________________________________ -->
				5279	<div class="doc_subsubsection">
				5280	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5281	</div>
				5282
				5283	<div class="doc_text">
				5284
				5285	<h5>Syntax:</h5>
				5286	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5287	floating point or vector of floating point type. Not all targets support all
				5288	types however.
				5289	<pre>
				5290	declare float @llvm.cos.f32(float %Val)
				5291	declare double @llvm.cos.f64(double %Val)
				5292	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5293	declare fp128 @llvm.cos.f128(fp128 %Val)
				5294	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5295	</pre>
				5296
				5297	<h5>Overview:</h5>
				5298
				5299	<p>
				5300	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5301	</p>
				5302
				5303	<h5>Arguments:</h5>
				5304
				5305	<p>
				5306	The argument and return value are floating point numbers of the same type.
				5307	</p>
				5308
				5309	<h5>Semantics:</h5>
				5310
				5311	<p>
				5312	This function returns the cosine of the specified operand, returning the
				5313	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]	5314	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5315	</div>
				5316
				5317	<!-- _______________________________________________________________________ -->
				5318	<div class="doc_subsubsection">
				5319	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5320	</div>
				5321
				5322	<div class="doc_text">
				5323
				5324	<h5>Syntax:</h5>
				5325	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5326	floating point or vector of floating point type. Not all targets support all
				5327	types however.
				5328	<pre>
				5329	declare float @llvm.pow.f32(float %Val, float %Power)
				5330	declare double @llvm.pow.f64(double %Val, double %Power)
				5331	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5332	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5333	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5334	</pre>
				5335
				5336	<h5>Overview:</h5>
				5337
				5338	<p>
				5339	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5340	specified (positive or negative) power.
				5341	</p>
				5342
				5343	<h5>Arguments:</h5>
				5344
				5345	<p>
				5346	The second argument is a floating point power, and the first is a value to
				5347	raise to that power.
				5348	</p>
				5349
				5350	<h5>Semantics:</h5>
				5351
				5352	<p>
				5353	This function returns the first value raised to the second power,
				5354	returning the
				5355	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]	5356	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5357	</div>
				5358
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5359
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5360	<!-- ======================================================================= -->
				5361	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5362	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5363	</div>
				5364
				5365	<div class="doc_text">
				5366	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5367	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5368	These allow efficient code generation for some algorithms.
				5369	</p>
				5370
				5371	</div>
				5372
				5373	<!-- _______________________________________________________________________ -->
				5374	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5375	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5376	</div>
				5377
				5378	<div class="doc_text">
				5379
				5380	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5381	<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]	5382	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]	5383	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5384	declare i16 @llvm.bswap.i16(i16 <id>)
				5385	declare i32 @llvm.bswap.i32(i32 <id>)
				5386	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5387	</pre>
				5388
				5389	<h5>Overview:</h5>
				5390
				5391	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5392	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]	5393	values with an even number of bytes (positive multiple of 16 bits). These are
				5394	useful for performing operations on data that is not in the target's native
				5395	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5396	</p>
				5397
				5398	<h5>Semantics:</h5>
				5399
				5400	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5401	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]	5402	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5403	intrinsic returns an i32 value that has the four bytes of the input i32
				5404	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]	5405	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5406	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5407	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5408	</p>
				5409
				5410	</div>
				5411
				5412	<!-- _______________________________________________________________________ -->
				5413	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5414	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5415	</div>
				5416
				5417	<div class="doc_text">
				5418
				5419	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5420	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5421	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5422	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5423	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5424	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5425	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5426	declare i64 @llvm.ctpop.i64(i64 <src>)
				5427	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5428	</pre>
				5429
				5430	<h5>Overview:</h5>
				5431
				5432	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5433	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5434	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5435	</p>
				5436
				5437	<h5>Arguments:</h5>
				5438
				5439	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5440	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]	5441	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5442	</p>
				5443
				5444	<h5>Semantics:</h5>
				5445
				5446	<p>
				5447	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5448	</p>
				5449	</div>
				5450
				5451	<!-- _______________________________________________________________________ -->
				5452	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5453	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5454	</div>
				5455
				5456	<div class="doc_text">
				5457
				5458	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5459	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5460	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5461	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5462	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5463	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5464	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5465	declare i64 @llvm.ctlz.i64(i64 <src>)
				5466	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5467	</pre>
				5468
				5469	<h5>Overview:</h5>
				5470
				5471	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5472	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5473	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5474	</p>
				5475
				5476	<h5>Arguments:</h5>
				5477
				5478	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5479	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]	5480	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5481	</p>
				5482
				5483	<h5>Semantics:</h5>
				5484
				5485	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5486	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5487	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]	5488	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5489	</p>
				5490	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5491
				5492
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5493
				5494	<!-- _______________________________________________________________________ -->
