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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
Chris Lattner	fa73021	2004-12-09 16:11:40 +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
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	488	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	489
				490	<dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
				491	except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	492	used for globals that may be emitted in multiple translation units, but that
				493	are not guaranteed to be emitted into every translation unit that uses them.
				494	One example of this are common globals in C, such as "<tt>int X;</tt>" at
				495	global scope.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	496	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	497
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	498	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	499
				500	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				501	pointer to array type. When two global variables with appending linkage are
				502	linked together, the two global arrays are appended together. This is the
				503	LLVM, typesafe, equivalent of having the system linker append together
				504	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	505	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	506
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	507	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
				508	<dd>The semantics of this linkage follow the ELF model: the symbol is weak
				509	until linked, if not linked, the symbol becomes null instead of being an
				510	undefined reference.
				511	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	512
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	513	<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]	514
				515	<dd>If none of the above identifiers are used, the global is externally
				516	visible, meaning that it participates in linkage and can be used to resolve
				517	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	518	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	519	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	520
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	521	<p>
				522	The next two types of linkage are targeted for Microsoft Windows platform
				523	only. They are designed to support importing (exporting) symbols from (to)
				524	DLLs.
				525	</p>
				526
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	527	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	528	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				529
				530	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				531	or variable via a global pointer to a pointer that is set up by the DLL
				532	exporting the symbol. On Microsoft Windows targets, the pointer name is
				533	formed by combining <code>_imp__</code> and the function or variable name.
				534	</dd>
				535
				536	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				537
				538	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				539	pointer to a pointer in a DLL, so that it can be referenced with the
				540	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				541	name is formed by combining <code>_imp__</code> and the function or variable
				542	name.
				543	</dd>
				544
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	545	</dl>
				546
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	547	<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]	548	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				549	variable and was linked with this one, one of the two would be renamed,
				550	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				551	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	552	outside of the current module.</p>
				553	<p>It is illegal for a function <i>declaration</i>
				554	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	555	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	556	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				557	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	558	</div>
				559
				560	<!-- ======================================================================= -->
				561	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	562	<a name="callingconv">Calling Conventions</a>
				563	</div>
				564
				565	<div class="doc_text">
				566
				567	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				568	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				569	specified for the call. The calling convention of any pair of dynamic
				570	caller/callee must match, or the behavior of the program is undefined. The
				571	following calling conventions are supported by LLVM, and more may be added in
				572	the future:</p>
				573
				574	<dl>
				575	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				576
				577	<dd>This calling convention (the default if no other calling convention is
				578	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	579	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	580	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	581	</dd>
				582
				583	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				584
				585	<dd>This calling convention attempts to make calls as fast as possible
				586	(e.g. by passing things in registers). This calling convention allows the
				587	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]	588	without having to conform to an externally specified ABI. Implementations of
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	589	this convention should allow arbitrary
				590	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				591	supported. This calling convention does not support varargs and requires the
				592	prototype of all callees to exactly match the prototype of the function
				593	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	594	</dd>
				595
				596	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				597
				598	<dd>This calling convention attempts to make code in the caller as efficient
				599	as possible under the assumption that the call is not commonly executed. As
				600	such, these calls often preserve all registers so that the call does not break
				601	any live ranges in the caller side. This calling convention does not support
				602	varargs and requires the prototype of all callees to exactly match the
				603	prototype of the function definition.
				604	</dd>
				605
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	606	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	607
				608	<dd>Any calling convention may be specified by number, allowing
				609	target-specific calling conventions to be used. Target specific calling
				610	conventions start at 64.
				611	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	612	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	613
				614	<p>More calling conventions can be added/defined on an as-needed basis, to
				615	support pascal conventions or any other well-known target-independent
				616	convention.</p>
				617
				618	</div>
				619
				620	<!-- ======================================================================= -->
				621	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	622	<a name="visibility">Visibility Styles</a>
				623	</div>
				624
				625	<div class="doc_text">
				626
				627	<p>
				628	All Global Variables and Functions have one of the following visibility styles:
				629	</p>
				630
				631	<dl>
				632	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				633
				634	<dd>On ELF, default visibility means that the declaration is visible to other
				635	modules and, in shared libraries, means that the declared entity may be
				636	overridden. On Darwin, default visibility means that the declaration is
				637	visible to other modules. Default visibility corresponds to "external
				638	linkage" in the language.
				639	</dd>
				640
				641	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				642
				643	<dd>Two declarations of an object with hidden visibility refer to the same
				644	object if they are in the same shared object. Usually, hidden visibility
				645	indicates that the symbol will not be placed into the dynamic symbol table,
				646	so no other module (executable or shared library) can reference it
				647	directly.
				648	</dd>
				649
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	650	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				651
				652	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				653	the dynamic symbol table, but that references within the defining module will
				654	bind to the local symbol. That is, the symbol cannot be overridden by another
				655	module.
				656	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	657	</dl>
				658
				659	</div>
				660
				661	<!-- ======================================================================= -->
				662	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	663	<a name="globalvars">Global Variables</a>
				664	</div>
				665
				666	<div class="doc_text">
				667
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	668	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	669	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	670	an explicit section to be placed in, and may have an optional explicit alignment
				671	specified. A variable may be defined as "thread_local", which means that it
				672	will not be shared by threads (each thread will have a separated copy of the
				673	variable). A variable may be defined as a global "constant," which indicates
				674	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]	675	optimization, allowing the global data to be placed in the read-only section of
				676	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	677	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]	678
				679	<p>
				680	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				681	constant, even if the final definition of the global is not. This capability
				682	can be used to enable slightly better optimization of the program, but requires
				683	the language definition to guarantee that optimizations based on the
				684	'constantness' are valid for the translation units that do not include the
				685	definition.
				686	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	687
				688	<p>As SSA values, global variables define pointer values that are in
				689	scope (i.e. they dominate) all basic blocks in the program. Global
				690	variables always define a pointer to their "content" type because they
				691	describe a region of memory, and all memory objects in LLVM are
				692	accessed through pointers.</p>
				693
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	694	<p>A global variable may be declared to reside in a target-specifc numbered
				695	address space. For targets that support them, address spaces may affect how
				696	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	697	the variable. The default address space is zero. The address space qualifier
				698	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	699
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	700	<p>LLVM allows an explicit section to be specified for globals. If the target
				701	supports it, it will emit globals to the section specified.</p>
				702
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	703	<p>An explicit alignment may be specified for a global. If not present, or if
				704	the alignment is set to zero, the alignment of the global is set by the target
				705	to whatever it feels convenient. If an explicit alignment is specified, the
				706	global is forced to have at least that much alignment. All alignments must be
				707	a power of 2.</p>
				708
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	709	<p>For example, the following defines a global in a numbered address space with
				710	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	711
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	712	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	713	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	714	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	715	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	716	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	717
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	718	</div>
				719
				720
				721	<!-- ======================================================================= -->
				722	<div class="doc_subsection">
				723	<a name="functionstructure">Functions</a>
				724	</div>
				725
				726	<div class="doc_text">
				727
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	728	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				729	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	730	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	731	<a href="#callingconv">calling convention</a>, a return type, an optional
				732	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				733	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	734	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	735	optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	736	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]	737
				738	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				739	optional <a href="#linkage">linkage type</a>, an optional
				740	<a href="#visibility">visibility style</a>, an optional
				741	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	742	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	743	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]	744	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	745
				746	<p>A function definition contains a list of basic blocks, forming the CFG for
				747	the function. Each basic block may optionally start with a label (giving the
				748	basic block a symbol table entry), contains a list of instructions, and ends
				749	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				750	function return).</p>
				751
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	752	<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]	753	executed on entrance to the function, and it is not allowed to have predecessor
				754	basic blocks (i.e. there can not be any branches to the entry block of a
				755	function). Because the block can have no predecessors, it also cannot have any
				756	<a href="#i_phi">PHI nodes</a>.</p>
				757
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	758	<p>LLVM allows an explicit section to be specified for functions. If the target
				759	supports it, it will emit functions to the section specified.</p>
				760
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	761	<p>An explicit alignment may be specified for a function. If not present, or if
				762	the alignment is set to zero, the alignment of the function is set by the target
				763	to whatever it feels convenient. If an explicit alignment is specified, the
				764	function is forced to have at least that much alignment. All alignments must be
				765	a power of 2.</p>
				766
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	767	</div>
				768
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	769
				770	<!-- ======================================================================= -->
				771	<div class="doc_subsection">
				772	<a name="aliasstructure">Aliases</a>
				773	</div>
				774	<div class="doc_text">
				775	<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]	776	function, global variable, another alias or bitcast of global value). Aliases
				777	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	778	optional <a href="#visibility">visibility style</a>.</p>
				779
				780	<h5>Syntax:</h5>
				781
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	782	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	783	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	784	@<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	785	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	786	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	787
				788	</div>
				789
				790
				791
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	792	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	793	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				794	<div class="doc_text">
				795	<p>The return type and each parameter of a function type may have a set of
				796	<i>parameter attributes</i> associated with them. Parameter attributes are
				797	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	798	a function. Parameter attributes are considered to be part of the function,
				799	not of the function type, so functions with different parameter attributes
				800	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	801
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	802	<p>Parameter attributes are simple keywords that follow the type specified. If
				803	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	804	example:</p>
				805
				806	<div class="doc_code">
				807	<pre>
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	808	declare i32 @printf(i8* noalias , ...) nounwind
				809	declare i32 @atoi(i8*) nounwind readonly
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	810	</pre>
				811	</div>
				812
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	813	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				814	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	815
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	816	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	817	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	818	<dt><tt>zeroext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	819	<dd>This indicates that the parameter should be zero extended just before
				820	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	821
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	822	<dt><tt>signext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	823	<dd>This indicates that the parameter should be sign extended just before
				824	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	825
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	826	<dt><tt>inreg</tt></dt>
				827	<dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov	66a8c8c	2007-01-28 15:27:21 +0000	[diff] [blame]	828	possible) during assembling function call. Support for this attribute is
				829	target-specific</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	830
				831	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	832	<dd>This indicates that the pointer parameter should really be passed by
				833	value to the function. The attribute implies that a hidden copy of the
				834	pointee is made between the caller and the callee, so the callee is unable
				835	to modify the value in the callee. This attribute is only valid on llvm
				836	pointer arguments. It is generally used to pass structs and arrays by
				837	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]	838
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	839	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	840	<dd>This indicates that the pointer parameter specifies the address of a
				841	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]	842	Loads and stores to the structure are assumed not to trap.
