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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>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	29	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	30	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	31	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	32	</ol>
				33	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	34	<li><a href="#typesystem">Type System</a>
				35	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	36	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	37	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	38	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	39	<li><a href="#t_floating">Floating Point Types</a></li>
				40	<li><a href="#t_void">Void Type</a></li>
				41	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	42	</ol>
				43	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	44	<li><a href="#t_derived">Derived Types</a>
				45	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	46	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	47	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	48	<li><a href="#t_function">Function Type</a></li>
				49	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	50	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	51	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	52	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	53	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	54	</ol>
				55	</li>
				56	</ol>
				57	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	58	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	59	<ol>
				60	<li><a href="#simpleconstants">Simple Constants</a>
				61	<li><a href="#aggregateconstants">Aggregate Constants</a>
				62	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				63	<li><a href="#undefvalues">Undefined Values</a>
				64	<li><a href="#constantexprs">Constant Expressions</a>
				65	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	66	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	67	<li><a href="#othervalues">Other Values</a>
				68	<ol>
				69	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				70	</ol>
				71	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	72	<li><a href="#instref">Instruction Reference</a>
				73	<ol>
				74	<li><a href="#terminators">Terminator Instructions</a>
				75	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	76	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				77	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	78	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				79	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	80	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	81	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	82	</ol>
				83	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	84	<li><a href="#binaryops">Binary Operations</a>
				85	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	86	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				87	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				88	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	89	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				90	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				91	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	92	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				93	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				94	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	95	</ol>
				96	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	97	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				98	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	99	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				100	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				101	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	102	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	103	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	104	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	105	</ol>
				106	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	107	<li><a href="#vectorops">Vector Operations</a>
				108	<ol>
				109	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				110	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				111	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	112	</ol>
				113	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	114	<li><a href="#aggregateops">Aggregate Operations</a>
				115	<ol>
				116	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				117	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				118	</ol>
				119	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	120	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	121	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	122	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				123	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				124	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	125	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				126	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				127	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	128	</ol>
				129	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	130	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	131	<ol>
				132	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				133	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	137	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	141	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	143	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	144	</ol>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	145	<li><a href="#otherops">Other Operations</a>
				146	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	147	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				148	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	149	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				150	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	151	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	152	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	153	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	154	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	155	<li><a href="#i_getresult">'<tt>getresult</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.
				258	LLVM is an SSA based representation that provides type safety,
				259	low-level operations, flexibility, and the capability of representing
				260	'all' high-level languages cleanly. It is the common code
				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>
				525	<dd>The semantics of this linkage follow the ELF model: the symbol is weak
				526	until linked, if not linked, the symbol becomes null instead of being an
				527	undefined reference.
				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)
				541	DLLs.
				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	8cdc5bc	2005-05-06 23:08:23 +0000	[diff] [blame]	605	without having to conform to an externally specified ABI. Implementations of
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	606	this convention should allow arbitrary
				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
				651	<dd>On ELF, default visibility means that the declaration is visible to other
				652	modules and, in shared libraries, means that the declared entity may be
				653	overridden. On Darwin, default visibility means that the declaration is
				654	visible to other modules. Default visibility corresponds to "external
				655	linkage" in the language.
				656	</dd>
				657
				658	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				659
				660	<dd>Two declarations of an object with hidden visibility refer to the same
				661	object if they are in the same shared object. Usually, hidden visibility
				662	indicates that the symbol will not be placed into the dynamic symbol table,
				663	so no other module (executable or shared library) can reference it
				664	directly.
				665	</dd>
				666
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	667	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				668
				669	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				670	the dynamic symbol table, but that references within the defining module will
				671	bind to the local symbol. That is, the symbol cannot be overridden by another
				672	module.
				673	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	674	</dl>
				675
				676	</div>
				677
				678	<!-- ======================================================================= -->
				679	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	680	<a name="globalvars">Global Variables</a>
				681	</div>
				682
				683	<div class="doc_text">
				684
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	685	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	686	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	687	an explicit section to be placed in, and may have an optional explicit alignment
				688	specified. A variable may be defined as "thread_local", which means that it
				689	will not be shared by threads (each thread will have a separated copy of the
				690	variable). A variable may be defined as a global "constant," which indicates
				691	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]	692	optimization, allowing the global data to be placed in the read-only section of
				693	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	694	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]	695
				696	<p>
				697	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				698	constant, even if the final definition of the global is not. This capability
				699	can be used to enable slightly better optimization of the program, but requires
				700	the language definition to guarantee that optimizations based on the
				701	'constantness' are valid for the translation units that do not include the
				702	definition.
				703	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	704
				705	<p>As SSA values, global variables define pointer values that are in
				706	scope (i.e. they dominate) all basic blocks in the program. Global
				707	variables always define a pointer to their "content" type because they
				708	describe a region of memory, and all memory objects in LLVM are
				709	accessed through pointers.</p>
				710
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	711	<p>A global variable may be declared to reside in a target-specifc numbered
				712	address space. For targets that support them, address spaces may affect how
				713	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	714	the variable. The default address space is zero. The address space qualifier
				715	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	716
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	717	<p>LLVM allows an explicit section to be specified for globals. If the target
				718	supports it, it will emit globals to the section specified.</p>
				719
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	720	<p>An explicit alignment may be specified for a global. If not present, or if
				721	the alignment is set to zero, the alignment of the global is set by the target
				722	to whatever it feels convenient. If an explicit alignment is specified, the
				723	global is forced to have at least that much alignment. All alignments must be
				724	a power of 2.</p>
				725
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	726	<p>For example, the following defines a global in a numbered address space with
				727	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	728
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	729	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	730	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	731	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	732	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	733	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	734
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	735	</div>
				736
				737
				738	<!-- ======================================================================= -->
				739	<div class="doc_subsection">
				740	<a name="functionstructure">Functions</a>
				741	</div>
				742
				743	<div class="doc_text">
				744
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	745	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				746	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	747	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	748	<a href="#callingconv">calling convention</a>, a return type, an optional
				749	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				750	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	751	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	752	optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	753	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]	754
				755	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				756	optional <a href="#linkage">linkage type</a>, an optional
				757	<a href="#visibility">visibility style</a>, an optional
				758	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	759	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	760	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]	761	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	762
				763	<p>A function definition contains a list of basic blocks, forming the CFG for
				764	the function. Each basic block may optionally start with a label (giving the
				765	basic block a symbol table entry), contains a list of instructions, and ends
				766	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				767	function return).</p>
				768
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	769	<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]	770	executed on entrance to the function, and it is not allowed to have predecessor
				771	basic blocks (i.e. there can not be any branches to the entry block of a
				772	function). Because the block can have no predecessors, it also cannot have any
				773	<a href="#i_phi">PHI nodes</a>.</p>
				774
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	775	<p>LLVM allows an explicit section to be specified for functions. If the target
				776	supports it, it will emit functions to the section specified.</p>
				777
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	778	<p>An explicit alignment may be specified for a function. If not present, or if
				779	the alignment is set to zero, the alignment of the function is set by the target
				780	to whatever it feels convenient. If an explicit alignment is specified, the
				781	function is forced to have at least that much alignment. All alignments must be
				782	a power of 2.</p>
				783
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	784	</div>
				785
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	786
				787	<!-- ======================================================================= -->
				788	<div class="doc_subsection">
				789	<a name="aliasstructure">Aliases</a>
				790	</div>
				791	<div class="doc_text">
				792	<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]	793	function, global variable, another alias or bitcast of global value). Aliases
				794	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	795	optional <a href="#visibility">visibility style</a>.</p>
				796
				797	<h5>Syntax:</h5>
				798
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	799	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	800	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	801	@<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	802	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	803	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	804
				805	</div>
				806
				807
				808
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	809	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	810	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				811	<div class="doc_text">
				812	<p>The return type and each parameter of a function type may have a set of
				813	<i>parameter attributes</i> associated with them. Parameter attributes are
				814	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	815	a function. Parameter attributes are considered to be part of the function,
				816	not of the function type, so functions with different parameter attributes
				817	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	818
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	819	<p>Parameter attributes are simple keywords that follow the type specified. If
				820	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	821	example:</p>
				822
				823	<div class="doc_code">
				824	<pre>
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	825	declare i32 @printf(i8* noalias , ...) nounwind
				826	declare i32 @atoi(i8*) nounwind readonly
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	827	</pre>
				828	</div>
				829
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	830	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				831	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	832
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	833	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	834	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	835	<dt><tt>zeroext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	836	<dd>This indicates that the parameter should be zero extended just before
				837	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	838
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	839	<dt><tt>signext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	840	<dd>This indicates that the parameter should be sign extended just before
				841	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	842
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	843	<dt><tt>inreg</tt></dt>
				844	<dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov	66a8c8c	2007-01-28 15:27:21 +0000	[diff] [blame]	845	possible) during assembling function call. Support for this attribute is
				846	target-specific</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	847
				848	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	849	<dd>This indicates that the pointer parameter should really be passed by
				850	value to the function. The attribute implies that a hidden copy of the
				851	pointee is made between the caller and the callee, so the callee is unable
				852	to modify the value in the callee. This attribute is only valid on llvm
				853	pointer arguments. It is generally used to pass structs and arrays by
				854	value, but is also valid on scalars (even though this is silly).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	855
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	856	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	857	<dd>This indicates that the pointer parameter specifies the address of a
				858	structure that is the return value of the function in the source program.
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	859	Loads and stores to the structure are assumed not to trap.
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	860	May only be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	861
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	862	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	863	<dd>This indicates that the parameter does not alias any global or any other
				864	parameter. The caller is responsible for ensuring that this is the case,
				865	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	866
Reid Spencer	2dc5201	2007-03-22 02:18:56 +0000	[diff] [blame]	867	<dt><tt>noreturn</tt></dt>
				868	<dd>This function attribute indicates that the function never returns. This
				869	indicates to LLVM that every call to this function should be treated as if
				870	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	871
Reid Spencer	6760612	2007-03-22 02:02:11 +0000	[diff] [blame]	872	<dt><tt>nounwind</tt></dt>
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	873	<dd>This function attribute indicates that no exceptions unwind out of the
				874	function. Usually this is because the function makes no use of exceptions,
				875	but it may also be that the function catches any exceptions thrown when
				876	executing it.</dd>
				877
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	878	<dt><tt>nest</tt></dt>
				879	<dd>This indicates that the parameter can be excised using the
				880	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	881	<dt><tt>readonly</tt></dt>
Duncan Sands	f04d584	2007-11-14 21:14:02 +0000	[diff] [blame]	882	<dd>This function attribute indicates that the function has no side-effects
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	883	except for producing a return value or throwing an exception. The value
				884	returned must only depend on the function arguments and/or global variables.
				885	It may use values obtained by dereferencing pointers.</dd>
				886	<dt><tt>readnone</tt></dt>
				887	<dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sands	f04d584	2007-11-14 21:14:02 +0000	[diff] [blame]	888	function, but in addition it is not allowed to dereference any pointer arguments
				889	or global variables.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	890	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	891
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	892	</div>
				893
				894	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	895	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	896	<a name="gc">Garbage Collector Names</a>
				897	</div>
				898
				899	<div class="doc_text">
				900	<p>Each function may specify a garbage collector name, which is simply a
				901	string.</p>
				902
				903	<div class="doc_code"><pre
				904	>define void @f() gc "name" { ...</pre></div>
				905
				906	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				907	collector which will cause the compiler to alter its output in order to support
				908	the named garbage collection algorithm.</p>
				909	</div>
				910
				911	<!-- ======================================================================= -->
				912	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	913	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	914	</div>
				915
				916	<div class="doc_text">
				917	<p>
				918	Modules may contain "module-level inline asm" blocks, which corresponds to the
				919	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				920	LLVM and treated as a single unit, but may be separated in the .ll file if
				921	desired. The syntax is very simple:
				922	</p>
				923
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	924	<div class="doc_code">
				925	<pre>
				926	module asm "inline asm code goes here"
				927	module asm "more can go here"
				928	</pre>
				929	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	930
				931	<p>The strings can contain any character by escaping non-printable characters.
				932	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				933	for the number.
				934	</p>
				935
				936	<p>
				937	The inline asm code is simply printed to the machine code .s file when
				938	assembly code is generated.
				939	</p>
				940	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	941
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	942	<!-- ======================================================================= -->
				943	<div class="doc_subsection">
				944	<a name="datalayout">Data Layout</a>
				945	</div>
				946
				947	<div class="doc_text">
				948	<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]	949	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				950	<pre> target datalayout = "<i>layout specification</i>"</pre>
				951	<p>The <i>layout specification</i> consists of a list of specifications
				952	separated by the minus sign character ('-'). Each specification starts with a
				953	letter and may include other information after the letter to define some
				954	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	955	<dl>
				956	<dt><tt>E</tt></dt>
				957	<dd>Specifies that the target lays out data in big-endian form. That is, the
				958	bits with the most significance have the lowest address location.</dd>
				959	<dt><tt>e</tt></dt>
				960	<dd>Specifies that hte target lays out data in little-endian form. That is,
				961	the bits with the least significance have the lowest address location.</dd>
				962	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				963	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				964	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				965	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				966	too.</dd>
				967	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				968	<dd>This specifies the alignment for an integer type of a given bit
				969	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				970	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				971	<dd>This specifies the alignment for a vector type of a given bit
				972	<i>size</i>.</dd>
				973	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				974	<dd>This specifies the alignment for a floating point type of a given bit
				975	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				976	(double).</dd>
				977	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				978	<dd>This specifies the alignment for an aggregate type of a given bit
				979	<i>size</i>.</dd>
				980	</dl>
				981	<p>When constructing the data layout for a given target, LLVM starts with a
				982	default set of specifications which are then (possibly) overriden by the
				983	specifications in the <tt>datalayout</tt> keyword. The default specifications
				984	are given in this list:</p>
				985	<ul>
				986	<li><tt>E</tt> - big endian</li>
				987	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				988	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				989	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				990	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				991	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
				992	<li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
				993	alignment of 64-bits</li>
				994	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				995	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				996	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				997	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				998	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				999	</ul>
				1000	<p>When llvm is determining the alignment for a given type, it uses the
				1001	following rules:
				1002	<ol>
				1003	<li>If the type sought is an exact match for one of the specifications, that
				1004	specification is used.</li>
				1005	<li>If no match is found, and the type sought is an integer type, then the
				1006	smallest integer type that is larger than the bitwidth of the sought type is
				1007	used. If none of the specifications are larger than the bitwidth then the the
				1008	largest integer type is used. For example, given the default specifications
				1009	above, the i7 type will use the alignment of i8 (next largest) while both
				1010	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1011	<li>If no match is found, and the type sought is a vector type, then the
				1012	largest vector type that is smaller than the sought vector type will be used
				1013	as a fall back. This happens because <128 x double> can be implemented in
				1014	terms of 64 <2 x double>, for example.</li>
				1015	</ol>
				1016	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1017
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1018	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1019	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1020	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1021
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1022	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1023
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1024	<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]	1025	intermediate representation. Being typed enables a number of
				1026	optimizations to be performed on the IR directly, without having to do
				1027	extra analyses on the side before the transformation. A strong type
				1028	system makes it easier to read the generated code and enables novel
				1029	analyses and transformations that are not feasible to perform on normal
				1030	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1031
				1032	</div>
				1033
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1034	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1035	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1036	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1037	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1038	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1039	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1040
				1041	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1042	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1043	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1044	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1045	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1046	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1047	</tr>
				1048	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1049	<td><a href="#t_floating">floating point</a></td>
				1050	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1051	</tr>
				1052	<tr>
				1053	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1054	<td><a href="#t_integer">integer</a>,
				1055	<a href="#t_floating">floating point</a>,
				1056	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1057	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1058	<a href="#t_struct">structure</a>,
				1059	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1060	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1061	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1062	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1063	<tr>
				1064	<td><a href="#t_primitive">primitive</a></td>
				1065	<td><a href="#t_label">label</a>,
				1066	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1067	<a href="#t_floating">floating point</a>.</td>
				1068	</tr>
				1069	<tr>
				1070	<td><a href="#t_derived">derived</a></td>
				1071	<td><a href="#t_integer">integer</a>,
				1072	<a href="#t_array">array</a>,
				1073	<a href="#t_function">function</a>,
				1074	<a href="#t_pointer">pointer</a>,
				1075	<a href="#t_struct">structure</a>,
				1076	<a href="#t_pstruct">packed structure</a>,
				1077	<a href="#t_vector">vector</a>,
				1078	<a href="#t_opaque">opaque</a>.
				1079	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1080	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1081	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1082
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1083	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1084	most important. Values of these types are the only ones which can be
				1085	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1086	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1087	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1088
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1089	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1090	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1091
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1092	<div class="doc_text">
				1093	<p>The primitive types are the fundamental building blocks of the LLVM
				1094	system.</p>
				1095
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1096	</div>
				1097
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1098	<!-- _______________________________________________________________________ -->
				1099	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1100
				1101	<div class="doc_text">
				1102	<table>
				1103	<tbody>
				1104	<tr><th>Type</th><th>Description</th></tr>
				1105	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1106	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1107	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1108	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1109	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1110	</tbody>
				1111	</table>
				1112	</div>
				1113
				1114	<!-- _______________________________________________________________________ -->
				1115	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1116
				1117	<div class="doc_text">
				1118	<h5>Overview:</h5>
				1119	<p>The void type does not represent any value and has no size.</p>
				1120
				1121	<h5>Syntax:</h5>
				1122
				1123	<pre>
				1124	void
				1125	</pre>
				1126	</div>
				1127
				1128	<!-- _______________________________________________________________________ -->
				1129	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1130
				1131	<div class="doc_text">
				1132	<h5>Overview:</h5>
				1133	<p>The label type represents code labels.</p>
				1134
				1135	<h5>Syntax:</h5>
				1136
				1137	<pre>
				1138	label
				1139	</pre>
				1140	</div>
				1141
				1142
				1143	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1144	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1145
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1146	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1147
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1148	<p>The real power in LLVM comes from the derived types in the system.