				5495	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5496	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5497	</div>
				5498
				5499	<div class="doc_text">
				5500
				5501	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5502	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5503	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5504	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5505	declare i8 @llvm.cttz.i8 (i8 <src>)
				5506	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5507	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5508	declare i64 @llvm.cttz.i64(i64 <src>)
				5509	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5510	</pre>
				5511
				5512	<h5>Overview:</h5>
				5513
				5514	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5515	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5516	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5517	</p>
				5518
				5519	<h5>Arguments:</h5>
				5520
				5521	<p>
				5522	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]	5523	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5524	</p>
				5525
				5526	<h5>Semantics:</h5>
				5527
				5528	<p>
				5529	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5530	in a variable. If the src == 0 then the result is the size in bits of the type
				5531	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5532	</p>
				5533	</div>
				5534
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5535	<!-- _______________________________________________________________________ -->
				5536	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5537	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5538	</div>
				5539
				5540	<div class="doc_text">
				5541
				5542	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5543	<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]	5544	on any integer bit width.
				5545	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5546	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5547	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5548	</pre>
				5549
				5550	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5551	<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]	5552	range of bits from an integer value and returns them in the same bit width as
				5553	the original value.</p>
				5554
				5555	<h5>Arguments:</h5>
				5556	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5557	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]	5558	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]	5559
				5560	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5561	<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]	5562	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5563	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5564	operates in forward mode.</p>
				5565	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5566	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]	5567	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5568	<ol>
				5569	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5570	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5571	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5572	to determine the number of bits to retain.</li>
				5573	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5574	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5575	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5576	<p>In reverse mode, a similar computation is made except that the bits are
				5577	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5578	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5579	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5580	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5581	</div>
				5582
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5583	<div class="doc_subsubsection">
				5584	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5585	</div>
				5586
				5587	<div class="doc_text">
				5588
				5589	<h5>Syntax:</h5>
				5590	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5591	on any integer bit width.
				5592	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5593	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5594	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]	5595	</pre>
				5596
				5597	<h5>Overview:</h5>
				5598	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5599	of bits in an integer value with another integer value. It returns the integer
				5600	with the replaced bits.</p>
				5601
				5602	<h5>Arguments:</h5>
				5603	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5604	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5605	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5606	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5607	type since they specify only a bit index.</p>
				5608
				5609	<h5>Semantics:</h5>
				5610	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5611	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5612	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5613	operates in forward mode.</p>
				5614	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5615	truncating it down to the size of the replacement area or zero extending it
				5616	up to that size.</p>
				5617	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5618	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5619	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5620	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5621	<p>In reverse mode, a similar computation is made except that the bits are
				5622	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5623	<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]	5624	<h5>Examples:</h5>
				5625	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5626	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5627	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5628	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5629	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5630	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5631	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5632	</div>
				5633
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5634	<!-- ======================================================================= -->
				5635	<div class="doc_subsection">
				5636	<a name="int_debugger">Debugger Intrinsics</a>
				5637	</div>
				5638
				5639	<div class="doc_text">
				5640	<p>
				5641	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5642	are described in the <a
				5643	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5644	Debugging</a> document.
				5645	</p>
				5646	</div>
				5647
				5648
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5649	<!-- ======================================================================= -->
				5650	<div class="doc_subsection">
				5651	<a name="int_eh">Exception Handling Intrinsics</a>
				5652	</div>
				5653
				5654	<div class="doc_text">
				5655	<p> The LLVM exception handling intrinsics (which all start with
				5656	<tt>llvm.eh.</tt> prefix), are described in the <a
				5657	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5658	Handling</a> document. </p>
				5659	</div>
				5660
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5661	<!-- ======================================================================= -->
				5662	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5663	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5664	</div>
				5665
				5666	<div class="doc_text">
				5667	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5668	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5669	the <tt>nest</tt> attribute, from a function. The result is a callable
				5670	function pointer lacking the nest parameter - the caller does not need
				5671	to provide a value for it. Instead, the value to use is stored in
				5672	advance in a "trampoline", a block of memory usually allocated
				5673	on the stack, which also contains code to splice the nest value into the
				5674	argument list. This is used to implement the GCC nested function address
				5675	extension.
