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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>
				219	<li><a href="#int_atomic_lcs"><tt>llvm.atomic.lcs</tt></a></li>
				220	<li><a href="#int_atomic_las"><tt>llvm.atomic.las</tt></a></li>
				221	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	222	</ol>
				223	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	224	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	225	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	226	<li><a href="#int_var_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	227	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	228	<li><a href="#int_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	229	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	230	<li><a href="#int_trap">
				231	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	232	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	233	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	234	</ol>
				235	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	236	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	237
				238	<div class="doc_author">
				239	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				240	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	241	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	242
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	243	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	244	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				245	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	246
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	247	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	248	<p>This document is a reference manual for the LLVM assembly language.
				249	LLVM is an SSA based representation that provides type safety,
				250	low-level operations, flexibility, and the capability of representing
				251	'all' high-level languages cleanly. It is the common code
				252	representation used throughout all phases of the LLVM compilation
				253	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	254	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	255
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	256	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	257	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				258	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	259
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	260	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	261
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	262	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	263	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]	264	representation (suitable for fast loading by a Just-In-Time compiler),
				265	and as a human readable assembly language representation. This allows
				266	LLVM to provide a powerful intermediate representation for efficient
				267	compiler transformations and analysis, while providing a natural means
				268	to debug and visualize the transformations. The three different forms
				269	of LLVM are all equivalent. This document describes the human readable
				270	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	272	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	while being expressive, typed, and extensible at the same time. It
				274	aims to be a "universal IR" of sorts, by being at a low enough level
				275	that high-level ideas may be cleanly mapped to it (similar to how
				276	microprocessors are "universal IR's", allowing many source languages to
				277	be mapped to them). By providing type information, LLVM can be used as
				278	the target of optimizations: for example, through pointer analysis, it
				279	can be proven that a C automatic variable is never accessed outside of
				280	the current function... allowing it to be promoted to a simple SSA
				281	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	282
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	283	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	285	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	287
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	288	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	289
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	290	<p>It is important to note that this document describes 'well formed'
				291	LLVM assembly language. There is a difference between what the parser
				292	accepts and what is considered 'well formed'. For example, the
				293	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	294
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	295	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	296	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	297	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	298	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	299	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	300
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	301	<p>...because the definition of <tt>%x</tt> does not dominate all of
				302	its uses. The LLVM infrastructure provides a verification pass that may
				303	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]	304	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	305	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	306	by the verifier pass indicate bugs in transformation passes or input to
				307	the parser.</p>
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	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	310	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	312	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	313	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	314	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	315
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	316	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	317
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	318	<p>LLVM identifiers come in two basic types: global and local. Global
				319	identifiers (functions, global variables) begin with the @ character. Local
				320	identifiers (register names, types) begin with the % character. Additionally,
				321	there are three different formats for identifiers, for different purposes:
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	322
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	323	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	324	<li>Named values are represented as a string of characters with their prefix.
				325	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				326	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]	327	Identifiers which require other characters in their names can be surrounded
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	328	with quotes. In this way, anything except a <tt>"</tt> character can
				329	be used in a named value.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	330
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	331	<li>Unnamed values are represented as an unsigned numeric value with their
				332	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	333
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	334	<li>Constants, which are described in a <a href="#constants">section about
				335	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	336	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	337
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	338	<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]	339	don't need to worry about name clashes with reserved words, and the set of
				340	reserved words may be expanded in the future without penalty. Additionally,
				341	unnamed identifiers allow a compiler to quickly come up with a temporary
				342	variable without having to avoid symbol table conflicts.</p>
				343
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	344	<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]	345	languages. There are keywords for different opcodes
				346	('<tt><a href="#i_add">add</a></tt>',
				347	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				348	'<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]	349	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]	350	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	351	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	352
				353	<p>Here is an example of LLVM code to multiply the integer variable
				354	'<tt>%X</tt>' by 8:</p>
				355
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	356	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	357
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	358	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	359	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	360	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	361	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	362	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	364	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	365
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	366	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	367	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	368	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	369	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	370	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	371
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	372	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	373
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	374	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	375	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	376	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				377	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				378	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	379	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	380	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	381
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	382	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				383	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	384
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	385	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	386
				387	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				388	line.</li>
				389
				390	<li>Unnamed temporaries are created when the result of a computation is not
				391	assigned to a named value.</li>
				392
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	393	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	394
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	395	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	396
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	397	<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]	398	demonstrating instructions, we will follow an instruction with a comment that
				399	defines the type and name of value produced. Comments are shown in italic
				400	text.</p>
				401
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	402	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	403
				404	<!-- *********************************************************************** -->
				405	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				406	<!-- *********************************************************************** -->
				407
				408	<!-- ======================================================================= -->
				409	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				410	</div>
				411
				412	<div class="doc_text">
				413
				414	<p>LLVM programs are composed of "Module"s, each of which is a
				415	translation unit of the input programs. Each module consists of
				416	functions, global variables, and symbol table entries. Modules may be
				417	combined together with the LLVM linker, which merges function (and
				418	global variable) definitions, resolves forward declarations, and merges
				419	symbol table entries. Here is an example of the "hello world" module:</p>
				420
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	421	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	422	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	423	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				424	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]	425
				426	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	427	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	428
				429	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	430	define i32 @main() { <i>; i32()* </i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	431	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	432	%cast210 = <a
Chris Lattner	6c0955b	2007-06-12 17:01:15 +0000	[diff] [blame]	433	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]	434
				435	<i>; Call puts function to write out the string to stdout...</i>
				436	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	437	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	438	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	439	href="#i_ret">ret</a> i32 0<br>}<br>
				440	</pre>
				441	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	442
				443	<p>This example is made up of a <a href="#globalvars">global variable</a>
				444	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				445	function, and a <a href="#functionstructure">function definition</a>
				446	for "<tt>main</tt>".</p>
				447
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	448	<p>In general, a module is made up of a list of global values,
				449	where both functions and global variables are global values. Global values are
				450	represented by a pointer to a memory location (in this case, a pointer to an
				451	array of char, and a pointer to a function), and have one of the following <a
				452	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	453
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	454	</div>
				455
				456	<!-- ======================================================================= -->
				457	<div class="doc_subsection">
				458	<a name="linkage">Linkage Types</a>
				459	</div>
				460
				461	<div class="doc_text">
				462
				463	<p>
				464	All Global Variables and Functions have one of the following types of linkage:
				465	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	466
				467	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	468
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	469	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	470
				471	<dd>Global values with internal linkage are only directly accessible by
				472	objects in the current module. In particular, linking code into a module with
				473	an internal global value may cause the internal to be renamed as necessary to
				474	avoid collisions. Because the symbol is internal to the module, all
				475	references can be updated. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	476	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	477	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	478
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	479	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	480
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	481	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				482	the same name when linkage occurs. This is typically used to implement
				483	inline functions, templates, or other code which must be generated in each
				484	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				485	allowed to be discarded.
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
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	488	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				489
				490	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				491	linkage, except that unreferenced <tt>common</tt> globals may not be
				492	discarded. This is used for globals that may be emitted in multiple
				493	translation units, but that are not guaranteed to be emitted into every
				494	translation unit that uses them. One example of this is tentative
				495	definitions in C, such as "<tt>int X;</tt>" at global scope.
				496	</dd>
				497
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	498	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	499
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	500	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				501	that some targets may choose to emit different assembly sequences for them
				502	for target-dependent reasons. This is used for globals that are declared
				503	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	504	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	505
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	506	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	507
				508	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				509	pointer to array type. When two global variables with appending linkage are
				510	linked together, the two global arrays are appended together. This is the
				511	LLVM, typesafe, equivalent of having the system linker append together
				512	"sections" with identical names when .o files are linked.
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
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	515	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
				516	<dd>The semantics of this linkage follow the ELF model: the symbol is weak
				517	until linked, if not linked, the symbol becomes null instead of being an
				518	undefined reference.
				519	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	520
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	521	<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]	522
				523	<dd>If none of the above identifiers are used, the global is externally
				524	visible, meaning that it participates in linkage and can be used to resolve
				525	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	526	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	527	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	528
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	529	<p>
				530	The next two types of linkage are targeted for Microsoft Windows platform
				531	only. They are designed to support importing (exporting) symbols from (to)
				532	DLLs.
				533	</p>
				534
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	535	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	536	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				537
				538	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				539	or variable via a global pointer to a pointer that is set up by the DLL
				540	exporting the symbol. On Microsoft Windows targets, the pointer name is
				541	formed by combining <code>_imp__</code> and the function or variable name.
				542	</dd>
				543
				544	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				545
				546	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				547	pointer to a pointer in a DLL, so that it can be referenced with the
				548	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				549	name is formed by combining <code>_imp__</code> and the function or variable
				550	name.
				551	</dd>
				552
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	553	</dl>
				554
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	555	<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]	556	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				557	variable and was linked with this one, one of the two would be renamed,
				558	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				559	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	560	outside of the current module.</p>
				561	<p>It is illegal for a function <i>declaration</i>
				562	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	563	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	564	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				565	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	566	</div>
				567
				568	<!-- ======================================================================= -->
				569	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	570	<a name="callingconv">Calling Conventions</a>
				571	</div>
				572
				573	<div class="doc_text">
				574
				575	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				576	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				577	specified for the call. The calling convention of any pair of dynamic
				578	caller/callee must match, or the behavior of the program is undefined. The
				579	following calling conventions are supported by LLVM, and more may be added in
				580	the future:</p>
				581
				582	<dl>
				583	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				584
				585	<dd>This calling convention (the default if no other calling convention is
				586	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	587	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	588	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	589	</dd>
				590
				591	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				592
				593	<dd>This calling convention attempts to make calls as fast as possible
				594	(e.g. by passing things in registers). This calling convention allows the
				595	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]	596	without having to conform to an externally specified ABI. Implementations of
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	597	this convention should allow arbitrary
				598	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				599	supported. This calling convention does not support varargs and requires the
				600	prototype of all callees to exactly match the prototype of the function
				601	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	602	</dd>
				603
				604	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				605
				606	<dd>This calling convention attempts to make code in the caller as efficient
				607	as possible under the assumption that the call is not commonly executed. As
				608	such, these calls often preserve all registers so that the call does not break
				609	any live ranges in the caller side. This calling convention does not support
				610	varargs and requires the prototype of all callees to exactly match the
				611	prototype of the function definition.
				612	</dd>
				613
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	614	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	615
				616	<dd>Any calling convention may be specified by number, allowing
				617	target-specific calling conventions to be used. Target specific calling
				618	conventions start at 64.
				619	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	620	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	621
				622	<p>More calling conventions can be added/defined on an as-needed basis, to
				623	support pascal conventions or any other well-known target-independent
				624	convention.</p>
				625
				626	</div>
				627
				628	<!-- ======================================================================= -->
				629	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	630	<a name="visibility">Visibility Styles</a>
				631	</div>
				632
				633	<div class="doc_text">
				634
				635	<p>
				636	All Global Variables and Functions have one of the following visibility styles:
				637	</p>
				638
				639	<dl>
				640	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				641
				642	<dd>On ELF, default visibility means that the declaration is visible to other
				643	modules and, in shared libraries, means that the declared entity may be
				644	overridden. On Darwin, default visibility means that the declaration is
				645	visible to other modules. Default visibility corresponds to "external
				646	linkage" in the language.
				647	</dd>
				648
				649	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				650
				651	<dd>Two declarations of an object with hidden visibility refer to the same
				652	object if they are in the same shared object. Usually, hidden visibility
				653	indicates that the symbol will not be placed into the dynamic symbol table,
				654	so no other module (executable or shared library) can reference it
				655	directly.
				656	</dd>
				657
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	658	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				659
				660	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				661	the dynamic symbol table, but that references within the defining module will
				662	bind to the local symbol. That is, the symbol cannot be overridden by another
				663	module.
				664	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	665	</dl>
				666
				667	</div>
				668
				669	<!-- ======================================================================= -->
				670	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	671	<a name="globalvars">Global Variables</a>
				672	</div>
				673
				674	<div class="doc_text">
				675
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	676	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	677	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	678	an explicit section to be placed in, and may have an optional explicit alignment
				679	specified. A variable may be defined as "thread_local", which means that it
				680	will not be shared by threads (each thread will have a separated copy of the
				681	variable). A variable may be defined as a global "constant," which indicates
				682	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]	683	optimization, allowing the global data to be placed in the read-only section of
				684	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	685	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]	686
				687	<p>
				688	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				689	constant, even if the final definition of the global is not. This capability
				690	can be used to enable slightly better optimization of the program, but requires
				691	the language definition to guarantee that optimizations based on the
				692	'constantness' are valid for the translation units that do not include the
				693	definition.
				694	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	695
				696	<p>As SSA values, global variables define pointer values that are in
				697	scope (i.e. they dominate) all basic blocks in the program. Global
				698	variables always define a pointer to their "content" type because they
				699	describe a region of memory, and all memory objects in LLVM are
				700	accessed through pointers.</p>
				701
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	702	<p>A global variable may be declared to reside in a target-specifc numbered
				703	address space. For targets that support them, address spaces may affect how
				704	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	705	the variable. The default address space is zero. The address space qualifier
				706	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	707
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	708	<p>LLVM allows an explicit section to be specified for globals. If the target
				709	supports it, it will emit globals to the section specified.</p>
				710
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	711	<p>An explicit alignment may be specified for a global. If not present, or if
				712	the alignment is set to zero, the alignment of the global is set by the target
				713	to whatever it feels convenient. If an explicit alignment is specified, the
				714	global is forced to have at least that much alignment. All alignments must be
				715	a power of 2.</p>
				716
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	717	<p>For example, the following defines a global in a numbered address space with
				718	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	719
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	720	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	721	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	722	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	723	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	724	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	725
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	726	</div>
				727
				728
				729	<!-- ======================================================================= -->
				730	<div class="doc_subsection">
				731	<a name="functionstructure">Functions</a>
				732	</div>
				733
				734	<div class="doc_text">
				735
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	736	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				737	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	738	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	739	<a href="#callingconv">calling convention</a>, a return type, an optional
				740	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				741	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	742	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	743	optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	744	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]	745
				746	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				747	optional <a href="#linkage">linkage type</a>, an optional
				748	<a href="#visibility">visibility style</a>, an optional
				749	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	750	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	751	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]	752	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	753
				754	<p>A function definition contains a list of basic blocks, forming the CFG for
				755	the function. Each basic block may optionally start with a label (giving the
				756	basic block a symbol table entry), contains a list of instructions, and ends
				757	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				758	function return).</p>
				759
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	760	<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]	761	executed on entrance to the function, and it is not allowed to have predecessor
				762	basic blocks (i.e. there can not be any branches to the entry block of a
				763	function). Because the block can have no predecessors, it also cannot have any
				764	<a href="#i_phi">PHI nodes</a>.</p>
				765
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	766	<p>LLVM allows an explicit section to be specified for functions. If the target
				767	supports it, it will emit functions to the section specified.</p>
				768
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	769	<p>An explicit alignment may be specified for a function. If not present, or if
				770	the alignment is set to zero, the alignment of the function is set by the target
				771	to whatever it feels convenient. If an explicit alignment is specified, the
				772	function is forced to have at least that much alignment. All alignments must be
				773	a power of 2.</p>
				774
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	775	</div>
				776
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	777
				778	<!-- ======================================================================= -->
				779	<div class="doc_subsection">
				780	<a name="aliasstructure">Aliases</a>
				781	</div>
				782	<div class="doc_text">
				783	<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]	784	function, global variable, another alias or bitcast of global value). Aliases
				785	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	786	optional <a href="#visibility">visibility style</a>.</p>
				787
				788	<h5>Syntax:</h5>
				789
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	790	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	791	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	792	@<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	793	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	794	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	795
				796	</div>
				797
				798
				799
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	800	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	801	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				802	<div class="doc_text">
				803	<p>The return type and each parameter of a function type may have a set of
				804	<i>parameter attributes</i> associated with them. Parameter attributes are
				805	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	806	a function. Parameter attributes are considered to be part of the function,
				807	not of the function type, so functions with different parameter attributes
				808	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	809
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	810	<p>Parameter attributes are simple keywords that follow the type specified. If
				811	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	812	example:</p>
				813
				814	<div class="doc_code">
				815	<pre>
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	816	declare i32 @printf(i8* noalias , ...) nounwind
				817	declare i32 @atoi(i8*) nounwind readonly
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	818	</pre>
				819	</div>
				820
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	821	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				822	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	823
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	824	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	825	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	826	<dt><tt>zeroext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	827	<dd>This indicates that the parameter should be zero extended just before
				828	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	829
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	830	<dt><tt>signext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	831	<dd>This indicates that the parameter should be sign extended just before
				832	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	833
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	834	<dt><tt>inreg</tt></dt>
				835	<dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov	66a8c8c	2007-01-28 15:27:21 +0000	[diff] [blame]	836	possible) during assembling function call. Support for this attribute is
				837	target-specific</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	838
				839	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	840	<dd>This indicates that the pointer parameter should really be passed by
				841	value to the function. The attribute implies that a hidden copy of the
				842	pointee is made between the caller and the callee, so the callee is unable
				843	to modify the value in the callee. This attribute is only valid on llvm
				844	pointer arguments. It is generally used to pass structs and arrays by
				845	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]	846
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	847	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	848	<dd>This indicates that the pointer parameter specifies the address of a
				849	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]	850	Loads and stores to the structure are assumed not to trap.