				1149	This is what allows a programmer to represent arrays, functions,
				1150	pointers, and other useful types. Note that these derived types may be
				1151	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]	1152
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1153	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1154
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1155	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1156	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1157
				1158	<div class="doc_text">
				1159
				1160	<h5>Overview:</h5>
				1161	<p>The integer type is a very simple derived type that simply specifies an
				1162	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1163	2^23-1 (about 8 million) can be specified.</p>
				1164
				1165	<h5>Syntax:</h5>
				1166
				1167	<pre>
				1168	iN
				1169	</pre>
				1170
				1171	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1172	value.</p>
				1173
				1174	<h5>Examples:</h5>
				1175	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1176	<tbody>
				1177	<tr>
				1178	<td><tt>i1</tt></td>
				1179	<td>a single-bit integer.</td>
				1180	</tr><tr>
				1181	<td><tt>i32</tt></td>
				1182	<td>a 32-bit integer.</td>
				1183	</tr><tr>
				1184	<td><tt>i1942652</tt></td>
				1185	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1186	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1187	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1188	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1189	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1190
				1191	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1192	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1193
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1194	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1195
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1196	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1197
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1198	<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]	1199	sequentially in memory. The array type requires a size (number of
				1200	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1201
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1202	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1203
				1204	<pre>
				1205	[<# elements> x <elementtype>]
				1206	</pre>
				1207
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1208	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1209	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1210
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1211	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1212	<table class="layout">
				1213	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1214	<td class="left"><tt>[40 x i32]</tt></td>
				1215	<td class="left">Array of 40 32-bit integer values.</td>
				1216	</tr>
				1217	<tr class="layout">
				1218	<td class="left"><tt>[41 x i32]</tt></td>
				1219	<td class="left">Array of 41 32-bit integer values.</td>
				1220	</tr>
				1221	<tr class="layout">
				1222	<td class="left"><tt>[4 x i8]</tt></td>
				1223	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1224	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1225	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1226	<p>Here are some examples of multidimensional arrays:</p>
				1227	<table class="layout">
				1228	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1229	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1230	<td class="left">3x4 array of 32-bit integer values.</td>
				1231	</tr>
				1232	<tr class="layout">
				1233	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1234	<td class="left">12x10 array of single precision floating point values.</td>
				1235	</tr>
				1236	<tr class="layout">
				1237	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1238	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1239	</tr>
				1240	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1241
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1242	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1243	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]	1244	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1245	As a special case, however, zero length arrays are recognized to be variable
				1246	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1247	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1248
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1249	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1250
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1251	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1252	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1253	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1254
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1255	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1256
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1257	<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]	1258	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]	1259	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]	1260	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]	1261	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1262
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1263	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1264
				1265	<pre>
				1266	<returntype list> (<parameter list>)
				1267	</pre>
				1268
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1269	<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]	1270	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1271	which indicates that the function takes a variable number of arguments.
				1272	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1273	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1274	'<tt><returntype list></tt>' is a comma-separated list of
				1275	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1276
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1277	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1278	<table class="layout">
				1279	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1280	<td class="left"><tt>i32 (i32)</tt></td>
				1281	<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]	1282	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1283	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1284	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1285	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1286	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1287	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1288	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1289	<tt>float</tt>.
				1290	</td>
				1291	</tr><tr class="layout">
				1292	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1293	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1294	<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]	1295	which returns an integer. This is the signature for <tt>printf</tt> in
				1296	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1297	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1298	</tr><tr class="layout">
				1299	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1300	<td class="left">A function taking an <tt>i32></tt>, returning two
				1301	<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]	1302	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1303	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1304	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1305
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1306	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1307	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1308	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1309	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1310	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1311	<p>The structure type is used to represent a collection of data members
				1312	together in memory. The packing of the field types is defined to match
				1313	the ABI of the underlying processor. The elements of a structure may
				1314	be any type that has a size.</p>
				1315	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1316	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1317	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1318	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1319	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1320	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1321	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1322	<table class="layout">
				1323	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1324	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1325	<td class="left">A triple of three <tt>i32</tt> values</td>
				1326	</tr><tr class="layout">
				1327	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1328	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1329	second element is a <a href="#t_pointer">pointer</a> to a
				1330	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1331	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1332	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1333	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1334	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1335
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1336	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1337	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1338	</div>
				1339	<div class="doc_text">
				1340	<h5>Overview:</h5>
				1341	<p>The packed structure type is used to represent a collection of data members
				1342	together in memory. There is no padding between fields. Further, the alignment
				1343	of a packed structure is 1 byte. The elements of a packed structure may
				1344	be any type that has a size.</p>
				1345	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1346	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1347	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1348	instruction.</p>
				1349	<h5>Syntax:</h5>
				1350	<pre> < { <type list> } > <br></pre>
				1351	<h5>Examples:</h5>
				1352	<table class="layout">
				1353	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1354	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1355	<td class="left">A triple of three <tt>i32</tt> values</td>
				1356	</tr><tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1357	<td class="left"><tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1358	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1359	second element is a <a href="#t_pointer">pointer</a> to a
				1360	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1361	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1362	</tr>
				1363	</table>
				1364	</div>
				1365
				1366	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1367	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1368	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1369	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1370	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1371	reference to another object, which must live in memory. Pointer types may have
				1372	an optional address space attribute defining the target-specific numbered
				1373	address space where the pointed-to object resides. The default address space is
				1374	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1375	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1376	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1377	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1378	<table class="layout">
				1379	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1380	<td class="left"><tt>[4x i32]*</tt></td>
				1381	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1382	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1383	</tr>
				1384	<tr class="layout">
				1385	<td class="left"><tt>i32 (i32 ) </tt></td>
				1386	<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]	1387	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]	1388	<tt>i32</tt>.</td>
				1389	</tr>
				1390	<tr class="layout">
				1391	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1392	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1393	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1394	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1395	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1396	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1397
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1398	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1399	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1400	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1401
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1402	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1403
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1404	<p>A vector type is a simple derived type that represents a vector
				1405	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1406	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1407	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1408	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1409	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1410	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1411
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1412	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1413
				1414	<pre>
				1415	< <# elements> x <elementtype> >
				1416	</pre>
				1417
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1418	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1419	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1420
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1421	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1422
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1423	<table class="layout">
				1424	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1425	<td class="left"><tt><4 x i32></tt></td>
				1426	<td class="left">Vector of 4 32-bit integer values.</td>
				1427	</tr>
				1428	<tr class="layout">
				1429	<td class="left"><tt><8 x float></tt></td>
				1430	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1431	</tr>
				1432	<tr class="layout">
				1433	<td class="left"><tt><2 x i64></tt></td>
				1434	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1435	</tr>
				1436	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1437	</div>
				1438
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1439	<!-- _______________________________________________________________________ -->
				1440	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1441	<div class="doc_text">
				1442
				1443	<h5>Overview:</h5>
				1444
				1445	<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]	1446	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]	1447	In LLVM, opaque types can eventually be resolved to any type (not just a
				1448	structure type).</p>
				1449
				1450	<h5>Syntax:</h5>
				1451
				1452	<pre>
				1453	opaque
				1454	</pre>
				1455
				1456	<h5>Examples:</h5>
				1457
				1458	<table class="layout">
				1459	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1460	<td class="left"><tt>opaque</tt></td>
				1461	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1462	</tr>
				1463	</table>
				1464	</div>
				1465
				1466
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1467	<!-- *********************************************************************** -->
				1468	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1469	<!-- *********************************************************************** -->
				1470
				1471	<div class="doc_text">
				1472
				1473	<p>LLVM has several different basic types of constants. This section describes
				1474	them all and their syntax.</p>
				1475
				1476	</div>
				1477
				1478	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1479	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1480
				1481	<div class="doc_text">
				1482
				1483	<dl>
				1484	<dt><b>Boolean constants</b></dt>
				1485
				1486	<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]	1487	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1488	</dd>
				1489
				1490	<dt><b>Integer constants</b></dt>
				1491
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1492	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1493	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1494	integer types.
				1495	</dd>
				1496
				1497	<dt><b>Floating point constants</b></dt>
				1498
				1499	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1500	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1501	notation (see below). The assembler requires the exact decimal value of
				1502	a floating-point constant. For example, the assembler accepts 1.25 but
				1503	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1504	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]	1505
				1506	<dt><b>Null pointer constants</b></dt>
				1507
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1508	<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]	1509	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1510
				1511	</dl>
				1512
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1513	<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]	1514	of floating point constants. For example, the form '<tt>double
				1515	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1516	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]	1517	(and the only time that they are generated by the disassembler) is when a
				1518	floating point constant must be emitted but it cannot be represented as a
				1519	decimal floating point number. For example, NaN's, infinities, and other
				1520	special values are represented in their IEEE hexadecimal format so that
				1521	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]	1522
				1523	</div>
				1524
				1525	<!-- ======================================================================= -->
				1526	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1527	</div>
				1528
				1529	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1530	<p>Aggregate constants arise from aggregation of simple constants
				1531	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1532
				1533	<dl>
				1534	<dt><b>Structure constants</b></dt>
				1535
				1536	<dd>Structure constants are represented with notation similar to structure
				1537	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1538	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1539	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]	1540	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]	1541	types of elements must match those specified by the type.
				1542	</dd>
				1543
				1544	<dt><b>Array constants</b></dt>
				1545
				1546	<dd>Array constants are represented with notation similar to array type
				1547	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1548	(<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]	1549	constants must have <a href="#t_array">array type</a>, and the number and
				1550	types of elements must match those specified by the type.
				1551	</dd>
				1552
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1553	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1554
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1555	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1556	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1557	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1558	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1559	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]	1560	match those specified by the type.
				1561	</dd>
				1562
				1563	<dt><b>Zero initialization</b></dt>
				1564
				1565	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1566	value to zero of <em>any</em> type, including scalar and aggregate types.
				1567	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]	1568	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1569	initializers.
				1570	</dd>
				1571	</dl>
				1572
				1573	</div>
				1574
				1575	<!-- ======================================================================= -->
				1576	<div class="doc_subsection">
				1577	<a name="globalconstants">Global Variable and Function Addresses</a>
				1578	</div>
				1579
				1580	<div class="doc_text">
				1581
				1582	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1583	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1584	constants. These constants are explicitly referenced when the <a
				1585	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]	1586	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1587	file:</p>
				1588
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1589	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1590	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1591	@X = global i32 17
				1592	@Y = global i32 42
				1593	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1594	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1595	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1596
				1597	</div>
				1598
				1599	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1600	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1601	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1602	<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]	1603	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]	1604	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1605
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1606	<p>Undefined values indicate to the compiler that the program is well defined
				1607	no matter what value is used, giving the compiler more freedom to optimize.
				1608	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1609	</div>
				1610
				1611	<!-- ======================================================================= -->
				1612	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1613	</div>
				1614
				1615	<div class="doc_text">
				1616
				1617	<p>Constant expressions are used to allow expressions involving other constants
				1618	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1619	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]	1620	that does not have side effects (e.g. load and call are not supported). The
				1621	following is the syntax for constant expressions:</p>
				1622
				1623	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1624	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1625	<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]	1626	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1627
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1628	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1629	<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]	1630	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]	1631
				1632	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1633	<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]	1634	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]	1635
				1636	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1637	<dd>Truncate a floating point constant to another floating point type. The
				1638	size of CST must be larger than the size of TYPE. Both types must be
				1639	floating point.</dd>
				1640
				1641	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1642	<dd>Floating point extend a constant to another type. The size of CST must be
				1643	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1644
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1645	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1646	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1647	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1648	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1649	of the same number of elements. If the value won't fit in the integer type,
				1650	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1651
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1652	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1653	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1654	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1655	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1656	of the same number of elements. If the value won't fit in the integer type,
				1657	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1658
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1659	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1660	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1661	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1662	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1663	of the same number of elements. If the value won't fit in the floating point
				1664	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1665
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1666	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1667	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1668	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1669	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1670	of the same number of elements. If the value won't fit in the floating point
				1671	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1672
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1673	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1674	<dd>Convert a pointer typed constant to the corresponding integer constant
				1675	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1676	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1677
				1678	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1679	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1680	pointer type. CST must be of integer type. The CST value is zero extended,
				1681	truncated, or unchanged to make it fit in a pointer size. This one is
				1682	<i>really</i> dangerous!</dd>
				1683
				1684	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1685	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1686	identical (same number of bits). The conversion is done as if the CST value
				1687	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]	1688	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]	1689	vector types to any other type, as long as they have the same bit width. For
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1690	pointers it is only valid to cast to another pointer type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1691	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1692
				1693	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1694
				1695	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1696	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1697	instruction, the index list may have zero or more indexes, which are required
				1698	to make sense for the type of "CSTPTR".</dd>
				1699
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1700	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1701
				1702	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1703	constants.</dd>
				1704
				1705	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1706	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1707
				1708	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1709	<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]	1710
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1711	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1712	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1713
				1714	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1715	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1716
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1717	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1718
				1719	<dd>Perform the <a href="#i_extractelement">extractelement
				1720	operation</a> on constants.
				1721
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1722	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1723
				1724	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1725	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1726
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1727
				1728	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1729
				1730	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1731	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1732
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1733	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1734
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1735	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1736	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]	1737	binary</a> operations. The constraints on operands are the same as those for
				1738	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1739	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1740	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1741	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1742
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1743	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1744	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1745	<!-- *********************************************************************** -->
				1746
				1747	<!-- ======================================================================= -->
				1748	<div class="doc_subsection">
				1749	<a name="inlineasm">Inline Assembler Expressions</a>
				1750	</div>
				1751
				1752	<div class="doc_text">
				1753
				1754	<p>
				1755	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1756	Module-Level Inline Assembly</a>) through the use of a special value. This
				1757	value represents the inline assembler as a string (containing the instructions
				1758	to emit), a list of operand constraints (stored as a string), and a flag that
				1759	indicates whether or not the inline asm expression has side effects. An example
				1760	inline assembler expression is:
				1761	</p>
				1762
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1763	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1764	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1765	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1766	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1767	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1768
				1769	<p>
				1770	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1771	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1772	</p>
				1773
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1774	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1775	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1776	%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]	1777	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1778	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1779
				1780	<p>
				1781	Inline asms with side effects not visible in the constraint list must be marked
				1782	as having side effects. This is done through the use of the
				1783	'<tt>sideeffect</tt>' keyword, like so:
				1784	</p>
				1785
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1786	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1787	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1788	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1789	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1790	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1791
				1792	<p>TODO: The format of the asm and constraints string still need to be
				1793	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1794	need to be documented).
				1795	</p>
				1796
				1797	</div>
				1798
				1799	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1800	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1801	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1802
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1803	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1804
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1805	<p>The LLVM instruction set consists of several different
				1806	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1807	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1808	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1809	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1810	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1811
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1812	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1813
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1814	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1815	<div class="doc_subsection"> <a name="terminators">Terminator
				1816	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1817
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1818	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1819
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1820	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1821	basic block in a program ends with a "Terminator" instruction, which
				1822	indicates which block should be executed after the current block is
				1823	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1824	value: they produce control flow, not values (the one exception being
				1825	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1826	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1827	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1828	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1829	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1830	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1831	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1832
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1833	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1834
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1835	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1836	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1837	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1838	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1839	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1840	<pre> ret <type> <value> <i>; Return a value from a non-void function</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1841	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1842	ret <type> <value>, <type> <value> <i>; Return two values from a non-void function </i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1843	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1844
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1845	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1846
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1847	<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1848	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1849	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1850	returns value(s) and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1851	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1852
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1853	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1854
				1855	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1856	The type of each return value must be a '<a href="#t_firstclass">first
				1857	class</a>' type. Note that a function is not <a href="#wellformed">well
				1858	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1859	function that returns values that do not match the return type of the
				1860	function.</p>
				1861
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1862	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1863
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1864	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1865	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]	1866	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1867	the instruction after the call. If the caller was an "<a
				1868	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1869	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1870	returns a value, that value shall set the call or invoke instruction's
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1871	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1872	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1873	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1874
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1875	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1876
				1877	<pre>
				1878	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1879	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1880	ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1881	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1882	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1883	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1884	<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]	1885	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1886	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1887	<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]	1888	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1889	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1890	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1891	transfer to a different basic block in the current function. There are
				1892	two forms of this instruction, corresponding to a conditional branch
				1893	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1894	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1895	<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]	1896	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1897	unconditional form of the '<tt>br</tt>' instruction takes a single
				1898	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1899	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1900	<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]	1901	argument is evaluated. If the value is <tt>true</tt>, control flows
				1902	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1903	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1904	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1905	<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]	1906	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]	1907	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1908	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1909	<div class="doc_subsubsection">
				1910	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1911	</div>
				1912
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1913	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1914	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1915
				1916	<pre>
				1917	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1918	</pre>
				1919
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1920	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1921
				1922	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1923	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1924	instruction, allowing a branch to occur to one of many possible
				1925	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1926
				1927
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1928	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1929
				1930	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1931	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1932	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1933	table is not allowed to contain duplicate constant entries.</p>
				1934
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1935	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1936
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1937	<p>The <tt>switch</tt> instruction specifies a table of values and
				1938	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1939	table is searched for the given value. If the value is found, control flow is
				1940	transfered to the corresponding destination; otherwise, control flow is
				1941	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1942
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1943	<h5>Implementation:</h5>
				1944
				1945	<p>Depending on properties of the target machine and the particular
				1946	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1947	ways. For example, it could be generated as a series of chained conditional
				1948	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1949
				1950	<h5>Example:</h5>
				1951
				1952	<pre>
				1953	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1954	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1955	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1956
				1957	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1958	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1959
				1960	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1961	switch i32 %val, label %otherwise [ i32 0, label %onzero
				1962	i32 1, label %onone
				1963	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1964	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1965	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1966
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1967	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1968	<div class="doc_subsubsection">
				1969	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				1970	</div>
				1971
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1972	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1973
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1974	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1975
				1976	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	1977	<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]	1978	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1979	</pre>
				1980
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	1981	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1982
				1983	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				1984	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1985	'<tt>normal</tt>' label or the
				1986	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1987	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				1988	"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]	1989	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1990	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1991	returns multiple values then individual return values are only accessible through
				1992	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1993
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1994	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1995
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1996	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1997
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1998	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1999	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2000	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2001	convention</a> the call should use. If none is specified, the call defaults
				2002	to using C calling conventions.