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	843	May only be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	844
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	845	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	846	<dd>This indicates that the parameter does not alias any global or any other
				847	parameter. The caller is responsible for ensuring that this is the case,
				848	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	849
Reid Spencer	2dc5201	2007-03-22 02:18:56 +0000	[diff] [blame]	850	<dt><tt>noreturn</tt></dt>
				851	<dd>This function attribute indicates that the function never returns. This
				852	indicates to LLVM that every call to this function should be treated as if
				853	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	854
Reid Spencer	6760612	2007-03-22 02:02:11 +0000	[diff] [blame]	855	<dt><tt>nounwind</tt></dt>
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	856	<dd>This function attribute indicates that no exceptions unwind out of the
				857	function. Usually this is because the function makes no use of exceptions,
				858	but it may also be that the function catches any exceptions thrown when
				859	executing it.</dd>
				860
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	861	<dt><tt>nest</tt></dt>
				862	<dd>This indicates that the parameter can be excised using the
				863	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	864	<dt><tt>readonly</tt></dt>
Duncan Sands	f04d584	2007-11-14 21:14:02 +0000	[diff] [blame]	865	<dd>This function attribute indicates that the function has no side-effects
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	866	except for producing a return value or throwing an exception. The value
				867	returned must only depend on the function arguments and/or global variables.
				868	It may use values obtained by dereferencing pointers.</dd>
				869	<dt><tt>readnone</tt></dt>
				870	<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]	871	function, but in addition it is not allowed to dereference any pointer arguments
				872	or global variables.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	873	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	874
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	875	</div>
				876
				877	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	878	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	879	<a name="gc">Garbage Collector Names</a>
				880	</div>
				881
				882	<div class="doc_text">
				883	<p>Each function may specify a garbage collector name, which is simply a
				884	string.</p>
				885
				886	<div class="doc_code"><pre
				887	>define void @f() gc "name" { ...</pre></div>
				888
				889	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				890	collector which will cause the compiler to alter its output in order to support
				891	the named garbage collection algorithm.</p>
				892	</div>
				893
				894	<!-- ======================================================================= -->
				895	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	896	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	897	</div>
				898
				899	<div class="doc_text">
				900	<p>
				901	Modules may contain "module-level inline asm" blocks, which corresponds to the
				902	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				903	LLVM and treated as a single unit, but may be separated in the .ll file if
				904	desired. The syntax is very simple:
				905	</p>
				906
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	907	<div class="doc_code">
				908	<pre>
				909	module asm "inline asm code goes here"
				910	module asm "more can go here"
				911	</pre>
				912	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	913
				914	<p>The strings can contain any character by escaping non-printable characters.
				915	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				916	for the number.
				917	</p>
				918
				919	<p>
				920	The inline asm code is simply printed to the machine code .s file when
				921	assembly code is generated.
				922	</p>
				923	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	924
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	925	<!-- ======================================================================= -->
				926	<div class="doc_subsection">
				927	<a name="datalayout">Data Layout</a>
				928	</div>
				929
				930	<div class="doc_text">
				931	<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]	932	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				933	<pre> target datalayout = "<i>layout specification</i>"</pre>
				934	<p>The <i>layout specification</i> consists of a list of specifications
				935	separated by the minus sign character ('-'). Each specification starts with a
				936	letter and may include other information after the letter to define some
				937	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	938	<dl>
				939	<dt><tt>E</tt></dt>
				940	<dd>Specifies that the target lays out data in big-endian form. That is, the
				941	bits with the most significance have the lowest address location.</dd>
				942	<dt><tt>e</tt></dt>
				943	<dd>Specifies that hte target lays out data in little-endian form. That is,
				944	the bits with the least significance have the lowest address location.</dd>
				945	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				946	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				947	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				948	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				949	too.</dd>
				950	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				951	<dd>This specifies the alignment for an integer type of a given bit
				952	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				953	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				954	<dd>This specifies the alignment for a vector type of a given bit
				955	<i>size</i>.</dd>
				956	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				957	<dd>This specifies the alignment for a floating point type of a given bit
				958	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				959	(double).</dd>
				960	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				961	<dd>This specifies the alignment for an aggregate type of a given bit
				962	<i>size</i>.</dd>
				963	</dl>
				964	<p>When constructing the data layout for a given target, LLVM starts with a
				965	default set of specifications which are then (possibly) overriden by the
				966	specifications in the <tt>datalayout</tt> keyword. The default specifications
				967	are given in this list:</p>
				968	<ul>
				969	<li><tt>E</tt> - big endian</li>
				970	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				971	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				972	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				973	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				974	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
				975	<li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
				976	alignment of 64-bits</li>
				977	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				978	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				979	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				980	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				981	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				982	</ul>
				983	<p>When llvm is determining the alignment for a given type, it uses the
				984	following rules:
				985	<ol>
				986	<li>If the type sought is an exact match for one of the specifications, that
				987	specification is used.</li>
				988	<li>If no match is found, and the type sought is an integer type, then the
				989	smallest integer type that is larger than the bitwidth of the sought type is
				990	used. If none of the specifications are larger than the bitwidth then the the
				991	largest integer type is used. For example, given the default specifications
				992	above, the i7 type will use the alignment of i8 (next largest) while both
				993	i65 and i256 will use the alignment of i64 (largest specified).</li>
				994	<li>If no match is found, and the type sought is a vector type, then the
				995	largest vector type that is smaller than the sought vector type will be used
				996	as a fall back. This happens because <128 x double> can be implemented in
				997	terms of 64 <2 x double>, for example.</li>
				998	</ol>
				999	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1000
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1001	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1002	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1003	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1004
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1005	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1006
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1007	<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]	1008	intermediate representation. Being typed enables a number of
				1009	optimizations to be performed on the IR directly, without having to do
				1010	extra analyses on the side before the transformation. A strong type
				1011	system makes it easier to read the generated code and enables novel
				1012	analyses and transformations that are not feasible to perform on normal
				1013	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1014
				1015	</div>
				1016
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1017	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1018	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1019	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1020	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1021	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1022	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1023
				1024	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1025	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1026	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1027	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1028	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1029	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1030	</tr>
				1031	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1032	<td><a href="#t_floating">floating point</a></td>
				1033	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1034	</tr>
				1035	<tr>
				1036	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1037	<td><a href="#t_integer">integer</a>,
				1038	<a href="#t_floating">floating point</a>,
				1039	<a href="#t_pointer">pointer</a>,
				1040	<a href="#t_vector">vector</a>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1041	<a href="#t_struct">structure</a>,
				1042	<a href="#t_array">array</a>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1043	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1044	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1045	<tr>
				1046	<td><a href="#t_primitive">primitive</a></td>
				1047	<td><a href="#t_label">label</a>,
				1048	<a href="#t_void">void</a>,
				1049	<a href="#t_integer">integer</a>,
				1050	<a href="#t_floating">floating point</a>.</td>
				1051	</tr>
				1052	<tr>
				1053	<td><a href="#t_derived">derived</a></td>
				1054	<td><a href="#t_integer">integer</a>,
				1055	<a href="#t_array">array</a>,
				1056	<a href="#t_function">function</a>,
				1057	<a href="#t_pointer">pointer</a>,
				1058	<a href="#t_struct">structure</a>,
				1059	<a href="#t_pstruct">packed structure</a>,
				1060	<a href="#t_vector">vector</a>,
				1061	<a href="#t_opaque">opaque</a>.
				1062	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1063	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1064	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1065
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1066	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1067	most important. Values of these types are the only ones which can be
				1068	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame^]	1069	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1070	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1071
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1072	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1073	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1074
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1075	<div class="doc_text">
				1076	<p>The primitive types are the fundamental building blocks of the LLVM
				1077	system.</p>
				1078
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1079	</div>
				1080
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1081	<!-- _______________________________________________________________________ -->
				1082	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1083
				1084	<div class="doc_text">
				1085	<table>
				1086	<tbody>
				1087	<tr><th>Type</th><th>Description</th></tr>
				1088	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1089	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1090	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1091	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1092	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1093	</tbody>
				1094	</table>
				1095	</div>
				1096
				1097	<!-- _______________________________________________________________________ -->
				1098	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1099
				1100	<div class="doc_text">
				1101	<h5>Overview:</h5>
				1102	<p>The void type does not represent any value and has no size.</p>
				1103
				1104	<h5>Syntax:</h5>
				1105
				1106	<pre>
				1107	void
				1108	</pre>
				1109	</div>
				1110
				1111	<!-- _______________________________________________________________________ -->
				1112	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1113
				1114	<div class="doc_text">
				1115	<h5>Overview:</h5>
				1116	<p>The label type represents code labels.</p>
				1117
				1118	<h5>Syntax:</h5>
				1119
				1120	<pre>
				1121	label
				1122	</pre>
				1123	</div>
				1124
				1125
				1126	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1127	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1128
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1129	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1130
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1131	<p>The real power in LLVM comes from the derived types in the system.
				1132	This is what allows a programmer to represent arrays, functions,
				1133	pointers, and other useful types. Note that these derived types may be
				1134	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]	1135
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1136	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1137
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1138	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1139	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1140
				1141	<div class="doc_text">
				1142
				1143	<h5>Overview:</h5>
				1144	<p>The integer type is a very simple derived type that simply specifies an
				1145	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1146	2^23-1 (about 8 million) can be specified.</p>
				1147
				1148	<h5>Syntax:</h5>
				1149
				1150	<pre>
				1151	iN
				1152	</pre>
				1153
				1154	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1155	value.</p>
				1156
				1157	<h5>Examples:</h5>
				1158	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1159	<tbody>
				1160	<tr>
				1161	<td><tt>i1</tt></td>
				1162	<td>a single-bit integer.</td>
				1163	</tr><tr>
				1164	<td><tt>i32</tt></td>
				1165	<td>a 32-bit integer.</td>
				1166	</tr><tr>
				1167	<td><tt>i1942652</tt></td>
				1168	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1169	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1170	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1171	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1172	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1173
				1174	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1175	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1176
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1177	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1178
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1179	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1180
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1181	<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]	1182	sequentially in memory. The array type requires a size (number of
				1183	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1184
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1185	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1186
				1187	<pre>
				1188	[<# elements> x <elementtype>]
				1189	</pre>
				1190
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1191	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1192	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1193
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1194	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1195	<table class="layout">
				1196	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1197	<td class="left"><tt>[40 x i32]</tt></td>
				1198	<td class="left">Array of 40 32-bit integer values.</td>
				1199	</tr>
				1200	<tr class="layout">
				1201	<td class="left"><tt>[41 x i32]</tt></td>
				1202	<td class="left">Array of 41 32-bit integer values.</td>
				1203	</tr>
				1204	<tr class="layout">
				1205	<td class="left"><tt>[4 x i8]</tt></td>
				1206	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1207	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1208	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1209	<p>Here are some examples of multidimensional arrays:</p>
				1210	<table class="layout">
				1211	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1212	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1213	<td class="left">3x4 array of 32-bit integer values.</td>
				1214	</tr>
				1215	<tr class="layout">
				1216	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1217	<td class="left">12x10 array of single precision floating point values.</td>
				1218	</tr>
				1219	<tr class="layout">
				1220	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1221	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1222	</tr>
				1223	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1224
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1225	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1226	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]	1227	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1228	As a special case, however, zero length arrays are recognized to be variable
				1229	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1230	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1231
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1232	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1233
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1234	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1235	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1236	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1237
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1238	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1239
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1240	<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]	1241	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]	1242	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]	1243	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]	1244	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1245
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1246	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1247
				1248	<pre>
				1249	<returntype list> (<parameter list>)
				1250	</pre>
				1251
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1252	<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]	1253	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1254	which indicates that the function takes a variable number of arguments.