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	851	May only be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	852
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	853	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	854	<dd>This indicates that the parameter does not alias any global or any other
				855	parameter. The caller is responsible for ensuring that this is the case,
				856	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	857
Reid Spencer	2dc5201	2007-03-22 02:18:56 +0000	[diff] [blame]	858	<dt><tt>noreturn</tt></dt>
				859	<dd>This function attribute indicates that the function never returns. This
				860	indicates to LLVM that every call to this function should be treated as if
				861	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	862
Reid Spencer	6760612	2007-03-22 02:02:11 +0000	[diff] [blame]	863	<dt><tt>nounwind</tt></dt>
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	864	<dd>This function attribute indicates that no exceptions unwind out of the
				865	function. Usually this is because the function makes no use of exceptions,
				866	but it may also be that the function catches any exceptions thrown when
				867	executing it.</dd>
				868
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	869	<dt><tt>nest</tt></dt>
				870	<dd>This indicates that the parameter can be excised using the
				871	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	872	<dt><tt>readonly</tt></dt>
Duncan Sands	f04d584	2007-11-14 21:14:02 +0000	[diff] [blame]	873	<dd>This function attribute indicates that the function has no side-effects
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	874	except for producing a return value or throwing an exception. The value
				875	returned must only depend on the function arguments and/or global variables.
				876	It may use values obtained by dereferencing pointers.</dd>
				877	<dt><tt>readnone</tt></dt>
				878	<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]	879	function, but in addition it is not allowed to dereference any pointer arguments
				880	or global variables.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	881	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	882
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	883	</div>
				884
				885	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	886	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	887	<a name="gc">Garbage Collector Names</a>
				888	</div>
				889
				890	<div class="doc_text">
				891	<p>Each function may specify a garbage collector name, which is simply a
				892	string.</p>
				893
				894	<div class="doc_code"><pre
				895	>define void @f() gc "name" { ...</pre></div>
				896
				897	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				898	collector which will cause the compiler to alter its output in order to support
				899	the named garbage collection algorithm.</p>
				900	</div>
				901
				902	<!-- ======================================================================= -->
				903	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	904	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	905	</div>
				906
				907	<div class="doc_text">
				908	<p>
				909	Modules may contain "module-level inline asm" blocks, which corresponds to the
				910	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				911	LLVM and treated as a single unit, but may be separated in the .ll file if
				912	desired. The syntax is very simple:
				913	</p>
				914
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	915	<div class="doc_code">
				916	<pre>
				917	module asm "inline asm code goes here"
				918	module asm "more can go here"
				919	</pre>
				920	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	921
				922	<p>The strings can contain any character by escaping non-printable characters.
				923	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				924	for the number.
				925	</p>
				926
				927	<p>
				928	The inline asm code is simply printed to the machine code .s file when
				929	assembly code is generated.
				930	</p>
				931	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	932
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	933	<!-- ======================================================================= -->
				934	<div class="doc_subsection">
				935	<a name="datalayout">Data Layout</a>
				936	</div>
				937
				938	<div class="doc_text">
				939	<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]	940	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				941	<pre> target datalayout = "<i>layout specification</i>"</pre>
				942	<p>The <i>layout specification</i> consists of a list of specifications
				943	separated by the minus sign character ('-'). Each specification starts with a
				944	letter and may include other information after the letter to define some
				945	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	946	<dl>
				947	<dt><tt>E</tt></dt>
				948	<dd>Specifies that the target lays out data in big-endian form. That is, the
				949	bits with the most significance have the lowest address location.</dd>
				950	<dt><tt>e</tt></dt>
				951	<dd>Specifies that hte target lays out data in little-endian form. That is,
				952	the bits with the least significance have the lowest address location.</dd>
				953	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				954	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				955	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				956	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				957	too.</dd>
				958	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				959	<dd>This specifies the alignment for an integer type of a given bit
				960	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				961	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				962	<dd>This specifies the alignment for a vector type of a given bit
				963	<i>size</i>.</dd>
				964	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				965	<dd>This specifies the alignment for a floating point type of a given bit
				966	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				967	(double).</dd>
				968	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				969	<dd>This specifies the alignment for an aggregate type of a given bit
				970	<i>size</i>.</dd>
				971	</dl>
				972	<p>When constructing the data layout for a given target, LLVM starts with a
				973	default set of specifications which are then (possibly) overriden by the
				974	specifications in the <tt>datalayout</tt> keyword. The default specifications
				975	are given in this list:</p>
				976	<ul>
				977	<li><tt>E</tt> - big endian</li>
				978	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				979	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				980	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				981	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				982	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
				983	<li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
				984	alignment of 64-bits</li>
				985	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				986	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				987	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				988	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				989	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				990	</ul>
				991	<p>When llvm is determining the alignment for a given type, it uses the
				992	following rules:
				993	<ol>
				994	<li>If the type sought is an exact match for one of the specifications, that
				995	specification is used.</li>
				996	<li>If no match is found, and the type sought is an integer type, then the
				997	smallest integer type that is larger than the bitwidth of the sought type is
				998	used. If none of the specifications are larger than the bitwidth then the the
				999	largest integer type is used. For example, given the default specifications
				1000	above, the i7 type will use the alignment of i8 (next largest) while both
				1001	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1002	<li>If no match is found, and the type sought is a vector type, then the
				1003	largest vector type that is smaller than the sought vector type will be used
				1004	as a fall back. This happens because <128 x double> can be implemented in
				1005	terms of 64 <2 x double>, for example.</li>
				1006	</ol>
				1007	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1008
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1009	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1010	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1011	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1012
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1013	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1014
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1015	<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]	1016	intermediate representation. Being typed enables a number of
				1017	optimizations to be performed on the IR directly, without having to do
				1018	extra analyses on the side before the transformation. A strong type
				1019	system makes it easier to read the generated code and enables novel
				1020	analyses and transformations that are not feasible to perform on normal
				1021	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1022
				1023	</div>
				1024
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1025	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1026	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1027	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1028	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1029	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1030	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1031
				1032	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1033	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1034	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1035	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1036	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1037	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1038	</tr>
				1039	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1040	<td><a href="#t_floating">floating point</a></td>
				1041	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1042	</tr>
				1043	<tr>
				1044	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1045	<td><a href="#t_integer">integer</a>,
				1046	<a href="#t_floating">floating point</a>,
				1047	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1048	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1049	<a href="#t_struct">structure</a>,
				1050	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1051	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1052	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1053	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1054	<tr>
				1055	<td><a href="#t_primitive">primitive</a></td>
				1056	<td><a href="#t_label">label</a>,
				1057	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1058	<a href="#t_floating">floating point</a>.</td>
				1059	</tr>
				1060	<tr>
				1061	<td><a href="#t_derived">derived</a></td>
				1062	<td><a href="#t_integer">integer</a>,
				1063	<a href="#t_array">array</a>,
				1064	<a href="#t_function">function</a>,
				1065	<a href="#t_pointer">pointer</a>,
				1066	<a href="#t_struct">structure</a>,
				1067	<a href="#t_pstruct">packed structure</a>,
				1068	<a href="#t_vector">vector</a>,
				1069	<a href="#t_opaque">opaque</a>.
				1070	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1071	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1072	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1073
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1074	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1075	most important. Values of these types are the only ones which can be
				1076	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1077	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1078	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1079
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1080	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1081	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1082
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1083	<div class="doc_text">
				1084	<p>The primitive types are the fundamental building blocks of the LLVM
				1085	system.</p>
				1086
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1087	</div>
				1088
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1089	<!-- _______________________________________________________________________ -->
				1090	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1091
				1092	<div class="doc_text">
				1093	<table>
				1094	<tbody>
				1095	<tr><th>Type</th><th>Description</th></tr>
				1096	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1097	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1098	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1099	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1100	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1101	</tbody>
				1102	</table>
				1103	</div>
				1104
				1105	<!-- _______________________________________________________________________ -->
				1106	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1107
				1108	<div class="doc_text">
				1109	<h5>Overview:</h5>
				1110	<p>The void type does not represent any value and has no size.</p>
				1111
				1112	<h5>Syntax:</h5>
				1113
				1114	<pre>
				1115	void
				1116	</pre>
				1117	</div>
				1118
				1119	<!-- _______________________________________________________________________ -->
				1120	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1121
				1122	<div class="doc_text">
				1123	<h5>Overview:</h5>
				1124	<p>The label type represents code labels.</p>
				1125
				1126	<h5>Syntax:</h5>
				1127
				1128	<pre>
				1129	label
				1130	</pre>
				1131	</div>
				1132
				1133
				1134	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1135	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1136
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1137	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1138
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1139	<p>The real power in LLVM comes from the derived types in the system.
				1140	This is what allows a programmer to represent arrays, functions,
				1141	pointers, and other useful types. Note that these derived types may be
				1142	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]	1143
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1144	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1145
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1146	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1147	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1148
				1149	<div class="doc_text">
				1150
				1151	<h5>Overview:</h5>
				1152	<p>The integer type is a very simple derived type that simply specifies an
				1153	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1154	2^23-1 (about 8 million) can be specified.</p>
				1155
				1156	<h5>Syntax:</h5>
				1157
				1158	<pre>
				1159	iN
				1160	</pre>
				1161
				1162	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1163	value.</p>
				1164
				1165	<h5>Examples:</h5>
				1166	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1167	<tbody>
				1168	<tr>
				1169	<td><tt>i1</tt></td>
				1170	<td>a single-bit integer.</td>
				1171	</tr><tr>
				1172	<td><tt>i32</tt></td>
				1173	<td>a 32-bit integer.</td>
				1174	</tr><tr>
				1175	<td><tt>i1942652</tt></td>
				1176	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1177	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1178	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1179	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1180	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1181
				1182	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1183	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1184
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1185	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1186
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1187	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1188
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1189	<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]	1190	sequentially in memory. The array type requires a size (number of
				1191	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1192
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1193	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1194
				1195	<pre>
				1196	[<# elements> x <elementtype>]
				1197	</pre>
				1198
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1199	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1200	be any type with a size.</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>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1203	<table class="layout">
				1204	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1205	<td class="left"><tt>[40 x i32]</tt></td>
				1206	<td class="left">Array of 40 32-bit integer values.</td>
				1207	</tr>
				1208	<tr class="layout">
				1209	<td class="left"><tt>[41 x i32]</tt></td>
				1210	<td class="left">Array of 41 32-bit integer values.</td>
				1211	</tr>
				1212	<tr class="layout">
				1213	<td class="left"><tt>[4 x i8]</tt></td>
				1214	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1215	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1216	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1217	<p>Here are some examples of multidimensional arrays:</p>
				1218	<table class="layout">
				1219	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1220	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1221	<td class="left">3x4 array of 32-bit integer values.</td>
				1222	</tr>
				1223	<tr class="layout">
				1224	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1225	<td class="left">12x10 array of single precision floating point values.</td>
				1226	</tr>
				1227	<tr class="layout">
				1228	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1229	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1230	</tr>
				1231	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1232
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1233	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1234	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]	1235	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1236	As a special case, however, zero length arrays are recognized to be variable
				1237	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1238	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1239
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1240	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1241
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1242	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1243	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1244	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1245
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1246	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1247
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1248	<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]	1249	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]	1250	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]	1251	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]	1252	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1253
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1254	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1255
				1256	<pre>
				1257	<returntype list> (<parameter list>)
				1258	</pre>
				1259
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1260	<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]	1261	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1262	which indicates that the function takes a variable number of arguments.
				1263	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1264	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1265	'<tt><returntype list></tt>' is a comma-separated list of
				1266	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1267
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1268	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1269	<table class="layout">
				1270	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1271	<td class="left"><tt>i32 (i32)</tt></td>
				1272	<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]	1273	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1274	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1275	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1276	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1277	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1278	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1279	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1280	<tt>float</tt>.
				1281	</td>
				1282	</tr><tr class="layout">
				1283	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1284	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1285	<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]	1286	which returns an integer. This is the signature for <tt>printf</tt> in
				1287	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1288	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1289	</tr><tr class="layout">
				1290	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1291	<td class="left">A function taking an <tt>i32></tt>, returning two
				1292	<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]	1293	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1294	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1295	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1296
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1297	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1298	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1299	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1300	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1301	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1302	<p>The structure type is used to represent a collection of data members
				1303	together in memory. The packing of the field types is defined to match
				1304	the ABI of the underlying processor. The elements of a structure may
				1305	be any type that has a size.</p>
				1306	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1307	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1308	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1309	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1310	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1311	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1312	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1313	<table class="layout">
				1314	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1315	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1316	<td class="left">A triple of three <tt>i32</tt> values</td>
				1317	</tr><tr class="layout">
				1318	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1319	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1320	second element is a <a href="#t_pointer">pointer</a> to a
				1321	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1322	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1323	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1324	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1325	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1326
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1327	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1328	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1329	</div>
				1330	<div class="doc_text">
				1331	<h5>Overview:</h5>
				1332	<p>The packed structure type is used to represent a collection of data members
				1333	together in memory. There is no padding between fields. Further, the alignment
				1334	of a packed structure is 1 byte. The elements of a packed structure may
				1335	be any type that has a size.</p>
				1336	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1337	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1338	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1339	instruction.</p>
				1340	<h5>Syntax:</h5>
				1341	<pre> < { <type list> } > <br></pre>
				1342	<h5>Examples:</h5>
				1343	<table class="layout">
				1344	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1345	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1346	<td class="left">A triple of three <tt>i32</tt> values</td>
				1347	</tr><tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1348	<td class="left"><tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1349	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1350	second element is a <a href="#t_pointer">pointer</a> to a
				1351	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1352	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1353	</tr>
				1354	</table>
				1355	</div>
				1356
				1357	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1358	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1359	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1360	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1361	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1362	reference to another object, which must live in memory. Pointer types may have
				1363	an optional address space attribute defining the target-specific numbered
				1364	address space where the pointed-to object resides. The default address space is
				1365	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1366	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1367	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1368	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1369	<table class="layout">
				1370	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1371	<td class="left"><tt>[4x i32]*</tt></td>
				1372	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1373	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1374	</tr>
				1375	<tr class="layout">
				1376	<td class="left"><tt>i32 (i32 ) </tt></td>
				1377	<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]	1378	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]	1379	<tt>i32</tt>.</td>
				1380	</tr>
				1381	<tr class="layout">
				1382	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1383	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1384	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1385	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1386	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1387	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1388
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1389	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1390	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1391	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1392
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1393	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1394
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1395	<p>A vector type is a simple derived type that represents a vector
				1396	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1397	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1398	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1399	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1400	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1401	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1402
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1403	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1404
				1405	<pre>
				1406	< <# elements> x <elementtype> >
				1407	</pre>
				1408
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1409	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1410	be any integer or floating point type.</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>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1413
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1414	<table class="layout">
				1415	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1416	<td class="left"><tt><4 x i32></tt></td>
				1417	<td class="left">Vector of 4 32-bit integer values.</td>
				1418	</tr>
				1419	<tr class="layout">
				1420	<td class="left"><tt><8 x float></tt></td>
				1421	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1422	</tr>
				1423	<tr class="layout">
				1424	<td class="left"><tt><2 x i64></tt></td>
				1425	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1426	</tr>
				1427	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1428	</div>
				1429
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1430	<!-- _______________________________________________________________________ -->
				1431	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1432	<div class="doc_text">
				1433
				1434	<h5>Overview:</h5>
				1435
				1436	<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]	1437	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]	1438	In LLVM, opaque types can eventually be resolved to any type (not just a
				1439	structure type).</p>
				1440
				1441	<h5>Syntax:</h5>
				1442
				1443	<pre>
				1444	opaque
				1445	</pre>
				1446
				1447	<h5>Examples:</h5>
				1448
				1449	<table class="layout">
				1450	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1451	<td class="left"><tt>opaque</tt></td>
				1452	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1453	</tr>
				1454	</table>
				1455	</div>
				1456
				1457
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1458	<!-- *********************************************************************** -->
				1459	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1460	<!-- *********************************************************************** -->
				1461
				1462	<div class="doc_text">
				1463
				1464	<p>LLVM has several different basic types of constants. This section describes
				1465	them all and their syntax.</p>
				1466
				1467	</div>
				1468
				1469	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1470	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1471
				1472	<div class="doc_text">
				1473
				1474	<dl>
				1475	<dt><b>Boolean constants</b></dt>
				1476
				1477	<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]	1478	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1479	</dd>
				1480
				1481	<dt><b>Integer constants</b></dt>
				1482
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1483	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1484	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1485	integer types.