				2003	</li>
				2004	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2005	function value being invoked. In most cases, this is a direct function
				2006	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2007	an arbitrary pointer to function value.
				2008	</li>
				2009
				2010	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2011	function to be invoked. </li>
				2012
				2013	<li>'<tt>function args</tt>': argument list whose types match the function
				2014	signature argument types. If the function signature indicates the function
				2015	accepts a variable number of arguments, the extra arguments can be
				2016	specified. </li>
				2017
				2018	<li>'<tt>normal label</tt>': the label reached when the called function
				2019	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2020
				2021	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2022	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2023
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2024	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2025
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2026	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2027
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2028	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2029	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2030	difference is that it establishes an association with a label, which is used by
				2031	the runtime library to unwind the stack.</p>
				2032
				2033	<p>This instruction is used in languages with destructors to ensure that proper
				2034	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2035	exception. Additionally, this is important for implementation of
				2036	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2037
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2038	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2039	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2040	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2041	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2042	%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]	2043	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2044	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2045	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2046
				2047
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2048	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2049
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2050	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2051	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2052
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2053	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2054
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2055	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2056	<pre>
				2057	unwind
				2058	</pre>
				2059
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2060	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2061
				2062	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2063	at the first callee in the dynamic call stack which used an <a
				2064	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2065	primarily used to implement exception handling.</p>
				2066
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2067	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2068
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2069	<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]	2070	immediately halt. The dynamic call stack is then searched for the first <a
				2071	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2072	execution continues at the "exceptional" destination block specified by the
				2073	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2074	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2075	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2076
				2077	<!-- _______________________________________________________________________ -->
				2078
				2079	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2080	Instruction</a> </div>
				2081
				2082	<div class="doc_text">
				2083
				2084	<h5>Syntax:</h5>
				2085	<pre>
				2086	unreachable
				2087	</pre>
				2088
				2089	<h5>Overview:</h5>
				2090
				2091	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2092	instruction is used to inform the optimizer that a particular portion of the
				2093	code is not reachable. This can be used to indicate that the code after a
				2094	no-return function cannot be reached, and other facts.</p>
				2095
				2096	<h5>Semantics:</h5>
				2097
				2098	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2099	</div>
				2100
				2101
				2102
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2103	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2104	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2105	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2106	<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]	2107	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]	2108	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2109	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]	2110	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2111	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2112	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2113	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2114	<div class="doc_subsubsection">
				2115	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2116	</div>
				2117
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2118	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2119
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2120	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2121
				2122	<pre>
				2123	<result> = add <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2124	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2125
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2126	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2127
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2128	<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]	2129
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2130	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2131
				2132	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2133	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2134	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2135	types.</p>
				2136
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2137	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2138
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2139	<p>The value produced is the integer or floating point sum of the two
				2140	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2141
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2142	<p>If an integer sum has unsigned overflow, the result returned is the
				2143	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2144	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2145
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2146	<p>Because LLVM integers use a two's complement representation, this
				2147	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2148
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2149	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2150
				2151	<pre>
				2152	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2153	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2154	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2155	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2156	<div class="doc_subsubsection">
				2157	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2158	</div>
				2159
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2160	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2161
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2162	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2163
				2164	<pre>
				2165	<result> = sub <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2166	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2167
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2168	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2169
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2170	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2171	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2172
				2173	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2174	'<tt>neg</tt>' instruction present in most other intermediate
				2175	representations.</p>
				2176
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2177	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2178
				2179	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2180	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2181	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2182	types.</p>
				2183
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2184	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2185
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2186	<p>The value produced is the integer or floating point difference of
				2187	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2188
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2189	<p>If an integer difference has unsigned overflow, the result returned is the
				2190	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2191	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2192
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2193	<p>Because LLVM integers use a two's complement representation, this
				2194	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2195
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2196	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2197	<pre>
				2198	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2199	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2200	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2201	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2202
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2204	<div class="doc_subsubsection">
				2205	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2206	</div>
				2207
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2208	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2209
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2210	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2211	<pre> <result> = mul <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2212	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2213	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2214	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2215	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2216
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2217	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2218
				2219	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2220	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2221	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2222	types.</p>
				2223
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2224	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2225
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2226	<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]	2227	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2228
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2229	<p>If the result of an integer multiplication has unsigned overflow,
				2230	the result returned is the mathematical result modulo
				2231	2<sup>n</sup>, where n is the bit width of the result.</p>
				2232	<p>Because LLVM integers use a two's complement representation, and the
				2233	result is the same width as the operands, this instruction returns the
				2234	correct result for both signed and unsigned integers. If a full product
				2235	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2236	should be sign-extended or zero-extended as appropriate to the
				2237	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2238	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2239	<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]	2240	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2241	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2242
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2243	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2244	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2245	</a></div>
				2246	<div class="doc_text">
				2247	<h5>Syntax:</h5>
				2248	<pre> <result> = udiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2249	</pre>
				2250	<h5>Overview:</h5>
				2251	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2252	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2253
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2254	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2255
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2256	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2257	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2258	values. Both arguments must have identical types.</p>
				2259
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2260	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2261
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2262	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2263	<p>Note that unsigned integer division and signed integer division are distinct
				2264	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2265	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2266	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2267	<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]	2268	</pre>
				2269	</div>
				2270	<!-- _______________________________________________________________________ -->
				2271	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2272	</a> </div>
				2273	<div class="doc_text">
				2274	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2275	<pre>
				2276	<result> = sdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2277	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2278
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2279	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2280
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2281	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2282	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2283
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2284	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2285
				2286	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2287	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2288	values. Both arguments must have identical types.</p>
				2289
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2290	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2291	<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]	2292	<p>Note that signed integer division and unsigned integer division are distinct
				2293	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2294	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2295	undefined behavior; this is a rare case, but can occur, for example,
				2296	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2297	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2298	<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]	2299	</pre>
				2300	</div>
				2301	<!-- _______________________________________________________________________ -->
				2302	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2303	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2304	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2305	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2306	<pre>
				2307	<result> = fdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2308	</pre>
				2309	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2310
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2311	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2312	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2313
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2314	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2315
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2316	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2317	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2318	of floating point values. Both arguments must have identical types.</p>
				2319
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2320	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2321
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2322	<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]	2323
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2324	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2325
				2326	<pre>
				2327	<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]	2328	</pre>
				2329	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2330
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2331	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2332	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2333	</div>
				2334	<div class="doc_text">
				2335	<h5>Syntax:</h5>
				2336	<pre> <result> = urem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2337	</pre>
				2338	<h5>Overview:</h5>
				2339	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2340	unsigned division of its two arguments.</p>
				2341	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2342	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2343	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2344	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2345	<h5>Semantics:</h5>
				2346	<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]	2347	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2348	<p>Note that unsigned integer remainder and signed integer remainder are
				2349	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2350	<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]	2351	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2352	<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]	2353	</pre>
				2354
				2355	</div>
				2356	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2357	<div class="doc_subsubsection">
				2358	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2359	</div>
				2360
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2361	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2362
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2363	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2364
				2365	<pre>
				2366	<result> = srem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2367	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2368
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2369	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2370
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2371	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2372	signed division of its two operands. This instruction can also take
				2373	<a href="#t_vector">vector</a> versions of the values in which case
				2374	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2375
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2376	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2377
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2378	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2379	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2380	values. Both arguments must have identical types.</p>
				2381
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2382	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2383
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2384	<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2385	has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
				2386	operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
				2387	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2388	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]	2389	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]	2390	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2391	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2392	<p>Note that signed integer remainder and unsigned integer remainder are
				2393	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2394	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2395	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2396	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2397	(The remainder doesn't actually overflow, but this rule lets srem be
				2398	implemented using instructions that return both the result of the division
				2399	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2400	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2401	<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]	2402	</pre>
				2403
				2404	</div>
				2405	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2406	<div class="doc_subsubsection">
				2407	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2408
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2409	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2410
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2411	<h5>Syntax:</h5>
				2412	<pre> <result> = frem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2413	</pre>
				2414	<h5>Overview:</h5>
				2415	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2416	division of its two operands.</p>
				2417	<h5>Arguments:</h5>
				2418	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2419	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2420	of floating point values. Both arguments must have identical types.</p>
				2421
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2422	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2423
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2424	<p>This instruction returns the <i>remainder</i> of a division.
				2425	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2426
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2427	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2428
				2429	<pre>
				2430	<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]	2431	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2432	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2433
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2434	<!-- ======================================================================= -->
				2435	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2436	Operations</a> </div>
				2437	<div class="doc_text">
				2438	<p>Bitwise binary operators are used to do various forms of
				2439	bit-twiddling in a program. They are generally very efficient
				2440	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2441	instructions. They require two operands of the same type, execute an operation on them,
				2442	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]	2443	</div>
				2444
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2445	<!-- _______________________________________________________________________ -->
				2446	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2447	Instruction</a> </div>
				2448	<div class="doc_text">
				2449	<h5>Syntax:</h5>
				2450	<pre> <result> = shl <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2451	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2452
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2453	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2454
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2455	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2456	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2457
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2458	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2459
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2460	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2461	href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2462	unsigned value. This instruction does not support
				2463	<a href="#t_vector">vector</a> operands.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2464
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2465	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2466
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2467	<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup> mod 2<sup>n</sup>,
				2468	where n is the width of the result. If <tt>var2</tt> is (statically or dynamically) negative or
				2469	equal to or larger than the number of bits in <tt>var1</tt>, the result is undefined.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2470
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2471	<h5>Example:</h5><pre>
				2472	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2473	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2474	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2475	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2476	</pre>
				2477	</div>
				2478	<!-- _______________________________________________________________________ -->
				2479	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2480	Instruction</a> </div>
				2481	<div class="doc_text">
				2482	<h5>Syntax:</h5>
				2483	<pre> <result> = lshr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2484	</pre>
				2485
				2486	<h5>Overview:</h5>
				2487	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2488	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]	2489
				2490	<h5>Arguments:</h5>
				2491	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2492	<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2493	unsigned value. This instruction does not support
				2494	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2495
				2496	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2497
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2498	<p>This instruction always performs a logical shift right operation. The most
				2499	significant bits of the result will be filled with zero bits after the
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2500	shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
				2501	the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2502
				2503	<h5>Example:</h5>
				2504	<pre>
				2505	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2506	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2507	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2508	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2509	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2510	</pre>
				2511	</div>
				2512
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2513	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2514	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2515	Instruction</a> </div>
				2516	<div class="doc_text">
				2517
				2518	<h5>Syntax:</h5>
				2519	<pre> <result> = ashr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2520	</pre>
				2521
				2522	<h5>Overview:</h5>
				2523	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2524	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]	2525
				2526	<h5>Arguments:</h5>
				2527	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2528	<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2529	unsigned value. This instruction does not support
				2530	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2531
				2532	<h5>Semantics:</h5>
				2533	<p>This instruction always performs an arithmetic shift right operation,
				2534	The most significant bits of the result will be filled with the sign bit
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2535	of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
				2536	larger than the number of bits in <tt>var1</tt>, the result is undefined.
				2537	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2538
				2539	<h5>Example:</h5>
				2540	<pre>
				2541	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2542	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2543	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2544	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2545	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2546	</pre>
				2547	</div>
				2548
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2549	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2550	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2551	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2552
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2553	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2554
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2555	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2556
				2557	<pre>
				2558	<result> = and <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2559	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2560
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2561	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2562
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2563	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2564	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2565
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2566	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2567
				2568	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2569	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2570	values. Both arguments must have identical types.</p>
				2571
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2572	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2573	<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]	2574	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2575	<div style="align: center">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2576	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2577	<tbody>
				2578	<tr>
				2579	<td>In0</td>
				2580	<td>In1</td>
				2581	<td>Out</td>
				2582	</tr>
				2583	<tr>
				2584	<td>0</td>
				2585	<td>0</td>
				2586	<td>0</td>
				2587	</tr>
				2588	<tr>
				2589	<td>0</td>
				2590	<td>1</td>
				2591	<td>0</td>
				2592	</tr>
				2593	<tr>
				2594	<td>1</td>
				2595	<td>0</td>
				2596	<td>0</td>
				2597	</tr>
				2598	<tr>
				2599	<td>1</td>
				2600	<td>1</td>
				2601	<td>1</td>
				2602	</tr>
				2603	</tbody>
				2604	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2605	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2606	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2607	<pre>
				2608	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2609	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2610	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2611	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2612	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2613	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2614	<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]	2615	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2616	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2617	<pre> <result> = or <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2618	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2619	<h5>Overview:</h5>
				2620	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2621	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2622	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2623
				2624	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2625	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2626	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2627	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2628	<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]	2629	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2630	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2631	<table border="1" cellspacing="0" cellpadding="4">
				2632	<tbody>
				2633	<tr>
				2634	<td>In0</td>
				2635	<td>In1</td>
				2636	<td>Out</td>
				2637	</tr>
				2638	<tr>
				2639	<td>0</td>
				2640	<td>0</td>
				2641	<td>0</td>
				2642	</tr>
				2643	<tr>
				2644	<td>0</td>
				2645	<td>1</td>
				2646	<td>1</td>
				2647	</tr>
				2648	<tr>
				2649	<td>1</td>
				2650	<td>0</td>
				2651	<td>1</td>
				2652	</tr>
				2653	<tr>
				2654	<td>1</td>
				2655	<td>1</td>
				2656	<td>1</td>
				2657	</tr>
				2658	</tbody>
				2659	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2660	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2661	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2662	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2663	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2664	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2665	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2666	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2667	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2668	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2669	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2670	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2671	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2672	<pre> <result> = xor <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2673	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2674	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2675	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2676	or of its two operands. The <tt>xor</tt> is used to implement the
				2677	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2678	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2679	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2680	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2681	values. Both arguments must have identical types.</p>
				2682
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2683	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2684
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2685	<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]	2686	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2687	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2688	<table border="1" cellspacing="0" cellpadding="4">
				2689	<tbody>
				2690	<tr>
				2691	<td>In0</td>
				2692	<td>In1</td>
				2693	<td>Out</td>
				2694	</tr>
				2695	<tr>
				2696	<td>0</td>
				2697	<td>0</td>
				2698	<td>0</td>
				2699	</tr>
				2700	<tr>
				2701	<td>0</td>
				2702	<td>1</td>
				2703	<td>1</td>
				2704	</tr>
				2705	<tr>
				2706	<td>1</td>
				2707	<td>0</td>
				2708	<td>1</td>
				2709	</tr>
				2710	<tr>
				2711	<td>1</td>
				2712	<td>1</td>
				2713	<td>0</td>
				2714	</tr>
				2715	</tbody>
				2716	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2717	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2718	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2719	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2720	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2721	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2722	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2723	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2724	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2725	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2726
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2727	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2728	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2729	<a name="vectorops">Vector Operations</a>
				2730	</div>
				2731
				2732	<div class="doc_text">
				2733
				2734	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2735	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2736	vector-specific operations needed to process vectors effectively. While LLVM
				2737	does directly support these vector operations, many sophisticated algorithms
				2738	will want to use target-specific intrinsics to take full advantage of a specific
				2739	target.</p>
				2740
				2741	</div>
				2742
				2743	<!-- _______________________________________________________________________ -->
				2744	<div class="doc_subsubsection">
				2745	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2746	</div>
				2747
				2748	<div class="doc_text">
				2749
				2750	<h5>Syntax:</h5>
				2751
				2752	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2753	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2754	</pre>
				2755
				2756	<h5>Overview:</h5>
				2757
				2758	<p>
				2759	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2760	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2761	</p>
				2762
				2763
				2764	<h5>Arguments:</h5>
				2765
				2766	<p>
				2767	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2768	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]	2769	an index indicating the position from which to extract the element.
				2770	The index may be a variable.</p>
				2771
				2772	<h5>Semantics:</h5>
				2773
				2774	<p>
				2775	The result is a scalar of the same type as the element type of
				2776	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2777	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2778	results are undefined.