				1255	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1256	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1257	'<tt><returntype list></tt>' is a comma-separated list of
				1258	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1259
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1260	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1261	<table class="layout">
				1262	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1263	<td class="left"><tt>i32 (i32)</tt></td>
				1264	<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]	1265	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1266	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1267	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1268	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1269	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1270	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1271	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1272	<tt>float</tt>.
				1273	</td>
				1274	</tr><tr class="layout">
				1275	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1276	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1277	<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]	1278	which returns an integer. This is the signature for <tt>printf</tt> in
				1279	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1280	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1281	</tr><tr class="layout">
				1282	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1283	<td class="left">A function taking an <tt>i32></tt>, returning two
				1284	<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]	1285	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1286	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1287	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1288
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1289	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1290	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1291	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1292	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1293	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1294	<p>The structure type is used to represent a collection of data members
				1295	together in memory. The packing of the field types is defined to match
				1296	the ABI of the underlying processor. The elements of a structure may
				1297	be any type that has a size.</p>
				1298	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1299	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1300	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1301	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1302	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1303	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1304	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1305	<table class="layout">
				1306	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1307	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1308	<td class="left">A triple of three <tt>i32</tt> values</td>
				1309	</tr><tr class="layout">
				1310	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1311	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1312	second element is a <a href="#t_pointer">pointer</a> to a
				1313	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1314	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1315	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1316	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1317	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1318
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1319	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1320	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1321	</div>
				1322	<div class="doc_text">
				1323	<h5>Overview:</h5>
				1324	<p>The packed structure type is used to represent a collection of data members
				1325	together in memory. There is no padding between fields. Further, the alignment
				1326	of a packed structure is 1 byte. The elements of a packed structure may
				1327	be any type that has a size.</p>
				1328	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1329	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1330	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1331	instruction.</p>
				1332	<h5>Syntax:</h5>
				1333	<pre> < { <type list> } > <br></pre>
				1334	<h5>Examples:</h5>
				1335	<table class="layout">
				1336	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1337	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1338	<td class="left">A triple of three <tt>i32</tt> values</td>
				1339	</tr><tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1340	<td class="left"><tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1341	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1342	second element is a <a href="#t_pointer">pointer</a> to a
				1343	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1344	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1345	</tr>
				1346	</table>
				1347	</div>
				1348
				1349	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1350	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1351	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1352	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1353	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1354	reference to another object, which must live in memory. Pointer types may have
				1355	an optional address space attribute defining the target-specific numbered
				1356	address space where the pointed-to object resides. The default address space is
				1357	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1358	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1359	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1360	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1361	<table class="layout">
				1362	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1363	<td class="left"><tt>[4x i32]*</tt></td>
				1364	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1365	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1366	</tr>
				1367	<tr class="layout">
				1368	<td class="left"><tt>i32 (i32 ) </tt></td>
				1369	<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]	1370	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]	1371	<tt>i32</tt>.</td>
				1372	</tr>
				1373	<tr class="layout">
				1374	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1375	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1376	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1377	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1378	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1379	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1380
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1381	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1382	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1383	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1384
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1385	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1386
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1387	<p>A vector type is a simple derived type that represents a vector
				1388	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1389	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1390	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1391	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1392	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1393	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1394
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1395	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1396
				1397	<pre>
				1398	< <# elements> x <elementtype> >
				1399	</pre>
				1400
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1401	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1402	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1403
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1404	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1405
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1406	<table class="layout">
				1407	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1408	<td class="left"><tt><4 x i32></tt></td>
				1409	<td class="left">Vector of 4 32-bit integer values.</td>
				1410	</tr>
				1411	<tr class="layout">
				1412	<td class="left"><tt><8 x float></tt></td>
				1413	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1414	</tr>
				1415	<tr class="layout">
				1416	<td class="left"><tt><2 x i64></tt></td>
				1417	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1418	</tr>
				1419	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1420	</div>
				1421
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1422	<!-- _______________________________________________________________________ -->
				1423	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1424	<div class="doc_text">
				1425
				1426	<h5>Overview:</h5>
				1427
				1428	<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]	1429	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]	1430	In LLVM, opaque types can eventually be resolved to any type (not just a
				1431	structure type).</p>
				1432
				1433	<h5>Syntax:</h5>
				1434
				1435	<pre>
				1436	opaque
				1437	</pre>
				1438
				1439	<h5>Examples:</h5>
				1440
				1441	<table class="layout">
				1442	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1443	<td class="left"><tt>opaque</tt></td>
				1444	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1445	</tr>
				1446	</table>
				1447	</div>
				1448
				1449
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1450	<!-- *********************************************************************** -->
				1451	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1452	<!-- *********************************************************************** -->
				1453
				1454	<div class="doc_text">
				1455
				1456	<p>LLVM has several different basic types of constants. This section describes
				1457	them all and their syntax.</p>
				1458
				1459	</div>
				1460
				1461	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1462	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1463
				1464	<div class="doc_text">
				1465
				1466	<dl>
				1467	<dt><b>Boolean constants</b></dt>
				1468
				1469	<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]	1470	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1471	</dd>
				1472
				1473	<dt><b>Integer constants</b></dt>
				1474
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1475	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1476	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1477	integer types.
				1478	</dd>
				1479
				1480	<dt><b>Floating point constants</b></dt>
				1481
				1482	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1483	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1484	notation (see below). The assembler requires the exact decimal value of
				1485	a floating-point constant. For example, the assembler accepts 1.25 but
				1486	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1487	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]	1488
				1489	<dt><b>Null pointer constants</b></dt>
				1490
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1491	<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]	1492	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1493
				1494	</dl>
				1495
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1496	<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]	1497	of floating point constants. For example, the form '<tt>double
				1498	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1499	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]	1500	(and the only time that they are generated by the disassembler) is when a
				1501	floating point constant must be emitted but it cannot be represented as a
				1502	decimal floating point number. For example, NaN's, infinities, and other
				1503	special values are represented in their IEEE hexadecimal format so that
				1504	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]	1505
				1506	</div>
				1507
				1508	<!-- ======================================================================= -->
				1509	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1510	</div>
				1511
				1512	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1513	<p>Aggregate constants arise from aggregation of simple constants
				1514	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1515
				1516	<dl>
				1517	<dt><b>Structure constants</b></dt>
				1518
				1519	<dd>Structure constants are represented with notation similar to structure
				1520	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1521	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1522	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]	1523	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]	1524	types of elements must match those specified by the type.
				1525	</dd>
				1526
				1527	<dt><b>Array constants</b></dt>
				1528
				1529	<dd>Array constants are represented with notation similar to array type
				1530	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1531	(<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]	1532	constants must have <a href="#t_array">array type</a>, and the number and
				1533	types of elements must match those specified by the type.
				1534	</dd>
				1535
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1536	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1537
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1538	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1539	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1540	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1541	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1542	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]	1543	match those specified by the type.
				1544	</dd>
				1545
				1546	<dt><b>Zero initialization</b></dt>
				1547
				1548	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1549	value to zero of <em>any</em> type, including scalar and aggregate types.
				1550	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]	1551	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1552	initializers.
				1553	</dd>
				1554	</dl>
				1555
				1556	</div>
				1557
				1558	<!-- ======================================================================= -->
				1559	<div class="doc_subsection">
				1560	<a name="globalconstants">Global Variable and Function Addresses</a>
				1561	</div>
				1562
				1563	<div class="doc_text">
				1564
				1565	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1566	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1567	constants. These constants are explicitly referenced when the <a
				1568	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]	1569	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1570	file:</p>
				1571
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1572	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1573	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1574	@X = global i32 17
				1575	@Y = global i32 42
				1576	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1577	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1578	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1579
				1580	</div>
				1581
				1582	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1583	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1584	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1585	<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]	1586	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]	1587	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1588
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1589	<p>Undefined values indicate to the compiler that the program is well defined
				1590	no matter what value is used, giving the compiler more freedom to optimize.
				1591	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1592	</div>
				1593
				1594	<!-- ======================================================================= -->
				1595	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1596	</div>
				1597
				1598	<div class="doc_text">
				1599
				1600	<p>Constant expressions are used to allow expressions involving other constants
				1601	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1602	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]	1603	that does not have side effects (e.g. load and call are not supported). The
				1604	following is the syntax for constant expressions:</p>
				1605
				1606	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1607	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1608	<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]	1609	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1610
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1611	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1612	<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]	1613	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]	1614
				1615	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1616	<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]	1617	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]	1618
				1619	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1620	<dd>Truncate a floating point constant to another floating point type. The
				1621	size of CST must be larger than the size of TYPE. Both types must be
				1622	floating point.</dd>
				1623
				1624	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1625	<dd>Floating point extend a constant to another type. The size of CST must be
				1626	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1627
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1628	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1629	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1630	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1631	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1632	of the same number of elements. If the value won't fit in the integer type,
				1633	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1634
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1635	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1636	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1637	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1638	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1639	of the same number of elements. If the value won't fit in the integer type,
				1640	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1641
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1642	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1643	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1644	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1645	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1646	of the same number of elements. If the value won't fit in the floating point
				1647	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1648
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1649	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1650	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1651	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1652	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1653	of the same number of elements. If the value won't fit in the floating point
				1654	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1655
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1656	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1657	<dd>Convert a pointer typed constant to the corresponding integer constant
				1658	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1659	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1660
				1661	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1662	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1663	pointer type. CST must be of integer type. The CST value is zero extended,
				1664	truncated, or unchanged to make it fit in a pointer size. This one is
				1665	<i>really</i> dangerous!</dd>
				1666
				1667	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1668	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1669	identical (same number of bits). The conversion is done as if the CST value
				1670	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]	1671	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]	1672	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]	1673	pointers it is only valid to cast to another pointer type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1674	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1675
				1676	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1677
				1678	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1679	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1680	instruction, the index list may have zero or more indexes, which are required
				1681	to make sense for the type of "CSTPTR".</dd>
				1682
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1683	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1684
				1685	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1686	constants.</dd>
				1687
				1688	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1689	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1690
				1691	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1692	<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]	1693
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1694	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1695	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1696
				1697	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1698	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1699
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1700	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1701
				1702	<dd>Perform the <a href="#i_extractelement">extractelement
				1703	operation</a> on constants.