				5676	</p>
				5677	<p>
				5678	For example, if the function is
				5679	<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]	5680	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]	5681	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5682	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5683	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5684	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5685	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5686	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5687	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5688	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]	5689	</div>
				5690
				5691	<!-- _______________________________________________________________________ -->
				5692	<div class="doc_subsubsection">
				5693	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5694	</div>
				5695	<div class="doc_text">
				5696	<h5>Syntax:</h5>
				5697	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5698	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5699	</pre>
				5700	<h5>Overview:</h5>
				5701	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5702	This fills the memory pointed to by <tt>tramp</tt> with code
				5703	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5704	</p>
				5705	<h5>Arguments:</h5>
				5706	<p>
				5707	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5708	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5709	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]	5710	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5711	currently provides no portable way of determining them, so a front-end that
				5712	generates this intrinsic needs to have some target-specific knowledge.
				5713	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]	5714	</p>
				5715	<h5>Semantics:</h5>
				5716	<p>
				5717	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]	5718	dependent code, turning it into a function. A pointer to this function is
				5719	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5720	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5721	before being called. The new function's signature is the same as that of
				5722	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5723	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5724	of pointer type. Calling the new function is equivalent to calling
				5725	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5726	missing <tt>nest</tt> argument. If, after calling
				5727	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5728	modified, then the effect of any later call to the returned function pointer is
				5729	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5730	</p>
				5731	</div>
				5732
				5733	<!-- ======================================================================= -->
				5734	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5735	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5736	</div>
				5737
				5738	<div class="doc_text">
				5739	<p>
				5740	These intrinsic functions expand the "universal IR" of LLVM to represent
				5741	hardware constructs for atomic operations and memory synchronization. This
				5742	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]	5743	is aimed at a low enough level to allow any programming models or APIs
				5744	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5745	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5746	hardware behavior. Just as hardware provides a "universal IR" for source
				5747	languages, it also provides a starting point for developing a "universal"
				5748	atomic operation and synchronization IR.
				5749	</p>
				5750	<p>
				5751	These do <em>not</em> form an API such as high-level threading libraries,
				5752	software transaction memory systems, atomic primitives, and intrinsic
				5753	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5754	application libraries. The hardware interface provided by LLVM should allow
				5755	a clean implementation of all of these APIs and parallel programming models.
				5756	No one model or paradigm should be selected above others unless the hardware
				5757	itself ubiquitously does so.
				5758
				5759	</p>
				5760	</div>
				5761
				5762	<!-- _______________________________________________________________________ -->
				5763	<div class="doc_subsubsection">
				5764	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5765	</div>
				5766	<div class="doc_text">
				5767	<h5>Syntax:</h5>
				5768	<pre>
				5769	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5770	i1 <device> )
				5771
				5772	</pre>
				5773	<h5>Overview:</h5>
				5774	<p>
				5775	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5776	specific pairs of memory access types.
				5777	</p>
				5778	<h5>Arguments:</h5>
				5779	<p>
				5780	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5781	The first four arguments enables a specific barrier as listed below. The fith
				5782	argument specifies that the barrier applies to io or device or uncached memory.
				5783
				5784	</p>
				5785	<ul>
				5786	<li><tt>ll</tt>: load-load barrier</li>
				5787	<li><tt>ls</tt>: load-store barrier</li>
				5788	<li><tt>sl</tt>: store-load barrier</li>
				5789	<li><tt>ss</tt>: store-store barrier</li>
				5790	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5791	</ul>
				5792	<h5>Semantics:</h5>
				5793	<p>
				5794	This intrinsic causes the system to enforce some ordering constraints upon
				5795	the loads and stores of the program. This barrier does not indicate
				5796	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5797	which they occur. For any of the specified pairs of load and store operations
				5798	(f.ex. load-load, or store-load), all of the first operations preceding the
				5799	barrier will complete before any of the second operations succeeding the
				5800	barrier begin. Specifically the semantics for each pairing is as follows:
				5801	</p>
				5802	<ul>
				5803	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5804	after the barrier begins.</li>
				5805
				5806	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5807	store after the barrier begins.</li>
				5808	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5809	store after the barrier begins.</li>
				5810	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5811	load after the barrier begins.</li>
				5812	</ul>
				5813	<p>
				5814	These semantics are applied with a logical "and" behavior when more than one
				5815	is enabled in a single memory barrier intrinsic.