				2779	</p>
				2780
				2781	<h5>Example:</h5>
				2782
				2783	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2784	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2785	</pre>
				2786	</div>
				2787
				2788
				2789	<!-- _______________________________________________________________________ -->
				2790	<div class="doc_subsubsection">
				2791	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2792	</div>
				2793
				2794	<div class="doc_text">
				2795
				2796	<h5>Syntax:</h5>
				2797
				2798	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2799	<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]	2800	</pre>
				2801
				2802	<h5>Overview:</h5>
				2803
				2804	<p>
				2805	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2806	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2807	</p>
				2808
				2809
				2810	<h5>Arguments:</h5>
				2811
				2812	<p>
				2813	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2814	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]	2815	scalar value whose type must equal the element type of the first
				2816	operand. The third operand is an index indicating the position at
				2817	which to insert the value. The index may be a variable.</p>
				2818
				2819	<h5>Semantics:</h5>
				2820
				2821	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2822	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]	2823	element values are those of <tt>val</tt> except at position
				2824	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2825	exceeds the length of <tt>val</tt>, the results are undefined.
				2826	</p>
				2827
				2828	<h5>Example:</h5>
				2829
				2830	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2831	%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]	2832	</pre>
				2833	</div>
				2834
				2835	<!-- _______________________________________________________________________ -->
				2836	<div class="doc_subsubsection">
				2837	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2838	</div>
				2839
				2840	<div class="doc_text">
				2841
				2842	<h5>Syntax:</h5>
				2843
				2844	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2845	<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]	2846	</pre>
				2847
				2848	<h5>Overview:</h5>
				2849
				2850	<p>
				2851	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2852	from two input vectors, returning a vector of the same type.
				2853	</p>
				2854
				2855	<h5>Arguments:</h5>
				2856
				2857	<p>
				2858	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2859	with types that match each other and types that match the result of the
				2860	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]	2861	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]	2862	</p>
				2863
				2864	<p>
				2865	The shuffle mask operand is required to be a constant vector with either
				2866	constant integer or undef values.
				2867	</p>
				2868
				2869	<h5>Semantics:</h5>
				2870
				2871	<p>
				2872	The elements of the two input vectors are numbered from left to right across
				2873	both of the vectors. The shuffle mask operand specifies, for each element of
				2874	the result vector, which element of the two input registers the result element
				2875	gets. The element selector may be undef (meaning "don't care") and the second
				2876	operand may be undef if performing a shuffle from only one vector.
				2877	</p>
				2878
				2879	<h5>Example:</h5>
				2880
				2881	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2882	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2883	<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]	2884	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2885	<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]	2886	</pre>
				2887	</div>
				2888
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2889
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2890	<!-- ======================================================================= -->
				2891	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2892	<a name="aggregateops">Aggregate Operations</a>
				2893	</div>
				2894
				2895	<div class="doc_text">
				2896
				2897	<p>LLVM supports several instructions for working with aggregate values.
				2898	</p>
				2899
				2900	</div>
				2901
				2902	<!-- _______________________________________________________________________ -->
				2903	<div class="doc_subsubsection">
				2904	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2905	</div>
				2906
				2907	<div class="doc_text">
				2908
				2909	<h5>Syntax:</h5>
				2910
				2911	<pre>
				2912	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2913	</pre>
				2914
				2915	<h5>Overview:</h5>
				2916
				2917	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2918	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2919	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2920	</p>
				2921
				2922
				2923	<h5>Arguments:</h5>
				2924
				2925	<p>
				2926	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2927	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]	2928	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2929	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2930	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2931	</p>
				2932
				2933	<h5>Semantics:</h5>
				2934
				2935	<p>
				2936	The result is the value at the position in the aggregate specified by
				2937	the index operands.
				2938	</p>
				2939
				2940	<h5>Example:</h5>
				2941
				2942	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2943	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2944	</pre>
				2945	</div>
				2946
				2947
				2948	<!-- _______________________________________________________________________ -->
				2949	<div class="doc_subsubsection">
				2950	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				2951	</div>
				2952
				2953	<div class="doc_text">
				2954
				2955	<h5>Syntax:</h5>
				2956
				2957	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2958	<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]	2959	</pre>
				2960
				2961	<h5>Overview:</h5>
				2962
				2963	<p>
				2964	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2965	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2966	</p>
				2967
				2968
				2969	<h5>Arguments:</h5>
				2970
				2971	<p>
				2972	The first operand of an '<tt>insertvalue</tt>' instruction is a
				2973	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				2974	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	2975	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2976	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]	2977	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2978	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2979	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]	2980	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2981
				2982	<h5>Semantics:</h5>
				2983
				2984	<p>
				2985	The result is an aggregate of the same type as <tt>val</tt>. Its
				2986	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]	2987	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2988	</p>
				2989
				2990	<h5>Example:</h5>
				2991
				2992	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	2993	%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]	2994	</pre>
				2995	</div>
				2996
				2997
				2998	<!-- ======================================================================= -->
				2999	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3000	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3001	</div>
				3002
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3003	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3004
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3005	<p>A key design point of an SSA-based representation is how it
				3006	represents memory. In LLVM, no memory locations are in SSA form, which
				3007	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3008	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3009
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3010	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3011
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3012	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3013	<div class="doc_subsubsection">
				3014	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3015	</div>
				3016
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3017	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3018
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3019	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3020
				3021	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3022	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3023	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3024
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3025	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3026
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3027	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3028	heap and returns a pointer to it. The object is always allocated in the generic
				3029	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3030
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3031	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3032
				3033	<p>The '<tt>malloc</tt>' instruction allocates
				3034	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3035	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]	3036	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3037	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3038	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]	3039	be aligned to at least that boundary. If not specified, or if zero, the target can
				3040	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3041
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3042	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3043
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3044	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3045
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3046	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3047	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3048	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3049
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3050	<h5>Example:</h5>
				3051
				3052	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3053	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3054
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3055	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3056	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3057	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3058	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3059	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3060	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3061	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3062
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3063	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3064	<div class="doc_subsubsection">
				3065	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3066	</div>
				3067
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3068	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3069
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3070	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3071
				3072	<pre>
				3073	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3074	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3075
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3076	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3077
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3078	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3079	memory heap to be reallocated in the future.</p>
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>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3082
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3083	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3084	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3085	instruction.</p>
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>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3088
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3089	<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]	3090	after this instruction executes. If the pointer is null, the operation
				3091	is a noop.</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>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3094
				3095	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3096	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3097	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3098	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3099	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3100
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3101	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3102	<div class="doc_subsubsection">
				3103	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3104	</div>
				3105
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3106	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3107
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3108	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3109
				3110	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3111	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3112	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3113
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3114	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3115
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3116	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3117	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3118	returns to its caller. The object is always allocated in the generic address
				3119	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3120
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3121	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3122
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3123	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3124	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3125	appropriate type to the program. If "NumElements" is specified, it is the
				3126	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3127	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]	3128	to be aligned to at least that boundary. If not specified, or if zero, the target
				3129	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3130
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3131	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3132
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3133	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3134
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3135	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3136	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3137	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3138	instruction is commonly used to represent automatic variables that must
				3139	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]	3140	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]	3141	instructions), the memory is reclaimed. Allocating zero bytes
				3142	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3143
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3144	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3145
				3146	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3147	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3148	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3149	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3150	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3151	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3152	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3153
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3154	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3155	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3156	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3157	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3158	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3159	<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]	3160	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3161	<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]	3162	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3163	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3164	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3165	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]	3166	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]	3167	the number or order of execution of this <tt>load</tt> with other
				3168	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3169	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3170	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3171	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3172	(that is, the alignment of the memory address). A value of 0 or an
				3173	omitted "align" argument means that the operation has the preferential
				3174	alignment for the target. It is the responsibility of the code emitter
				3175	to ensure that the alignment information is correct. Overestimating
				3176	the alignment results in an undefined behavior. Underestimating the
				3177	alignment may produce less efficient code. An alignment of 1 is always
				3178	safe.
				3179	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3180	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3181	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3182	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3183	<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]	3184	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3185	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3186	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3187	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3188	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3189	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3190	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3191	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3192	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3193	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3194	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3195	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3196	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3197	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3198	<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]	3199	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3200	<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]	3201	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]	3202	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3203	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3204	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]	3205	optimizer is not allowed to modify the number or order of execution of
				3206	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3207	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3208	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3209	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3210	(that is, the alignment of the memory address). A value of 0 or an
				3211	omitted "align" argument means that the operation has the preferential
				3212	alignment for the target. It is the responsibility of the code emitter
				3213	to ensure that the alignment information is correct. Overestimating
				3214	the alignment results in an undefined behavior. Underestimating the
				3215	alignment may produce less efficient code. An alignment of 1 is always
				3216	safe.
				3217	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3218	<h5>Semantics:</h5>
				3219	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3220	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3221	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3222	<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]	3223	store i32 3, i32* %ptr <i>; yields {void}</i>
				3224	%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]	3225	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3226	</div>
				3227
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3228	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3229	<div class="doc_subsubsection">
				3230	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3231	</div>
				3232
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3233	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3234	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3235	<pre>
				3236	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3237	</pre>
				3238
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3239	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3240
				3241	<p>
				3242	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3243	subelement of an aggregate data structure.</p>
				3244
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3245	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3246
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3247	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3248	elements of the aggregate object to index to. The actual types of the arguments
				3249	provided depend on the type of the first pointer argument. The
				3250	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3251	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]	3252	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3253	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3254	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3255
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3256	<p>For example, let's consider a C code fragment and how it gets
				3257	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3258
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3259	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3260	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3261	struct RT {
				3262	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3263	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3264	char C;
				3265	};
				3266	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3267	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3268	double Y;
				3269	struct RT Z;
				3270	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3271
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3272	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3273	return &s[1].Z.B[5][13];
				3274	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3275	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3276	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3277
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3278	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3279
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3280	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3281	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3282	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3283	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3284
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3285	define i32* %foo(%ST* %s) {
				3286	entry:
				3287	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3288	ret i32* %reg
				3289	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3290	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3291	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3292
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3293	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3294
				3295	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3296	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]	3297	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]	3298	<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]	3299	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3300	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3301
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3302	<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]	3303	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]	3304	}</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]	3305	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3306	i8 }</tt>' type, another structure. The third index indexes into the second
				3307	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]	3308	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3309	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3310	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]	3311
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3312	<p>Note that it is perfectly legal to index partially through a
				3313	structure, returning a pointer to an inner element. Because of this,
				3314	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3315
				3316	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3317	define i32* %foo(%ST* %s) {
				3318	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3319	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3320	%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]	3321	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3322	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3323	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3324	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3325	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3326
				3327	<p>Note that it is undefined to access an array out of bounds: array and
				3328	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]	3329	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]	3330	defined to be accessible as variable length arrays, which requires access
				3331	beyond the zero'th element.</p>
				3332
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3333	<p>The getelementptr instruction is often confusing. For some more insight
				3334	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3335	FAQ</a>.</p>
				3336
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3337	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3338
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3339	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3340	<i>; yields [12 x i8]*:aptr</i>
				3341	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3342	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3343	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3344
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3345	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3346	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3347	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3348	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3349	<p>The instructions in this category are the conversion instructions (casting)
				3350	which all take a single operand and a type. They perform various bit conversions
				3351	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3352	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3353
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3354	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3355	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3356	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3357	</div>
				3358	<div class="doc_text">
				3359
				3360	<h5>Syntax:</h5>
				3361	<pre>
				3362	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3363	</pre>
				3364
				3365	<h5>Overview:</h5>
				3366	<p>
				3367	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3368	</p>
				3369
				3370	<h5>Arguments:</h5>
				3371	<p>
				3372	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3373	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]	3374	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]	3375	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3376	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3377
				3378	<h5>Semantics:</h5>
				3379	<p>
				3380	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]	3381	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3382	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3383	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3384
				3385	<h5>Example:</h5>
				3386	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3387	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3388	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3389	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3390	</pre>
				3391	</div>
				3392
				3393	<!-- _______________________________________________________________________ -->
				3394	<div class="doc_subsubsection">
				3395	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3396	</div>
				3397	<div class="doc_text">
				3398
				3399	<h5>Syntax:</h5>
				3400	<pre>
				3401	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3402	</pre>
				3403
				3404	<h5>Overview:</h5>
				3405	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3406	<tt>ty2</tt>.</p>
				3407
				3408
				3409	<h5>Arguments:</h5>
				3410	<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]	3411	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3412	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]	3413	<tt>value</tt> must be smaller than the bit size of the destination type,
				3414	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3415
				3416	<h5>Semantics:</h5>
				3417	<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]	3418	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]	3419
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3420	<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]	3421
				3422	<h5>Example:</h5>
				3423	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3424	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3425	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3426	</pre>
				3427	</div>
				3428
				3429	<!-- _______________________________________________________________________ -->
				3430	<div class="doc_subsubsection">
				3431	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3432	</div>
				3433	<div class="doc_text">
				3434
				3435	<h5>Syntax:</h5>
				3436	<pre>
				3437	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3438	</pre>
				3439
				3440	<h5>Overview:</h5>
				3441	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3442
				3443	<h5>Arguments:</h5>
				3444	<p>
				3445	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]	3446	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3447	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]	3448	<tt>value</tt> must be smaller than the bit size of the destination type,
				3449	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3450
				3451	<h5>Semantics:</h5>
				3452	<p>
				3453	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3454	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]	3455	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3456
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3457	<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]	3458
				3459	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3460	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3461	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3462	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3463	</pre>
				3464	</div>
				3465
				3466	<!-- _______________________________________________________________________ -->
				3467	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3468	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3469	</div>
				3470
				3471	<div class="doc_text">
				3472
				3473	<h5>Syntax:</h5>
				3474
				3475	<pre>
				3476	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3477	</pre>
				3478
				3479	<h5>Overview:</h5>
				3480	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3481	<tt>ty2</tt>.</p>
				3482
				3483
				3484	<h5>Arguments:</h5>
				3485	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3486	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3487	cast it to. The size of <tt>value</tt> must be larger than the size of
				3488	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3489	<i>no-op cast</i>.</p>
				3490
				3491	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3492	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3493	<a href="#t_floating">floating point</a> type to a smaller
				3494	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3495	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3496
				3497	<h5>Example:</h5>
				3498	<pre>
				3499	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3500	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3501	</pre>
				3502	</div>
				3503
				3504	<!-- _______________________________________________________________________ -->
				3505	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3506	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3507	</div>
				3508	<div class="doc_text">
				3509
				3510	<h5>Syntax:</h5>
				3511	<pre>
				3512	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3513	</pre>
				3514
				3515	<h5>Overview:</h5>
				3516	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3517	floating point value.</p>
				3518
				3519	<h5>Arguments:</h5>
				3520	<p>The '<tt>fpext</tt>' instruction takes a
				3521	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3522	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3523	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3524
				3525	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3526	<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]	3527	<a href="#t_floating">floating point</a> type to a larger
				3528	<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]	3529	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]	3530	<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]	3531
				3532	<h5>Example:</h5>
				3533	<pre>
				3534	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3535	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3536	</pre>
				3537	</div>
				3538
				3539	<!-- _______________________________________________________________________ -->
				3540	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3541	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3542	</div>
				3543	<div class="doc_text">
				3544
				3545	<h5>Syntax:</h5>
				3546	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3547	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3548	</pre>
				3549
				3550	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3551	<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]	3552	unsigned integer equivalent of type <tt>ty2</tt>.