				1704
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1705	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1706
				1707	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1708	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1709
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1710
				1711	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1712
				1713	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1714	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1715
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1716	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1717
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1718	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1719	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]	1720	binary</a> operations. The constraints on operands are the same as those for
				1721	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1722	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1723	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1724	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1725
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1726	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1727	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1728	<!-- *********************************************************************** -->
				1729
				1730	<!-- ======================================================================= -->
				1731	<div class="doc_subsection">
				1732	<a name="inlineasm">Inline Assembler Expressions</a>
				1733	</div>
				1734
				1735	<div class="doc_text">
				1736
				1737	<p>
				1738	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1739	Module-Level Inline Assembly</a>) through the use of a special value. This
				1740	value represents the inline assembler as a string (containing the instructions
				1741	to emit), a list of operand constraints (stored as a string), and a flag that
				1742	indicates whether or not the inline asm expression has side effects. An example
				1743	inline assembler expression is:
				1744	</p>
				1745
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1746	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1747	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1748	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1749	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1750	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1751
				1752	<p>
				1753	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1754	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1755	</p>
				1756
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1757	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1758	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1759	%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]	1760	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1761	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1762
				1763	<p>
				1764	Inline asms with side effects not visible in the constraint list must be marked
				1765	as having side effects. This is done through the use of the
				1766	'<tt>sideeffect</tt>' keyword, like so:
				1767	</p>
				1768
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1769	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1770	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1771	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1772	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1773	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1774
				1775	<p>TODO: The format of the asm and constraints string still need to be
				1776	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1777	need to be documented).
				1778	</p>
				1779
				1780	</div>
				1781
				1782	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1783	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1784	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1785
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1786	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1787
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1788	<p>The LLVM instruction set consists of several different
				1789	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1790	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1791	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1792	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1793	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1794
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1795	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1796
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1797	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1798	<div class="doc_subsection"> <a name="terminators">Terminator
				1799	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1800
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1801	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1802
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1803	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1804	basic block in a program ends with a "Terminator" instruction, which
				1805	indicates which block should be executed after the current block is
				1806	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1807	value: they produce control flow, not values (the one exception being
				1808	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1809	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1810	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1811	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1812	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1813	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1814	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1815
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1816	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1817
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1818	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1819	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1820	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1821	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1822	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1823	<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]	1824	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1825	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]	1826	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1827
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1828	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1829
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1830	<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]	1831	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1832	<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]	1833	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]	1834	control flow to occur.</p>
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>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1837
				1838	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1839	The type of each return value must be a '<a href="#t_firstclass">first
				1840	class</a>' type. Note that a function is not <a href="#wellformed">well
				1841	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1842	function that returns values that do not match the return type of the
				1843	function.</p>
				1844
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1845	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1846
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1847	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1848	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]	1849	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1850	the instruction after the call. If the caller was an "<a
				1851	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1852	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1853	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]	1854	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1855	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1856	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1857
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1858	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1859
				1860	<pre>
				1861	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1862	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1863	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]	1864	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1865	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1866	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1867	<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]	1868	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1869	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1870	<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]	1871	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1872	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1873	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1874	transfer to a different basic block in the current function. There are
				1875	two forms of this instruction, corresponding to a conditional branch
				1876	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1877	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1878	<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]	1879	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1880	unconditional form of the '<tt>br</tt>' instruction takes a single
				1881	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1882	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1883	<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]	1884	argument is evaluated. If the value is <tt>true</tt>, control flows
				1885	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1886	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1887	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1888	<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]	1889	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]	1890	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1891	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1892	<div class="doc_subsubsection">
				1893	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1894	</div>
				1895
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1896	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1897	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1898
				1899	<pre>
				1900	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1901	</pre>
				1902
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1903	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1904
				1905	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1906	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1907	instruction, allowing a branch to occur to one of many possible
				1908	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1909
				1910
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1911	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1912
				1913	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1914	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1915	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1916	table is not allowed to contain duplicate constant entries.</p>
				1917
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1918	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1919
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1920	<p>The <tt>switch</tt> instruction specifies a table of values and
				1921	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1922	table is searched for the given value. If the value is found, control flow is
				1923	transfered to the corresponding destination; otherwise, control flow is
				1924	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1925
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1926	<h5>Implementation:</h5>
				1927
				1928	<p>Depending on properties of the target machine and the particular
				1929	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1930	ways. For example, it could be generated as a series of chained conditional
				1931	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1932
				1933	<h5>Example:</h5>
				1934
				1935	<pre>
				1936	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1937	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1938	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1939
				1940	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1941	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1942
				1943	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1944	switch i32 %val, label %otherwise [ i32 0, label %onzero
				1945	i32 1, label %onone
				1946	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1947	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1948	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1949
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1950	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1951	<div class="doc_subsubsection">
				1952	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				1953	</div>
				1954
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1955	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1956
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1957	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1958
				1959	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	1960	<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]	1961	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1962	</pre>
				1963
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	1964	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1965
				1966	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				1967	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1968	'<tt>normal</tt>' label or the
				1969	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1970	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				1971	"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]	1972	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1973	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1974	returns multiple values then individual return values are only accessible through
				1975	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1976
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1977	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1978
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1979	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1980
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1981	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1982	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	1983	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1984	convention</a> the call should use. If none is specified, the call defaults
				1985	to using C calling conventions.
				1986	</li>
				1987	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				1988	function value being invoked. In most cases, this is a direct function
				1989	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				1990	an arbitrary pointer to function value.
				1991	</li>
				1992
				1993	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				1994	function to be invoked. </li>
				1995
				1996	<li>'<tt>function args</tt>': argument list whose types match the function
				1997	signature argument types. If the function signature indicates the function
				1998	accepts a variable number of arguments, the extra arguments can be
				1999	specified. </li>
				2000
				2001	<li>'<tt>normal label</tt>': the label reached when the called function
				2002	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2003
				2004	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2005	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2006
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2007	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2008
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2009	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2010
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2011	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2012	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2013	difference is that it establishes an association with a label, which is used by
				2014	the runtime library to unwind the stack.</p>
				2015
				2016	<p>This instruction is used in languages with destructors to ensure that proper
				2017	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2018	exception. Additionally, this is important for implementation of
				2019	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2020
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2021	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2022	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2023	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2024	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2025	%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]	2026	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2027	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2028	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2029
				2030
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2031	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2032
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2033	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2034	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2035
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2036	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2037
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2038	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2039	<pre>
				2040	unwind
				2041	</pre>
				2042
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2043	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2044
				2045	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2046	at the first callee in the dynamic call stack which used an <a
				2047	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2048	primarily used to implement exception handling.</p>
				2049
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2050	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2051
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2052	<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]	2053	immediately halt. The dynamic call stack is then searched for the first <a
				2054	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2055	execution continues at the "exceptional" destination block specified by the
				2056	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2057	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2058	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2059
				2060	<!-- _______________________________________________________________________ -->
				2061
				2062	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2063	Instruction</a> </div>
				2064
				2065	<div class="doc_text">
				2066
				2067	<h5>Syntax:</h5>
				2068	<pre>
				2069	unreachable
				2070	</pre>
				2071
				2072	<h5>Overview:</h5>
				2073
				2074	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2075	instruction is used to inform the optimizer that a particular portion of the
				2076	code is not reachable. This can be used to indicate that the code after a
				2077	no-return function cannot be reached, and other facts.</p>
				2078
				2079	<h5>Semantics:</h5>
				2080
				2081	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2082	</div>
				2083
				2084
				2085
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2086	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2087	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2088	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2089	<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]	2090	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]	2091	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2092	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]	2093	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2094	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2095	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2096	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2097	<div class="doc_subsubsection">
				2098	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2099	</div>
				2100
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2101	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2102
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2103	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2104
				2105	<pre>
				2106	<result> = add <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2107	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2108
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2109	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2110
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2111	<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]	2112
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2113	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2114
				2115	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2116	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2117	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2118	types.</p>
				2119
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2120	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2121
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2122	<p>The value produced is the integer or floating point sum of the two
				2123	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2124
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2125	<p>If an integer sum has unsigned overflow, the result returned is the
				2126	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2127	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2128
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2129	<p>Because LLVM integers use a two's complement representation, this
				2130	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2131
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2132	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2133
				2134	<pre>
				2135	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2136	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2137	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2138	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2139	<div class="doc_subsubsection">
				2140	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2141	</div>
				2142
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2143	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2144
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2145	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2146
				2147	<pre>
				2148	<result> = sub <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2149	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2150
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2151	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2152
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2153	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2154	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2155
				2156	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2157	'<tt>neg</tt>' instruction present in most other intermediate
				2158	representations.</p>
				2159
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2160	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2161
				2162	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2163	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2164	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2165	types.</p>
				2166
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2167	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2168
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2169	<p>The value produced is the integer or floating point difference of
				2170	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2171
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2172	<p>If an integer difference has unsigned overflow, the result returned is the
				2173	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2174	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2175
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2176	<p>Because LLVM integers use a two's complement representation, this
				2177	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2178
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2179	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2180	<pre>
				2181	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2182	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2183	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2184	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2185
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2186	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2187	<div class="doc_subsubsection">
				2188	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2189	</div>
				2190
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2191	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2192
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2193	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2194	<pre> <result> = mul <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2195	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2196	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2197	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2198	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2199
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2200	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2201
				2202	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2203	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2204	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2205	types.</p>
				2206
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2207	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2208
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2209	<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]	2210	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2211
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2212	<p>If the result of an integer multiplication has unsigned overflow,
				2213	the result returned is the mathematical result modulo
				2214	2<sup>n</sup>, where n is the bit width of the result.</p>
				2215	<p>Because LLVM integers use a two's complement representation, and the
				2216	result is the same width as the operands, this instruction returns the
				2217	correct result for both signed and unsigned integers. If a full product
				2218	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2219	should be sign-extended or zero-extended as appropriate to the
				2220	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2221	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2222	<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]	2223	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2224	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2225
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2226	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2227	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2228	</a></div>
				2229	<div class="doc_text">
				2230	<h5>Syntax:</h5>
				2231	<pre> <result> = udiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2232	</pre>
				2233	<h5>Overview:</h5>
				2234	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2235	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2236
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2237	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2238
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2239	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2240	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2241	values. Both arguments must have identical types.</p>
				2242
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2243	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2244
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2245	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2246	<p>Note that unsigned integer division and signed integer division are distinct
				2247	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2248	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2249	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2250	<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]	2251	</pre>
				2252	</div>
				2253	<!-- _______________________________________________________________________ -->
				2254	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2255	</a> </div>
				2256	<div class="doc_text">
				2257	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2258	<pre>
				2259	<result> = sdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2260	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2261
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2262	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2263
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2264	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2265	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2266
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2267	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2268
				2269	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2270	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2271	values. Both arguments must have identical types.</p>
				2272
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2273	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2274	<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]	2275	<p>Note that signed integer division and unsigned integer division are distinct
				2276	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2277	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2278	undefined behavior; this is a rare case, but can occur, for example,
				2279	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2280	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2281	<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]	2282	</pre>
				2283	</div>
				2284	<!-- _______________________________________________________________________ -->
				2285	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2286	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2287	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2288	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2289	<pre>
				2290	<result> = fdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2291	</pre>
				2292	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2293
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2294	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2295	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2296
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2297	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2298
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2299	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2300	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2301	of floating point values. Both arguments must have identical types.</p>
				2302
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2303	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2304
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2305	<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]	2306
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2307	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2308
				2309	<pre>
				2310	<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]	2311	</pre>
				2312	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2313
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2314	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2315	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2316	</div>
				2317	<div class="doc_text">
				2318	<h5>Syntax:</h5>
				2319	<pre> <result> = urem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2320	</pre>
				2321	<h5>Overview:</h5>
				2322	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2323	unsigned division of its two arguments.</p>
				2324	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2325	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2326	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2327	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2328	<h5>Semantics:</h5>
				2329	<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]	2330	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2331	<p>Note that unsigned integer remainder and signed integer remainder are
				2332	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2333	<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]	2334	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2335	<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]	2336	</pre>
				2337
				2338	</div>
				2339	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2340	<div class="doc_subsubsection">
				2341	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2342	</div>
				2343
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2344	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2345
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2346	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2347
				2348	<pre>
				2349	<result> = srem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2350	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2351
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2352	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2353
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2354	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2355	signed division of its two operands. This instruction can also take
				2356	<a href="#t_vector">vector</a> versions of the values in which case
				2357	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2358
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2359	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2360
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2361	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2362	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2363	values. Both arguments must have identical types.</p>
				2364
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2365	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2366
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2367	<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]	2368	has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
				2369	operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
				2370	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2371	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]	2372	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]	2373	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2374	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2375	<p>Note that signed integer remainder and unsigned integer remainder are
				2376	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2377	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2378	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2379	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2380	(The remainder doesn't actually overflow, but this rule lets srem be
				2381	implemented using instructions that return both the result of the division
				2382	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2383	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2384	<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]	2385	</pre>
				2386
				2387	</div>
				2388	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2389	<div class="doc_subsubsection">
				2390	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2391
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2392	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2393
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2394	<h5>Syntax:</h5>
				2395	<pre> <result> = frem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2396	</pre>
				2397	<h5>Overview:</h5>
				2398	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2399	division of its two operands.</p>
				2400	<h5>Arguments:</h5>
				2401	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2402	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2403	of floating point values. Both arguments must have identical types.</p>
				2404
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2405	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2406
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2407	<p>This instruction returns the <i>remainder</i> of a division.