				1486	</dd>
				1487
				1488	<dt><b>Floating point constants</b></dt>
				1489
				1490	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1491	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1492	notation (see below). The assembler requires the exact decimal value of
				1493	a floating-point constant. For example, the assembler accepts 1.25 but
				1494	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1495	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]	1496
				1497	<dt><b>Null pointer constants</b></dt>
				1498
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1499	<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]	1500	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1501
				1502	</dl>
				1503
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1504	<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]	1505	of floating point constants. For example, the form '<tt>double
				1506	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1507	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]	1508	(and the only time that they are generated by the disassembler) is when a
				1509	floating point constant must be emitted but it cannot be represented as a
				1510	decimal floating point number. For example, NaN's, infinities, and other
				1511	special values are represented in their IEEE hexadecimal format so that
				1512	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]	1513
				1514	</div>
				1515
				1516	<!-- ======================================================================= -->
				1517	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1518	</div>
				1519
				1520	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1521	<p>Aggregate constants arise from aggregation of simple constants
				1522	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1523
				1524	<dl>
				1525	<dt><b>Structure constants</b></dt>
				1526
				1527	<dd>Structure constants are represented with notation similar to structure
				1528	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1529	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1530	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]	1531	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]	1532	types of elements must match those specified by the type.
				1533	</dd>
				1534
				1535	<dt><b>Array constants</b></dt>
				1536
				1537	<dd>Array constants are represented with notation similar to array type
				1538	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1539	(<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]	1540	constants must have <a href="#t_array">array type</a>, and the number and
				1541	types of elements must match those specified by the type.
				1542	</dd>
				1543
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1544	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1545
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1546	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1547	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1548	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1549	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1550	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]	1551	match those specified by the type.
				1552	</dd>
				1553
				1554	<dt><b>Zero initialization</b></dt>
				1555
				1556	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1557	value to zero of <em>any</em> type, including scalar and aggregate types.
				1558	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]	1559	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1560	initializers.
				1561	</dd>
				1562	</dl>
				1563
				1564	</div>
				1565
				1566	<!-- ======================================================================= -->
				1567	<div class="doc_subsection">
				1568	<a name="globalconstants">Global Variable and Function Addresses</a>
				1569	</div>
				1570
				1571	<div class="doc_text">
				1572
				1573	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1574	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1575	constants. These constants are explicitly referenced when the <a
				1576	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]	1577	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1578	file:</p>
				1579
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1580	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1581	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1582	@X = global i32 17
				1583	@Y = global i32 42
				1584	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1585	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1586	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1587
				1588	</div>
				1589
				1590	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1591	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1592	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1593	<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]	1594	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]	1595	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1596
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1597	<p>Undefined values indicate to the compiler that the program is well defined
				1598	no matter what value is used, giving the compiler more freedom to optimize.
				1599	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1600	</div>
				1601
				1602	<!-- ======================================================================= -->
				1603	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1604	</div>
				1605
				1606	<div class="doc_text">
				1607
				1608	<p>Constant expressions are used to allow expressions involving other constants
				1609	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1610	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]	1611	that does not have side effects (e.g. load and call are not supported). The
				1612	following is the syntax for constant expressions:</p>
				1613
				1614	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1615	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1616	<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]	1617	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1618
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1619	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1620	<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]	1621	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]	1622
				1623	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1624	<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]	1625	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]	1626
				1627	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1628	<dd>Truncate a floating point constant to another floating point type. The
				1629	size of CST must be larger than the size of TYPE. Both types must be
				1630	floating point.</dd>
				1631
				1632	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1633	<dd>Floating point extend a constant to another type. The size of CST must be
				1634	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1635
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1636	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1637	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1638	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1639	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1640	of the same number of elements. If the value won't fit in the integer type,
				1641	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1642
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1643	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1644	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1645	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1646	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1647	of the same number of elements. If the value won't fit in the integer type,
				1648	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1649
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1650	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1651	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1652	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1653	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1654	of the same number of elements. If the value won't fit in the floating point
				1655	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1656
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1657	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1658	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1659	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1660	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1661	of the same number of elements. If the value won't fit in the floating point
				1662	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1663
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1664	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1665	<dd>Convert a pointer typed constant to the corresponding integer constant
				1666	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1667	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1668
				1669	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1670	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1671	pointer type. CST must be of integer type. The CST value is zero extended,
				1672	truncated, or unchanged to make it fit in a pointer size. This one is
				1673	<i>really</i> dangerous!</dd>
				1674
				1675	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1676	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1677	identical (same number of bits). The conversion is done as if the CST value
				1678	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]	1679	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]	1680	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]	1681	pointers it is only valid to cast to another pointer type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1682	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1683
				1684	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1685
				1686	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1687	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1688	instruction, the index list may have zero or more indexes, which are required
				1689	to make sense for the type of "CSTPTR".</dd>
				1690
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1691	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1692
				1693	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1694	constants.</dd>
				1695
				1696	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1697	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1698
				1699	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1700	<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]	1701
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1702	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1703	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1704
				1705	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1706	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1707
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1708	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1709
				1710	<dd>Perform the <a href="#i_extractelement">extractelement
				1711	operation</a> on constants.
				1712
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1713	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1714
				1715	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1716	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1717
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1718
				1719	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1720
				1721	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1722	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1723
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1724	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1725
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1726	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1727	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]	1728	binary</a> operations. The constraints on operands are the same as those for
				1729	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1730	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1731	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1732	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1733
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1734	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1735	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1736	<!-- *********************************************************************** -->
				1737
				1738	<!-- ======================================================================= -->
				1739	<div class="doc_subsection">
				1740	<a name="inlineasm">Inline Assembler Expressions</a>
				1741	</div>
				1742
				1743	<div class="doc_text">
				1744
				1745	<p>
				1746	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1747	Module-Level Inline Assembly</a>) through the use of a special value. This
				1748	value represents the inline assembler as a string (containing the instructions
				1749	to emit), a list of operand constraints (stored as a string), and a flag that
				1750	indicates whether or not the inline asm expression has side effects. An example
				1751	inline assembler expression is:
				1752	</p>
				1753
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1754	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1755	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1756	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1757	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1758	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1759
				1760	<p>
				1761	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1762	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1763	</p>
				1764
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1765	<div class="doc_code">
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	%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]	1768	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1769	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1770
				1771	<p>
				1772	Inline asms with side effects not visible in the constraint list must be marked
				1773	as having side effects. This is done through the use of the
				1774	'<tt>sideeffect</tt>' keyword, like so:
				1775	</p>
				1776
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1777	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1778	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1779	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1780	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1781	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1782
				1783	<p>TODO: The format of the asm and constraints string still need to be
				1784	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1785	need to be documented).
				1786	</p>
				1787
				1788	</div>
				1789
				1790	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1791	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1792	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1793
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1794	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1795
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1796	<p>The LLVM instruction set consists of several different
				1797	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1798	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1799	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1800	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1801	instructions</a>.</p>
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>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1804
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1805	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1806	<div class="doc_subsection"> <a name="terminators">Terminator
				1807	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1808
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1809	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1810
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1811	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1812	basic block in a program ends with a "Terminator" instruction, which
				1813	indicates which block should be executed after the current block is
				1814	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1815	value: they produce control flow, not values (the one exception being
				1816	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1817	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1818	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1819	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1820	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1821	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1822	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1823
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1824	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1825
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1826	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1827	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1828	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1829	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1830	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1831	<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]	1832	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1833	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]	1834	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1835
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1836	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1837
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1838	<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]	1839	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1840	<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]	1841	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]	1842	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1843
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1844	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1845
				1846	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1847	The type of each return value must be a '<a href="#t_firstclass">first
				1848	class</a>' type. Note that a function is not <a href="#wellformed">well
				1849	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1850	function that returns values that do not match the return type of the
				1851	function.</p>
				1852
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1853	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1854
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1855	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1856	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]	1857	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1858	the instruction after the call. If the caller was an "<a
				1859	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1860	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1861	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]	1862	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1863	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1864	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1865
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1866	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1867
				1868	<pre>
				1869	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1870	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1871	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]	1872	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1873	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1874	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1875	<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]	1876	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1877	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1878	<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]	1879	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1880	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1881	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1882	transfer to a different basic block in the current function. There are
				1883	two forms of this instruction, corresponding to a conditional branch
				1884	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1885	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1886	<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]	1887	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1888	unconditional form of the '<tt>br</tt>' instruction takes a single
				1889	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1890	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1891	<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]	1892	argument is evaluated. If the value is <tt>true</tt>, control flows
				1893	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1894	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1895	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1896	<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]	1897	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]	1898	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1899	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1900	<div class="doc_subsubsection">
				1901	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1902	</div>
				1903
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1904	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1905	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1906
				1907	<pre>
				1908	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1909	</pre>
				1910
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1911	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1912
				1913	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1914	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1915	instruction, allowing a branch to occur to one of many possible
				1916	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1917
				1918
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1919	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1920
				1921	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1922	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1923	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1924	table is not allowed to contain duplicate constant entries.</p>
				1925
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1926	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1927
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1928	<p>The <tt>switch</tt> instruction specifies a table of values and
				1929	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1930	table is searched for the given value. If the value is found, control flow is
				1931	transfered to the corresponding destination; otherwise, control flow is
				1932	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1933
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1934	<h5>Implementation:</h5>
				1935
				1936	<p>Depending on properties of the target machine and the particular
				1937	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1938	ways. For example, it could be generated as a series of chained conditional
				1939	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1940
				1941	<h5>Example:</h5>
				1942
				1943	<pre>
				1944	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1945	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1946	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1947
				1948	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1949	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1950
				1951	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1952	switch i32 %val, label %otherwise [ i32 0, label %onzero
				1953	i32 1, label %onone
				1954	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1955	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1956	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1957
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1958	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1959	<div class="doc_subsubsection">
				1960	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				1961	</div>
				1962
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1963	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1964
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1965	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1966
				1967	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	1968	<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]	1969	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1970	</pre>
				1971
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	1972	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1973
				1974	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				1975	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1976	'<tt>normal</tt>' label or the
				1977	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1978	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				1979	"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]	1980	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1981	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1982	returns multiple values then individual return values are only accessible through
				1983	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1984
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1985	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1986
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1987	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1988
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1989	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1990	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	1991	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1992	convention</a> the call should use. If none is specified, the call defaults
				1993	to using C calling conventions.
				1994	</li>
				1995	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				1996	function value being invoked. In most cases, this is a direct function
				1997	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				1998	an arbitrary pointer to function value.
				1999	</li>
				2000
				2001	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2002	function to be invoked. </li>
				2003
				2004	<li>'<tt>function args</tt>': argument list whose types match the function
				2005	signature argument types. If the function signature indicates the function
				2006	accepts a variable number of arguments, the extra arguments can be
				2007	specified. </li>
				2008
				2009	<li>'<tt>normal label</tt>': the label reached when the called function
				2010	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2011
				2012	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2013	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2014
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2015	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2016
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2017	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2018
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2019	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2020	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2021	difference is that it establishes an association with a label, which is used by
				2022	the runtime library to unwind the stack.</p>
				2023
				2024	<p>This instruction is used in languages with destructors to ensure that proper
				2025	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2026	exception. Additionally, this is important for implementation of
				2027	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2028
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2029	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2030	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2031	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2032	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2033	%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]	2034	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2035	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2036	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2037
				2038
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2039	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2040
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2041	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2042	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2043
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2044	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2045
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2046	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2047	<pre>
				2048	unwind
				2049	</pre>
				2050
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2051	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2052
				2053	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2054	at the first callee in the dynamic call stack which used an <a
				2055	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2056	primarily used to implement exception handling.</p>
				2057
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2058	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2059
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2060	<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]	2061	immediately halt. The dynamic call stack is then searched for the first <a
				2062	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2063	execution continues at the "exceptional" destination block specified by the
				2064	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2065	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2066	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2067
				2068	<!-- _______________________________________________________________________ -->
				2069
				2070	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2071	Instruction</a> </div>
				2072
				2073	<div class="doc_text">
				2074
				2075	<h5>Syntax:</h5>
				2076	<pre>
				2077	unreachable
				2078	</pre>
				2079
				2080	<h5>Overview:</h5>
				2081
				2082	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2083	instruction is used to inform the optimizer that a particular portion of the
				2084	code is not reachable. This can be used to indicate that the code after a
				2085	no-return function cannot be reached, and other facts.</p>
				2086
				2087	<h5>Semantics:</h5>
				2088
				2089	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2090	</div>
				2091
				2092
				2093
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2094	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2095	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2096	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2097	<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]	2098	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]	2099	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2100	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]	2101	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2102	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2103	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2104	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2105	<div class="doc_subsubsection">
				2106	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2107	</div>
				2108
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2109	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2110
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2111	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2112
				2113	<pre>
				2114	<result> = add <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2115	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2116
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2117	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2118
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2119	<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]	2120
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2121	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2122
				2123	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2124	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2125	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2126	types.</p>
				2127
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2128	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2129
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2130	<p>The value produced is the integer or floating point sum of the two
				2131	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2132
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2133	<p>If an integer sum has unsigned overflow, the result returned is the
				2134	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2135	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2136
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2137	<p>Because LLVM integers use a two's complement representation, this
				2138	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2139
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2140	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2141
				2142	<pre>
				2143	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2144	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2145	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2146	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2147	<div class="doc_subsubsection">
				2148	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2149	</div>
				2150
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2151	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2152
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2153	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2154
				2155	<pre>
				2156	<result> = sub <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2157	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2158
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2159	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2160
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2161	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2162	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2163
				2164	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2165	'<tt>neg</tt>' instruction present in most other intermediate
				2166	representations.</p>
				2167
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2168	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2169
				2170	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2171	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2172	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2173	types.</p>
				2174
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2175	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2176
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2177	<p>The value produced is the integer or floating point difference of
				2178	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2179
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2180	<p>If an integer difference has unsigned overflow, the result returned is the
				2181	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2182	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2183
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2184	<p>Because LLVM integers use a two's complement representation, this
				2185	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2186
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2187	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2188	<pre>
				2189	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2190	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2191	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2192	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2193
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2194	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2195	<div class="doc_subsubsection">
				2196	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2197	</div>
				2198
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2199	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2200
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2201	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2202	<pre> <result> = mul <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2204	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2205	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2206	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2207
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2208	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2209
				2210	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2211	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2212	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2213	types.</p>
				2214
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2215	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2216
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2217	<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]	2218	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2219
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2220	<p>If the result of an integer multiplication has unsigned overflow,
				2221	the result returned is the mathematical result modulo
				2222	2<sup>n</sup>, where n is the bit width of the result.</p>
				2223	<p>Because LLVM integers use a two's complement representation, and the
				2224	result is the same width as the operands, this instruction returns the
				2225	correct result for both signed and unsigned integers. If a full product
				2226	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2227	should be sign-extended or zero-extended as appropriate to the
				2228	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2229	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2230	<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]	2231	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2232	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2233
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2234	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2235	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2236	</a></div>
				2237	<div class="doc_text">
				2238	<h5>Syntax:</h5>
				2239	<pre> <result> = udiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2240	</pre>
				2241	<h5>Overview:</h5>
				2242	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2243	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2244
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2245	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2246
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2247	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2248	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2249	values. Both arguments must have identical types.</p>
				2250
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2251	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2252
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2253	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2254	<p>Note that unsigned integer division and signed integer division are distinct
				2255	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2256	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2257	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2258	<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]	2259	</pre>
				2260	</div>
				2261	<!-- _______________________________________________________________________ -->
				2262	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2263	</a> </div>
				2264	<div class="doc_text">
				2265	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2266	<pre>
				2267	<result> = sdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2268	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2269
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2270	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2271
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2272	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2273	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2274
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2275	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2276
				2277	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2278	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2279	values. Both arguments must have identical types.</p>
				2280
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2281	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2282	<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]	2283	<p>Note that signed integer division and unsigned integer division are distinct
				2284	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2285	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2286	undefined behavior; this is a rare case, but can occur, for example,
				2287	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2288	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2289	<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]	2290	</pre>
				2291	</div>
				2292	<!-- _______________________________________________________________________ -->
				2293	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2294	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2295	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2296	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2297	<pre>
				2298	<result> = fdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2299	</pre>
				2300	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2301
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2302	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2303	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2304
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2305	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2306
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2307	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2308	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2309	of floating point values. Both arguments must have identical types.</p>
				2310
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2311	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2312
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2313	<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]	2314
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2315	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2316
				2317	<pre>
				2318	<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]	2319	</pre>
				2320	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2321
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2322	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2323	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2324	</div>
				2325	<div class="doc_text">
				2326	<h5>Syntax:</h5>
				2327	<pre> <result> = urem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2328	</pre>
				2329	<h5>Overview:</h5>
				2330	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2331	unsigned division of its two arguments.</p>
				2332	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2333	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2334	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2335	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2336	<h5>Semantics:</h5>
				2337	<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]	2338	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2339	<p>Note that unsigned integer remainder and signed integer remainder are
				2340	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2341	<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]	2342	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2343	<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]	2344	</pre>
				2345
				2346	</div>
				2347	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2348	<div class="doc_subsubsection">
				2349	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2350	</div>
				2351
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2352	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2353
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2354	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2355
				2356	<pre>
				2357	<result> = srem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2358	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2359
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2360	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2361
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2362	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2363	signed division of its two operands. This instruction can also take
				2364	<a href="#t_vector">vector</a> versions of the values in which case
				2365	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2366
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2367	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2368
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2369	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2370	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2371	values. Both arguments must have identical types.</p>
				2372
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2373	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2374
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2375	<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]	2376	has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
				2377	operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
				2378	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2379	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]	2380	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]	2381	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2382	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2383	<p>Note that signed integer remainder and unsigned integer remainder are
				2384	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2385	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2386	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2387	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2388	(The remainder doesn't actually overflow, but this rule lets srem be
				2389	implemented using instructions that return both the result of the division
				2390	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2391	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2392	<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]	2393	</pre>
				2394
				2395	</div>
				2396	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2397	<div class="doc_subsubsection">
				2398	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2399
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2400	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2401
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2402	<h5>Syntax:</h5>
				2403	<pre> <result> = frem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2404	</pre>
				2405	<h5>Overview:</h5>
				2406	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2407	division of its two operands.</p>
				2408	<h5>Arguments:</h5>
				2409	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2410	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2411	of floating point values. Both arguments must have identical types.</p>
				2412
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2413	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2414
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2415	<p>This instruction returns the <i>remainder</i> of a division.