				3553	</p>
				3554
				3555	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3556	<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]	3557	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3558	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3559	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3560	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]	3561
				3562	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3563	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3564	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3565	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3566	the results are undefined.</p>
				3567
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3568	<h5>Example:</h5>
				3569	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3570	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3571	%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]	3572	%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]	3573	</pre>
				3574	</div>
				3575
				3576	<!-- _______________________________________________________________________ -->
				3577	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3578	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3579	</div>
				3580	<div class="doc_text">
				3581
				3582	<h5>Syntax:</h5>
				3583	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3584	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3585	</pre>
				3586
				3587	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3588	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3589	<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]	3590	</p>
				3591
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3592	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3593	<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]	3594	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3595	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3596	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3597	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]	3598
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3599	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3600	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3601	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3602	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3603	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3604
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3605	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3606	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3607	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3608	%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]	3609	%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]	3610	</pre>
				3611	</div>
				3612
				3613	<!-- _______________________________________________________________________ -->
				3614	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3615	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3616	</div>
				3617	<div class="doc_text">
				3618
				3619	<h5>Syntax:</h5>
				3620	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3621	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3622	</pre>
				3623
				3624	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3625	<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]	3626	integer and converts that value to the <tt>ty2</tt> type.</p>
				3627
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3628	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3629	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3630	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3631	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3632	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3633	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]	3634
				3635	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3636	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3637	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3638	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]	3639
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3640	<h5>Example:</h5>
				3641	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3642	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3643	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3644	</pre>
				3645	</div>
				3646
				3647	<!-- _______________________________________________________________________ -->
				3648	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3649	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3650	</div>
				3651	<div class="doc_text">
				3652
				3653	<h5>Syntax:</h5>
				3654	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3655	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3656	</pre>
				3657
				3658	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3659	<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]	3660	integer and converts that value to the <tt>ty2</tt> type.</p>
				3661
				3662	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3663	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3664	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3665	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3666	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3667	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]	3668
				3669	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3670	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3671	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3672	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]	3673
				3674	<h5>Example:</h5>
				3675	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3676	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3677	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3678	</pre>
				3679	</div>
				3680
				3681	<!-- _______________________________________________________________________ -->
				3682	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3683	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3684	</div>
				3685	<div class="doc_text">
				3686
				3687	<h5>Syntax:</h5>
				3688	<pre>
				3689	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3690	</pre>
				3691
				3692	<h5>Overview:</h5>
				3693	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3694	the integer type <tt>ty2</tt>.</p>
				3695
				3696	<h5>Arguments:</h5>
				3697	<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]	3698	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]	3699	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3700
				3701	<h5>Semantics:</h5>
				3702	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3703	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3704	truncating or zero extending that value to the size of the integer type. If
				3705	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3706	<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]	3707	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3708	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3709
				3710	<h5>Example:</h5>
				3711	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3712	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3713	%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]	3714	</pre>
				3715	</div>
				3716
				3717	<!-- _______________________________________________________________________ -->
				3718	<div class="doc_subsubsection">
				3719	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3720	</div>
				3721	<div class="doc_text">
				3722
				3723	<h5>Syntax:</h5>
				3724	<pre>
				3725	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3726	</pre>
				3727
				3728	<h5>Overview:</h5>
				3729	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3730	a pointer type, <tt>ty2</tt>.</p>
				3731
				3732	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3733	<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]	3734	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]	3735	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3736
				3737	<h5>Semantics:</h5>
				3738	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3739	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3740	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3741	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3742	the size of a pointer then a zero extension is done. If they are the same size,
				3743	nothing is done (<i>no-op cast</i>).</p>
				3744
				3745	<h5>Example:</h5>
				3746	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3747	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3748	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3749	%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]	3750	</pre>
				3751	</div>
				3752
				3753	<!-- _______________________________________________________________________ -->
				3754	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3755	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3756	</div>
				3757	<div class="doc_text">
				3758
				3759	<h5>Syntax:</h5>
				3760	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3761	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3762	</pre>
				3763
				3764	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3765
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3766	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3767	<tt>ty2</tt> without changing any bits.</p>
				3768
				3769	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3770
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3771	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3772	a first class value, and a type to cast it to, which must also be a <a
				3773	href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	3774	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]	3775	type is a pointer, the destination type must also be a pointer. This
				3776	instruction supports bitwise conversion of vectors to integers and to vectors
				3777	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3778
				3779	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3780	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3781	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3782	this conversion. The conversion is done as if the <tt>value</tt> had been
				3783	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3784	converted to other pointer types with this instruction. To convert pointers to
				3785	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3786	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3787
				3788	<h5>Example:</h5>
				3789	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3790	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3791	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3792	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3793	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3794	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3795
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3796	<!-- ======================================================================= -->
				3797	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3798	<div class="doc_text">
				3799	<p>The instructions in this category are the "miscellaneous"
				3800	instructions, which defy better classification.</p>
				3801	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3802
				3803	<!-- _______________________________________________________________________ -->
				3804	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3805	</div>
				3806	<div class="doc_text">
				3807	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3808	<pre> <result> = icmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3809	</pre>
				3810	<h5>Overview:</h5>
				3811	<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3812	of its two integer or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3813	<h5>Arguments:</h5>
				3814	<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]	3815	the condition code indicating the kind of comparison to perform. It is not
				3816	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3817	<ol>
				3818	<li><tt>eq</tt>: equal</li>
				3819	<li><tt>ne</tt>: not equal </li>
				3820	<li><tt>ugt</tt>: unsigned greater than</li>
				3821	<li><tt>uge</tt>: unsigned greater or equal</li>
				3822	<li><tt>ult</tt>: unsigned less than</li>
				3823	<li><tt>ule</tt>: unsigned less or equal</li>
				3824	<li><tt>sgt</tt>: signed greater than</li>
				3825	<li><tt>sge</tt>: signed greater or equal</li>
				3826	<li><tt>slt</tt>: signed less than</li>
				3827	<li><tt>sle</tt>: signed less or equal</li>
				3828	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3829	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer	350f8aa	2007-01-04 05:19:58 +0000	[diff] [blame]	3830	<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3831	<h5>Semantics:</h5>
				3832	<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
				3833	the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3834	yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3835	<ol>
				3836	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3837	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3838	</li>
				3839	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3840	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3841	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
				3842	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3843	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
				3844	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3845	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
				3846	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3847	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
				3848	<tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
				3849	<li><tt>sgt</tt>: interprets the operands as signed values and yields
				3850	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3851	<li><tt>sge</tt>: interprets the operands as signed values and yields
				3852	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3853	<li><tt>slt</tt>: interprets the operands as signed values and yields
				3854	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3855	<li><tt>sle</tt>: interprets the operands as signed values and yields
				3856	<tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3857	</ol>
				3858	<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]	3859	values are compared as if they were integers.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3860
				3861	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3862	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3863	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3864	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3865	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3866	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3867	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3868	</pre>
				3869	</div>
				3870
				3871	<!-- _______________________________________________________________________ -->
				3872	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3873	</div>
				3874	<div class="doc_text">
				3875	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3876	<pre> <result> = fcmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3877	</pre>
				3878	<h5>Overview:</h5>
				3879	<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
				3880	of its floating point operands.</p>
				3881	<h5>Arguments:</h5>
				3882	<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]	3883	the condition code indicating the kind of comparison to perform. It is not
				3884	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3885	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3886	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3887	<li><tt>oeq</tt>: ordered and equal</li>
				3888	<li><tt>ogt</tt>: ordered and greater than </li>
				3889	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3890	<li><tt>olt</tt>: ordered and less than </li>
				3891	<li><tt>ole</tt>: ordered and less than or equal</li>
				3892	<li><tt>one</tt>: ordered and not equal</li>
				3893	<li><tt>ord</tt>: ordered (no nans)</li>
				3894	<li><tt>ueq</tt>: unordered or equal</li>
				3895	<li><tt>ugt</tt>: unordered or greater than </li>
				3896	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3897	<li><tt>ult</tt>: unordered or less than </li>
				3898	<li><tt>ule</tt>: unordered or less than or equal</li>
				3899	<li><tt>une</tt>: unordered or not equal</li>
				3900	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3901	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3902	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3903	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3904	<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer	350f8aa	2007-01-04 05:19:58 +0000	[diff] [blame]	3905	<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
				3906	<a href="#t_floating">floating point</a> typed. They must have identical
				3907	types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3908	<h5>Semantics:</h5>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3909	<p>The '<tt>fcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3910	according to the condition code given as <tt>cond</tt>. The comparison performed
				3911	always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3912	<ol>
				3913	<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]	3914	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3915	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3916	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3917	<tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3918	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3919	<tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3920	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3921	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3922	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3923	<tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3924	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3925	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3926	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3927	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3928	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3929	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3930	<tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3931	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3932	<tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3933	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3934	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3935	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3936	<tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3937	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3938	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3939	<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]	3940	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				3941	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3942
				3943	<h5>Example:</h5>
				3944	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
				3945	<result> = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
				3946	<result> = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				3947	<result> = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
				3948	</pre>
				3949	</div>
				3950
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3951	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3952	<div class="doc_subsubsection">
				3953	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				3954	</div>
				3955	<div class="doc_text">
				3956	<h5>Syntax:</h5>
				3957	<pre> <result> = vicmp <cond> <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				3958	</pre>
				3959	<h5>Overview:</h5>
				3960	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				3961	element-wise comparison of its two integer vector operands.</p>
				3962	<h5>Arguments:</h5>
				3963	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				3964	the condition code indicating the kind of comparison to perform. It is not
				3965	a value, just a keyword. The possible condition code are:
				3966	<ol>
				3967	<li><tt>eq</tt>: equal</li>
				3968	<li><tt>ne</tt>: not equal </li>
				3969	<li><tt>ugt</tt>: unsigned greater than</li>
				3970	<li><tt>uge</tt>: unsigned greater or equal</li>
				3971	<li><tt>ult</tt>: unsigned less than</li>
				3972	<li><tt>ule</tt>: unsigned less or equal</li>
				3973	<li><tt>sgt</tt>: signed greater than</li>
				3974	<li><tt>sge</tt>: signed greater or equal</li>
				3975	<li><tt>slt</tt>: signed less than</li>
				3976	<li><tt>sle</tt>: signed less or equal</li>
				3977	</ol>
				3978	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				3979	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				3980	<h5>Semantics:</h5>
				3981	<p>The '<tt>vicmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3982	according to the condition code given as <tt>cond</tt>. The comparison yields a
				3983	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				3984	identical type as the values being compared. The most significant bit in each
				3985	element is 1 if the element-wise comparison evaluates to true, and is 0
				3986	otherwise. All other bits of the result are undefined. The condition codes
				3987	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				3988	instruction</a>.
				3989
				3990	<h5>Example:</h5>
				3991	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3992	<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>
				3993	<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]	3994	</pre>
				3995	</div>
				3996
				3997	<!-- _______________________________________________________________________ -->
				3998	<div class="doc_subsubsection">
				3999	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4000	</div>
				4001	<div class="doc_text">
				4002	<h5>Syntax:</h5>
				4003	<pre> <result> = vfcmp <cond> <ty> <var1>, <var2></pre>
				4004	<h5>Overview:</h5>
				4005	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4006	element-wise comparison of its two floating point vector operands. The output
				4007	elements have the same width as the input elements.</p>
				4008	<h5>Arguments:</h5>
				4009	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4010	the condition code indicating the kind of comparison to perform. It is not
				4011	a value, just a keyword. The possible condition code are:
				4012	<ol>
				4013	<li><tt>false</tt>: no comparison, always returns false</li>
				4014	<li><tt>oeq</tt>: ordered and equal</li>
				4015	<li><tt>ogt</tt>: ordered and greater than </li>
				4016	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4017	<li><tt>olt</tt>: ordered and less than </li>
				4018	<li><tt>ole</tt>: ordered and less than or equal</li>
				4019	<li><tt>one</tt>: ordered and not equal</li>
				4020	<li><tt>ord</tt>: ordered (no nans)</li>
				4021	<li><tt>ueq</tt>: unordered or equal</li>
				4022	<li><tt>ugt</tt>: unordered or greater than </li>
				4023	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4024	<li><tt>ult</tt>: unordered or less than </li>
				4025	<li><tt>ule</tt>: unordered or less than or equal</li>
				4026	<li><tt>une</tt>: unordered or not equal</li>
				4027	<li><tt>uno</tt>: unordered (either nans)</li>
				4028	<li><tt>true</tt>: no comparison, always returns true</li>
				4029	</ol>
				4030	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4031	<a href="#t_floating">floating point</a> typed. They must also be identical
				4032	types.</p>
				4033	<h5>Semantics:</h5>
				4034	<p>The '<tt>vfcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				4035	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4036	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4037	an identical number of elements as the values being compared, and each element
				4038	having identical with to the width of the floating point elements. The most
				4039	significant bit in each element is 1 if the element-wise comparison evaluates to
				4040	true, and is 0 otherwise. All other bits of the result are undefined. The
				4041	condition codes are evaluated identically to the
				4042	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4043
				4044	<h5>Example:</h5>
				4045	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4046	<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>
				4047	<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]	4048	</pre>
				4049	</div>
				4050
				4051	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4052	<div class="doc_subsubsection">
				4053	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4054	</div>
				4055
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4056	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4057
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4058	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4059
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4060	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4061	<h5>Overview:</h5>
				4062	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4063	the SSA graph representing the function.</p>
				4064	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4065
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4066	<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]	4067	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4068	as arguments, with one pair for each predecessor basic block of the
				4069	current block. Only values of <a href="#t_firstclass">first class</a>
				4070	type may be used as the value arguments to the PHI node. Only labels
				4071	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4072
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4073	<p>There must be no non-phi instructions between the start of a basic
				4074	block and the PHI instructions: i.e. PHI instructions must be first in
				4075	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4076
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4077	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4078
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4079	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4080	specified by the pair corresponding to the predecessor basic block that executed
				4081	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4082
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4083	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4084	<pre>
				4085	Loop: ; Infinite loop that counts from 0 on up...
				4086	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4087	%nextindvar = add i32 %indvar, 1
				4088	br label %Loop
				4089	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4090	</div>
				4091
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4092	<!-- _______________________________________________________________________ -->
				4093	<div class="doc_subsubsection">
				4094	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4095	</div>
				4096
				4097	<div class="doc_text">
				4098
				4099	<h5>Syntax:</h5>
				4100
				4101	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4102	<result> = select i1 <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4103	</pre>
				4104
				4105	<h5>Overview:</h5>
				4106
				4107	<p>
				4108	The '<tt>select</tt>' instruction is used to choose one value based on a
				4109	condition, without branching.
				4110	</p>
				4111
				4112
				4113	<h5>Arguments:</h5>
				4114
				4115	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4116	The '<tt>select</tt>' instruction requires an 'i1' value indicating the
				4117	condition, and two values of the same <a href="#t_firstclass">first class</a>
				4118	type. If the val1/val2 are vectors, the entire vectors are selected, not
				4119	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4120	</p>
				4121
				4122	<h5>Semantics:</h5>
				4123
				4124	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4125	If the i1 condition evaluates is 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4126	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4127	</p>
				4128
				4129	<h5>Example:</h5>
				4130
				4131	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4132	%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]	4133	</pre>
				4134	</div>
				4135
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4136
				4137	<!-- _______________________________________________________________________ -->
				4138	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4139	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4140	</div>
				4141
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4142	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4143
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4144	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4145	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4146	<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]	4147	</pre>
				4148
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4149	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4150
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4151	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4152
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4153	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4154
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4155	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4156
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4157	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4158	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4159	<p>The optional "tail" marker indicates whether the callee function accesses
				4160	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]	4161	function call is eligible for tail call optimization. Note that calls may
				4162	be marked "tail" even if they do not occur before a <a
				4163	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4164	</li>
				4165	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4166	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4167	convention</a> the call should use. If none is specified, the call defaults
				4168	to using C calling conventions.
				4169	</li>
				4170	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4171	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4172	the type of the return value. Functions that return no value are marked
				4173	<tt><a href="#t_void">void</a></tt>.</p>
				4174	</li>
				4175	<li>
				4176	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4177	value being invoked. The argument types must match the types implied by
				4178	this signature. This type can be omitted if the function is not varargs
				4179	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]	4180	</li>
				4181	<li>
				4182	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4183	be invoked. In most cases, this is a direct function invocation, but
				4184	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]	4185	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4186	</li>
				4187	<li>
				4188	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4189	function signature argument types. All arguments must be of
				4190	<a href="#t_firstclass">first class</a> type. If the function signature
				4191	indicates the function accepts a variable number of arguments, the extra
				4192	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4193	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4194	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4195
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4196	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4197
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4198	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4199	transfer to a specified function, with its incoming arguments bound to
				4200	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4201	instruction in the called function, control flow continues with the
				4202	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4203	function is bound to the result argument. If the callee returns multiple
				4204	values then the return values of the function are only accessible through
				4205	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4206
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4207	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4208
				4209	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4210	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4211	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4212	%X = tail call i32 @foo() <i>; yields i32</i>
				4213	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4214	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4215
				4216	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4217	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4218	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4219	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4220	</pre>
				4221
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4222	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4223
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4224	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4225	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4226	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4227	</div>
				4228
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4229	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4230
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4231	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4232
				4233	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4234	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4235	</pre>
				4236
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4237	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4238
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4239	<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]	4240	the "variable argument" area of a function call. It is used to implement the
				4241	<tt>va_arg</tt> macro in C.</p>
				4242
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4243	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4244
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4245	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4246	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4247	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]	4248	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4249
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4250	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4251
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4252	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4253	type from the specified <tt>va_list</tt> and causes the
				4254	<tt>va_list</tt> to point to the next argument. For more information,
				4255	see the variable argument handling <a href="#int_varargs">Intrinsic
				4256	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4257
				4258	<p>It is legal for this instruction to be called in a function which does not
				4259	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4260	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4261
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4262	<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]	4263	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4264	argument.</p>
				4265
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4266	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4267
				4268	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4269
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4270	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4271
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4272	<!-- _______________________________________________________________________ -->
				4273	<div class="doc_subsubsection">
				4274	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4275	</div>
				4276
				4277	<div class="doc_text">
				4278
				4279	<h5>Syntax:</h5>
				4280	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4281	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4282	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4283
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4284	<h5>Overview:</h5>
				4285
				4286	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4287	from a '<tt><a href="#i_call">call</a></tt>'
				4288	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4289	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4290
				4291	<h5>Arguments:</h5>
				4292
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4293	<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner	1c406d7	2008-04-23 04:06:52 +0000	[diff] [blame]	4294	first argument, or an undef value. The value must have <a
				4295	href="#t_struct">structure type</a>. The second argument is a constant
				4296	unsigned index value which must be in range for the number of values returned
				4297	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4298
				4299	<h5>Semantics:</h5>
				4300
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4301	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4302	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4303
				4304	<h5>Example:</h5>
				4305
				4306	<pre>
				4307	%struct.A = type { i32, i8 }
				4308
				4309	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4310	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4311	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4312	add i32 %gr, 42
				4313	add i8 %gr1, 41
				4314	</pre>
				4315
				4316	</div>
				4317
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4318	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4319	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4320	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4321
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4322	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4323
				4324	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4325	well known names and semantics and are required to follow certain restrictions.