				2408	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2409
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2410	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2411
				2412	<pre>
				2413	<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]	2414	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2415	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2416
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2417	<!-- ======================================================================= -->
				2418	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2419	Operations</a> </div>
				2420	<div class="doc_text">
				2421	<p>Bitwise binary operators are used to do various forms of
				2422	bit-twiddling in a program. They are generally very efficient
				2423	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2424	instructions. They require two operands of the same type, execute an operation on them,
				2425	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]	2426	</div>
				2427
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2428	<!-- _______________________________________________________________________ -->
				2429	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2430	Instruction</a> </div>
				2431	<div class="doc_text">
				2432	<h5>Syntax:</h5>
				2433	<pre> <result> = shl <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2434	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2435
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2436	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2437
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2438	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2439	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2440
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2441	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2442
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2443	<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]	2444	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]	2445	unsigned value. This instruction does not support
				2446	<a href="#t_vector">vector</a> operands.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2447
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2448	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2449
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2450	<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup> mod 2<sup>n</sup>,
				2451	where n is the width of the result. If <tt>var2</tt> is (statically or dynamically) negative or
				2452	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]	2453
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2454	<h5>Example:</h5><pre>
				2455	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2456	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2457	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2458	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2459	</pre>
				2460	</div>
				2461	<!-- _______________________________________________________________________ -->
				2462	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2463	Instruction</a> </div>
				2464	<div class="doc_text">
				2465	<h5>Syntax:</h5>
				2466	<pre> <result> = lshr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2467	</pre>
				2468
				2469	<h5>Overview:</h5>
				2470	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2471	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]	2472
				2473	<h5>Arguments:</h5>
				2474	<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]	2475	<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]	2476	unsigned value. This instruction does not support
				2477	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2478
				2479	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2480
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2481	<p>This instruction always performs a logical shift right operation. The most
				2482	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]	2483	shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
				2484	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]	2485
				2486	<h5>Example:</h5>
				2487	<pre>
				2488	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2489	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2490	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2491	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2492	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2493	</pre>
				2494	</div>
				2495
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2496	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2497	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2498	Instruction</a> </div>
				2499	<div class="doc_text">
				2500
				2501	<h5>Syntax:</h5>
				2502	<pre> <result> = ashr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2503	</pre>
				2504
				2505	<h5>Overview:</h5>
				2506	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2507	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]	2508
				2509	<h5>Arguments:</h5>
				2510	<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]	2511	<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]	2512	unsigned value. This instruction does not support
				2513	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2514
				2515	<h5>Semantics:</h5>
				2516	<p>This instruction always performs an arithmetic shift right operation,
				2517	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]	2518	of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
				2519	larger than the number of bits in <tt>var1</tt>, the result is undefined.
				2520	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2521
				2522	<h5>Example:</h5>
				2523	<pre>
				2524	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2525	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2526	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2527	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2528	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2529	</pre>
				2530	</div>
				2531
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2532	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2533	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2534	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2535
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2536	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2537
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2538	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2539
				2540	<pre>
				2541	<result> = and <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2542	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2543
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2544	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2545
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2546	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2547	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2548
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2549	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2550
				2551	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2552	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2553	values. Both arguments must have identical types.</p>
				2554
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2555	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2556	<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]	2557	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2558	<div style="align: center">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2559	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2560	<tbody>
				2561	<tr>
				2562	<td>In0</td>
				2563	<td>In1</td>
				2564	<td>Out</td>
				2565	</tr>
				2566	<tr>
				2567	<td>0</td>
				2568	<td>0</td>
				2569	<td>0</td>
				2570	</tr>
				2571	<tr>
				2572	<td>0</td>
				2573	<td>1</td>
				2574	<td>0</td>
				2575	</tr>
				2576	<tr>
				2577	<td>1</td>
				2578	<td>0</td>
				2579	<td>0</td>
				2580	</tr>
				2581	<tr>
				2582	<td>1</td>
				2583	<td>1</td>
				2584	<td>1</td>
				2585	</tr>
				2586	</tbody>
				2587	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2588	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2589	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2590	<pre>
				2591	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2592	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2593	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2594	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2595	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2596	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2597	<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]	2598	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2599	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2600	<pre> <result> = or <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2601	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2602	<h5>Overview:</h5>
				2603	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2604	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2605	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2606
				2607	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2608	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2609	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2610	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2611	<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]	2612	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2613	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2614	<table border="1" cellspacing="0" cellpadding="4">
				2615	<tbody>
				2616	<tr>
				2617	<td>In0</td>
				2618	<td>In1</td>
				2619	<td>Out</td>
				2620	</tr>
				2621	<tr>
				2622	<td>0</td>
				2623	<td>0</td>
				2624	<td>0</td>
				2625	</tr>
				2626	<tr>
				2627	<td>0</td>
				2628	<td>1</td>
				2629	<td>1</td>
				2630	</tr>
				2631	<tr>
				2632	<td>1</td>
				2633	<td>0</td>
				2634	<td>1</td>
				2635	</tr>
				2636	<tr>
				2637	<td>1</td>
				2638	<td>1</td>
				2639	<td>1</td>
				2640	</tr>
				2641	</tbody>
				2642	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2643	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2644	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2645	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2646	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2647	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2648	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2649	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2650	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2651	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2652	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2653	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2654	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2655	<pre> <result> = xor <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2656	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2657	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2658	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2659	or of its two operands. The <tt>xor</tt> is used to implement the
				2660	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2661	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2662	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2663	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2664	values. Both arguments must have identical types.</p>
				2665
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2666	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2667
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2668	<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]	2669	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2670	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2671	<table border="1" cellspacing="0" cellpadding="4">
				2672	<tbody>
				2673	<tr>
				2674	<td>In0</td>
				2675	<td>In1</td>
				2676	<td>Out</td>
				2677	</tr>
				2678	<tr>
				2679	<td>0</td>
				2680	<td>0</td>
				2681	<td>0</td>
				2682	</tr>
				2683	<tr>
				2684	<td>0</td>
				2685	<td>1</td>
				2686	<td>1</td>
				2687	</tr>
				2688	<tr>
				2689	<td>1</td>
				2690	<td>0</td>
				2691	<td>1</td>
				2692	</tr>
				2693	<tr>
				2694	<td>1</td>
				2695	<td>1</td>
				2696	<td>0</td>
				2697	</tr>
				2698	</tbody>
				2699	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2700	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2701	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2702	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2703	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2704	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2705	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2706	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2707	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2708	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2709
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2710	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2711	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2712	<a name="vectorops">Vector Operations</a>
				2713	</div>
				2714
				2715	<div class="doc_text">
				2716
				2717	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2718	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2719	vector-specific operations needed to process vectors effectively. While LLVM
				2720	does directly support these vector operations, many sophisticated algorithms
				2721	will want to use target-specific intrinsics to take full advantage of a specific
				2722	target.</p>
				2723
				2724	</div>
				2725
				2726	<!-- _______________________________________________________________________ -->
				2727	<div class="doc_subsubsection">
				2728	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2729	</div>
				2730
				2731	<div class="doc_text">
				2732
				2733	<h5>Syntax:</h5>
				2734
				2735	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2736	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2737	</pre>
				2738
				2739	<h5>Overview:</h5>
				2740
				2741	<p>
				2742	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2743	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2744	</p>
				2745
				2746
				2747	<h5>Arguments:</h5>
				2748
				2749	<p>
				2750	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2751	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]	2752	an index indicating the position from which to extract the element.
				2753	The index may be a variable.</p>
				2754
				2755	<h5>Semantics:</h5>
				2756
				2757	<p>
				2758	The result is a scalar of the same type as the element type of
				2759	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2760	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2761	results are undefined.
				2762	</p>
				2763
				2764	<h5>Example:</h5>
				2765
				2766	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2767	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2768	</pre>
				2769	</div>
				2770
				2771
				2772	<!-- _______________________________________________________________________ -->
				2773	<div class="doc_subsubsection">
				2774	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2775	</div>
				2776
				2777	<div class="doc_text">
				2778
				2779	<h5>Syntax:</h5>
				2780
				2781	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2782	<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]	2783	</pre>
				2784
				2785	<h5>Overview:</h5>
				2786
				2787	<p>
				2788	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2789	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2790	</p>
				2791
				2792
				2793	<h5>Arguments:</h5>
				2794
				2795	<p>
				2796	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2797	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]	2798	scalar value whose type must equal the element type of the first
				2799	operand. The third operand is an index indicating the position at
				2800	which to insert the value. The index may be a variable.</p>
				2801
				2802	<h5>Semantics:</h5>
				2803
				2804	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2805	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]	2806	element values are those of <tt>val</tt> except at position
				2807	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2808	exceeds the length of <tt>val</tt>, the results are undefined.