				2416	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2417
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2418	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2419
				2420	<pre>
				2421	<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]	2422	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2423	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2424
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2425	<!-- ======================================================================= -->
				2426	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2427	Operations</a> </div>
				2428	<div class="doc_text">
				2429	<p>Bitwise binary operators are used to do various forms of
				2430	bit-twiddling in a program. They are generally very efficient
				2431	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2432	instructions. They require two operands of the same type, execute an operation on them,
				2433	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]	2434	</div>
				2435
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2436	<!-- _______________________________________________________________________ -->
				2437	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2438	Instruction</a> </div>
				2439	<div class="doc_text">
				2440	<h5>Syntax:</h5>
				2441	<pre> <result> = shl <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2442	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2443
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2444	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2445
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2446	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2447	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2448
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2449	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2450
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2451	<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]	2452	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]	2453	unsigned value. This instruction does not support
				2454	<a href="#t_vector">vector</a> operands.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2455
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2456	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2457
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2458	<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup> mod 2<sup>n</sup>,
				2459	where n is the width of the result. If <tt>var2</tt> is (statically or dynamically) negative or
				2460	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]	2461
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2462	<h5>Example:</h5><pre>
				2463	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2464	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2465	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2466	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2467	</pre>
				2468	</div>
				2469	<!-- _______________________________________________________________________ -->
				2470	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2471	Instruction</a> </div>
				2472	<div class="doc_text">
				2473	<h5>Syntax:</h5>
				2474	<pre> <result> = lshr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2475	</pre>
				2476
				2477	<h5>Overview:</h5>
				2478	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2479	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]	2480
				2481	<h5>Arguments:</h5>
				2482	<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]	2483	<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]	2484	unsigned value. This instruction does not support
				2485	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2486
				2487	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2488
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2489	<p>This instruction always performs a logical shift right operation. The most
				2490	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]	2491	shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
				2492	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]	2493
				2494	<h5>Example:</h5>
				2495	<pre>
				2496	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2497	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2498	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2499	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2500	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2501	</pre>
				2502	</div>
				2503
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2504	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2505	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2506	Instruction</a> </div>
				2507	<div class="doc_text">
				2508
				2509	<h5>Syntax:</h5>
				2510	<pre> <result> = ashr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2511	</pre>
				2512
				2513	<h5>Overview:</h5>
				2514	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2515	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]	2516
				2517	<h5>Arguments:</h5>
				2518	<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]	2519	<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]	2520	unsigned value. This instruction does not support
				2521	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2522
				2523	<h5>Semantics:</h5>
				2524	<p>This instruction always performs an arithmetic shift right operation,
				2525	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]	2526	of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
				2527	larger than the number of bits in <tt>var1</tt>, the result is undefined.
				2528	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2529
				2530	<h5>Example:</h5>
				2531	<pre>
				2532	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2533	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2534	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2535	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2536	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2537	</pre>
				2538	</div>
				2539
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2540	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2541	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2542	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2543
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2544	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2545
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2546	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2547
				2548	<pre>
				2549	<result> = and <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2550	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2551
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2552	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2553
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2554	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2555	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2556
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2557	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2558
				2559	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2560	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2561	values. Both arguments must have identical types.</p>
				2562
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2563	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2564	<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]	2565	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2566	<div style="align: center">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2567	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2568	<tbody>
				2569	<tr>
				2570	<td>In0</td>
				2571	<td>In1</td>
				2572	<td>Out</td>
				2573	</tr>
				2574	<tr>
				2575	<td>0</td>
				2576	<td>0</td>
				2577	<td>0</td>
				2578	</tr>
				2579	<tr>
				2580	<td>0</td>
				2581	<td>1</td>
				2582	<td>0</td>
				2583	</tr>
				2584	<tr>
				2585	<td>1</td>
				2586	<td>0</td>
				2587	<td>0</td>
				2588	</tr>
				2589	<tr>
				2590	<td>1</td>
				2591	<td>1</td>
				2592	<td>1</td>
				2593	</tr>
				2594	</tbody>
				2595	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2596	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2597	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2598	<pre>
				2599	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2600	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2601	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2602	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2603	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2604	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2605	<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]	2606	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2607	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2608	<pre> <result> = or <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2609	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2610	<h5>Overview:</h5>
				2611	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2612	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2613	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2614
				2615	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2616	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2617	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2618	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2619	<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]	2620	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2621	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2622	<table border="1" cellspacing="0" cellpadding="4">
				2623	<tbody>
				2624	<tr>
				2625	<td>In0</td>
				2626	<td>In1</td>
				2627	<td>Out</td>
				2628	</tr>
				2629	<tr>
				2630	<td>0</td>
				2631	<td>0</td>
				2632	<td>0</td>
				2633	</tr>
				2634	<tr>
				2635	<td>0</td>
				2636	<td>1</td>
				2637	<td>1</td>
				2638	</tr>
				2639	<tr>
				2640	<td>1</td>
				2641	<td>0</td>
				2642	<td>1</td>
				2643	</tr>
				2644	<tr>
				2645	<td>1</td>
				2646	<td>1</td>
				2647	<td>1</td>
				2648	</tr>
				2649	</tbody>
				2650	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2651	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2652	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2653	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2654	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2655	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2656	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2657	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2658	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2659	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2660	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2661	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2662	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2663	<pre> <result> = xor <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2664	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2665	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2666	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2667	or of its two operands. The <tt>xor</tt> is used to implement the
				2668	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2669	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2670	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2671	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2672	values. Both arguments must have identical types.</p>
				2673
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2674	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2675
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2676	<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]	2677	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2678	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2679	<table border="1" cellspacing="0" cellpadding="4">
				2680	<tbody>
				2681	<tr>
				2682	<td>In0</td>
				2683	<td>In1</td>
				2684	<td>Out</td>
				2685	</tr>
				2686	<tr>
				2687	<td>0</td>
				2688	<td>0</td>
				2689	<td>0</td>
				2690	</tr>
				2691	<tr>
				2692	<td>0</td>
				2693	<td>1</td>
				2694	<td>1</td>
				2695	</tr>
				2696	<tr>
				2697	<td>1</td>
				2698	<td>0</td>
				2699	<td>1</td>
				2700	</tr>
				2701	<tr>
				2702	<td>1</td>
				2703	<td>1</td>
				2704	<td>0</td>
				2705	</tr>
				2706	</tbody>
				2707	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2708	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2709	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2710	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2711	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2712	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2713	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2714	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2715	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2716	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2717
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2718	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2719	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2720	<a name="vectorops">Vector Operations</a>
				2721	</div>
				2722
				2723	<div class="doc_text">
				2724
				2725	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2726	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2727	vector-specific operations needed to process vectors effectively. While LLVM
				2728	does directly support these vector operations, many sophisticated algorithms
				2729	will want to use target-specific intrinsics to take full advantage of a specific
				2730	target.</p>
				2731
				2732	</div>
				2733
				2734	<!-- _______________________________________________________________________ -->
				2735	<div class="doc_subsubsection">
				2736	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2737	</div>
				2738
				2739	<div class="doc_text">
				2740
				2741	<h5>Syntax:</h5>
				2742
				2743	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2744	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2745	</pre>
				2746
				2747	<h5>Overview:</h5>
				2748
				2749	<p>
				2750	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2751	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2752	</p>
				2753
				2754
				2755	<h5>Arguments:</h5>
				2756
				2757	<p>
				2758	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2759	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]	2760	an index indicating the position from which to extract the element.
				2761	The index may be a variable.</p>
				2762
				2763	<h5>Semantics:</h5>
				2764
				2765	<p>
				2766	The result is a scalar of the same type as the element type of
				2767	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2768	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2769	results are undefined.
				2770	</p>
				2771
				2772	<h5>Example:</h5>
				2773
				2774	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2775	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2776	</pre>
				2777	</div>
				2778
				2779
				2780	<!-- _______________________________________________________________________ -->
				2781	<div class="doc_subsubsection">
				2782	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2783	</div>
				2784
				2785	<div class="doc_text">
				2786
				2787	<h5>Syntax:</h5>
				2788
				2789	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2790	<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]	2791	</pre>
				2792
				2793	<h5>Overview:</h5>
				2794
				2795	<p>
				2796	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2797	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2798	</p>
				2799
				2800
				2801	<h5>Arguments:</h5>
				2802
				2803	<p>
				2804	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2805	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]	2806	scalar value whose type must equal the element type of the first
				2807	operand. The third operand is an index indicating the position at
				2808	which to insert the value. The index may be a variable.</p>
				2809
				2810	<h5>Semantics:</h5>
				2811
				2812	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2813	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]	2814	element values are those of <tt>val</tt> except at position
				2815	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2816	exceeds the length of <tt>val</tt>, the results are undefined.
				2817	</p>
				2818
				2819	<h5>Example:</h5>
				2820
				2821	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2822	%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]	2823	</pre>
				2824	</div>
				2825
				2826	<!-- _______________________________________________________________________ -->
				2827	<div class="doc_subsubsection">
				2828	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2829	</div>
				2830
				2831	<div class="doc_text">
				2832
				2833	<h5>Syntax:</h5>
				2834
				2835	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2836	<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]	2837	</pre>
				2838
				2839	<h5>Overview:</h5>
				2840
				2841	<p>
				2842	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2843	from two input vectors, returning a vector of the same type.
				2844	</p>
				2845
				2846	<h5>Arguments:</h5>
				2847
				2848	<p>
				2849	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2850	with types that match each other and types that match the result of the
				2851	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]	2852	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]	2853	</p>
				2854
				2855	<p>
				2856	The shuffle mask operand is required to be a constant vector with either
				2857	constant integer or undef values.
				2858	</p>
				2859
				2860	<h5>Semantics:</h5>
				2861
				2862	<p>
				2863	The elements of the two input vectors are numbered from left to right across
				2864	both of the vectors. The shuffle mask operand specifies, for each element of
				2865	the result vector, which element of the two input registers the result element
				2866	gets. The element selector may be undef (meaning "don't care") and the second
				2867	operand may be undef if performing a shuffle from only one vector.
				2868	</p>
				2869
				2870	<h5>Example:</h5>
				2871
				2872	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2873	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2874	<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]	2875	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2876	<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]	2877	</pre>
				2878	</div>
				2879
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2880
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2881	<!-- ======================================================================= -->
				2882	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2883	<a name="aggregateops">Aggregate Operations</a>
				2884	</div>
				2885
				2886	<div class="doc_text">
				2887
				2888	<p>LLVM supports several instructions for working with aggregate values.
				2889	</p>
				2890
				2891	</div>
				2892
				2893	<!-- _______________________________________________________________________ -->
				2894	<div class="doc_subsubsection">
				2895	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2896	</div>
				2897
				2898	<div class="doc_text">
				2899
				2900	<h5>Syntax:</h5>
				2901
				2902	<pre>
				2903	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2904	</pre>
				2905
				2906	<h5>Overview:</h5>
				2907
				2908	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2909	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2910	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2911	</p>
				2912
				2913
				2914	<h5>Arguments:</h5>
				2915
				2916	<p>
				2917	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2918	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]	2919	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2920	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2921	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2922	</p>
				2923
				2924	<h5>Semantics:</h5>
				2925
				2926	<p>
				2927	The result is the value at the position in the aggregate specified by
				2928	the index operands.
				2929	</p>
				2930
				2931	<h5>Example:</h5>
				2932
				2933	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2934	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2935	</pre>
				2936	</div>
				2937
				2938
				2939	<!-- _______________________________________________________________________ -->
				2940	<div class="doc_subsubsection">
				2941	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				2942	</div>
				2943
				2944	<div class="doc_text">
				2945
				2946	<h5>Syntax:</h5>
				2947
				2948	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2949	<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]	2950	</pre>
				2951
				2952	<h5>Overview:</h5>
				2953
				2954	<p>
				2955	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2956	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2957	</p>
				2958
				2959
				2960	<h5>Arguments:</h5>
				2961
				2962	<p>
				2963	The first operand of an '<tt>insertvalue</tt>' instruction is a
				2964	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				2965	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	2966	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2967	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]	2968	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2969	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2970	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]	2971	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2972
				2973	<h5>Semantics:</h5>
				2974
				2975	<p>
				2976	The result is an aggregate of the same type as <tt>val</tt>. Its
				2977	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]	2978	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2979	</p>
				2980
				2981	<h5>Example:</h5>
				2982
				2983	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame^]	2984	%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]	2985	</pre>
				2986	</div>
				2987
				2988
				2989	<!-- ======================================================================= -->
				2990	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	2991	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2992	</div>
				2993
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2994	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2995
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2996	<p>A key design point of an SSA-based representation is how it
				2997	represents memory. In LLVM, no memory locations are in SSA form, which
				2998	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2999	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3000
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3001	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3002
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3003	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3004	<div class="doc_subsubsection">
				3005	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3006	</div>
				3007
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3008	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3009
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3010	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3011
				3012	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3013	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3014	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3015
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3016	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3017
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3018	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3019	heap and returns a pointer to it. The object is always allocated in the generic
				3020	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3021
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3022	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3023
				3024	<p>The '<tt>malloc</tt>' instruction allocates
				3025	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3026	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]	3027	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3028	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3029	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]	3030	be aligned to at least that boundary. If not specified, or if zero, the target can
				3031	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3032
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3033	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3034
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3035	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3036
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3037	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3038	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3039	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3040
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3041	<h5>Example:</h5>
				3042
				3043	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3044	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3045
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3046	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3047	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3048	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3049	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3050	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3051	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3052	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3053
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3054	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3055	<div class="doc_subsubsection">
				3056	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3057	</div>
				3058
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3059	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3060
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3061	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3062
				3063	<pre>
				3064	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3065	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3066
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3067	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3068
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3069	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3070	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3071
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3072	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3073
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3074	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3075	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3076	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3077
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3078	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3079
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3080	<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]	3081	after this instruction executes. If the pointer is null, the operation
				3082	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3083
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3084	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3085
				3086	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3087	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3088	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3089	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3090	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3091
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3092	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3093	<div class="doc_subsubsection">
				3094	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3095	</div>
				3096
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3097	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3098
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3099	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3100
				3101	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3102	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3103	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3104
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3105	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3106
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3107	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3108	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3109	returns to its caller. The object is always allocated in the generic address
				3110	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3111
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3112	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3113
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3114	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3115	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3116	appropriate type to the program. If "NumElements" is specified, it is the
				3117	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3118	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]	3119	to be aligned to at least that boundary. If not specified, or if zero, the target
				3120	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3121
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3122	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3123
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3124	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3125
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3126	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3127	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3128	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3129	instruction is commonly used to represent automatic variables that must
				3130	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]	3131	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]	3132	instructions), the memory is reclaimed. Allocating zero bytes
				3133	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3134
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3135	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3136
				3137	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3138	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3139	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3140	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3141	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3142	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3143	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3144
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3145	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3146	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3147	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3148	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3149	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3150	<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]	3151	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3152	<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]	3153	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3154	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3155	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3156	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]	3157	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]	3158	the number or order of execution of this <tt>load</tt> with other
				3159	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3160	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3161	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3162	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3163	(that is, the alignment of the memory address). A value of 0 or an
				3164	omitted "align" argument means that the operation has the preferential
				3165	alignment for the target. It is the responsibility of the code emitter
				3166	to ensure that the alignment information is correct. Overestimating
				3167	the alignment results in an undefined behavior. Underestimating the
				3168	alignment may produce less efficient code. An alignment of 1 is always
				3169	safe.
				3170	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3171	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3172	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3173	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3174	<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]	3175	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3176	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3177	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3178	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3179	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3180	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3181	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3182	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3183	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3184	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3185	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3186	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3187	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3188	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3189	<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]	3190	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3191	<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]	3192	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]	3193	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3194	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3195	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]	3196	optimizer is not allowed to modify the number or order of execution of
				3197	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3198	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3199	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3200	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3201	(that is, the alignment of the memory address). A value of 0 or an
				3202	omitted "align" argument means that the operation has the preferential
				3203	alignment for the target. It is the responsibility of the code emitter
				3204	to ensure that the alignment information is correct. Overestimating
				3205	the alignment results in an undefined behavior. Underestimating the
				3206	alignment may produce less efficient code. An alignment of 1 is always
				3207	safe.