				4326	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4327	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]	4328	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]	4329
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4330	<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]	4331	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4332	begin with this prefix. Intrinsic functions must always be external functions:
				4333	you cannot define the body of intrinsic functions. Intrinsic functions may
				4334	only be used in call or invoke instructions: it is illegal to take the address
				4335	of an intrinsic function. Additionally, because intrinsic functions are part
				4336	of the LLVM language, it is required if any are added that they be documented
				4337	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4338
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4339	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4340	a family of functions that perform the same operation but on different data
				4341	types. Because LLVM can represent over 8 million different integer types,
				4342	overloading is used commonly to allow an intrinsic function to operate on any
				4343	integer type. One or more of the argument types or the result type can be
				4344	overloaded to accept any integer type. Argument types may also be defined as
				4345	exactly matching a previous argument's type or the result type. This allows an
				4346	intrinsic function which accepts multiple arguments, but needs all of them to
				4347	be of the same type, to only be overloaded with respect to a single argument or
				4348	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4349
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4350	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4351	encoded into its function name, each preceded by a period. Only those types
				4352	which are overloaded result in a name suffix. Arguments whose type is matched
				4353	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4354	take an integer of any width and returns an integer of exactly the same integer
				4355	width. This leads to a family of functions such as
				4356	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4357	Only one type, the return type, is overloaded, and only one type suffix is
				4358	required. Because the argument's type is matched against the return type, it
				4359	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4360
				4361	<p>To learn how to add an intrinsic function, please see the
				4362	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4363	</p>
				4364
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4365	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4366
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4367	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4368	<div class="doc_subsection">
				4369	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4370	</div>
				4371
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4372	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4373
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4374	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4375	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]	4376	intrinsic functions. These functions are related to the similarly
				4377	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4378
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4379	<p>All of these functions operate on arguments that use a
				4380	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4381	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4382	transformations should be prepared to handle these functions regardless of
				4383	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4384
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4385	<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]	4386	instruction and the variable argument handling intrinsic functions are
				4387	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4388
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4389	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4390	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4391	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4392	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4393	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4394	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4395	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4396
				4397	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4398	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4399
				4400	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4401	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4402	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4403	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4404	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4405
				4406	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4407	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4408	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4409	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4410
				4411	declare void @llvm.va_start(i8*)
				4412	declare void @llvm.va_copy(i8, i8)
				4413	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4414	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4415	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4416
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4417	</div>
				4418
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4419	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4420	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4421	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4422	</div>
				4423
				4424
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4425	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4426	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4427	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4428	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4429	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4430	<tt>*<arglist></tt> for subsequent use by <tt><a
				4431	href="#i_va_arg">va_arg</a></tt>.</p>
				4432
				4433	<h5>Arguments:</h5>
				4434
				4435	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4436
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4437	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4438
				4439	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4440	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4441	<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]	4442	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4443	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]	4444	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]	4445
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4446	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4447
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4448	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4449	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4450	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4451	</div>
				4452
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4453	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4454	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4455	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4456	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4457
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4458	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4459	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]	4460	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]	4461
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4462	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4463
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4464	<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]	4465
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4466	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4467
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4468	<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]	4469	macro available in C. In a target-dependent way, it destroys the
				4470	<tt>va_list</tt> element to which the argument points. Calls to <a
				4471	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4472	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4473	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4474
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4475	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4476
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4477	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4478	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4479	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4480	</div>
				4481
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4482	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4483
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4484	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4485
				4486	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4487	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4488	</pre>
				4489
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4490	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4491
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4492	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4493	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4494
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4495	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4496
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4497	<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]	4498	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]	4499
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4500
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4501	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4502
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4503	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4504	macro available in C. In a target-dependent way, it copies the source
				4505	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4506	intrinsic is necessary because the <tt><a href="#int_va_start">
				4507	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4508	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4509
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4510	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4511
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4512	<!-- ======================================================================= -->
				4513	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4514	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4515	</div>
				4516
				4517	<div class="doc_text">
				4518
				4519	<p>
				4520	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
				4521	Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4522	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]	4523	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4524	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]	4525	Front-ends for type-safe garbage collected languages should generate these
				4526	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4527	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4528	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4529
				4530	<p>The garbage collection intrinsics only operate on objects in the generic
				4531	address space (address space zero).</p>
				4532
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4533	</div>
				4534
				4535	<!-- _______________________________________________________________________ -->
				4536	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4537	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4538	</div>
				4539
				4540	<div class="doc_text">
				4541
				4542	<h5>Syntax:</h5>
				4543
				4544	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4545	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4546	</pre>
				4547
				4548	<h5>Overview:</h5>
				4549
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4550	<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]	4551	the code generator, and allows some metadata to be associated with it.</p>
				4552
				4553	<h5>Arguments:</h5>
				4554
				4555	<p>The first argument specifies the address of a stack object that contains the
				4556	root pointer. The second pointer (which must be either a constant or a global
				4557	value address) contains the meta-data to be associated with the root.</p>
				4558
				4559	<h5>Semantics:</h5>
				4560
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4561	<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]	4562	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4563	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4564	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4565	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4566
				4567	</div>
				4568
				4569
				4570	<!-- _______________________________________________________________________ -->
				4571	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4572	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4573	</div>
				4574
				4575	<div class="doc_text">
				4576
				4577	<h5>Syntax:</h5>
				4578
				4579	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4580	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4581	</pre>
				4582
				4583	<h5>Overview:</h5>
				4584
				4585	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4586	locations, allowing garbage collector implementations that require read
				4587	barriers.</p>
				4588
				4589	<h5>Arguments:</h5>
				4590
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4591	<p>The second argument is the address to read from, which should be an address
				4592	allocated from the garbage collector. The first object is a pointer to the
				4593	start of the referenced object, if needed by the language runtime (otherwise
				4594	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4595
				4596	<h5>Semantics:</h5>
				4597
				4598	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4599	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4600	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4601	may only be used in a function which <a href="#gc">specifies a GC
				4602	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4603
				4604	</div>
				4605
				4606
				4607	<!-- _______________________________________________________________________ -->
				4608	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4609	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4610	</div>
				4611
				4612	<div class="doc_text">
				4613
				4614	<h5>Syntax:</h5>
				4615
				4616	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4617	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4618	</pre>
				4619
				4620	<h5>Overview:</h5>
				4621
				4622	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4623	locations, allowing garbage collector implementations that require write
				4624	barriers (such as generational or reference counting collectors).</p>
				4625
				4626	<h5>Arguments:</h5>
				4627
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4628	<p>The first argument is the reference to store, the second is the start of the
				4629	object to store it to, and the third is the address of the field of Obj to
				4630	store to. If the runtime does not require a pointer to the object, Obj may be
				4631	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4632
				4633	<h5>Semantics:</h5>
				4634
				4635	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4636	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4637	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4638	may only be used in a function which <a href="#gc">specifies a GC
				4639	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4640
				4641	</div>
				4642
				4643
				4644
				4645	<!-- ======================================================================= -->
				4646	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4647	<a name="int_codegen">Code Generator Intrinsics</a>
				4648	</div>
				4649
				4650	<div class="doc_text">
				4651	<p>
				4652	These intrinsics are provided by LLVM to expose special features that may only
				4653	be implemented with code generator support.
				4654	</p>
				4655
				4656	</div>
				4657
				4658	<!-- _______________________________________________________________________ -->
				4659	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4660	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4661	</div>
				4662
				4663	<div class="doc_text">
				4664
				4665	<h5>Syntax:</h5>
				4666	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4667	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4668	</pre>
				4669
				4670	<h5>Overview:</h5>
				4671
				4672	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4673	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4674	target-specific value indicating the return address of the current function
				4675	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4676	</p>
				4677
				4678	<h5>Arguments:</h5>
				4679
				4680	<p>
				4681	The argument to this intrinsic indicates which function to return the address
				4682	for. Zero indicates the calling function, one indicates its caller, etc. The
				4683	argument is <b>required</b> to be a constant integer value.
				4684	</p>
				4685
				4686	<h5>Semantics:</h5>
				4687
				4688	<p>
				4689	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4690	the return address of the specified call frame, or zero if it cannot be
				4691	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4692	for arguments other than zero, so it should only be used for debugging purposes.
				4693	</p>
				4694
				4695	<p>
				4696	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4697	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]	4698	source-language caller.
				4699	</p>
				4700	</div>
				4701
				4702
				4703	<!-- _______________________________________________________________________ -->
				4704	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4705	<a name="int_frameaddress">'<tt>llvm.frameaddress</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>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4712	declare i8 *@llvm.frameaddress(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.frameaddress</tt>' intrinsic attempts to return the
				4719	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4720	</p>
				4721
				4722	<h5>Arguments:</h5>
				4723
				4724	<p>
				4725	The argument to this intrinsic indicates which function to return the frame
				4726	pointer for. Zero indicates the calling function, one indicates its caller,
				4727	etc. The argument is <b>required</b> to be a constant integer value.
				4728	</p>
				4729
				4730	<h5>Semantics:</h5>
				4731
				4732	<p>
				4733	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4734	the frame address of the specified call frame, or zero if it cannot be
				4735	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4736	for arguments other than zero, so it should only be used for debugging purposes.
				4737	</p>
				4738
				4739	<p>
				4740	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4741	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]	4742	source-language caller.
				4743	</p>
				4744	</div>
				4745
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4746	<!-- _______________________________________________________________________ -->
				4747	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4748	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4749	</div>
				4750
				4751	<div class="doc_text">
				4752
				4753	<h5>Syntax:</h5>
				4754	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4755	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4756	</pre>
				4757
				4758	<h5>Overview:</h5>
				4759
				4760	<p>
				4761	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]	4762	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4763	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4764	features like scoped automatic variable sized arrays in C99.
				4765	</p>
				4766
				4767	<h5>Semantics:</h5>
				4768
				4769	<p>
				4770	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]	4771	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4772	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4773	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4774	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4775	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4776	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4777	</p>
				4778
				4779	</div>
				4780
				4781	<!-- _______________________________________________________________________ -->
				4782	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4783	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4784	</div>
				4785
				4786	<div class="doc_text">
				4787
				4788	<h5>Syntax:</h5>
				4789	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4790	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4791	</pre>
				4792
				4793	<h5>Overview:</h5>
				4794
				4795	<p>
				4796	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4797	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]	4798	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4799	useful for implementing language features like scoped automatic variable sized
				4800	arrays in C99.
				4801	</p>
				4802
				4803	<h5>Semantics:</h5>
				4804
				4805	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4806	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]	4807	</p>
				4808
				4809	</div>
				4810
				4811
				4812	<!-- _______________________________________________________________________ -->
				4813	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4814	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4815	</div>
				4816
				4817	<div class="doc_text">
				4818
				4819	<h5>Syntax:</h5>
				4820	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4821	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4822	</pre>
				4823
				4824	<h5>Overview:</h5>
				4825
				4826
				4827	<p>
				4828	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]	4829	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4830	no
				4831	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4832	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4833	</p>
				4834
				4835	<h5>Arguments:</h5>
				4836
				4837	<p>
				4838	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4839	determining if the fetch should be for a read (0) or write (1), and
				4840	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4841	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]	4842	<tt>locality</tt> arguments must be constant integers.
				4843	</p>
				4844
				4845	<h5>Semantics:</h5>
				4846
				4847	<p>
				4848	This intrinsic does not modify the behavior of the program. In particular,
				4849	prefetches cannot trap and do not produce a value. On targets that support this
				4850	intrinsic, the prefetch can provide hints to the processor cache for better
				4851	performance.
				4852	</p>
				4853
				4854	</div>
				4855
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4856	<!-- _______________________________________________________________________ -->
				4857	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4858	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4859	</div>
				4860
				4861	<div class="doc_text">
				4862
				4863	<h5>Syntax:</h5>
				4864	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4865	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4866	</pre>
				4867
				4868	<h5>Overview:</h5>
				4869
				4870
				4871	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4872	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
				4873	(PC) in a region of
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4874	code to simulators and other tools. The method is target specific, but it is
				4875	expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen	25d4f7e	2005-11-11 02:15:27 +0000	[diff] [blame]	4876	The marker makes no guarantees that it will remain with any specific instruction
Chris Lattner	d07c3f4	2005-11-15 06:07:55 +0000	[diff] [blame]	4877	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]	4878	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4879	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4880	</p>
				4881
				4882	<h5>Arguments:</h5>
				4883
				4884	<p>
				4885	<tt>id</tt> is a numerical id identifying the marker.
				4886	</p>
				4887
				4888	<h5>Semantics:</h5>
				4889
				4890	<p>
				4891	This intrinsic does not modify the behavior of the program. Backends that do not
				4892	support this intrinisic may ignore it.
				4893	</p>
				4894
				4895	</div>
				4896
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4897	<!-- _______________________________________________________________________ -->
				4898	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4899	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4900	</div>
				4901
				4902	<div class="doc_text">
				4903
				4904	<h5>Syntax:</h5>
				4905	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4906	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4907	</pre>
				4908
				4909	<h5>Overview:</h5>
				4910
				4911
				4912	<p>
				4913	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4914	counter register (or similar low latency, high accuracy clocks) on those targets
				4915	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4916	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4917	should only be used for small timings.
				4918	</p>
				4919
				4920	<h5>Semantics:</h5>
				4921
				4922	<p>
				4923	When directly supported, reading the cycle counter should not modify any memory.
				4924	Implementations are allowed to either return a application specific value or a
				4925	system wide value. On backends without support, this is lowered to a constant 0.
				4926	</p>
				4927
				4928	</div>
				4929
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4930	<!-- ======================================================================= -->
				4931	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4932	<a name="int_libc">Standard C Library Intrinsics</a>
				4933	</div>
				4934
				4935	<div class="doc_text">
				4936	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4937	LLVM provides intrinsics for a few important standard C library functions.
				4938	These intrinsics allow source-language front-ends to pass information about the
				4939	alignment of the pointer arguments to the code generator, providing opportunity
				4940	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4941	</p>
				4942
				4943	</div>
				4944
				4945	<!-- _______________________________________________________________________ -->
				4946	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4947	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4948	</div>
				4949
				4950	<div class="doc_text">
				4951
				4952	<h5>Syntax:</h5>
				4953	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4954	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4955	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4956	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4957	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4958	</pre>
				4959
				4960	<h5>Overview:</h5>
				4961
				4962	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4963	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]	4964	location to the destination location.
				4965	</p>
				4966
				4967	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4968	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				4969	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4970	</p>
				4971
				4972	<h5>Arguments:</h5>
				4973
				4974	<p>
				4975	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]	4976	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4977	specifying the number of bytes to copy, and the fourth argument is the alignment
				4978	of the source and destination locations.
				4979	</p>
				4980
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4981	<p>
				4982	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]	4983	the caller guarantees that both the source and destination pointers are aligned
				4984	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4985	</p>
				4986
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4987	<h5>Semantics:</h5>
				4988
				4989	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4990	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]	4991	location to the destination location, which are not allowed to overlap. It
				4992	copies "len" bytes of memory over. If the argument is known to be aligned to
				4993	some boundary, this can be specified as the fourth argument, otherwise it should
				4994	be set to 0 or 1.
				4995	</p>
				4996	</div>
				4997
				4998
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4999	<!-- _______________________________________________________________________ -->
				5000	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5001	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5002	</div>
				5003
				5004	<div class="doc_text">
				5005
				5006	<h5>Syntax:</h5>
				5007	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5008	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5009	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5010	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5011	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5012	</pre>
				5013
				5014	<h5>Overview:</h5>
				5015
				5016	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5017	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5018	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5019	'<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]	5020	</p>
				5021
				5022	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5023	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5024	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5025	</p>
				5026
				5027	<h5>Arguments:</h5>
				5028
				5029	<p>
				5030	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]	5031	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5032	specifying the number of bytes to copy, and the fourth argument is the alignment
				5033	of the source and destination locations.
				5034	</p>
				5035
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5036	<p>
				5037	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]	5038	the caller guarantees that the source and destination pointers are aligned to
				5039	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5040	</p>
				5041
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5042	<h5>Semantics:</h5>
				5043
				5044	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5045	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]	5046	location to the destination location, which may overlap. It
				5047	copies "len" bytes of memory over. If the argument is known to be aligned to
				5048	some boundary, this can be specified as the fourth argument, otherwise it should
				5049	be set to 0 or 1.
				5050	</p>
				5051	</div>
				5052
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5053
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5054	<!-- _______________________________________________________________________ -->
				5055	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5056	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5057	</div>
				5058
				5059	<div class="doc_text">
				5060
				5061	<h5>Syntax:</h5>
				5062	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5063	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5064	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5065	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5066	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5067	</pre>
				5068
				5069	<h5>Overview:</h5>
				5070
				5071	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5072	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]	5073	byte value.
				5074	</p>
				5075
				5076	<p>
				5077	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5078	does not return a value, and takes an extra alignment argument.
				5079	</p>
				5080
				5081	<h5>Arguments:</h5>
				5082
				5083	<p>
				5084	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]	5085	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5086	argument specifying the number of bytes to fill, and the fourth argument is the
				5087	known alignment of destination location.
				5088	</p>
				5089
				5090	<p>
				5091	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]	5092	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5093	</p>
				5094
				5095	<h5>Semantics:</h5>
				5096
				5097	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5098	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5099	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5100	destination location. If the argument is known to be aligned to some boundary,
				5101	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5102	1.
				5103	</p>
				5104	</div>
				5105
				5106
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5107	<!-- _______________________________________________________________________ -->
				5108	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5109	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5110	</div>
				5111
				5112	<div class="doc_text">
				5113
				5114	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5115	<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]	5116	floating point or vector of floating point type. Not all targets support all
				5117	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5118	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5119	declare float @llvm.sqrt.f32(float %Val)
				5120	declare double @llvm.sqrt.f64(double %Val)
				5121	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5122	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5123	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5124	</pre>
				5125
				5126	<h5>Overview:</h5>
				5127
				5128	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5129	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]	5130	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]	5131	<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]	5132	negative numbers other than -0.0 (which allows for better optimization, because
				5133	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5134	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5135	</p>
				5136
				5137	<h5>Arguments:</h5>
				5138
				5139	<p>
				5140	The argument and return value are floating point numbers of the same type.
				5141	</p>
				5142
				5143	<h5>Semantics:</h5>
				5144
				5145	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5146	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]	5147	floating point number.