				2809	</p>
				2810
				2811	<h5>Example:</h5>
				2812
				2813	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2814	%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]	2815	</pre>
				2816	</div>
				2817
				2818	<!-- _______________________________________________________________________ -->
				2819	<div class="doc_subsubsection">
				2820	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2821	</div>
				2822
				2823	<div class="doc_text">
				2824
				2825	<h5>Syntax:</h5>
				2826
				2827	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2828	<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]	2829	</pre>
				2830
				2831	<h5>Overview:</h5>
				2832
				2833	<p>
				2834	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2835	from two input vectors, returning a vector of the same type.
				2836	</p>
				2837
				2838	<h5>Arguments:</h5>
				2839
				2840	<p>
				2841	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2842	with types that match each other and types that match the result of the
				2843	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]	2844	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]	2845	</p>
				2846
				2847	<p>
				2848	The shuffle mask operand is required to be a constant vector with either
				2849	constant integer or undef values.
				2850	</p>
				2851
				2852	<h5>Semantics:</h5>
				2853
				2854	<p>
				2855	The elements of the two input vectors are numbered from left to right across
				2856	both of the vectors. The shuffle mask operand specifies, for each element of
				2857	the result vector, which element of the two input registers the result element
				2858	gets. The element selector may be undef (meaning "don't care") and the second
				2859	operand may be undef if performing a shuffle from only one vector.
				2860	</p>
				2861
				2862	<h5>Example:</h5>
				2863
				2864	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2865	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2866	<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]	2867	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2868	<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]	2869	</pre>
				2870	</div>
				2871
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2872
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2873	<!-- ======================================================================= -->
				2874	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2875	<a name="aggregateops">Aggregate Operations</a>
				2876	</div>
				2877
				2878	<div class="doc_text">
				2879
				2880	<p>LLVM supports several instructions for working with aggregate values.
				2881	</p>
				2882
				2883	</div>
				2884
				2885	<!-- _______________________________________________________________________ -->
				2886	<div class="doc_subsubsection">
				2887	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2888	</div>
				2889
				2890	<div class="doc_text">
				2891
				2892	<h5>Syntax:</h5>
				2893
				2894	<pre>
				2895	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2896	</pre>
				2897
				2898	<h5>Overview:</h5>
				2899
				2900	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2901	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2902	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2903	</p>
				2904
				2905
				2906	<h5>Arguments:</h5>
				2907
				2908	<p>
				2909	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2910	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]	2911	type. The operands are constant indices to specify which value to extract
				2912	in the same manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2913	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2914	</p>
				2915
				2916	<h5>Semantics:</h5>
				2917
				2918	<p>
				2919	The result is the value at the position in the aggregate specified by
				2920	the index operands.
				2921	</p>
				2922
				2923	<h5>Example:</h5>
				2924
				2925	<pre>
				2926	%result = extractvalue {i32, float} %agg, i32 0 <i>; yields i32</i>
				2927	</pre>
				2928	</div>
				2929
				2930
				2931	<!-- _______________________________________________________________________ -->
				2932	<div class="doc_subsubsection">
				2933	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				2934	</div>
				2935
				2936	<div class="doc_text">
				2937
				2938	<h5>Syntax:</h5>
				2939
				2940	<pre>
				2941	<result> = insertvalue <aggregate type> <val>, <ty> <val>, i32 <idx> <i>; yields <n x <ty>></i>
				2942	</pre>
				2943
				2944	<h5>Overview:</h5>
				2945
				2946	<p>
				2947	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2948	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2949	</p>
				2950
				2951
				2952	<h5>Arguments:</h5>
				2953
				2954	<p>
				2955	The first operand of an '<tt>insertvalue</tt>' instruction is a
				2956	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				2957	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame^]	2958	The following operands are constant indices
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2959	indicating the position at which to insert the value in the same manner as
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2960	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2961	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2962	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]	2963	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2964
				2965	<h5>Semantics:</h5>
				2966
				2967	<p>
				2968	The result is an aggregate of the same type as <tt>val</tt>. Its
				2969	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]	2970	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2971	</p>
				2972
				2973	<h5>Example:</h5>
				2974
				2975	<pre>
				2976	%result = insertvalue {i32, float} %agg, i32 1, i32 0 <i>; yields {i32, float}</i>
				2977	</pre>
				2978	</div>
				2979
				2980
				2981	<!-- ======================================================================= -->
				2982	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	2983	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2984	</div>
				2985
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2986	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2987
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2988	<p>A key design point of an SSA-based representation is how it
				2989	represents memory. In LLVM, no memory locations are in SSA form, which
				2990	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2991	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2992
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2993	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2994
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2995	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2996	<div class="doc_subsubsection">
				2997	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				2998	</div>
				2999
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3000	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3001
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3002	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3003
				3004	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3005	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3006	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3007
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3008	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3009
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3010	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3011	heap and returns a pointer to it. The object is always allocated in the generic
				3012	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3013
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3014	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3015
				3016	<p>The '<tt>malloc</tt>' instruction allocates
				3017	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3018	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]	3019	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3020	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3021	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]	3022	be aligned to at least that boundary. If not specified, or if zero, the target can
				3023	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3024
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3025	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3026
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3027	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3028
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3029	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3030	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3031	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3032
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3033	<h5>Example:</h5>
				3034
				3035	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3036	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3037
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3038	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3039	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3040	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3041	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3042	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3043	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3044	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3045
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3046	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3047	<div class="doc_subsubsection">
				3048	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3049	</div>
				3050
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3051	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3052
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3053	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3054
				3055	<pre>
				3056	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3057	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3058
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3059	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3060
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3061	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3062	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3063
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3064	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3065
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3066	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3067	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3068	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3069
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3070	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3071
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3072	<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]	3073	after this instruction executes. If the pointer is null, the operation
				3074	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3075
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3076	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3077
				3078	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3079	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3080	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3081	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3082	</div>
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	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3085	<div class="doc_subsubsection">
				3086	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3087	</div>
				3088
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3089	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3090
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3091	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3092
				3093	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3094	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3095	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3096
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3097	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3098
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3099	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3100	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3101	returns to its caller. The object is always allocated in the generic address
				3102	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3103
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3104	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3105
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3106	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3107	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3108	appropriate type to the program. If "NumElements" is specified, it is the
				3109	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3110	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]	3111	to be aligned to at least that boundary. If not specified, or if zero, the target
				3112	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3113
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3114	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3115
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3116	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3117
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3118	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3119	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3120	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3121	instruction is commonly used to represent automatic variables that must
				3122	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]	3123	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]	3124	instructions), the memory is reclaimed. Allocating zero bytes
				3125	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3126
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3127	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3128
				3129	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3130	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3131	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3132	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3133	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3134	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3135	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3136
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3137	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3138	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3139	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3140	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3141	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3142	<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]	3143	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3144	<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]	3145	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3146	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3147	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3148	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]	3149	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]	3150	the number or order of execution of this <tt>load</tt> with other
				3151	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3152	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3153	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3154	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3155	(that is, the alignment of the memory address). A value of 0 or an
				3156	omitted "align" argument means that the operation has the preferential
				3157	alignment for the target. It is the responsibility of the code emitter
				3158	to ensure that the alignment information is correct. Overestimating
				3159	the alignment results in an undefined behavior. Underestimating the
				3160	alignment may produce less efficient code. An alignment of 1 is always
				3161	safe.
				3162	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3163	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3164	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3165	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3166	<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]	3167	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3168	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3169	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3170	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3171	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3172	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3173	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3174	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3175	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3176	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3177	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3178	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3179	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3180	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3181	<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]	3182	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3183	<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]	3184	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]	3185	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3186	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3187	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]	3188	optimizer is not allowed to modify the number or order of execution of
				3189	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3190	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3191	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3192	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3193	(that is, the alignment of the memory address). A value of 0 or an
				3194	omitted "align" argument means that the operation has the preferential
				3195	alignment for the target. It is the responsibility of the code emitter
				3196	to ensure that the alignment information is correct. Overestimating
				3197	the alignment results in an undefined behavior. Underestimating the
				3198	alignment may produce less efficient code. An alignment of 1 is always
				3199	safe.