				3208	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3209	<h5>Semantics:</h5>
				3210	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3211	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3212	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3213	<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]	3214	store i32 3, i32* %ptr <i>; yields {void}</i>
				3215	%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]	3216	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3217	</div>
				3218
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3219	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3220	<div class="doc_subsubsection">
				3221	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3222	</div>
				3223
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3224	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3225	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3226	<pre>
				3227	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3228	</pre>
				3229
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3230	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3231
				3232	<p>
				3233	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3234	subelement of an aggregate data structure.</p>
				3235
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3236	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3237
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3238	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3239	elements of the aggregate object to index to. The actual types of the arguments
				3240	provided depend on the type of the first pointer argument. The
				3241	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3242	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]	3243	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3244	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3245	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3246
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3247	<p>For example, let's consider a C code fragment and how it gets
				3248	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3249
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3250	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3251	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3252	struct RT {
				3253	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3254	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3255	char C;
				3256	};
				3257	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3258	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3259	double Y;
				3260	struct RT Z;
				3261	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3262
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3263	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3264	return &s[1].Z.B[5][13];
				3265	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3266	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3267	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3268
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3269	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3270
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3271	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3272	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3273	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3274	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3275
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3276	define i32* %foo(%ST* %s) {
				3277	entry:
				3278	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3279	ret i32* %reg
				3280	}
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	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3283
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3284	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3285
				3286	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3287	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]	3288	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]	3289	<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]	3290	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3291	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3292
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3293	<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]	3294	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]	3295	}</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]	3296	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3297	i8 }</tt>' type, another structure. The third index indexes into the second
				3298	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]	3299	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3300	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3301	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]	3302
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3303	<p>Note that it is perfectly legal to index partially through a
				3304	structure, returning a pointer to an inner element. Because of this,
				3305	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3306
				3307	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3308	define i32* %foo(%ST* %s) {
				3309	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3310	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3311	%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]	3312	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3313	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3314	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3315	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3316	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3317
				3318	<p>Note that it is undefined to access an array out of bounds: array and
				3319	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]	3320	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]	3321	defined to be accessible as variable length arrays, which requires access
				3322	beyond the zero'th element.</p>
				3323
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3324	<p>The getelementptr instruction is often confusing. For some more insight
				3325	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3326	FAQ</a>.</p>
				3327
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3328	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3329
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3330	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3331	<i>; yields [12 x i8]*:aptr</i>
				3332	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3333	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3334	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3335
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3336	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3337	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3338	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3339	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3340	<p>The instructions in this category are the conversion instructions (casting)
				3341	which all take a single operand and a type. They perform various bit conversions
				3342	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3343	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3344
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3345	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3346	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3347	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3348	</div>
				3349	<div class="doc_text">
				3350
				3351	<h5>Syntax:</h5>
				3352	<pre>
				3353	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3354	</pre>
				3355
				3356	<h5>Overview:</h5>
				3357	<p>
				3358	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3359	</p>
				3360
				3361	<h5>Arguments:</h5>
				3362	<p>
				3363	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3364	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]	3365	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]	3366	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3367	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3368
				3369	<h5>Semantics:</h5>
				3370	<p>
				3371	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]	3372	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3373	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3374	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3375
				3376	<h5>Example:</h5>
				3377	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3378	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3379	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3380	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3381	</pre>
				3382	</div>
				3383
				3384	<!-- _______________________________________________________________________ -->
				3385	<div class="doc_subsubsection">
				3386	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3387	</div>
				3388	<div class="doc_text">
				3389
				3390	<h5>Syntax:</h5>
				3391	<pre>
				3392	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3393	</pre>
				3394
				3395	<h5>Overview:</h5>
				3396	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3397	<tt>ty2</tt>.</p>
				3398
				3399
				3400	<h5>Arguments:</h5>
				3401	<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]	3402	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3403	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]	3404	<tt>value</tt> must be smaller than the bit size of the destination type,
				3405	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3406
				3407	<h5>Semantics:</h5>
				3408	<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]	3409	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]	3410
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3411	<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]	3412
				3413	<h5>Example:</h5>
				3414	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3415	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3416	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3417	</pre>
				3418	</div>
				3419
				3420	<!-- _______________________________________________________________________ -->
				3421	<div class="doc_subsubsection">
				3422	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3423	</div>
				3424	<div class="doc_text">
				3425
				3426	<h5>Syntax:</h5>
				3427	<pre>
				3428	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3429	</pre>
				3430
				3431	<h5>Overview:</h5>
				3432	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3433
				3434	<h5>Arguments:</h5>
				3435	<p>
				3436	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]	3437	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3438	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]	3439	<tt>value</tt> must be smaller than the bit size of the destination type,
				3440	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3441
				3442	<h5>Semantics:</h5>
				3443	<p>
				3444	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3445	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]	3446	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3447
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3448	<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]	3449
				3450	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3451	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3452	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3453	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3454	</pre>
				3455	</div>
				3456
				3457	<!-- _______________________________________________________________________ -->
				3458	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3459	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3460	</div>
				3461
				3462	<div class="doc_text">
				3463
				3464	<h5>Syntax:</h5>
				3465
				3466	<pre>
				3467	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3468	</pre>
				3469
				3470	<h5>Overview:</h5>
				3471	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3472	<tt>ty2</tt>.</p>
				3473
				3474
				3475	<h5>Arguments:</h5>
				3476	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3477	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3478	cast it to. The size of <tt>value</tt> must be larger than the size of
				3479	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3480	<i>no-op cast</i>.</p>
				3481
				3482	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3483	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3484	<a href="#t_floating">floating point</a> type to a smaller
				3485	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3486	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3487
				3488	<h5>Example:</h5>
				3489	<pre>
				3490	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3491	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3492	</pre>
				3493	</div>
				3494
				3495	<!-- _______________________________________________________________________ -->
				3496	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3497	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3498	</div>
				3499	<div class="doc_text">
				3500
				3501	<h5>Syntax:</h5>
				3502	<pre>
				3503	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3504	</pre>
				3505
				3506	<h5>Overview:</h5>
				3507	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3508	floating point value.</p>
				3509
				3510	<h5>Arguments:</h5>
				3511	<p>The '<tt>fpext</tt>' instruction takes a
				3512	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3513	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3514	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3515
				3516	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3517	<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]	3518	<a href="#t_floating">floating point</a> type to a larger
				3519	<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]	3520	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]	3521	<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]	3522
				3523	<h5>Example:</h5>
				3524	<pre>
				3525	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3526	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3527	</pre>
				3528	</div>
				3529
				3530	<!-- _______________________________________________________________________ -->
				3531	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3532	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3533	</div>
				3534	<div class="doc_text">
				3535
				3536	<h5>Syntax:</h5>
				3537	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3538	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3539	</pre>
				3540
				3541	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3542	<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]	3543	unsigned integer equivalent of type <tt>ty2</tt>.
				3544	</p>
				3545
				3546	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3547	<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]	3548	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3549	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3550	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3551	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]	3552
				3553	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3554	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3555	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3556	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3557	the results are undefined.</p>
				3558
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3559	<h5>Example:</h5>
				3560	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3561	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3562	%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]	3563	%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]	3564	</pre>
				3565	</div>
				3566
				3567	<!-- _______________________________________________________________________ -->
				3568	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3569	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3570	</div>
				3571	<div class="doc_text">
				3572
				3573	<h5>Syntax:</h5>
				3574	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3575	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3576	</pre>
				3577
				3578	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3579	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3580	<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]	3581	</p>
				3582
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3583	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3584	<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]	3585	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3586	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3587	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3588	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]	3589
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3590	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3591	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3592	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3593	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3594	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3595
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3596	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3597	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3598	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3599	%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]	3600	%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]	3601	</pre>
				3602	</div>
				3603
				3604	<!-- _______________________________________________________________________ -->
				3605	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3606	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3607	</div>
				3608	<div class="doc_text">
				3609
				3610	<h5>Syntax:</h5>
				3611	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3612	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3613	</pre>
				3614
				3615	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3616	<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]	3617	integer and converts that value to the <tt>ty2</tt> type.</p>
				3618
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3619	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3620	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3621	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3622	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3623	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3624	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]	3625
				3626	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3627	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3628	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3629	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]	3630
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3631	<h5>Example:</h5>
				3632	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3633	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3634	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3635	</pre>
				3636	</div>
				3637
				3638	<!-- _______________________________________________________________________ -->
				3639	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3640	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3641	</div>
				3642	<div class="doc_text">
				3643
				3644	<h5>Syntax:</h5>
				3645	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3646	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3647	</pre>
				3648
				3649	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3650	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3651	integer and converts that value to the <tt>ty2</tt> type.</p>
				3652
				3653	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3654	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3655	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3656	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3657	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3658	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]	3659
				3660	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3661	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3662	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3663	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]	3664
				3665	<h5>Example:</h5>
				3666	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3667	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3668	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3669	</pre>
				3670	</div>
				3671
				3672	<!-- _______________________________________________________________________ -->
				3673	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3674	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3675	</div>
				3676	<div class="doc_text">
				3677
				3678	<h5>Syntax:</h5>
				3679	<pre>
				3680	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3681	</pre>
				3682
				3683	<h5>Overview:</h5>
				3684	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3685	the integer type <tt>ty2</tt>.</p>
				3686
				3687	<h5>Arguments:</h5>
				3688	<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]	3689	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]	3690	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3691
				3692	<h5>Semantics:</h5>
				3693	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3694	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3695	truncating or zero extending that value to the size of the integer type. If
				3696	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3697	<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]	3698	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3699	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3700
				3701	<h5>Example:</h5>
				3702	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3703	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3704	%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]	3705	</pre>
				3706	</div>
				3707
				3708	<!-- _______________________________________________________________________ -->
				3709	<div class="doc_subsubsection">
				3710	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3711	</div>
				3712	<div class="doc_text">
				3713
				3714	<h5>Syntax:</h5>
				3715	<pre>
				3716	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3717	</pre>
				3718
				3719	<h5>Overview:</h5>
				3720	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3721	a pointer type, <tt>ty2</tt>.</p>
				3722
				3723	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3724	<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]	3725	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]	3726	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3727
				3728	<h5>Semantics:</h5>
				3729	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3730	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3731	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3732	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3733	the size of a pointer then a zero extension is done. If they are the same size,
				3734	nothing is done (<i>no-op cast</i>).</p>
				3735
				3736	<h5>Example:</h5>
				3737	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3738	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3739	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3740	%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]	3741	</pre>
				3742	</div>
				3743
				3744	<!-- _______________________________________________________________________ -->
				3745	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3746	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3747	</div>
				3748	<div class="doc_text">
				3749
				3750	<h5>Syntax:</h5>
				3751	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3752	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3753	</pre>
				3754
				3755	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3756
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3757	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3758	<tt>ty2</tt> without changing any bits.</p>
				3759
				3760	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3761
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3762	<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]	3763	a first class value, and a type to cast it to, which must also be a <a
				3764	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]	3765	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]	3766	type is a pointer, the destination type must also be a pointer. This
				3767	instruction supports bitwise conversion of vectors to integers and to vectors
				3768	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3769
				3770	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3771	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3772	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3773	this conversion. The conversion is done as if the <tt>value</tt> had been
				3774	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3775	converted to other pointer types with this instruction. To convert pointers to
				3776	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3777	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3778
				3779	<h5>Example:</h5>
				3780	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3781	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3782	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3783	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3784	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3785	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3786
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3787	<!-- ======================================================================= -->
				3788	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3789	<div class="doc_text">
				3790	<p>The instructions in this category are the "miscellaneous"
				3791	instructions, which defy better classification.</p>
				3792	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3793
				3794	<!-- _______________________________________________________________________ -->
				3795	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3796	</div>
				3797	<div class="doc_text">
				3798	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3799	<pre> <result> = icmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3800	</pre>
				3801	<h5>Overview:</h5>
				3802	<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]	3803	of its two integer or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3804	<h5>Arguments:</h5>
				3805	<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]	3806	the condition code indicating the kind of comparison to perform. It is not
				3807	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3808	<ol>
				3809	<li><tt>eq</tt>: equal</li>
				3810	<li><tt>ne</tt>: not equal </li>
				3811	<li><tt>ugt</tt>: unsigned greater than</li>
				3812	<li><tt>uge</tt>: unsigned greater or equal</li>
				3813	<li><tt>ult</tt>: unsigned less than</li>
				3814	<li><tt>ule</tt>: unsigned less or equal</li>
				3815	<li><tt>sgt</tt>: signed greater than</li>
				3816	<li><tt>sge</tt>: signed greater or equal</li>
				3817	<li><tt>slt</tt>: signed less than</li>
				3818	<li><tt>sle</tt>: signed less or equal</li>
				3819	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3820	<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]	3821	<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]	3822	<h5>Semantics:</h5>
				3823	<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
				3824	the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3825	yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3826	<ol>
				3827	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3828	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3829	</li>
				3830	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3831	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3832	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
				3833	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3834	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
				3835	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3836	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
				3837	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3838	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
				3839	<tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
				3840	<li><tt>sgt</tt>: interprets the operands as signed values and yields
				3841	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3842	<li><tt>sge</tt>: interprets the operands as signed values and yields
				3843	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3844	<li><tt>slt</tt>: interprets the operands as signed values and yields
				3845	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3846	<li><tt>sle</tt>: interprets the operands as signed values and yields
				3847	<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]	3848	</ol>
				3849	<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]	3850	values are compared as if they were integers.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3851
				3852	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3853	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3854	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3855	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3856	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3857	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3858	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3859	</pre>
				3860	</div>
				3861
				3862	<!-- _______________________________________________________________________ -->
				3863	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3864	</div>
				3865	<div class="doc_text">
				3866	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3867	<pre> <result> = fcmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3868	</pre>
				3869	<h5>Overview:</h5>
				3870	<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
				3871	of its floating point operands.</p>
				3872	<h5>Arguments:</h5>
				3873	<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]	3874	the condition code indicating the kind of comparison to perform. It is not
				3875	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3876	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3877	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3878	<li><tt>oeq</tt>: ordered and equal</li>
				3879	<li><tt>ogt</tt>: ordered and greater than </li>
				3880	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3881	<li><tt>olt</tt>: ordered and less than </li>
				3882	<li><tt>ole</tt>: ordered and less than or equal</li>
				3883	<li><tt>one</tt>: ordered and not equal</li>
				3884	<li><tt>ord</tt>: ordered (no nans)</li>
				3885	<li><tt>ueq</tt>: unordered or equal</li>
				3886	<li><tt>ugt</tt>: unordered or greater than </li>
				3887	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3888	<li><tt>ult</tt>: unordered or less than </li>
				3889	<li><tt>ule</tt>: unordered or less than or equal</li>
				3890	<li><tt>une</tt>: unordered or not equal</li>
				3891	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3892	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3893	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3894	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3895	<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer	350f8aa	2007-01-04 05:19:58 +0000	[diff] [blame]	3896	<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
				3897	<a href="#t_floating">floating point</a> typed. They must have identical
				3898	types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3899	<h5>Semantics:</h5>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3900	<p>The '<tt>fcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3901	according to the condition code given as <tt>cond</tt>. The comparison performed
				3902	always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3903	<ol>
				3904	<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]	3905	<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]	3906	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3907	<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]	3908	<tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3909	<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]	3910	<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]	3911	<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]	3912	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3913	<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]	3914	<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]	3915	<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]	3916	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3917	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3918	<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]	3919	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3920	<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]	3921	<tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3922	<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]	3923	<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]	3924	<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]	3925	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3926	<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]	3927	<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]	3928	<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]	3929	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3930	<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]	3931	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				3932	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3933
				3934	<h5>Example:</h5>
				3935	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
				3936	<result> = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
				3937	<result> = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				3938	<result> = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
				3939	</pre>
				3940	</div>
				3941
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3942	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3943	<div class="doc_subsubsection">
				3944	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				3945	</div>
				3946	<div class="doc_text">
				3947	<h5>Syntax:</h5>
				3948	<pre> <result> = vicmp <cond> <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				3949	</pre>
				3950	<h5>Overview:</h5>
				3951	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				3952	element-wise comparison of its two integer vector operands.</p>
				3953	<h5>Arguments:</h5>
				3954	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				3955	the condition code indicating the kind of comparison to perform. It is not
				3956	a value, just a keyword. The possible condition code are:
				3957	<ol>
				3958	<li><tt>eq</tt>: equal</li>
				3959	<li><tt>ne</tt>: not equal </li>
				3960	<li><tt>ugt</tt>: unsigned greater than</li>
				3961	<li><tt>uge</tt>: unsigned greater or equal</li>
				3962	<li><tt>ult</tt>: unsigned less than</li>
				3963	<li><tt>ule</tt>: unsigned less or equal</li>
				3964	<li><tt>sgt</tt>: signed greater than</li>
				3965	<li><tt>sge</tt>: signed greater or equal</li>
				3966	<li><tt>slt</tt>: signed less than</li>
				3967	<li><tt>sle</tt>: signed less or equal</li>
				3968	</ol>
				3969	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				3970	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				3971	<h5>Semantics:</h5>
				3972	<p>The '<tt>vicmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3973	according to the condition code given as <tt>cond</tt>. The comparison yields a
				3974	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				3975	identical type as the values being compared. The most significant bit in each
				3976	element is 1 if the element-wise comparison evaluates to true, and is 0
				3977	otherwise. All other bits of the result are undefined. The condition codes
				3978	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				3979	instruction</a>.