				5148	</p>
				5149	</div>
				5150
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5151	<!-- _______________________________________________________________________ -->
				5152	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5153	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5154	</div>
				5155
				5156	<div class="doc_text">
				5157
				5158	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5159	<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]	5160	floating point or vector of floating point type. Not all targets support all
				5161	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5162	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5163	declare float @llvm.powi.f32(float %Val, i32 %power)
				5164	declare double @llvm.powi.f64(double %Val, i32 %power)
				5165	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5166	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5167	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5168	</pre>
				5169
				5170	<h5>Overview:</h5>
				5171
				5172	<p>
				5173	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5174	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5175	multiplications is not defined. When a vector of floating point type is
				5176	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5177	</p>
				5178
				5179	<h5>Arguments:</h5>
				5180
				5181	<p>
				5182	The second argument is an integer power, and the first is a value to raise to
				5183	that power.
				5184	</p>
				5185
				5186	<h5>Semantics:</h5>
				5187
				5188	<p>
				5189	This function returns the first value raised to the second power with an
				5190	unspecified sequence of rounding operations.</p>
				5191	</div>
				5192
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5193	<!-- _______________________________________________________________________ -->
				5194	<div class="doc_subsubsection">
				5195	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5196	</div>
				5197
				5198	<div class="doc_text">
				5199
				5200	<h5>Syntax:</h5>
				5201	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5202	floating point or vector of floating point type. Not all targets support all
				5203	types however.
				5204	<pre>
				5205	declare float @llvm.sin.f32(float %Val)
				5206	declare double @llvm.sin.f64(double %Val)
				5207	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5208	declare fp128 @llvm.sin.f128(fp128 %Val)
				5209	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5210	</pre>
				5211
				5212	<h5>Overview:</h5>
				5213
				5214	<p>
				5215	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5216	</p>
				5217
				5218	<h5>Arguments:</h5>
				5219
				5220	<p>
				5221	The argument and return value are floating point numbers of the same type.
				5222	</p>
				5223
				5224	<h5>Semantics:</h5>
				5225
				5226	<p>
				5227	This function returns the sine of the specified operand, returning the
				5228	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]	5229	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5230	</div>
				5231
				5232	<!-- _______________________________________________________________________ -->
				5233	<div class="doc_subsubsection">
				5234	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5235	</div>
				5236
				5237	<div class="doc_text">
				5238
				5239	<h5>Syntax:</h5>
				5240	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5241	floating point or vector of floating point type. Not all targets support all
				5242	types however.
				5243	<pre>
				5244	declare float @llvm.cos.f32(float %Val)
				5245	declare double @llvm.cos.f64(double %Val)
				5246	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5247	declare fp128 @llvm.cos.f128(fp128 %Val)
				5248	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5249	</pre>
				5250
				5251	<h5>Overview:</h5>
				5252
				5253	<p>
				5254	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5255	</p>
				5256
				5257	<h5>Arguments:</h5>
				5258
				5259	<p>
				5260	The argument and return value are floating point numbers of the same type.
				5261	</p>
				5262
				5263	<h5>Semantics:</h5>
				5264
				5265	<p>
				5266	This function returns the cosine of the specified operand, returning the
				5267	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]	5268	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5269	</div>
				5270
				5271	<!-- _______________________________________________________________________ -->
				5272	<div class="doc_subsubsection">
				5273	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5274	</div>
				5275
				5276	<div class="doc_text">
				5277
				5278	<h5>Syntax:</h5>
				5279	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5280	floating point or vector of floating point type. Not all targets support all
				5281	types however.
				5282	<pre>
				5283	declare float @llvm.pow.f32(float %Val, float %Power)
				5284	declare double @llvm.pow.f64(double %Val, double %Power)
				5285	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5286	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5287	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5288	</pre>
				5289
				5290	<h5>Overview:</h5>
				5291
				5292	<p>
				5293	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5294	specified (positive or negative) power.
				5295	</p>
				5296
				5297	<h5>Arguments:</h5>
				5298
				5299	<p>
				5300	The second argument is a floating point power, and the first is a value to
				5301	raise to that power.
				5302	</p>
				5303
				5304	<h5>Semantics:</h5>
				5305
				5306	<p>
				5307	This function returns the first value raised to the second power,
				5308	returning the
				5309	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]	5310	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5311	</div>
				5312
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5313
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5314	<!-- ======================================================================= -->
				5315	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5316	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5317	</div>
				5318
				5319	<div class="doc_text">
				5320	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5321	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5322	These allow efficient code generation for some algorithms.
				5323	</p>
				5324
				5325	</div>
				5326
				5327	<!-- _______________________________________________________________________ -->
				5328	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5329	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5330	</div>
				5331
				5332	<div class="doc_text">
				5333
				5334	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5335	<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]	5336	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]	5337	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5338	declare i16 @llvm.bswap.i16(i16 <id>)
				5339	declare i32 @llvm.bswap.i32(i32 <id>)
				5340	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5341	</pre>
				5342
				5343	<h5>Overview:</h5>
				5344
				5345	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5346	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]	5347	values with an even number of bytes (positive multiple of 16 bits). These are
				5348	useful for performing operations on data that is not in the target's native
				5349	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5350	</p>
				5351
				5352	<h5>Semantics:</h5>
				5353
				5354	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5355	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]	5356	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5357	intrinsic returns an i32 value that has the four bytes of the input i32
				5358	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]	5359	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5360	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5361	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5362	</p>
				5363
				5364	</div>
				5365
				5366	<!-- _______________________________________________________________________ -->
				5367	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5368	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5369	</div>
				5370
				5371	<div class="doc_text">
				5372
				5373	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5374	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5375	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5376	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5377	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5378	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5379	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5380	declare i64 @llvm.ctpop.i64(i64 <src>)
				5381	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5382	</pre>
				5383
				5384	<h5>Overview:</h5>
				5385
				5386	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5387	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5388	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5389	</p>
				5390
				5391	<h5>Arguments:</h5>
				5392
				5393	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5394	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]	5395	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5396	</p>
				5397
				5398	<h5>Semantics:</h5>
				5399
				5400	<p>
				5401	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5402	</p>
				5403	</div>
				5404
				5405	<!-- _______________________________________________________________________ -->
				5406	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5407	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5408	</div>
				5409
				5410	<div class="doc_text">
				5411
				5412	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5413	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5414	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5415	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5416	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5417	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5418	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5419	declare i64 @llvm.ctlz.i64(i64 <src>)
				5420	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5421	</pre>
				5422
				5423	<h5>Overview:</h5>
				5424
				5425	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5426	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5427	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5428	</p>
				5429
				5430	<h5>Arguments:</h5>
				5431
				5432	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5433	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]	5434	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5435	</p>
				5436
				5437	<h5>Semantics:</h5>
				5438
				5439	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5440	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5441	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]	5442	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5443	</p>
				5444	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5445
				5446
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5447
				5448	<!-- _______________________________________________________________________ -->
				5449	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5450	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5451	</div>
				5452
				5453	<div class="doc_text">
				5454
				5455	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5456	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5457	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5458	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5459	declare i8 @llvm.cttz.i8 (i8 <src>)
				5460	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5461	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5462	declare i64 @llvm.cttz.i64(i64 <src>)
				5463	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5464	</pre>
				5465
				5466	<h5>Overview:</h5>
				5467
				5468	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5469	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5470	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5471	</p>
				5472
				5473	<h5>Arguments:</h5>
				5474
				5475	<p>
				5476	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]	5477	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5478	</p>
				5479
				5480	<h5>Semantics:</h5>
				5481
				5482	<p>
				5483	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5484	in a variable. If the src == 0 then the result is the size in bits of the type
				5485	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5486	</p>
				5487	</div>
				5488
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5489	<!-- _______________________________________________________________________ -->
				5490	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5491	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5492	</div>
				5493
				5494	<div class="doc_text">
				5495
				5496	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5497	<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]	5498	on any integer bit width.
				5499	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5500	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5501	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5502	</pre>
				5503
				5504	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5505	<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]	5506	range of bits from an integer value and returns them in the same bit width as
				5507	the original value.</p>
				5508
				5509	<h5>Arguments:</h5>
				5510	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5511	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]	5512	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]	5513
				5514	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5515	<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]	5516	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5517	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5518	operates in forward mode.</p>
				5519	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5520	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]	5521	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5522	<ol>
				5523	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5524	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5525	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5526	to determine the number of bits to retain.</li>
				5527	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5528	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5529	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5530	<p>In reverse mode, a similar computation is made except that the bits are
				5531	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5532	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5533	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5534	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5535	</div>
				5536
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5537	<div class="doc_subsubsection">
				5538	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5539	</div>
				5540
				5541	<div class="doc_text">
				5542
				5543	<h5>Syntax:</h5>
				5544	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5545	on any integer bit width.
				5546	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5547	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5548	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]	5549	</pre>
				5550
				5551	<h5>Overview:</h5>
				5552	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5553	of bits in an integer value with another integer value. It returns the integer
				5554	with the replaced bits.</p>
				5555
				5556	<h5>Arguments:</h5>
				5557	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5558	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5559	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5560	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5561	type since they specify only a bit index.</p>
				5562
				5563	<h5>Semantics:</h5>
				5564	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5565	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5566	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5567	operates in forward mode.</p>
				5568	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5569	truncating it down to the size of the replacement area or zero extending it
				5570	up to that size.</p>
				5571	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5572	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5573	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5574	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5575	<p>In reverse mode, a similar computation is made except that the bits are
				5576	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5577	<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]	5578	<h5>Examples:</h5>
				5579	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5580	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5581	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5582	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5583	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5584	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5585	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5586	</div>
				5587
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5588	<!-- ======================================================================= -->
				5589	<div class="doc_subsection">
				5590	<a name="int_debugger">Debugger Intrinsics</a>
				5591	</div>
				5592
				5593	<div class="doc_text">
				5594	<p>
				5595	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5596	are described in the <a
				5597	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5598	Debugging</a> document.
				5599	</p>
				5600	</div>
				5601
				5602
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5603	<!-- ======================================================================= -->
				5604	<div class="doc_subsection">
				5605	<a name="int_eh">Exception Handling Intrinsics</a>
				5606	</div>
				5607
				5608	<div class="doc_text">
				5609	<p> The LLVM exception handling intrinsics (which all start with
				5610	<tt>llvm.eh.</tt> prefix), are described in the <a
				5611	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5612	Handling</a> document. </p>
				5613	</div>
				5614
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5615	<!-- ======================================================================= -->
				5616	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5617	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5618	</div>
				5619
				5620	<div class="doc_text">
				5621	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5622	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5623	the <tt>nest</tt> attribute, from a function. The result is a callable
				5624	function pointer lacking the nest parameter - the caller does not need
				5625	to provide a value for it. Instead, the value to use is stored in
				5626	advance in a "trampoline", a block of memory usually allocated
				5627	on the stack, which also contains code to splice the nest value into the
				5628	argument list. This is used to implement the GCC nested function address
				5629	extension.
				5630	</p>
				5631	<p>
				5632	For example, if the function is
				5633	<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]	5634	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]	5635	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5636	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5637	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5638	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5639	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5640	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5641	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5642	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]	5643	</div>
				5644
				5645	<!-- _______________________________________________________________________ -->
				5646	<div class="doc_subsubsection">
				5647	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5648	</div>
				5649	<div class="doc_text">
				5650	<h5>Syntax:</h5>
				5651	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5652	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5653	</pre>
				5654	<h5>Overview:</h5>
				5655	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5656	This fills the memory pointed to by <tt>tramp</tt> with code
				5657	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5658	</p>
				5659	<h5>Arguments:</h5>
				5660	<p>
				5661	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5662	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5663	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]	5664	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5665	currently provides no portable way of determining them, so a front-end that
				5666	generates this intrinsic needs to have some target-specific knowledge.
				5667	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]	5668	</p>
				5669	<h5>Semantics:</h5>
				5670	<p>
				5671	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]	5672	dependent code, turning it into a function. A pointer to this function is
				5673	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5674	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5675	before being called. The new function's signature is the same as that of
				5676	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5677	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5678	of pointer type. Calling the new function is equivalent to calling
				5679	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5680	missing <tt>nest</tt> argument. If, after calling
				5681	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5682	modified, then the effect of any later call to the returned function pointer is
				5683	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5684	</p>
				5685	</div>
				5686
				5687	<!-- ======================================================================= -->
				5688	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5689	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5690	</div>
				5691
				5692	<div class="doc_text">
				5693	<p>
				5694	These intrinsic functions expand the "universal IR" of LLVM to represent
				5695	hardware constructs for atomic operations and memory synchronization. This
				5696	provides an interface to the hardware, not an interface to the programmer. It
				5697	is aimed at a low enough level to allow any programming models or APIs which
				5698	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5699	hardware behavior. Just as hardware provides a "universal IR" for source
				5700	languages, it also provides a starting point for developing a "universal"
				5701	atomic operation and synchronization IR.
				5702	</p>
				5703	<p>
				5704	These do <em>not</em> form an API such as high-level threading libraries,
				5705	software transaction memory systems, atomic primitives, and intrinsic
				5706	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5707	application libraries. The hardware interface provided by LLVM should allow
				5708	a clean implementation of all of these APIs and parallel programming models.
				5709	No one model or paradigm should be selected above others unless the hardware
				5710	itself ubiquitously does so.
				5711
				5712	</p>
				5713	</div>
				5714
				5715	<!-- _______________________________________________________________________ -->
				5716	<div class="doc_subsubsection">
				5717	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5718	</div>
				5719	<div class="doc_text">
				5720	<h5>Syntax:</h5>
				5721	<pre>
				5722	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5723	i1 <device> )
				5724
				5725	</pre>
				5726	<h5>Overview:</h5>
				5727	<p>
				5728	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5729	specific pairs of memory access types.
				5730	</p>
				5731	<h5>Arguments:</h5>
				5732	<p>
				5733	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5734	The first four arguments enables a specific barrier as listed below. The fith
				5735	argument specifies that the barrier applies to io or device or uncached memory.
				5736
				5737	</p>
				5738	<ul>
				5739	<li><tt>ll</tt>: load-load barrier</li>
				5740	<li><tt>ls</tt>: load-store barrier</li>
				5741	<li><tt>sl</tt>: store-load barrier</li>
				5742	<li><tt>ss</tt>: store-store barrier</li>
				5743	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5744	</ul>
				5745	<h5>Semantics:</h5>
				5746	<p>
				5747	This intrinsic causes the system to enforce some ordering constraints upon
				5748	the loads and stores of the program. This barrier does not indicate
				5749	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5750	which they occur. For any of the specified pairs of load and store operations
				5751	(f.ex. load-load, or store-load), all of the first operations preceding the
				5752	barrier will complete before any of the second operations succeeding the
				5753	barrier begin. Specifically the semantics for each pairing is as follows:
				5754	</p>
				5755	<ul>
				5756	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5757	after the barrier begins.</li>
				5758
				5759	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5760	store after the barrier begins.</li>
				5761	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5762	store after the barrier begins.</li>
				5763	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5764	load after the barrier begins.</li>
				5765	</ul>
				5766	<p>
				5767	These semantics are applied with a logical "and" behavior when more than one
				5768	is enabled in a single memory barrier intrinsic.
				5769	</p>
				5770	<p>
				5771	Backends may implement stronger barriers than those requested when they do not
				5772	support as fine grained a barrier as requested. Some architectures do not
				5773	need all types of barriers and on such architectures, these become noops.
				5774	</p>
				5775	<h5>Example:</h5>
				5776	<pre>
				5777	%ptr = malloc i32
				5778	store i32 4, %ptr
				5779
				5780	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5781	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5782	<i>; guarantee the above finishes</i>
				5783	store i32 8, %ptr <i>; before this begins</i>
				5784	</pre>
				5785	</div>
				5786
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5787	<!-- _______________________________________________________________________ -->
				5788	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5789	<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]	5790	</div>
				5791	<div class="doc_text">
				5792	<h5>Syntax:</h5>
				5793	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5794	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on any
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5795	integer bit width. Not all targets support all bit widths however.</p>
				5796
				5797	<pre>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5798	declare i8 @llvm.atomic.cmp.swap.i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5799	declare i16 @llvm.atomic.cmp.swap.i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5800	declare i32 @llvm.atomic.cmp.swap.i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5801	declare i64 @llvm.atomic.cmp.swap.i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5802
				5803	</pre>
				5804	<h5>Overview:</h5>
				5805	<p>
				5806	This loads a value in memory and compares it to a given value. If they are
				5807	equal, it stores a new value into the memory.
				5808	</p>
				5809	<h5>Arguments:</h5>
				5810	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5811	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]	5812	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5813	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5814	this integer type. While any bit width integer may be used, targets may only
				5815	lower representations they support in hardware.
				5816
				5817	</p>
				5818	<h5>Semantics:</h5>
				5819	<p>
				5820	This entire intrinsic must be executed atomically. It first loads the value
				5821	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5822	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5823	loaded value is yielded in all cases. This provides the equivalent of an
				5824	atomic compare-and-swap operation within the SSA framework.