				3200	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3201	<h5>Semantics:</h5>
				3202	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3203	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3204	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3205	<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]	3206	store i32 3, i32* %ptr <i>; yields {void}</i>
				3207	%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]	3208	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3209	</div>
				3210
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3211	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3212	<div class="doc_subsubsection">
				3213	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3214	</div>
				3215
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3216	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3217	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3218	<pre>
				3219	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3220	</pre>
				3221
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3222	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3223
				3224	<p>
				3225	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3226	subelement of an aggregate data structure.</p>
				3227
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3228	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3229
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3230	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3231	elements of the aggregate object to index to. The actual types of the arguments
				3232	provided depend on the type of the first pointer argument. The
				3233	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3234	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]	3235	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3236	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3237	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3238
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3239	<p>For example, let's consider a C code fragment and how it gets
				3240	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3241
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3242	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3243	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3244	struct RT {
				3245	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3246	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3247	char C;
				3248	};
				3249	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3250	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3251	double Y;
				3252	struct RT Z;
				3253	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3254
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3255	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3256	return &s[1].Z.B[5][13];
				3257	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3258	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3259	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3260
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3261	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3262
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3263	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3264	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3265	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3266	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3267
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3268	define i32* %foo(%ST* %s) {
				3269	entry:
				3270	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3271	ret i32* %reg
				3272	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3273	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3274	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3275
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3276	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3277
				3278	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3279	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]	3280	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]	3281	<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]	3282	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3283	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3284
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3285	<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]	3286	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]	3287	}</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]	3288	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3289	i8 }</tt>' type, another structure. The third index indexes into the second
				3290	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]	3291	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3292	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3293	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]	3294
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3295	<p>Note that it is perfectly legal to index partially through a
				3296	structure, returning a pointer to an inner element. Because of this,
				3297	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3298
				3299	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3300	define i32* %foo(%ST* %s) {
				3301	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3302	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3303	%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]	3304	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3305	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3306	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3307	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3308	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3309
				3310	<p>Note that it is undefined to access an array out of bounds: array and
				3311	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]	3312	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]	3313	defined to be accessible as variable length arrays, which requires access
				3314	beyond the zero'th element.</p>
				3315
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3316	<p>The getelementptr instruction is often confusing. For some more insight
				3317	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3318	FAQ</a>.</p>
				3319
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3320	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3321
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3322	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3323	<i>; yields [12 x i8]*:aptr</i>
				3324	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3325	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3326	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3327
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3328	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3329	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3330	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3331	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3332	<p>The instructions in this category are the conversion instructions (casting)
				3333	which all take a single operand and a type. They perform various bit conversions
				3334	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3335	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3336
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3337	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3338	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3339	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3340	</div>
				3341	<div class="doc_text">
				3342
				3343	<h5>Syntax:</h5>
				3344	<pre>
				3345	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3346	</pre>
				3347
				3348	<h5>Overview:</h5>
				3349	<p>
				3350	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3351	</p>
				3352
				3353	<h5>Arguments:</h5>
				3354	<p>
				3355	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3356	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]	3357	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]	3358	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3359	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3360
				3361	<h5>Semantics:</h5>
				3362	<p>
				3363	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]	3364	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3365	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3366	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3367
				3368	<h5>Example:</h5>
				3369	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3370	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3371	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3372	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3373	</pre>
				3374	</div>
				3375
				3376	<!-- _______________________________________________________________________ -->
				3377	<div class="doc_subsubsection">
				3378	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3379	</div>
				3380	<div class="doc_text">
				3381
				3382	<h5>Syntax:</h5>
				3383	<pre>
				3384	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3385	</pre>
				3386
				3387	<h5>Overview:</h5>
				3388	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3389	<tt>ty2</tt>.</p>
				3390
				3391
				3392	<h5>Arguments:</h5>
				3393	<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]	3394	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3395	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]	3396	<tt>value</tt> must be smaller than the bit size of the destination type,
				3397	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3398
				3399	<h5>Semantics:</h5>
				3400	<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]	3401	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]	3402
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3403	<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]	3404
				3405	<h5>Example:</h5>
				3406	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3407	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3408	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3409	</pre>
				3410	</div>
				3411
				3412	<!-- _______________________________________________________________________ -->
				3413	<div class="doc_subsubsection">
				3414	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3415	</div>
				3416	<div class="doc_text">
				3417
				3418	<h5>Syntax:</h5>
				3419	<pre>
				3420	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3421	</pre>
				3422
				3423	<h5>Overview:</h5>
				3424	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3425
				3426	<h5>Arguments:</h5>
				3427	<p>
				3428	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]	3429	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3430	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]	3431	<tt>value</tt> must be smaller than the bit size of the destination type,
				3432	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3433
				3434	<h5>Semantics:</h5>
				3435	<p>
				3436	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3437	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]	3438	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3439
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3440	<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]	3441
				3442	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3443	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3444	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3445	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3446	</pre>
				3447	</div>
				3448
				3449	<!-- _______________________________________________________________________ -->
				3450	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3451	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3452	</div>
				3453
				3454	<div class="doc_text">
				3455
				3456	<h5>Syntax:</h5>
				3457
				3458	<pre>
				3459	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3460	</pre>
				3461
				3462	<h5>Overview:</h5>
				3463	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3464	<tt>ty2</tt>.</p>
				3465
				3466
				3467	<h5>Arguments:</h5>
				3468	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3469	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3470	cast it to. The size of <tt>value</tt> must be larger than the size of
				3471	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3472	<i>no-op cast</i>.</p>
				3473
				3474	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3475	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3476	<a href="#t_floating">floating point</a> type to a smaller
				3477	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3478	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3479
				3480	<h5>Example:</h5>
				3481	<pre>
				3482	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3483	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3484	</pre>
				3485	</div>
				3486
				3487	<!-- _______________________________________________________________________ -->
				3488	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3489	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3490	</div>
				3491	<div class="doc_text">
				3492
				3493	<h5>Syntax:</h5>
				3494	<pre>
				3495	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3496	</pre>
				3497
				3498	<h5>Overview:</h5>
				3499	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3500	floating point value.</p>
				3501
				3502	<h5>Arguments:</h5>
				3503	<p>The '<tt>fpext</tt>' instruction takes a
				3504	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3505	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3506	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3507
				3508	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3509	<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]	3510	<a href="#t_floating">floating point</a> type to a larger
				3511	<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]	3512	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]	3513	<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]	3514
				3515	<h5>Example:</h5>
				3516	<pre>
				3517	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3518	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3519	</pre>
				3520	</div>
				3521
				3522	<!-- _______________________________________________________________________ -->
				3523	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3524	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3525	</div>
				3526	<div class="doc_text">
				3527
				3528	<h5>Syntax:</h5>
				3529	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3530	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3531	</pre>
				3532
				3533	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3534	<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]	3535	unsigned integer equivalent of type <tt>ty2</tt>.
				3536	</p>
				3537
				3538	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3539	<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]	3540	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3541	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3542	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3543	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]	3544
				3545	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3546	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3547	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3548	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3549	the results are undefined.</p>
				3550
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3551	<h5>Example:</h5>
				3552	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3553	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3554	%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]	3555	%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]	3556	</pre>
				3557	</div>
				3558
				3559	<!-- _______________________________________________________________________ -->
				3560	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3561	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3562	</div>
				3563	<div class="doc_text">
				3564
				3565	<h5>Syntax:</h5>
				3566	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3567	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3568	</pre>
				3569
				3570	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3571	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3572	<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]	3573	</p>
				3574
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3575	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3576	<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]	3577	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3578	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3579	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3580	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]	3581
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3582	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3583	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3584	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3585	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3586	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3587
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3588	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3589	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3590	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3591	%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]	3592	%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]	3593	</pre>
				3594	</div>
				3595
				3596	<!-- _______________________________________________________________________ -->
				3597	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3598	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3599	</div>
				3600	<div class="doc_text">
				3601
				3602	<h5>Syntax:</h5>
				3603	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3604	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3605	</pre>
				3606
				3607	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3608	<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]	3609	integer and converts that value to the <tt>ty2</tt> type.</p>
				3610
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3611	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3612	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3613	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3614	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3615	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3616	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]	3617
				3618	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3619	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3620	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3621	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]	3622
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3623	<h5>Example:</h5>
				3624	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3625	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3626	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3627	</pre>
				3628	</div>
				3629
				3630	<!-- _______________________________________________________________________ -->
				3631	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3632	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3633	</div>
				3634	<div class="doc_text">
				3635
				3636	<h5>Syntax:</h5>
				3637	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3638	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3639	</pre>
				3640
				3641	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3642	<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]	3643	integer and converts that value to the <tt>ty2</tt> type.</p>
				3644
				3645	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3646	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3647	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3648	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3649	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3650	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]	3651
				3652	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3653	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3654	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3655	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]	3656
				3657	<h5>Example:</h5>
				3658	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3659	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3660	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3661	</pre>
				3662	</div>
				3663
				3664	<!-- _______________________________________________________________________ -->
				3665	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3666	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3667	</div>
				3668	<div class="doc_text">
				3669
				3670	<h5>Syntax:</h5>
				3671	<pre>
				3672	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3673	</pre>
				3674
				3675	<h5>Overview:</h5>
				3676	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3677	the integer type <tt>ty2</tt>.</p>
				3678
				3679	<h5>Arguments:</h5>
				3680	<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]	3681	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]	3682	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3683
				3684	<h5>Semantics:</h5>
				3685	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3686	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3687	truncating or zero extending that value to the size of the integer type. If
				3688	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3689	<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]	3690	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3691	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3692
				3693	<h5>Example:</h5>
				3694	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3695	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3696	%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]	3697	</pre>
				3698	</div>
				3699
				3700	<!-- _______________________________________________________________________ -->
				3701	<div class="doc_subsubsection">
				3702	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3703	</div>
				3704	<div class="doc_text">
				3705
				3706	<h5>Syntax:</h5>
				3707	<pre>
				3708	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3709	</pre>
				3710
				3711	<h5>Overview:</h5>
				3712	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3713	a pointer type, <tt>ty2</tt>.</p>
				3714
				3715	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3716	<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]	3717	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]	3718	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3719
				3720	<h5>Semantics:</h5>
				3721	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3722	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3723	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3724	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3725	the size of a pointer then a zero extension is done. If they are the same size,
				3726	nothing is done (<i>no-op cast</i>).</p>
				3727
				3728	<h5>Example:</h5>
				3729	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3730	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3731	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3732	%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]	3733	</pre>
				3734	</div>
				3735
				3736	<!-- _______________________________________________________________________ -->
				3737	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3738	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3739	</div>