				3980
				3981	<h5>Example:</h5>
				3982	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3983	<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>
				3984	<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]	3985	</pre>
				3986	</div>
				3987
				3988	<!-- _______________________________________________________________________ -->
				3989	<div class="doc_subsubsection">
				3990	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				3991	</div>
				3992	<div class="doc_text">
				3993	<h5>Syntax:</h5>
				3994	<pre> <result> = vfcmp <cond> <ty> <var1>, <var2></pre>
				3995	<h5>Overview:</h5>
				3996	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				3997	element-wise comparison of its two floating point vector operands. The output
				3998	elements have the same width as the input elements.</p>
				3999	<h5>Arguments:</h5>
				4000	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4001	the condition code indicating the kind of comparison to perform. It is not
				4002	a value, just a keyword. The possible condition code are:
				4003	<ol>
				4004	<li><tt>false</tt>: no comparison, always returns false</li>
				4005	<li><tt>oeq</tt>: ordered and equal</li>
				4006	<li><tt>ogt</tt>: ordered and greater than </li>
				4007	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4008	<li><tt>olt</tt>: ordered and less than </li>
				4009	<li><tt>ole</tt>: ordered and less than or equal</li>
				4010	<li><tt>one</tt>: ordered and not equal</li>
				4011	<li><tt>ord</tt>: ordered (no nans)</li>
				4012	<li><tt>ueq</tt>: unordered or equal</li>
				4013	<li><tt>ugt</tt>: unordered or greater than </li>
				4014	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4015	<li><tt>ult</tt>: unordered or less than </li>
				4016	<li><tt>ule</tt>: unordered or less than or equal</li>
				4017	<li><tt>une</tt>: unordered or not equal</li>
				4018	<li><tt>uno</tt>: unordered (either nans)</li>
				4019	<li><tt>true</tt>: no comparison, always returns true</li>
				4020	</ol>
				4021	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4022	<a href="#t_floating">floating point</a> typed. They must also be identical
				4023	types.</p>
				4024	<h5>Semantics:</h5>
				4025	<p>The '<tt>vfcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				4026	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4027	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4028	an identical number of elements as the values being compared, and each element
				4029	having identical with to the width of the floating point elements. The most
				4030	significant bit in each element is 1 if the element-wise comparison evaluates to
				4031	true, and is 0 otherwise. All other bits of the result are undefined. The
				4032	condition codes are evaluated identically to the
				4033	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4034
				4035	<h5>Example:</h5>
				4036	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4037	<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>
				4038	<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]	4039	</pre>
				4040	</div>
				4041
				4042	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4043	<div class="doc_subsubsection">
				4044	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4045	</div>
				4046
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4047	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4048
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4049	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4050
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4051	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4052	<h5>Overview:</h5>
				4053	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4054	the SSA graph representing the function.</p>
				4055	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4056
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4057	<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]	4058	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4059	as arguments, with one pair for each predecessor basic block of the
				4060	current block. Only values of <a href="#t_firstclass">first class</a>
				4061	type may be used as the value arguments to the PHI node. Only labels
				4062	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4063
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4064	<p>There must be no non-phi instructions between the start of a basic
				4065	block and the PHI instructions: i.e. PHI instructions must be first in
				4066	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4067
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4068	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4069
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4070	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4071	specified by the pair corresponding to the predecessor basic block that executed
				4072	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4073
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4074	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4075	<pre>
				4076	Loop: ; Infinite loop that counts from 0 on up...
				4077	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4078	%nextindvar = add i32 %indvar, 1
				4079	br label %Loop
				4080	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4081	</div>
				4082
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4083	<!-- _______________________________________________________________________ -->
				4084	<div class="doc_subsubsection">
				4085	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4086	</div>
				4087
				4088	<div class="doc_text">
				4089
				4090	<h5>Syntax:</h5>
				4091
				4092	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4093	<result> = select i1 <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4094	</pre>
				4095
				4096	<h5>Overview:</h5>
				4097
				4098	<p>
				4099	The '<tt>select</tt>' instruction is used to choose one value based on a
				4100	condition, without branching.
				4101	</p>
				4102
				4103
				4104	<h5>Arguments:</h5>
				4105
				4106	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4107	The '<tt>select</tt>' instruction requires an 'i1' value indicating the
				4108	condition, and two values of the same <a href="#t_firstclass">first class</a>
				4109	type. If the val1/val2 are vectors, the entire vectors are selected, not
				4110	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4111	</p>
				4112
				4113	<h5>Semantics:</h5>
				4114
				4115	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4116	If the i1 condition evaluates is 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4117	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4118	</p>
				4119
				4120	<h5>Example:</h5>
				4121
				4122	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4123	%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]	4124	</pre>
				4125	</div>
				4126
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4127
				4128	<!-- _______________________________________________________________________ -->
				4129	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4130	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4131	</div>
				4132
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4133	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4134
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4135	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4136	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4137	<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]	4138	</pre>
				4139
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4140	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4141
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4142	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
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>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4145
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4146	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4147
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4148	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4149	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4150	<p>The optional "tail" marker indicates whether the callee function accesses
				4151	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]	4152	function call is eligible for tail call optimization. Note that calls may
				4153	be marked "tail" even if they do not occur before a <a
				4154	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4155	</li>
				4156	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4157	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4158	convention</a> the call should use. If none is specified, the call defaults
				4159	to using C calling conventions.
				4160	</li>
				4161	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4162	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4163	the type of the return value. Functions that return no value are marked
				4164	<tt><a href="#t_void">void</a></tt>.</p>
				4165	</li>
				4166	<li>
				4167	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4168	value being invoked. The argument types must match the types implied by
				4169	this signature. This type can be omitted if the function is not varargs
				4170	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]	4171	</li>
				4172	<li>
				4173	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4174	be invoked. In most cases, this is a direct function invocation, but
				4175	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]	4176	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4177	</li>
				4178	<li>
				4179	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4180	function signature argument types. All arguments must be of
				4181	<a href="#t_firstclass">first class</a> type. If the function signature
				4182	indicates the function accepts a variable number of arguments, the extra
				4183	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4184	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4185	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4186
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4187	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4188
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4189	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4190	transfer to a specified function, with its incoming arguments bound to
				4191	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4192	instruction in the called function, control flow continues with the
				4193	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4194	function is bound to the result argument. If the callee returns multiple
				4195	values then the return values of the function are only accessible through
				4196	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4197
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4198	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4199
				4200	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4201	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4202	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4203	%X = tail call i32 @foo() <i>; yields i32</i>
				4204	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4205	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4206
				4207	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4208	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4209	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4210	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4211	</pre>
				4212
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4213	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4214
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4215	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4216	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4217	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4218	</div>
				4219
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4220	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4221
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4222	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4223
				4224	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4225	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4226	</pre>
				4227
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4228	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4229
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4230	<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]	4231	the "variable argument" area of a function call. It is used to implement the
				4232	<tt>va_arg</tt> macro in C.</p>
				4233
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4234	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4235
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4236	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4237	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4238	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]	4239	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4240
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4241	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4242
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4243	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4244	type from the specified <tt>va_list</tt> and causes the
				4245	<tt>va_list</tt> to point to the next argument. For more information,
				4246	see the variable argument handling <a href="#int_varargs">Intrinsic
				4247	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4248
				4249	<p>It is legal for this instruction to be called in a function which does not
				4250	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4251	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4252
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4253	<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]	4254	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4255	argument.</p>
				4256
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4257	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4258
				4259	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4260
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4261	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4262
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4263	<!-- _______________________________________________________________________ -->
				4264	<div class="doc_subsubsection">
				4265	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4266	</div>
				4267
				4268	<div class="doc_text">
				4269
				4270	<h5>Syntax:</h5>
				4271	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4272	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4273	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4274
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4275	<h5>Overview:</h5>
				4276
				4277	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4278	from a '<tt><a href="#i_call">call</a></tt>'
				4279	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4280	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4281
				4282	<h5>Arguments:</h5>
				4283
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4284	<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]	4285	first argument, or an undef value. The value must have <a
				4286	href="#t_struct">structure type</a>. The second argument is a constant
				4287	unsigned index value which must be in range for the number of values returned
				4288	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4289
				4290	<h5>Semantics:</h5>
				4291
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4292	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4293	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4294
				4295	<h5>Example:</h5>
				4296
				4297	<pre>
				4298	%struct.A = type { i32, i8 }
				4299
				4300	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4301	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4302	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4303	add i32 %gr, 42
				4304	add i8 %gr1, 41
				4305	</pre>
				4306
				4307	</div>
				4308
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4309	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4310	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4311	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4312
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4313	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4314
				4315	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4316	well known names and semantics and are required to follow certain restrictions.
				4317	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4318	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]	4319	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]	4320
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4321	<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]	4322	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4323	begin with this prefix. Intrinsic functions must always be external functions:
				4324	you cannot define the body of intrinsic functions. Intrinsic functions may
				4325	only be used in call or invoke instructions: it is illegal to take the address
				4326	of an intrinsic function. Additionally, because intrinsic functions are part
				4327	of the LLVM language, it is required if any are added that they be documented
				4328	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4329
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4330	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4331	a family of functions that perform the same operation but on different data
				4332	types. Because LLVM can represent over 8 million different integer types,
				4333	overloading is used commonly to allow an intrinsic function to operate on any
				4334	integer type. One or more of the argument types or the result type can be
				4335	overloaded to accept any integer type. Argument types may also be defined as
				4336	exactly matching a previous argument's type or the result type. This allows an
				4337	intrinsic function which accepts multiple arguments, but needs all of them to
				4338	be of the same type, to only be overloaded with respect to a single argument or
				4339	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4340
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4341	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4342	encoded into its function name, each preceded by a period. Only those types
				4343	which are overloaded result in a name suffix. Arguments whose type is matched
				4344	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4345	take an integer of any width and returns an integer of exactly the same integer
				4346	width. This leads to a family of functions such as
				4347	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4348	Only one type, the return type, is overloaded, and only one type suffix is
				4349	required. Because the argument's type is matched against the return type, it
				4350	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4351
				4352	<p>To learn how to add an intrinsic function, please see the
				4353	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4354	</p>
				4355
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4356	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4357
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4358	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4359	<div class="doc_subsection">
				4360	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4361	</div>
				4362
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4363	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4364
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4365	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4366	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]	4367	intrinsic functions. These functions are related to the similarly
				4368	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4369
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4370	<p>All of these functions operate on arguments that use a
				4371	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4372	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4373	transformations should be prepared to handle these functions regardless of
				4374	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4375
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4376	<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]	4377	instruction and the variable argument handling intrinsic functions are
				4378	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4379
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4380	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4381	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4382	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4383	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4384	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4385	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4386	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4387
				4388	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4389	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4390
				4391	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4392	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4393	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4394	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4395	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4396
				4397	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4398	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4399	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4400	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4401
				4402	declare void @llvm.va_start(i8*)
				4403	declare void @llvm.va_copy(i8, i8)
				4404	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4405	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4406	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4407
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4408	</div>
				4409
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4410	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4411	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4412	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4413	</div>
				4414
				4415
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4416	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4417	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4418	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4419	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4420	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4421	<tt>*<arglist></tt> for subsequent use by <tt><a
				4422	href="#i_va_arg">va_arg</a></tt>.</p>
				4423
				4424	<h5>Arguments:</h5>
				4425
				4426	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4427
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4428	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4429
				4430	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4431	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4432	<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]	4433	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4434	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]	4435	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]	4436
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4437	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4438
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4439	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4440	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4441	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4442	</div>
				4443
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4444	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4445	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4446	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4447	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4448
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4449	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4450	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]	4451	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]	4452
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4453	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4454
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4455	<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]	4456
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4457	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4458
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4459	<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]	4460	macro available in C. In a target-dependent way, it destroys the
				4461	<tt>va_list</tt> element to which the argument points. Calls to <a
				4462	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4463	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4464	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4465
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4466	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4467
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4468	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4469	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4470	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4471	</div>
				4472
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4473	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4474
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4475	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4476
				4477	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4478	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4479	</pre>
				4480
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4481	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4482
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4483	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4484	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4485
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4486	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4487
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4488	<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]	4489	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]	4490
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4491
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4492	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4493
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4494	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4495	macro available in C. In a target-dependent way, it copies the source
				4496	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4497	intrinsic is necessary because the <tt><a href="#int_va_start">
				4498	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4499	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4500
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4501	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4502
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4503	<!-- ======================================================================= -->
				4504	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4505	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4506	</div>
				4507
				4508	<div class="doc_text">
				4509
				4510	<p>
				4511	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
				4512	Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4513	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]	4514	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4515	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]	4516	Front-ends for type-safe garbage collected languages should generate these
				4517	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4518	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4519	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4520
				4521	<p>The garbage collection intrinsics only operate on objects in the generic
				4522	address space (address space zero).</p>
				4523
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4524	</div>
				4525
				4526	<!-- _______________________________________________________________________ -->
				4527	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4528	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4529	</div>
				4530
				4531	<div class="doc_text">
				4532
				4533	<h5>Syntax:</h5>
				4534
				4535	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4536	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4537	</pre>
				4538
				4539	<h5>Overview:</h5>
				4540
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4541	<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]	4542	the code generator, and allows some metadata to be associated with it.</p>
				4543
				4544	<h5>Arguments:</h5>
				4545
				4546	<p>The first argument specifies the address of a stack object that contains the
				4547	root pointer. The second pointer (which must be either a constant or a global
				4548	value address) contains the meta-data to be associated with the root.</p>
				4549
				4550	<h5>Semantics:</h5>
				4551
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4552	<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]	4553	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4554	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4555	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4556	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4557
				4558	</div>
				4559
				4560
				4561	<!-- _______________________________________________________________________ -->
				4562	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4563	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4564	</div>
				4565
				4566	<div class="doc_text">
				4567
				4568	<h5>Syntax:</h5>
				4569
				4570	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4571	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4572	</pre>
				4573
				4574	<h5>Overview:</h5>
				4575
				4576	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4577	locations, allowing garbage collector implementations that require read
				4578	barriers.</p>
				4579
				4580	<h5>Arguments:</h5>
				4581
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4582	<p>The second argument is the address to read from, which should be an address
				4583	allocated from the garbage collector. The first object is a pointer to the
				4584	start of the referenced object, if needed by the language runtime (otherwise
				4585	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4586
				4587	<h5>Semantics:</h5>
				4588
				4589	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4590	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4591	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4592	may only be used in a function which <a href="#gc">specifies a GC
				4593	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4594
				4595	</div>
				4596
				4597
				4598	<!-- _______________________________________________________________________ -->
				4599	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4600	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4601	</div>
				4602
				4603	<div class="doc_text">
				4604
				4605	<h5>Syntax:</h5>
				4606
				4607	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4608	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4609	</pre>
				4610
				4611	<h5>Overview:</h5>
				4612
				4613	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4614	locations, allowing garbage collector implementations that require write
				4615	barriers (such as generational or reference counting collectors).</p>
				4616
				4617	<h5>Arguments:</h5>
				4618
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4619	<p>The first argument is the reference to store, the second is the start of the
				4620	object to store it to, and the third is the address of the field of Obj to
				4621	store to. If the runtime does not require a pointer to the object, Obj may be
				4622	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4623
				4624	<h5>Semantics:</h5>
				4625
				4626	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4627	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4628	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4629	may only be used in a function which <a href="#gc">specifies a GC
				4630	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4631
				4632	</div>
				4633
				4634
				4635
				4636	<!-- ======================================================================= -->
				4637	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4638	<a name="int_codegen">Code Generator Intrinsics</a>
				4639	</div>
				4640
				4641	<div class="doc_text">
				4642	<p>
				4643	These intrinsics are provided by LLVM to expose special features that may only
				4644	be implemented with code generator support.
				4645	</p>
				4646
				4647	</div>
				4648
				4649	<!-- _______________________________________________________________________ -->
				4650	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4651	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4652	</div>
				4653
				4654	<div class="doc_text">
				4655
				4656	<h5>Syntax:</h5>
				4657	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4658	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4659	</pre>
				4660
				4661	<h5>Overview:</h5>
				4662
				4663	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4664	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4665	target-specific value indicating the return address of the current function
				4666	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4667	</p>
				4668
				4669	<h5>Arguments:</h5>
				4670
				4671	<p>
				4672	The argument to this intrinsic indicates which function to return the address
				4673	for. Zero indicates the calling function, one indicates its caller, etc. The
				4674	argument is <b>required</b> to be a constant integer value.
				4675	</p>
				4676
				4677	<h5>Semantics:</h5>
				4678
				4679	<p>
				4680	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4681	the return address of the specified call frame, or zero if it cannot be
				4682	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4683	for arguments other than zero, so it should only be used for debugging purposes.
				4684	</p>
				4685
				4686	<p>
				4687	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4688	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]	4689	source-language caller.
				4690	</p>
				4691	</div>
				4692
				4693
				4694	<!-- _______________________________________________________________________ -->
				4695	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4696	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4697	</div>
				4698
				4699	<div class="doc_text">
				4700
				4701	<h5>Syntax:</h5>
				4702	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4703	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4704	</pre>
				4705
				4706	<h5>Overview:</h5>
				4707
				4708	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4709	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4710	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4711	</p>
				4712
				4713	<h5>Arguments:</h5>
				4714
				4715	<p>
				4716	The argument to this intrinsic indicates which function to return the frame
				4717	pointer for. Zero indicates the calling function, one indicates its caller,
				4718	etc. The argument is <b>required</b> to be a constant integer value.