				5816	</p>
				5817	<p>
				5818	Backends may implement stronger barriers than those requested when they do not
				5819	support as fine grained a barrier as requested. Some architectures do not
				5820	need all types of barriers and on such architectures, these become noops.
				5821	</p>
				5822	<h5>Example:</h5>
				5823	<pre>
				5824	%ptr = malloc i32
				5825	store i32 4, %ptr
				5826
				5827	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5828	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5829	<i>; guarantee the above finishes</i>
				5830	store i32 8, %ptr <i>; before this begins</i>
				5831	</pre>
				5832	</div>
				5833
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5834	<!-- _______________________________________________________________________ -->
				5835	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5836	<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]	5837	</div>
				5838	<div class="doc_text">
				5839	<h5>Syntax:</h5>
				5840	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5841	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5842	any integer bit width and for different address spaces. Not all targets
				5843	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5844
				5845	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5846	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5847	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5848	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5849	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]	5850
				5851	</pre>
				5852	<h5>Overview:</h5>
				5853	<p>
				5854	This loads a value in memory and compares it to a given value. If they are
				5855	equal, it stores a new value into the memory.
				5856	</p>
				5857	<h5>Arguments:</h5>
				5858	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5859	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]	5860	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5861	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5862	this integer type. While any bit width integer may be used, targets may only
				5863	lower representations they support in hardware.
				5864
				5865	</p>
				5866	<h5>Semantics:</h5>
				5867	<p>
				5868	This entire intrinsic must be executed atomically. It first loads the value
				5869	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5870	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5871	loaded value is yielded in all cases. This provides the equivalent of an
				5872	atomic compare-and-swap operation within the SSA framework.
				5873	</p>
				5874	<h5>Examples:</h5>
				5875
				5876	<pre>
				5877	%ptr = malloc i32
				5878	store i32 4, %ptr
				5879
				5880	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5881	%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]	5882	<i>; yields {i32}:result1 = 4</i>
				5883	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5884	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5885
				5886	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5887	%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]	5888	<i>; yields {i32}:result2 = 8</i>
				5889	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5890
				5891	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5892	</pre>
				5893	</div>
				5894
				5895	<!-- _______________________________________________________________________ -->
				5896	<div class="doc_subsubsection">
				5897	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5898	</div>
				5899	<div class="doc_text">
				5900	<h5>Syntax:</h5>
				5901
				5902	<p>
				5903	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5904	integer bit width. Not all targets support all bit widths however.</p>
				5905	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5906	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5907	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5908	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5909	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5910
				5911	</pre>
				5912	<h5>Overview:</h5>
				5913	<p>
				5914	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5915	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5916	at <tt>ptr</tt>.
				5917	</p>
				5918	<h5>Arguments:</h5>
				5919
				5920	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5921	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5922	<tt>val</tt> argument and the result must be integers of the same bit width.
				5923	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5924	integer type. The targets may only lower integer representations they
				5925	support.
				5926	</p>
				5927	<h5>Semantics:</h5>
				5928	<p>
				5929	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5930	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5931	equivalent of an atomic swap operation within the SSA framework.
				5932
				5933	</p>
				5934	<h5>Examples:</h5>
				5935	<pre>
				5936	%ptr = malloc i32
				5937	store i32 4, %ptr
				5938
				5939	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5940	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5941	<i>; yields {i32}:result1 = 4</i>
				5942	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5943	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5944
				5945	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5946	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5947	<i>; yields {i32}:result2 = 8</i>
				5948
				5949	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5950	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5951	</pre>
				5952	</div>
				5953
				5954	<!-- _______________________________________________________________________ -->
				5955	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5956	<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]	5957
				5958	</div>
				5959	<div class="doc_text">
				5960	<h5>Syntax:</h5>
				5961	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5962	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]	5963	integer bit width. Not all targets support all bit widths however.</p>
				5964	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5965	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				5966	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				5967	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				5968	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5969
				5970	</pre>
				5971	<h5>Overview:</h5>
				5972	<p>
				5973	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5974	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5975	</p>
				5976	<h5>Arguments:</h5>
				5977	<p>
				5978
				5979	The intrinsic takes two arguments, the first a pointer to an integer value
				5980	and the second an integer value. The result is also an integer value. These
				5981	integer types can have any bit width, but they must all have the same bit
				5982	width. The targets may only lower integer representations they support.