				5825	</p>
				5826	<h5>Examples:</h5>
				5827
				5828	<pre>
				5829	%ptr = malloc i32
				5830	store i32 4, %ptr
				5831
				5832	%val1 = add i32 4, 4
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5833	%result1 = call i32 @llvm.atomic.cmp.swap.i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5834	<i>; yields {i32}:result1 = 4</i>
				5835	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5836	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5837
				5838	%val2 = add i32 1, 1
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5839	%result2 = call i32 @llvm.atomic.cmp.swap.i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5840	<i>; yields {i32}:result2 = 8</i>
				5841	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5842
				5843	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5844	</pre>
				5845	</div>
				5846
				5847	<!-- _______________________________________________________________________ -->
				5848	<div class="doc_subsubsection">
				5849	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5850	</div>
				5851	<div class="doc_text">
				5852	<h5>Syntax:</h5>
				5853
				5854	<p>
				5855	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5856	integer bit width. Not all targets support all bit widths however.</p>
				5857	<pre>
				5858	declare i8 @llvm.atomic.swap.i8( i8* <ptr>, i8 <val> )
				5859	declare i16 @llvm.atomic.swap.i16( i16* <ptr>, i16 <val> )
				5860	declare i32 @llvm.atomic.swap.i32( i32* <ptr>, i32 <val> )
				5861	declare i64 @llvm.atomic.swap.i64( i64* <ptr>, i64 <val> )
				5862
				5863	</pre>
				5864	<h5>Overview:</h5>
				5865	<p>
				5866	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5867	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5868	at <tt>ptr</tt>.
				5869	</p>
				5870	<h5>Arguments:</h5>
				5871
				5872	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5873	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5874	<tt>val</tt> argument and the result must be integers of the same bit width.
				5875	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5876	integer type. The targets may only lower integer representations they
				5877	support.
				5878	</p>
				5879	<h5>Semantics:</h5>
				5880	<p>
				5881	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5882	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5883	equivalent of an atomic swap operation within the SSA framework.
				5884
				5885	</p>
				5886	<h5>Examples:</h5>
				5887	<pre>
				5888	%ptr = malloc i32
				5889	store i32 4, %ptr
				5890
				5891	%val1 = add i32 4, 4
				5892	%result1 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val1 )
				5893	<i>; yields {i32}:result1 = 4</i>
				5894	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5895	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5896
				5897	%val2 = add i32 1, 1
				5898	%result2 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val2 )
				5899	<i>; yields {i32}:result2 = 8</i>
				5900
				5901	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5902	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5903	</pre>
				5904	</div>
				5905
				5906	<!-- _______________________________________________________________________ -->
				5907	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5908	<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]	5909
				5910	</div>
				5911	<div class="doc_text">
				5912	<h5>Syntax:</h5>
				5913	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5914	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]	5915	integer bit width. Not all targets support all bit widths however.</p>
				5916	<pre>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5917	declare i8 @llvm.atomic.load.add.i8.( i8* <ptr>, i8 <delta> )
				5918	declare i16 @llvm.atomic.load.add.i16.( i16* <ptr>, i16 <delta> )
				5919	declare i32 @llvm.atomic.load.add.i32.( i32* <ptr>, i32 <delta> )
				5920	declare i64 @llvm.atomic.load.add.i64.( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5921
				5922	</pre>
				5923	<h5>Overview:</h5>
				5924	<p>
				5925	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5926	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5927	</p>
				5928	<h5>Arguments:</h5>
				5929	<p>
				5930
				5931	The intrinsic takes two arguments, the first a pointer to an integer value
				5932	and the second an integer value. The result is also an integer value. These
				5933	integer types can have any bit width, but they must all have the same bit
				5934	width. The targets may only lower integer representations they support.
				5935	</p>
				5936	<h5>Semantics:</h5>
				5937	<p>
				5938	This intrinsic does a series of operations atomically. It first loads the
				5939	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5940	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5941	</p>
				5942
				5943	<h5>Examples:</h5>
				5944	<pre>
				5945	%ptr = malloc i32
				5946	store i32 4, %ptr
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5947	%result1 = call i32 @llvm.atomic.load.add.i32( i32* %ptr, i32 4 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5948	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5949	%result2 = call i32 @llvm.atomic.load.add.i32( i32* %ptr, i32 2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5950	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5951	%result3 = call i32 @llvm.atomic.load.add.i32( i32* %ptr, i32 5 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5952	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5953	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5954	</pre>
				5955	</div>
				5956
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame^]	5957	<!-- _______________________________________________________________________ -->
				5958	<div class="doc_subsubsection">
				5959	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				5960
				5961	</div>
				5962	<div class="doc_text">
				5963	<h5>Syntax:</h5>
				5964	<p>
				5965	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
				5966	any integer bit width. Not all targets support all bit widths however.</p>
				5967	<pre>
				5968	declare i8 @llvm.atomic.load.sub.i8.( i8* <ptr>, i8 <delta> )
				5969	declare i16 @llvm.atomic.load.sub.i16.( i16* <ptr>, i16 <delta> )
				5970	declare i32 @llvm.atomic.load.sub.i32.( i32* <ptr>, i32 <delta> )
				5971	declare i64 @llvm.atomic.load.sub.i64.( i64* <ptr>, i64 <delta> )
				5972
				5973	</pre>
				5974	<h5>Overview:</h5>
				5975	<p>
				5976	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				5977	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5978	</p>
				5979	<h5>Arguments:</h5>
				5980	<p>
				5981
				5982	The intrinsic takes two arguments, the first a pointer to an integer value
				5983	and the second an integer value. The result is also an integer value. These
				5984	integer types can have any bit width, but they must all have the same bit
				5985	width. The targets may only lower integer representations they support.
				5986	</p>
				5987	<h5>Semantics:</h5>
				5988	<p>
				5989	This intrinsic does a series of operations atomically. It first loads the
				5990	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				5991	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5992	</p>
				5993
				5994	<h5>Examples:</h5>
				5995	<pre>
				5996	%ptr = malloc i32
				5997	store i32 8, %ptr
				5998	%result1 = call i32 @llvm.atomic.load.sub.i32( i32* %ptr, i32 4 )
				5999	<i>; yields {i32}:result1 = 8</i>
				6000	%result2 = call i32 @llvm.atomic.load.sub.i32( i32* %ptr, i32 2 )
				6001	<i>; yields {i32}:result2 = 4</i>
				6002	%result3 = call i32 @llvm.atomic.load.sub.i32( i32* %ptr, i32 5 )
				6003	<i>; yields {i32}:result3 = 2</i>
				6004	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6005	</pre>
				6006	</div>
				6007
				6008	<!-- _______________________________________________________________________ -->
				6009	<div class="doc_subsubsection">
				6010	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6011	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6012	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6013	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6014
				6015	</div>
				6016	<div class="doc_text">
				6017	<h5>Syntax:</h5>
				6018	<p>
				6019	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6020	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
				6021	<tt>llvm.atomic.load_xor</tt> on any integer bit width. Not all targets
				6022	support all bit widths however.</p>
				6023	<pre>
				6024	declare i8 @llvm.atomic.load.and.i8.( i8* <ptr>, i8 <delta> )
				6025	declare i16 @llvm.atomic.load.and.i16.( i16* <ptr>, i16 <delta> )
				6026	declare i32 @llvm.atomic.load.and.i32.( i32* <ptr>, i32 <delta> )
				6027	declare i64 @llvm.atomic.load.and.i64.( i64* <ptr>, i64 <delta> )
				6028
				6029	</pre>
				6030
				6031	<pre>
				6032	declare i8 @llvm.atomic.load.or.i8.( i8* <ptr>, i8 <delta> )
				6033	declare i16 @llvm.atomic.load.or.i16.( i16* <ptr>, i16 <delta> )
				6034	declare i32 @llvm.atomic.load.or.i32.( i32* <ptr>, i32 <delta> )
				6035	declare i64 @llvm.atomic.load.or.i64.( i64* <ptr>, i64 <delta> )
				6036
				6037	</pre>
				6038
				6039	<pre>
				6040	declare i8 @llvm.atomic.load.nand.i8.( i8* <ptr>, i8 <delta> )
				6041	declare i16 @llvm.atomic.load.nand.i16.( i16* <ptr>, i16 <delta> )
				6042	declare i32 @llvm.atomic.load.nand.i32.( i32* <ptr>, i32 <delta> )
				6043	declare i64 @llvm.atomic.load.nand.i64.( i64* <ptr>, i64 <delta> )
				6044
				6045	</pre>
				6046
				6047	<pre>
				6048	declare i8 @llvm.atomic.load.xor.i8.( i8* <ptr>, i8 <delta> )
				6049	declare i16 @llvm.atomic.load.xor.i16.( i16* <ptr>, i16 <delta> )
				6050	declare i32 @llvm.atomic.load.xor.i32.( i32* <ptr>, i32 <delta> )
				6051	declare i64 @llvm.atomic.load.xor.i64.( i64* <ptr>, i64 <delta> )
				6052
				6053	</pre>
				6054	<h5>Overview:</h5>
				6055	<p>
				6056	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6057	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6058	at <tt>ptr</tt>.
				6059	</p>
				6060	<h5>Arguments:</h5>
				6061	<p>
				6062
				6063	These intrinsics take two arguments, the first a pointer to an integer value
				6064	and the second an integer value. The result is also an integer value. These
				6065	integer types can have any bit width, but they must all have the same bit
				6066	width. The targets may only lower integer representations they support.
				6067	</p>
				6068	<h5>Semantics:</h5>
				6069	<p>
				6070	These intrinsics does a series of operations atomically. They first load the
				6071	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6072	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6073	value stored at <tt>ptr</tt>.
				6074	</p>
				6075
				6076	<h5>Examples:</h5>
				6077	<pre>
				6078	%ptr = malloc i32
				6079	store i32 0x0F0F, %ptr
				6080	%result0 = call i32 @llvm.atomic.load.nand.i32( i32* %ptr, i32 0xFF )
				6081	<i>; yields {i32}:result0 = 0x0F0F</i>
				6082	%result1 = call i32 @llvm.atomic.load.and.i32( i32* %ptr, i32 0xFF )
				6083	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
				6084	%result2 = call i32 @llvm.atomic.load.or.i32( i32* %ptr, i32 0F )
				6085	<i>; yields {i32}:result2 = 0xF0</i>
				6086	%result3 = call i32 @llvm.atomic.load.xor.i32( i32* %ptr, i32 0F )
				6087	<i>; yields {i32}:result3 = FF</i>
				6088	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6089	</pre>
				6090	</div>
				6091
				6092
				6093	<!-- _______________________________________________________________________ -->
				6094	<div class="doc_subsubsection">
				6095	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6096	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6097	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6098	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6099
				6100	</div>
				6101	<div class="doc_text">
				6102	<h5>Syntax:</h5>
				6103	<p>
				6104	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6105	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
				6106	<tt>llvm.atomic.load_umin</tt> on any integer bit width. Not all targets
				6107	support all bit widths however.</p>
				6108	<pre>
				6109	declare i8 @llvm.atomic.load.max.i8.( i8* <ptr>, i8 <delta> )
				6110	declare i16 @llvm.atomic.load.max.i16.( i16* <ptr>, i16 <delta> )
				6111	declare i32 @llvm.atomic.load.max.i32.( i32* <ptr>, i32 <delta> )
				6112	declare i64 @llvm.atomic.load.max.i64.( i64* <ptr>, i64 <delta> )
				6113
				6114	</pre>
				6115
				6116	<pre>
				6117	declare i8 @llvm.atomic.load.min.i8.( i8* <ptr>, i8 <delta> )
				6118	declare i16 @llvm.atomic.load.min.i16.( i16* <ptr>, i16 <delta> )
				6119	declare i32 @llvm.atomic.load.min.i32.( i32* <ptr>, i32 <delta> )
				6120	declare i64 @llvm.atomic.load.min.i64.( i64* <ptr>, i64 <delta> )
				6121
				6122	</pre>
				6123
				6124	<pre>
				6125	declare i8 @llvm.atomic.load.umax.i8.( i8* <ptr>, i8 <delta> )
				6126	declare i16 @llvm.atomic.load.umax.i16.( i16* <ptr>, i16 <delta> )
				6127	declare i32 @llvm.atomic.load.umax.i32.( i32* <ptr>, i32 <delta> )
				6128	declare i64 @llvm.atomic.load.umax.i64.( i64* <ptr>, i64 <delta> )
				6129
				6130	</pre>
				6131
				6132	<pre>
				6133	declare i8 @llvm.atomic.load.umin.i8.( i8* <ptr>, i8 <delta> )
				6134	declare i16 @llvm.atomic.load.umin.i16.( i16* <ptr>, i16 <delta> )
				6135	declare i32 @llvm.atomic.load.umin.i32.( i32* <ptr>, i32 <delta> )
				6136	declare i64 @llvm.atomic.load.umin.i64.( i64* <ptr>, i64 <delta> )
				6137
				6138	</pre>
				6139	<h5>Overview:</h5>
				6140	<p>
				6141	These intrinsics takes the signed or unsigned minimum or maximum of
				6142	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6143	original value at <tt>ptr</tt>.
				6144	</p>
				6145	<h5>Arguments:</h5>
				6146	<p>
				6147
				6148	These intrinsics take two arguments, the first a pointer to an integer value
				6149	and the second an integer value. The result is also an integer value. These
				6150	integer types can have any bit width, but they must all have the same bit
				6151	width. The targets may only lower integer representations they support.
				6152	</p>
				6153	<h5>Semantics:</h5>
				6154	<p>
				6155	These intrinsics does a series of operations atomically. They first load the
				6156	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6157	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6158	the original value stored at <tt>ptr</tt>.
				6159	</p>
				6160
				6161	<h5>Examples:</h5>
				6162	<pre>
				6163	%ptr = malloc i32
				6164	store i32 7, %ptr
				6165	%result0 = call i32 @llvm.atomic.load.min.i32( i32* %ptr, i32 -2 )
				6166	<i>; yields {i32}:result0 = 7</i>
				6167	%result1 = call i32 @llvm.atomic.load.max.i32( i32* %ptr, i32 8 )
				6168	<i>; yields {i32}:result1 = -2</i>
				6169	%result2 = call i32 @llvm.atomic.load.umin.i32( i32* %ptr, i32 10 )
				6170	<i>; yields {i32}:result2 = 8</i>
				6171	%result3 = call i32 @llvm.atomic.load.umax.i32( i32* %ptr, i32 30 )
				6172	<i>; yields {i32}:result3 = 8</i>
				6173	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6174	</pre>
				6175	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6176
				6177	<!-- ======================================================================= -->
				6178	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6179	<a name="int_general">General Intrinsics</a>
				6180	</div>
				6181
				6182	<div class="doc_text">
				6183	<p> This class of intrinsics is designed to be generic and has
				6184	no specific purpose. </p>
				6185	</div>
				6186
				6187	<!-- _______________________________________________________________________ -->
				6188	<div class="doc_subsubsection">
				6189	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6190	</div>
				6191
				6192	<div class="doc_text">
				6193
				6194	<h5>Syntax:</h5>
				6195	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6196	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]	6197	</pre>
				6198
				6199	<h5>Overview:</h5>
				6200
				6201	<p>
				6202	The '<tt>llvm.var.annotation</tt>' intrinsic
				6203	</p>
				6204
				6205	<h5>Arguments:</h5>
				6206
				6207	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6208	The first argument is a pointer to a value, the second is a pointer to a
				6209	global string, the third is a pointer to a global string which is the source
				6210	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6211	</p>
				6212
				6213	<h5>Semantics:</h5>
				6214
				6215	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6216	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6217	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]	6218	annotations. These have no other defined use, they are ignored by code
				6219	generation and optimization.
				6220	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6221	</div>
				6222
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6223	<!-- _______________________________________________________________________ -->
				6224	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6225	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6226	</div>
				6227
				6228	<div class="doc_text">
				6229
				6230	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6231	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6232	any integer bit width.
				6233	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6234	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6235	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6236	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6237	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6238	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6239	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]	6240	</pre>
				6241
				6242	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6243
				6244	<p>
				6245	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6246	</p>
				6247
				6248	<h5>Arguments:</h5>
				6249
				6250	<p>
				6251	The first argument is an integer value (result of some expression),
				6252	the second is a pointer to a global string, the third is a pointer to a global
				6253	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]	6254	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6255	</p>
				6256
				6257	<h5>Semantics:</h5>
				6258
				6259	<p>
				6260	This intrinsic allows annotations to be put on arbitrary expressions
				6261	with arbitrary strings. This can be useful for special purpose optimizations
				6262	that want to look for these annotations. These have no other defined use, they
				6263	are ignored by code generation and optimization.
				6264	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6265
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6266	<!-- _______________________________________________________________________ -->
				6267	<div class="doc_subsubsection">
				6268	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6269	</div>
				6270
				6271	<div class="doc_text">
				6272
				6273	<h5>Syntax:</h5>
				6274	<pre>
				6275	declare void @llvm.trap()
				6276	</pre>
				6277
				6278	<h5>Overview:</h5>
				6279
				6280	<p>
				6281	The '<tt>llvm.trap</tt>' intrinsic
				6282	</p>
				6283
				6284	<h5>Arguments:</h5>
				6285
				6286	<p>
				6287	None
				6288	</p>
				6289
				6290	<h5>Semantics:</h5>
				6291
				6292	<p>
				6293	This intrinsics is lowered to the target dependent trap instruction. If the
				6294	target does not have a trap instruction, this intrinsic will be lowered to the
				6295	call of the abort() function.
				6296	</p>
				6297	</div>
				6298
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6299	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6300	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6301	<address>
				6302	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6303	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6305	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]	6306
				6307	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6308	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6309	Last modified: $Date$
				6310	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6311
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6312	</body>
				6313	</html>