				4719	</p>
				4720
				4721	<h5>Semantics:</h5>
				4722
				4723	<p>
				4724	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4725	the frame address of the specified call frame, or zero if it cannot be
				4726	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4727	for arguments other than zero, so it should only be used for debugging purposes.
				4728	</p>
				4729
				4730	<p>
				4731	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4732	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]	4733	source-language caller.
				4734	</p>
				4735	</div>
				4736
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4737	<!-- _______________________________________________________________________ -->
				4738	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4739	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4740	</div>
				4741
				4742	<div class="doc_text">
				4743
				4744	<h5>Syntax:</h5>
				4745	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4746	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4747	</pre>
				4748
				4749	<h5>Overview:</h5>
				4750
				4751	<p>
				4752	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]	4753	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4754	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4755	features like scoped automatic variable sized arrays in C99.
				4756	</p>
				4757
				4758	<h5>Semantics:</h5>
				4759
				4760	<p>
				4761	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]	4762	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4763	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4764	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4765	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4766	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4767	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4768	</p>
				4769
				4770	</div>
				4771
				4772	<!-- _______________________________________________________________________ -->
				4773	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4774	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4775	</div>
				4776
				4777	<div class="doc_text">
				4778
				4779	<h5>Syntax:</h5>
				4780	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4781	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4782	</pre>
				4783
				4784	<h5>Overview:</h5>
				4785
				4786	<p>
				4787	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4788	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]	4789	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4790	useful for implementing language features like scoped automatic variable sized
				4791	arrays in C99.
				4792	</p>
				4793
				4794	<h5>Semantics:</h5>
				4795
				4796	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4797	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]	4798	</p>
				4799
				4800	</div>
				4801
				4802
				4803	<!-- _______________________________________________________________________ -->
				4804	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4805	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4806	</div>
				4807
				4808	<div class="doc_text">
				4809
				4810	<h5>Syntax:</h5>
				4811	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4812	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4813	</pre>
				4814
				4815	<h5>Overview:</h5>
				4816
				4817
				4818	<p>
				4819	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]	4820	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4821	no
				4822	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4823	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4824	</p>
				4825
				4826	<h5>Arguments:</h5>
				4827
				4828	<p>
				4829	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4830	determining if the fetch should be for a read (0) or write (1), and
				4831	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4832	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]	4833	<tt>locality</tt> arguments must be constant integers.
				4834	</p>
				4835
				4836	<h5>Semantics:</h5>
				4837
				4838	<p>
				4839	This intrinsic does not modify the behavior of the program. In particular,
				4840	prefetches cannot trap and do not produce a value. On targets that support this
				4841	intrinsic, the prefetch can provide hints to the processor cache for better
				4842	performance.
				4843	</p>
				4844
				4845	</div>
				4846
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4847	<!-- _______________________________________________________________________ -->
				4848	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4849	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4850	</div>
				4851
				4852	<div class="doc_text">
				4853
				4854	<h5>Syntax:</h5>
				4855	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4856	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4857	</pre>
				4858
				4859	<h5>Overview:</h5>
				4860
				4861
				4862	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4863	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
				4864	(PC) in a region of
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4865	code to simulators and other tools. The method is target specific, but it is
				4866	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]	4867	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]	4868	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]	4869	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4870	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4871	</p>
				4872
				4873	<h5>Arguments:</h5>
				4874
				4875	<p>
				4876	<tt>id</tt> is a numerical id identifying the marker.
				4877	</p>
				4878
				4879	<h5>Semantics:</h5>
				4880
				4881	<p>
				4882	This intrinsic does not modify the behavior of the program. Backends that do not
				4883	support this intrinisic may ignore it.
				4884	</p>
				4885
				4886	</div>
				4887
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4888	<!-- _______________________________________________________________________ -->
				4889	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4890	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4891	</div>
				4892
				4893	<div class="doc_text">
				4894
				4895	<h5>Syntax:</h5>
				4896	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4897	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4898	</pre>
				4899
				4900	<h5>Overview:</h5>
				4901
				4902
				4903	<p>
				4904	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4905	counter register (or similar low latency, high accuracy clocks) on those targets
				4906	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4907	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4908	should only be used for small timings.
				4909	</p>
				4910
				4911	<h5>Semantics:</h5>
				4912
				4913	<p>
				4914	When directly supported, reading the cycle counter should not modify any memory.
				4915	Implementations are allowed to either return a application specific value or a
				4916	system wide value. On backends without support, this is lowered to a constant 0.
				4917	</p>
				4918
				4919	</div>
				4920
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4921	<!-- ======================================================================= -->
				4922	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4923	<a name="int_libc">Standard C Library Intrinsics</a>
				4924	</div>
				4925
				4926	<div class="doc_text">
				4927	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4928	LLVM provides intrinsics for a few important standard C library functions.
				4929	These intrinsics allow source-language front-ends to pass information about the
				4930	alignment of the pointer arguments to the code generator, providing opportunity
				4931	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4932	</p>
				4933
				4934	</div>
				4935
				4936	<!-- _______________________________________________________________________ -->
				4937	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4938	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4939	</div>
				4940
				4941	<div class="doc_text">
				4942
				4943	<h5>Syntax:</h5>
				4944	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4945	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4946	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4947	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4948	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4949	</pre>
				4950
				4951	<h5>Overview:</h5>
				4952
				4953	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4954	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]	4955	location to the destination location.
				4956	</p>
				4957
				4958	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4959	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				4960	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4961	</p>
				4962
				4963	<h5>Arguments:</h5>
				4964
				4965	<p>
				4966	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]	4967	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4968	specifying the number of bytes to copy, and the fourth argument is the alignment
				4969	of the source and destination locations.
				4970	</p>
				4971
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4972	<p>
				4973	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]	4974	the caller guarantees that both the source and destination pointers are aligned
				4975	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4976	</p>
				4977
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4978	<h5>Semantics:</h5>
				4979
				4980	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4981	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]	4982	location to the destination location, which are not allowed to overlap. It
				4983	copies "len" bytes of memory over. If the argument is known to be aligned to
				4984	some boundary, this can be specified as the fourth argument, otherwise it should
				4985	be set to 0 or 1.
				4986	</p>
				4987	</div>
				4988
				4989
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4990	<!-- _______________________________________________________________________ -->
				4991	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4992	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4993	</div>
				4994
				4995	<div class="doc_text">
				4996
				4997	<h5>Syntax:</h5>
				4998	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4999	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5000	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5001	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5002	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5003	</pre>
				5004
				5005	<h5>Overview:</h5>
				5006
				5007	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5008	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5009	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5010	'<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]	5011	</p>
				5012
				5013	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5014	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5015	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5016	</p>
				5017
				5018	<h5>Arguments:</h5>
				5019
				5020	<p>
				5021	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5022	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5023	specifying the number of bytes to copy, and the fourth argument is the alignment
				5024	of the source and destination locations.
				5025	</p>
				5026
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5027	<p>
				5028	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5029	the caller guarantees that the source and destination pointers are aligned to
				5030	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5031	</p>
				5032
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5033	<h5>Semantics:</h5>
				5034
				5035	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5036	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5037	location to the destination location, which may overlap. It
				5038	copies "len" bytes of memory over. If the argument is known to be aligned to
				5039	some boundary, this can be specified as the fourth argument, otherwise it should
				5040	be set to 0 or 1.
				5041	</p>
				5042	</div>
				5043
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5044
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5045	<!-- _______________________________________________________________________ -->
				5046	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5047	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5048	</div>
				5049
				5050	<div class="doc_text">
				5051
				5052	<h5>Syntax:</h5>
				5053	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5054	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5055	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5056	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5057	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5058	</pre>
				5059
				5060	<h5>Overview:</h5>
				5061
				5062	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5063	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5064	byte value.
				5065	</p>
				5066
				5067	<p>
				5068	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5069	does not return a value, and takes an extra alignment argument.
				5070	</p>
				5071
				5072	<h5>Arguments:</h5>
				5073
				5074	<p>
				5075	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]	5076	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5077	argument specifying the number of bytes to fill, and the fourth argument is the
				5078	known alignment of destination location.
				5079	</p>
				5080
				5081	<p>
				5082	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]	5083	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5084	</p>
				5085
				5086	<h5>Semantics:</h5>
				5087
				5088	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5089	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5090	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5091	destination location. If the argument is known to be aligned to some boundary,
				5092	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5093	1.
				5094	</p>
				5095	</div>
				5096
				5097
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5098	<!-- _______________________________________________________________________ -->
				5099	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5100	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5101	</div>
				5102
				5103	<div class="doc_text">
				5104
				5105	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5106	<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]	5107	floating point or vector of floating point type. Not all targets support all
				5108	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5109	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5110	declare float @llvm.sqrt.f32(float %Val)
				5111	declare double @llvm.sqrt.f64(double %Val)
				5112	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5113	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5114	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5115	</pre>
				5116
				5117	<h5>Overview:</h5>
				5118
				5119	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5120	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]	5121	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]	5122	<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]	5123	negative numbers other than -0.0 (which allows for better optimization, because
				5124	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5125	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5126	</p>
				5127
				5128	<h5>Arguments:</h5>
				5129
				5130	<p>
				5131	The argument and return value are floating point numbers of the same type.
				5132	</p>
				5133
				5134	<h5>Semantics:</h5>
				5135
				5136	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5137	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]	5138	floating point number.
				5139	</p>
				5140	</div>
				5141
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5142	<!-- _______________________________________________________________________ -->
				5143	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5144	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5145	</div>
				5146
				5147	<div class="doc_text">
				5148
				5149	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5150	<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]	5151	floating point or vector of floating point type. Not all targets support all
				5152	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5153	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5154	declare float @llvm.powi.f32(float %Val, i32 %power)
				5155	declare double @llvm.powi.f64(double %Val, i32 %power)
				5156	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5157	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5158	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5159	</pre>
				5160
				5161	<h5>Overview:</h5>
				5162
				5163	<p>
				5164	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5165	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5166	multiplications is not defined. When a vector of floating point type is
				5167	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5168	</p>
				5169
				5170	<h5>Arguments:</h5>
				5171
				5172	<p>
				5173	The second argument is an integer power, and the first is a value to raise to
				5174	that power.
				5175	</p>
				5176
				5177	<h5>Semantics:</h5>
				5178
				5179	<p>
				5180	This function returns the first value raised to the second power with an
				5181	unspecified sequence of rounding operations.</p>
				5182	</div>
				5183
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5184	<!-- _______________________________________________________________________ -->
				5185	<div class="doc_subsubsection">
				5186	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5187	</div>
				5188
				5189	<div class="doc_text">
				5190
				5191	<h5>Syntax:</h5>
				5192	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5193	floating point or vector of floating point type. Not all targets support all
				5194	types however.
				5195	<pre>
				5196	declare float @llvm.sin.f32(float %Val)
				5197	declare double @llvm.sin.f64(double %Val)
				5198	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5199	declare fp128 @llvm.sin.f128(fp128 %Val)
				5200	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5201	</pre>
				5202
				5203	<h5>Overview:</h5>
				5204
				5205	<p>
				5206	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5207	</p>
				5208
				5209	<h5>Arguments:</h5>
				5210
				5211	<p>
				5212	The argument and return value are floating point numbers of the same type.
				5213	</p>
				5214
				5215	<h5>Semantics:</h5>
				5216
				5217	<p>
				5218	This function returns the sine of the specified operand, returning the
				5219	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]	5220	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5221	</div>
				5222
				5223	<!-- _______________________________________________________________________ -->
				5224	<div class="doc_subsubsection">
				5225	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5226	</div>
				5227
				5228	<div class="doc_text">
				5229
				5230	<h5>Syntax:</h5>
				5231	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5232	floating point or vector of floating point type. Not all targets support all
				5233	types however.
				5234	<pre>
				5235	declare float @llvm.cos.f32(float %Val)
				5236	declare double @llvm.cos.f64(double %Val)
				5237	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5238	declare fp128 @llvm.cos.f128(fp128 %Val)
				5239	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5240	</pre>
				5241
				5242	<h5>Overview:</h5>
				5243
				5244	<p>
				5245	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5246	</p>
				5247
				5248	<h5>Arguments:</h5>
				5249
				5250	<p>
				5251	The argument and return value are floating point numbers of the same type.
				5252	</p>
				5253
				5254	<h5>Semantics:</h5>
				5255
				5256	<p>
				5257	This function returns the cosine of the specified operand, returning the
				5258	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]	5259	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5260	</div>
				5261
				5262	<!-- _______________________________________________________________________ -->
				5263	<div class="doc_subsubsection">
				5264	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5265	</div>
				5266
				5267	<div class="doc_text">
				5268
				5269	<h5>Syntax:</h5>
				5270	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5271	floating point or vector of floating point type. Not all targets support all
				5272	types however.
				5273	<pre>
				5274	declare float @llvm.pow.f32(float %Val, float %Power)
				5275	declare double @llvm.pow.f64(double %Val, double %Power)
				5276	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5277	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5278	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5279	</pre>
				5280
				5281	<h5>Overview:</h5>
				5282
				5283	<p>
				5284	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5285	specified (positive or negative) power.
				5286	</p>
				5287
				5288	<h5>Arguments:</h5>
				5289
				5290	<p>
				5291	The second argument is a floating point power, and the first is a value to
				5292	raise to that power.
				5293	</p>
				5294
				5295	<h5>Semantics:</h5>
				5296
				5297	<p>
				5298	This function returns the first value raised to the second power,
				5299	returning the
				5300	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]	5301	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5302	</div>
				5303
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5304
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5305	<!-- ======================================================================= -->
				5306	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5307	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5308	</div>
				5309
				5310	<div class="doc_text">
				5311	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5312	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5313	These allow efficient code generation for some algorithms.
				5314	</p>
				5315
				5316	</div>
				5317
				5318	<!-- _______________________________________________________________________ -->
				5319	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5320	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5321	</div>
				5322
				5323	<div class="doc_text">
				5324
				5325	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5326	<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]	5327	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]	5328	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5329	declare i16 @llvm.bswap.i16(i16 <id>)
				5330	declare i32 @llvm.bswap.i32(i32 <id>)
				5331	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5332	</pre>
				5333
				5334	<h5>Overview:</h5>
				5335
				5336	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5337	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]	5338	values with an even number of bytes (positive multiple of 16 bits). These are
				5339	useful for performing operations on data that is not in the target's native
				5340	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5341	</p>
				5342
				5343	<h5>Semantics:</h5>
				5344
				5345	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5346	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]	5347	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5348	intrinsic returns an i32 value that has the four bytes of the input i32
				5349	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]	5350	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5351	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5352	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5353	</p>
				5354
				5355	</div>
				5356
				5357	<!-- _______________________________________________________________________ -->
				5358	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5359	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5360	</div>
				5361
				5362	<div class="doc_text">
				5363
				5364	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5365	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5366	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5367	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5368	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5369	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5370	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5371	declare i64 @llvm.ctpop.i64(i64 <src>)
				5372	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5373	</pre>
				5374
				5375	<h5>Overview:</h5>
				5376
				5377	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5378	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5379	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5380	</p>
				5381
				5382	<h5>Arguments:</h5>
				5383
				5384	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5385	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]	5386	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5387	</p>
				5388
				5389	<h5>Semantics:</h5>
				5390
				5391	<p>
				5392	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5393	</p>
				5394	</div>
				5395
				5396	<!-- _______________________________________________________________________ -->
				5397	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5398	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5399	</div>
				5400
				5401	<div class="doc_text">
				5402
				5403	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5404	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5405	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5406	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5407	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5408	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5409	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5410	declare i64 @llvm.ctlz.i64(i64 <src>)
				5411	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5412	</pre>
				5413
				5414	<h5>Overview:</h5>
				5415
				5416	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5417	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5418	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5419	</p>
				5420
				5421	<h5>Arguments:</h5>
				5422
				5423	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5424	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]	5425	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5426	</p>
				5427
				5428	<h5>Semantics:</h5>
				5429
				5430	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5431	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5432	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]	5433	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5434	</p>
				5435	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5436
				5437
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5438
				5439	<!-- _______________________________________________________________________ -->
				5440	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5441	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5442	</div>
				5443
				5444	<div class="doc_text">
				5445
				5446	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5447	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5448	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5449	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5450	declare i8 @llvm.cttz.i8 (i8 <src>)
				5451	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5452	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5453	declare i64 @llvm.cttz.i64(i64 <src>)
				5454	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5455	</pre>
				5456
				5457	<h5>Overview:</h5>
				5458
				5459	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5460	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5461	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5462	</p>
				5463
				5464	<h5>Arguments:</h5>
				5465
				5466	<p>
				5467	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]	5468	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5469	</p>
				5470
				5471	<h5>Semantics:</h5>
				5472
				5473	<p>
				5474	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5475	in a variable. If the src == 0 then the result is the size in bits of the type
				5476	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5477	</p>
				5478	</div>
				5479
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5480	<!-- _______________________________________________________________________ -->
				5481	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5482	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5483	</div>
				5484
				5485	<div class="doc_text">
				5486
				5487	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5488	<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]	5489	on any integer bit width.