				5983	</p>
				5984	<h5>Semantics:</h5>
				5985	<p>
				5986	This intrinsic does a series of operations atomically. It first loads the
				5987	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5988	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5989	</p>
				5990
				5991	<h5>Examples:</h5>
				5992	<pre>
				5993	%ptr = malloc i32
				5994	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5995	%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]	5996	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5997	%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]	5998	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5999	%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]	6000	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6001	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6002	</pre>
				6003	</div>
				6004
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6005	<!-- _______________________________________________________________________ -->
				6006	<div class="doc_subsubsection">
				6007	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6008
				6009	</div>
				6010	<div class="doc_text">
				6011	<h5>Syntax:</h5>
				6012	<p>
				6013	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]	6014	any integer bit width and for different address spaces. Not all targets
				6015	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6016	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6017	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6018	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6019	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6020	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]	6021
				6022	</pre>
				6023	<h5>Overview:</h5>
				6024	<p>
				6025	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6026	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6027	</p>
				6028	<h5>Arguments:</h5>
				6029	<p>
				6030
				6031	The intrinsic takes two arguments, the first a pointer to an integer value
				6032	and the second an integer value. The result is also an integer value. These
				6033	integer types can have any bit width, but they must all have the same bit
				6034	width. The targets may only lower integer representations they support.
				6035	</p>
				6036	<h5>Semantics:</h5>
				6037	<p>
				6038	This intrinsic does a series of operations atomically. It first loads the
				6039	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6040	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6041	</p>
				6042
				6043	<h5>Examples:</h5>
				6044	<pre>
				6045	%ptr = malloc i32
				6046	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6047	%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]	6048	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6049	%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]	6050	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6051	%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]	6052	<i>; yields {i32}:result3 = 2</i>
				6053	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6054	</pre>
				6055	</div>
				6056
				6057	<!-- _______________________________________________________________________ -->
				6058	<div class="doc_subsubsection">
				6059	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6060	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6061	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6062	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6063
				6064	</div>
				6065	<div class="doc_text">
				6066	<h5>Syntax:</h5>
				6067	<p>
				6068	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6069	<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]	6070	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6071	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6072	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6073	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6074	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6075	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6076	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]	6077
				6078	</pre>
				6079
				6080	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6081	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6082	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6083	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6084	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]	6085
				6086	</pre>
				6087
				6088	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6089	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6090	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6091	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6092	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]	6093
				6094	</pre>
				6095
				6096	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6097	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6098	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6099	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6100	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]	6101
				6102	</pre>
				6103	<h5>Overview:</h5>
				6104	<p>
				6105	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6106	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6107	at <tt>ptr</tt>.
				6108	</p>
				6109	<h5>Arguments:</h5>
				6110	<p>
				6111
				6112	These intrinsics take two arguments, the first a pointer to an integer value
				6113	and the second an integer value. The result is also an integer value. These
				6114	integer types can have any bit width, but they must all have the same bit
				6115	width. The targets may only lower integer representations they support.
				6116	</p>
				6117	<h5>Semantics:</h5>
				6118	<p>
				6119	These intrinsics does a series of operations atomically. They first load the
				6120	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6121	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6122	value stored at <tt>ptr</tt>.
				6123	</p>
				6124
				6125	<h5>Examples:</h5>
				6126	<pre>
				6127	%ptr = malloc i32
				6128	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6129	%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]	6130	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6131	%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]	6132	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6133	%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]	6134	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6135	%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]	6136	<i>; yields {i32}:result3 = FF</i>
				6137	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6138	</pre>
				6139	</div>
				6140
				6141
				6142	<!-- _______________________________________________________________________ -->
				6143	<div class="doc_subsubsection">
				6144	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6145	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6146	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6147	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6148
				6149	</div>
				6150	<div class="doc_text">
				6151	<h5>Syntax:</h5>
				6152	<p>
				6153	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6154	<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]	6155	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6156	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6157	support all bit widths however.</p>
				6158	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6159	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6160	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6161	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6162	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]	6163
				6164	</pre>
				6165
				6166	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6167	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6168	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6169	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6170	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]	6171
				6172	</pre>
				6173
				6174	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6175	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6176	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6177	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6178	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]	6179
				6180	</pre>
				6181
				6182	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6183	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6184	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6185	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6186	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]	6187
				6188	</pre>
				6189	<h5>Overview:</h5>
				6190	<p>
				6191	These intrinsics takes the signed or unsigned minimum or maximum of
				6192	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6193	original value at <tt>ptr</tt>.
				6194	</p>
				6195	<h5>Arguments:</h5>
				6196	<p>
				6197
				6198	These intrinsics take two arguments, the first a pointer to an integer value
				6199	and the second an integer value. The result is also an integer value. These
				6200	integer types can have any bit width, but they must all have the same bit
				6201	width. The targets may only lower integer representations they support.
				6202	</p>
				6203	<h5>Semantics:</h5>
				6204	<p>
				6205	These intrinsics does a series of operations atomically. They first load the
				6206	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6207	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6208	the original value stored at <tt>ptr</tt>.
				6209	</p>
				6210
				6211	<h5>Examples:</h5>
				6212	<pre>
				6213	%ptr = malloc i32
				6214	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6215	%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]	6216	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6217	%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]	6218	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6219	%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]	6220	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6221	%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]	6222	<i>; yields {i32}:result3 = 8</i>
				6223	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6224	</pre>
				6225	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6226
				6227	<!-- ======================================================================= -->
				6228	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6229	<a name="int_general">General Intrinsics</a>
				6230	</div>
				6231
				6232	<div class="doc_text">
				6233	<p> This class of intrinsics is designed to be generic and has
				6234	no specific purpose. </p>
				6235	</div>
				6236
				6237	<!-- _______________________________________________________________________ -->
				6238	<div class="doc_subsubsection">
				6239	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6240	</div>
				6241
				6242	<div class="doc_text">
				6243
				6244	<h5>Syntax:</h5>
				6245	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6246	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]	6247	</pre>
				6248
				6249	<h5>Overview:</h5>
				6250
				6251	<p>
				6252	The '<tt>llvm.var.annotation</tt>' intrinsic
				6253	</p>
				6254
				6255	<h5>Arguments:</h5>
				6256
				6257	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6258	The first argument is a pointer to a value, the second is a pointer to a
				6259	global string, the third is a pointer to a global string which is the source
				6260	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6261	</p>
				6262
				6263	<h5>Semantics:</h5>
				6264
				6265	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6266	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6267	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]	6268	annotations. These have no other defined use, they are ignored by code
				6269	generation and optimization.
				6270	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6271	</div>
				6272
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6273	<!-- _______________________________________________________________________ -->
				6274	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6275	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6276	</div>
				6277
				6278	<div class="doc_text">
				6279
				6280	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6281	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6282	any integer bit width.
				6283	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6284	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6285	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6286	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6287	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6288	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6289	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]	6290	</pre>
				6291
				6292	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6293
				6294	<p>
				6295	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6296	</p>
				6297
				6298	<h5>Arguments:</h5>
				6299
				6300	<p>
				6301	The first argument is an integer value (result of some expression),
				6302	the second is a pointer to a global string, the third is a pointer to a global
				6303	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]	6304	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6305	</p>
				6306
				6307	<h5>Semantics:</h5>
				6308
				6309	<p>
				6310	This intrinsic allows annotations to be put on arbitrary expressions
				6311	with arbitrary strings. This can be useful for special purpose optimizations
				6312	that want to look for these annotations. These have no other defined use, they
				6313	are ignored by code generation and optimization.
				6314	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6315
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6316	<!-- _______________________________________________________________________ -->
				6317	<div class="doc_subsubsection">
				6318	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6319	</div>
				6320
				6321	<div class="doc_text">
				6322
				6323	<h5>Syntax:</h5>
				6324	<pre>
				6325	declare void @llvm.trap()
				6326	</pre>
				6327
				6328	<h5>Overview:</h5>
				6329
				6330	<p>
				6331	The '<tt>llvm.trap</tt>' intrinsic
				6332	</p>
				6333
				6334	<h5>Arguments:</h5>
				6335
				6336	<p>
				6337	None
				6338	</p>
				6339
				6340	<h5>Semantics:</h5>
				6341
				6342	<p>
				6343	This intrinsics is lowered to the target dependent trap instruction. If the
				6344	target does not have a trap instruction, this intrinsic will be lowered to the
				6345	call of the abort() function.
				6346	</p>
				6347	</div>
				6348
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6349	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6350	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6351	<address>
				6352	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6353	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6354	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6355	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]	6356
				6357	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6358	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6359	Last modified: $Date$
				6360	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6361
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6362	</body>
				6363	</html>