				5490	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5491	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5492	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5493	</pre>
				5494
				5495	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5496	<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]	5497	range of bits from an integer value and returns them in the same bit width as
				5498	the original value.</p>
				5499
				5500	<h5>Arguments:</h5>
				5501	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5502	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]	5503	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]	5504
				5505	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5506	<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]	5507	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5508	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5509	operates in forward mode.</p>
				5510	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5511	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]	5512	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5513	<ol>
				5514	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5515	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5516	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5517	to determine the number of bits to retain.</li>
				5518	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5519	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5520	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5521	<p>In reverse mode, a similar computation is made except that the bits are
				5522	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5523	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5524	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5525	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5526	</div>
				5527
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5528	<div class="doc_subsubsection">
				5529	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5530	</div>
				5531
				5532	<div class="doc_text">
				5533
				5534	<h5>Syntax:</h5>
				5535	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5536	on any integer bit width.
				5537	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5538	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5539	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]	5540	</pre>
				5541
				5542	<h5>Overview:</h5>
				5543	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5544	of bits in an integer value with another integer value. It returns the integer
				5545	with the replaced bits.</p>
				5546
				5547	<h5>Arguments:</h5>
				5548	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5549	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5550	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5551	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5552	type since they specify only a bit index.</p>
				5553
				5554	<h5>Semantics:</h5>
				5555	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5556	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5557	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5558	operates in forward mode.</p>
				5559	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5560	truncating it down to the size of the replacement area or zero extending it
				5561	up to that size.</p>
				5562	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5563	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5564	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5565	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5566	<p>In reverse mode, a similar computation is made except that the bits are
				5567	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5568	<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]	5569	<h5>Examples:</h5>
				5570	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5571	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5572	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5573	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5574	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5575	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5576	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5577	</div>
				5578
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5579	<!-- ======================================================================= -->
				5580	<div class="doc_subsection">
				5581	<a name="int_debugger">Debugger Intrinsics</a>
				5582	</div>
				5583
				5584	<div class="doc_text">
				5585	<p>
				5586	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5587	are described in the <a
				5588	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5589	Debugging</a> document.
				5590	</p>
				5591	</div>
				5592
				5593
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5594	<!-- ======================================================================= -->
				5595	<div class="doc_subsection">
				5596	<a name="int_eh">Exception Handling Intrinsics</a>
				5597	</div>
				5598
				5599	<div class="doc_text">
				5600	<p> The LLVM exception handling intrinsics (which all start with
				5601	<tt>llvm.eh.</tt> prefix), are described in the <a
				5602	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5603	Handling</a> document. </p>
				5604	</div>
				5605
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5606	<!-- ======================================================================= -->
				5607	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5608	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5609	</div>
				5610
				5611	<div class="doc_text">
				5612	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5613	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5614	the <tt>nest</tt> attribute, from a function. The result is a callable
				5615	function pointer lacking the nest parameter - the caller does not need
				5616	to provide a value for it. Instead, the value to use is stored in
				5617	advance in a "trampoline", a block of memory usually allocated
				5618	on the stack, which also contains code to splice the nest value into the
				5619	argument list. This is used to implement the GCC nested function address
				5620	extension.
				5621	</p>
				5622	<p>
				5623	For example, if the function is
				5624	<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]	5625	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]	5626	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5627	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5628	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5629	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5630	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5631	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5632	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5633	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]	5634	</div>
				5635
				5636	<!-- _______________________________________________________________________ -->
				5637	<div class="doc_subsubsection">
				5638	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5639	</div>
				5640	<div class="doc_text">
				5641	<h5>Syntax:</h5>
				5642	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5643	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5644	</pre>
				5645	<h5>Overview:</h5>
				5646	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5647	This fills the memory pointed to by <tt>tramp</tt> with code
				5648	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5649	</p>
				5650	<h5>Arguments:</h5>
				5651	<p>
				5652	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5653	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5654	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]	5655	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5656	currently provides no portable way of determining them, so a front-end that
				5657	generates this intrinsic needs to have some target-specific knowledge.
				5658	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]	5659	</p>
				5660	<h5>Semantics:</h5>
				5661	<p>
				5662	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]	5663	dependent code, turning it into a function. A pointer to this function is
				5664	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5665	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5666	before being called. The new function's signature is the same as that of
				5667	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5668	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5669	of pointer type. Calling the new function is equivalent to calling
				5670	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5671	missing <tt>nest</tt> argument. If, after calling
				5672	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5673	modified, then the effect of any later call to the returned function pointer is
				5674	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5675	</p>
				5676	</div>
				5677
				5678	<!-- ======================================================================= -->
				5679	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5680	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5681	</div>
				5682
				5683	<div class="doc_text">
				5684	<p>
				5685	These intrinsic functions expand the "universal IR" of LLVM to represent
				5686	hardware constructs for atomic operations and memory synchronization. This
				5687	provides an interface to the hardware, not an interface to the programmer. It
				5688	is aimed at a low enough level to allow any programming models or APIs which
				5689	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5690	hardware behavior. Just as hardware provides a "universal IR" for source
				5691	languages, it also provides a starting point for developing a "universal"
				5692	atomic operation and synchronization IR.
				5693	</p>
				5694	<p>
				5695	These do <em>not</em> form an API such as high-level threading libraries,
				5696	software transaction memory systems, atomic primitives, and intrinsic
				5697	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5698	application libraries. The hardware interface provided by LLVM should allow
				5699	a clean implementation of all of these APIs and parallel programming models.
				5700	No one model or paradigm should be selected above others unless the hardware
				5701	itself ubiquitously does so.
				5702
				5703	</p>
				5704	</div>
				5705
				5706	<!-- _______________________________________________________________________ -->
				5707	<div class="doc_subsubsection">
				5708	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5709	</div>
				5710	<div class="doc_text">
				5711	<h5>Syntax:</h5>
				5712	<pre>
				5713	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5714	i1 <device> )
				5715
				5716	</pre>
				5717	<h5>Overview:</h5>
				5718	<p>
				5719	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5720	specific pairs of memory access types.
				5721	</p>
				5722	<h5>Arguments:</h5>
				5723	<p>
				5724	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5725	The first four arguments enables a specific barrier as listed below. The fith
				5726	argument specifies that the barrier applies to io or device or uncached memory.
				5727
				5728	</p>
				5729	<ul>
				5730	<li><tt>ll</tt>: load-load barrier</li>
				5731	<li><tt>ls</tt>: load-store barrier</li>
				5732	<li><tt>sl</tt>: store-load barrier</li>
				5733	<li><tt>ss</tt>: store-store barrier</li>
				5734	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5735	</ul>
				5736	<h5>Semantics:</h5>
				5737	<p>
				5738	This intrinsic causes the system to enforce some ordering constraints upon
				5739	the loads and stores of the program. This barrier does not indicate
				5740	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5741	which they occur. For any of the specified pairs of load and store operations
				5742	(f.ex. load-load, or store-load), all of the first operations preceding the
				5743	barrier will complete before any of the second operations succeeding the
				5744	barrier begin. Specifically the semantics for each pairing is as follows:
				5745	</p>
				5746	<ul>
				5747	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5748	after the barrier begins.</li>
				5749
				5750	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5751	store after the barrier begins.</li>
				5752	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5753	store after the barrier begins.</li>
				5754	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5755	load after the barrier begins.</li>
				5756	</ul>
				5757	<p>
				5758	These semantics are applied with a logical "and" behavior when more than one
				5759	is enabled in a single memory barrier intrinsic.
				5760	</p>
				5761	<p>
				5762	Backends may implement stronger barriers than those requested when they do not
				5763	support as fine grained a barrier as requested. Some architectures do not
				5764	need all types of barriers and on such architectures, these become noops.
				5765	</p>
				5766	<h5>Example:</h5>
				5767	<pre>
				5768	%ptr = malloc i32
				5769	store i32 4, %ptr
				5770
				5771	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5772	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5773	<i>; guarantee the above finishes</i>
				5774	store i32 8, %ptr <i>; before this begins</i>
				5775	</pre>
				5776	</div>
				5777
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5778	<!-- _______________________________________________________________________ -->
				5779	<div class="doc_subsubsection">
				5780	<a name="int_atomic_lcs">'<tt>llvm.atomic.lcs.*</tt>' Intrinsic</a>
				5781	</div>
				5782	<div class="doc_text">
				5783	<h5>Syntax:</h5>
				5784	<p>
				5785	This is an overloaded intrinsic. You can use <tt>llvm.atomic.lcs</tt> on any
				5786	integer bit width. Not all targets support all bit widths however.</p>
				5787
				5788	<pre>
				5789	declare i8 @llvm.atomic.lcs.i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5790	declare i16 @llvm.atomic.lcs.i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5791	declare i32 @llvm.atomic.lcs.i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5792	declare i64 @llvm.atomic.lcs.i64( i64* <ptr>, i64 <cmp>, i64 <val> )
				5793
				5794	</pre>
				5795	<h5>Overview:</h5>
				5796	<p>
				5797	This loads a value in memory and compares it to a given value. If they are
				5798	equal, it stores a new value into the memory.
				5799	</p>
				5800	<h5>Arguments:</h5>
				5801	<p>
				5802	The <tt>llvm.atomic.lcs</tt> intrinsic takes three arguments. The result as
				5803	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5804	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5805	this integer type. While any bit width integer may be used, targets may only
				5806	lower representations they support in hardware.
				5807
				5808	</p>
				5809	<h5>Semantics:</h5>
				5810	<p>
				5811	This entire intrinsic must be executed atomically. It first loads the value
				5812	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5813	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5814	loaded value is yielded in all cases. This provides the equivalent of an
				5815	atomic compare-and-swap operation within the SSA framework.
				5816	</p>
				5817	<h5>Examples:</h5>
				5818
				5819	<pre>
				5820	%ptr = malloc i32
				5821	store i32 4, %ptr
				5822
				5823	%val1 = add i32 4, 4
				5824	%result1 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 4, %val1 )
				5825	<i>; yields {i32}:result1 = 4</i>
				5826	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5827	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5828
				5829	%val2 = add i32 1, 1
				5830	%result2 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 5, %val2 )
				5831	<i>; yields {i32}:result2 = 8</i>
				5832	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5833
				5834	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5835	</pre>
				5836	</div>
				5837
				5838	<!-- _______________________________________________________________________ -->
				5839	<div class="doc_subsubsection">
				5840	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5841	</div>
				5842	<div class="doc_text">
				5843	<h5>Syntax:</h5>
				5844
				5845	<p>
				5846	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5847	integer bit width. Not all targets support all bit widths however.</p>
				5848	<pre>
				5849	declare i8 @llvm.atomic.swap.i8( i8* <ptr>, i8 <val> )
				5850	declare i16 @llvm.atomic.swap.i16( i16* <ptr>, i16 <val> )
				5851	declare i32 @llvm.atomic.swap.i32( i32* <ptr>, i32 <val> )
				5852	declare i64 @llvm.atomic.swap.i64( i64* <ptr>, i64 <val> )
				5853
				5854	</pre>
				5855	<h5>Overview:</h5>
				5856	<p>
				5857	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5858	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5859	at <tt>ptr</tt>.
				5860	</p>
				5861	<h5>Arguments:</h5>
				5862
				5863	<p>
				5864	The <tt>llvm.atomic.ls</tt> intrinsic takes two arguments. Both the
				5865	<tt>val</tt> argument and the result must be integers of the same bit width.
				5866	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5867	integer type. The targets may only lower integer representations they
				5868	support.
				5869	</p>
				5870	<h5>Semantics:</h5>
				5871	<p>
				5872	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5873	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5874	equivalent of an atomic swap operation within the SSA framework.
				5875
				5876	</p>
				5877	<h5>Examples:</h5>
				5878	<pre>
				5879	%ptr = malloc i32
				5880	store i32 4, %ptr
				5881
				5882	%val1 = add i32 4, 4
				5883	%result1 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val1 )
				5884	<i>; yields {i32}:result1 = 4</i>
				5885	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5886	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5887
				5888	%val2 = add i32 1, 1
				5889	%result2 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val2 )
				5890	<i>; yields {i32}:result2 = 8</i>
				5891
				5892	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5893	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5894	</pre>
				5895	</div>
				5896
				5897	<!-- _______________________________________________________________________ -->
				5898	<div class="doc_subsubsection">
				5899	<a name="int_atomic_las">'<tt>llvm.atomic.las.*</tt>' Intrinsic</a>
				5900
				5901	</div>
				5902	<div class="doc_text">
				5903	<h5>Syntax:</h5>
				5904	<p>
				5905	This is an overloaded intrinsic. You can use <tt>llvm.atomic.las</tt> on any
				5906	integer bit width. Not all targets support all bit widths however.</p>
				5907	<pre>
				5908	declare i8 @llvm.atomic.las.i8.( i8* <ptr>, i8 <delta> )
				5909	declare i16 @llvm.atomic.las.i16.( i16* <ptr>, i16 <delta> )
				5910	declare i32 @llvm.atomic.las.i32.( i32* <ptr>, i32 <delta> )
				5911	declare i64 @llvm.atomic.las.i64.( i64* <ptr>, i64 <delta> )
				5912
				5913	</pre>
				5914	<h5>Overview:</h5>
				5915	<p>
				5916	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5917	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5918	</p>
				5919	<h5>Arguments:</h5>
				5920	<p>
				5921
				5922	The intrinsic takes two arguments, the first a pointer to an integer value
				5923	and the second an integer value. The result is also an integer value. These
				5924	integer types can have any bit width, but they must all have the same bit
				5925	width. The targets may only lower integer representations they support.
				5926	</p>
				5927	<h5>Semantics:</h5>
				5928	<p>
				5929	This intrinsic does a series of operations atomically. It first loads the
				5930	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5931	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5932	</p>
				5933
				5934	<h5>Examples:</h5>
				5935	<pre>
				5936	%ptr = malloc i32
				5937	store i32 4, %ptr
				5938	%result1 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 4 )
				5939	<i>; yields {i32}:result1 = 4</i>
				5940	%result2 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 2 )
				5941	<i>; yields {i32}:result2 = 8</i>
				5942	%result3 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 5 )
				5943	<i>; yields {i32}:result3 = 10</i>
				5944	%memval = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
				5945	</pre>
				5946	</div>
				5947
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5948
				5949	<!-- ======================================================================= -->
				5950	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5951	<a name="int_general">General Intrinsics</a>
				5952	</div>
				5953
				5954	<div class="doc_text">
				5955	<p> This class of intrinsics is designed to be generic and has
				5956	no specific purpose. </p>
				5957	</div>
				5958
				5959	<!-- _______________________________________________________________________ -->
				5960	<div class="doc_subsubsection">
				5961	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				5962	</div>
				5963
				5964	<div class="doc_text">
				5965
				5966	<h5>Syntax:</h5>
				5967	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5968	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]	5969	</pre>
				5970
				5971	<h5>Overview:</h5>
				5972
				5973	<p>
				5974	The '<tt>llvm.var.annotation</tt>' intrinsic
				5975	</p>
				5976
				5977	<h5>Arguments:</h5>
				5978
				5979	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5980	The first argument is a pointer to a value, the second is a pointer to a
				5981	global string, the third is a pointer to a global string which is the source
				5982	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5983	</p>
				5984
				5985	<h5>Semantics:</h5>
				5986
				5987	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	5988	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5989	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]	5990	annotations. These have no other defined use, they are ignored by code
				5991	generation and optimization.
				5992	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5993	</div>
				5994
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5995	<!-- _______________________________________________________________________ -->
				5996	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	5997	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5998	</div>
				5999
				6000	<div class="doc_text">
				6001
				6002	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6003	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6004	any integer bit width.
				6005	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6006	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6007	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6008	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6009	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6010	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6011	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]	6012	</pre>
				6013
				6014	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6015
				6016	<p>
				6017	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6018	</p>
				6019
				6020	<h5>Arguments:</h5>
				6021
				6022	<p>
				6023	The first argument is an integer value (result of some expression),
				6024	the second is a pointer to a global string, the third is a pointer to a global
				6025	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]	6026	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6027	</p>
				6028
				6029	<h5>Semantics:</h5>
				6030
				6031	<p>
				6032	This intrinsic allows annotations to be put on arbitrary expressions
				6033	with arbitrary strings. This can be useful for special purpose optimizations
				6034	that want to look for these annotations. These have no other defined use, they
				6035	are ignored by code generation and optimization.
				6036	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6037
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6038	<!-- _______________________________________________________________________ -->
				6039	<div class="doc_subsubsection">
				6040	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6041	</div>
				6042
				6043	<div class="doc_text">
				6044
				6045	<h5>Syntax:</h5>
				6046	<pre>
				6047	declare void @llvm.trap()
				6048	</pre>
				6049
				6050	<h5>Overview:</h5>
				6051
				6052	<p>
				6053	The '<tt>llvm.trap</tt>' intrinsic
				6054	</p>
				6055
				6056	<h5>Arguments:</h5>
				6057
				6058	<p>
				6059	None
				6060	</p>
				6061
				6062	<h5>Semantics:</h5>
				6063
				6064	<p>
				6065	This intrinsics is lowered to the target dependent trap instruction. If the
				6066	target does not have a trap instruction, this intrinsic will be lowered to the
				6067	call of the abort() function.
				6068	</p>
				6069	</div>
				6070
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6071	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6072	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6073	<address>
				6074	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6075	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6076	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6077	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]	6078
				6079	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6080	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6081	Last modified: $Date$
				6082	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6083
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6084	</body>
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