				3740	<div class="doc_text">
				3741
				3742	<h5>Syntax:</h5>
				3743	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3744	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3745	</pre>
				3746
				3747	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3748
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3749	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3750	<tt>ty2</tt> without changing any bits.</p>
				3751
				3752	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3753
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3754	<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]	3755	a first class value, and a type to cast it to, which must also be a <a
				3756	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]	3757	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]	3758	type is a pointer, the destination type must also be a pointer. This
				3759	instruction supports bitwise conversion of vectors to integers and to vectors
				3760	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3761
				3762	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3763	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3764	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3765	this conversion. The conversion is done as if the <tt>value</tt> had been
				3766	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3767	converted to other pointer types with this instruction. To convert pointers to
				3768	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3769	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3770
				3771	<h5>Example:</h5>
				3772	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3773	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3774	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3775	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3776	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3777	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3778
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3779	<!-- ======================================================================= -->
				3780	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3781	<div class="doc_text">
				3782	<p>The instructions in this category are the "miscellaneous"
				3783	instructions, which defy better classification.</p>
				3784	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3785
				3786	<!-- _______________________________________________________________________ -->
				3787	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3788	</div>
				3789	<div class="doc_text">
				3790	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3791	<pre> <result> = icmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3792	</pre>
				3793	<h5>Overview:</h5>
				3794	<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]	3795	of its two integer or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3796	<h5>Arguments:</h5>
				3797	<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]	3798	the condition code indicating the kind of comparison to perform. It is not
				3799	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3800	<ol>
				3801	<li><tt>eq</tt>: equal</li>
				3802	<li><tt>ne</tt>: not equal </li>
				3803	<li><tt>ugt</tt>: unsigned greater than</li>
				3804	<li><tt>uge</tt>: unsigned greater or equal</li>
				3805	<li><tt>ult</tt>: unsigned less than</li>
				3806	<li><tt>ule</tt>: unsigned less or equal</li>
				3807	<li><tt>sgt</tt>: signed greater than</li>
				3808	<li><tt>sge</tt>: signed greater or equal</li>
				3809	<li><tt>slt</tt>: signed less than</li>
				3810	<li><tt>sle</tt>: signed less or equal</li>
				3811	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3812	<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]	3813	<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]	3814	<h5>Semantics:</h5>
				3815	<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
				3816	the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3817	yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3818	<ol>
				3819	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3820	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3821	</li>
				3822	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3823	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3824	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
				3825	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3826	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
				3827	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3828	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
				3829	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3830	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
				3831	<tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
				3832	<li><tt>sgt</tt>: interprets the operands as signed values and yields
				3833	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3834	<li><tt>sge</tt>: interprets the operands as signed values and yields
				3835	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3836	<li><tt>slt</tt>: interprets the operands as signed values and yields
				3837	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3838	<li><tt>sle</tt>: interprets the operands as signed values and yields
				3839	<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]	3840	</ol>
				3841	<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]	3842	values are compared as if they were integers.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3843
				3844	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3845	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3846	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3847	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3848	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3849	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3850	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3851	</pre>
				3852	</div>
				3853
				3854	<!-- _______________________________________________________________________ -->
				3855	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3856	</div>
				3857	<div class="doc_text">
				3858	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3859	<pre> <result> = fcmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3860	</pre>
				3861	<h5>Overview:</h5>
				3862	<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
				3863	of its floating point operands.</p>
				3864	<h5>Arguments:</h5>
				3865	<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]	3866	the condition code indicating the kind of comparison to perform. It is not
				3867	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3868	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3869	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3870	<li><tt>oeq</tt>: ordered and equal</li>
				3871	<li><tt>ogt</tt>: ordered and greater than </li>
				3872	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3873	<li><tt>olt</tt>: ordered and less than </li>
				3874	<li><tt>ole</tt>: ordered and less than or equal</li>
				3875	<li><tt>one</tt>: ordered and not equal</li>
				3876	<li><tt>ord</tt>: ordered (no nans)</li>
				3877	<li><tt>ueq</tt>: unordered or equal</li>
				3878	<li><tt>ugt</tt>: unordered or greater than </li>
				3879	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3880	<li><tt>ult</tt>: unordered or less than </li>
				3881	<li><tt>ule</tt>: unordered or less than or equal</li>
				3882	<li><tt>une</tt>: unordered or not equal</li>
				3883	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3884	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3885	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3886	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3887	<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer	350f8aa	2007-01-04 05:19:58 +0000	[diff] [blame]	3888	<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
				3889	<a href="#t_floating">floating point</a> typed. They must have identical
				3890	types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3891	<h5>Semantics:</h5>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3892	<p>The '<tt>fcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3893	according to the condition code given as <tt>cond</tt>. The comparison performed
				3894	always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3895	<ol>
				3896	<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]	3897	<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]	3898	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3899	<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]	3900	<tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3901	<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]	3902	<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]	3903	<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]	3904	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3905	<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]	3906	<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]	3907	<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]	3908	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3909	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3910	<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]	3911	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3912	<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]	3913	<tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3914	<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]	3915	<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]	3916	<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]	3917	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3918	<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]	3919	<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]	3920	<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]	3921	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3922	<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]	3923	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				3924	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3925
				3926	<h5>Example:</h5>
				3927	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
				3928	<result> = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
				3929	<result> = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				3930	<result> = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
				3931	</pre>
				3932	</div>
				3933
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3934	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3935	<div class="doc_subsubsection">
				3936	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				3937	</div>
				3938	<div class="doc_text">
				3939	<h5>Syntax:</h5>
				3940	<pre> <result> = vicmp <cond> <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				3941	</pre>
				3942	<h5>Overview:</h5>
				3943	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				3944	element-wise comparison of its two integer vector operands.</p>
				3945	<h5>Arguments:</h5>
				3946	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				3947	the condition code indicating the kind of comparison to perform. It is not
				3948	a value, just a keyword. The possible condition code are:
				3949	<ol>
				3950	<li><tt>eq</tt>: equal</li>
				3951	<li><tt>ne</tt>: not equal </li>
				3952	<li><tt>ugt</tt>: unsigned greater than</li>
				3953	<li><tt>uge</tt>: unsigned greater or equal</li>
				3954	<li><tt>ult</tt>: unsigned less than</li>
				3955	<li><tt>ule</tt>: unsigned less or equal</li>
				3956	<li><tt>sgt</tt>: signed greater than</li>
				3957	<li><tt>sge</tt>: signed greater or equal</li>
				3958	<li><tt>slt</tt>: signed less than</li>
				3959	<li><tt>sle</tt>: signed less or equal</li>
				3960	</ol>
				3961	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				3962	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				3963	<h5>Semantics:</h5>
				3964	<p>The '<tt>vicmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3965	according to the condition code given as <tt>cond</tt>. The comparison yields a
				3966	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				3967	identical type as the values being compared. The most significant bit in each
				3968	element is 1 if the element-wise comparison evaluates to true, and is 0
				3969	otherwise. All other bits of the result are undefined. The condition codes
				3970	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				3971	instruction</a>.
				3972
				3973	<h5>Example:</h5>
				3974	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3975	<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>
				3976	<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]	3977	</pre>
				3978	</div>
				3979
				3980	<!-- _______________________________________________________________________ -->
				3981	<div class="doc_subsubsection">
				3982	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				3983	</div>
				3984	<div class="doc_text">
				3985	<h5>Syntax:</h5>
				3986	<pre> <result> = vfcmp <cond> <ty> <var1>, <var2></pre>
				3987	<h5>Overview:</h5>
				3988	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				3989	element-wise comparison of its two floating point vector operands. The output
				3990	elements have the same width as the input elements.</p>
				3991	<h5>Arguments:</h5>
				3992	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				3993	the condition code indicating the kind of comparison to perform. It is not
				3994	a value, just a keyword. The possible condition code are:
				3995	<ol>
				3996	<li><tt>false</tt>: no comparison, always returns false</li>
				3997	<li><tt>oeq</tt>: ordered and equal</li>
				3998	<li><tt>ogt</tt>: ordered and greater than </li>
				3999	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4000	<li><tt>olt</tt>: ordered and less than </li>
				4001	<li><tt>ole</tt>: ordered and less than or equal</li>
				4002	<li><tt>one</tt>: ordered and not equal</li>
				4003	<li><tt>ord</tt>: ordered (no nans)</li>
				4004	<li><tt>ueq</tt>: unordered or equal</li>
				4005	<li><tt>ugt</tt>: unordered or greater than </li>
				4006	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4007	<li><tt>ult</tt>: unordered or less than </li>
				4008	<li><tt>ule</tt>: unordered or less than or equal</li>
				4009	<li><tt>une</tt>: unordered or not equal</li>
				4010	<li><tt>uno</tt>: unordered (either nans)</li>
				4011	<li><tt>true</tt>: no comparison, always returns true</li>
				4012	</ol>
				4013	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4014	<a href="#t_floating">floating point</a> typed. They must also be identical
				4015	types.</p>
				4016	<h5>Semantics:</h5>
				4017	<p>The '<tt>vfcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				4018	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4019	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4020	an identical number of elements as the values being compared, and each element
				4021	having identical with to the width of the floating point elements. The most
				4022	significant bit in each element is 1 if the element-wise comparison evaluates to
				4023	true, and is 0 otherwise. All other bits of the result are undefined. The
				4024	condition codes are evaluated identically to the
				4025	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4026
				4027	<h5>Example:</h5>
				4028	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4029	<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>
				4030	<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]	4031	</pre>
				4032	</div>
				4033
				4034	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4035	<div class="doc_subsubsection">
				4036	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4037	</div>
				4038
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4039	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4040
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4041	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4042
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4043	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4044	<h5>Overview:</h5>
				4045	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4046	the SSA graph representing the function.</p>
				4047	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4048
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4049	<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]	4050	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4051	as arguments, with one pair for each predecessor basic block of the
				4052	current block. Only values of <a href="#t_firstclass">first class</a>
				4053	type may be used as the value arguments to the PHI node. Only labels
				4054	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4055
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4056	<p>There must be no non-phi instructions between the start of a basic
				4057	block and the PHI instructions: i.e. PHI instructions must be first in
				4058	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4059
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4060	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4061
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4062	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4063	specified by the pair corresponding to the predecessor basic block that executed
				4064	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4065
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4066	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4067	<pre>
				4068	Loop: ; Infinite loop that counts from 0 on up...
				4069	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4070	%nextindvar = add i32 %indvar, 1
				4071	br label %Loop
				4072	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4073	</div>
				4074
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4075	<!-- _______________________________________________________________________ -->
				4076	<div class="doc_subsubsection">
				4077	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4078	</div>
				4079
				4080	<div class="doc_text">
				4081
				4082	<h5>Syntax:</h5>
				4083
				4084	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4085	<result> = select i1 <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4086	</pre>
				4087
				4088	<h5>Overview:</h5>
				4089
				4090	<p>
				4091	The '<tt>select</tt>' instruction is used to choose one value based on a
				4092	condition, without branching.
				4093	</p>
				4094
				4095
				4096	<h5>Arguments:</h5>
				4097
				4098	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4099	The '<tt>select</tt>' instruction requires an 'i1' value indicating the
				4100	condition, and two values of the same <a href="#t_firstclass">first class</a>
				4101	type. If the val1/val2 are vectors, the entire vectors are selected, not
				4102	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4103	</p>
				4104
				4105	<h5>Semantics:</h5>
				4106
				4107	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4108	If the i1 condition evaluates is 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4109	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4110	</p>
				4111
				4112	<h5>Example:</h5>
				4113
				4114	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4115	%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]	4116	</pre>
				4117	</div>
				4118
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4119
				4120	<!-- _______________________________________________________________________ -->
				4121	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4122	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4123	</div>
				4124
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4125	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4126
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4127	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4128	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4129	<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]	4130	</pre>
				4131
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4132	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4133
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4134	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4135
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4136	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4137
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4138	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4139
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4140	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4141	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4142	<p>The optional "tail" marker indicates whether the callee function accesses
				4143	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]	4144	function call is eligible for tail call optimization. Note that calls may
				4145	be marked "tail" even if they do not occur before a <a
				4146	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4147	</li>
				4148	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4149	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4150	convention</a> the call should use. If none is specified, the call defaults
				4151	to using C calling conventions.
				4152	</li>
				4153	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4154	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4155	the type of the return value. Functions that return no value are marked
				4156	<tt><a href="#t_void">void</a></tt>.</p>
				4157	</li>
				4158	<li>
				4159	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4160	value being invoked. The argument types must match the types implied by
				4161	this signature. This type can be omitted if the function is not varargs
				4162	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]	4163	</li>
				4164	<li>
				4165	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4166	be invoked. In most cases, this is a direct function invocation, but
				4167	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]	4168	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4169	</li>
				4170	<li>
				4171	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4172	function signature argument types. All arguments must be of
				4173	<a href="#t_firstclass">first class</a> type. If the function signature
				4174	indicates the function accepts a variable number of arguments, the extra
				4175	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4176	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4177	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4178
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4179	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4180
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4181	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4182	transfer to a specified function, with its incoming arguments bound to
				4183	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4184	instruction in the called function, control flow continues with the
				4185	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4186	function is bound to the result argument. If the callee returns multiple
				4187	values then the return values of the function are only accessible through
				4188	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4189
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4190	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4191
				4192	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4193	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4194	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4195	%X = tail call i32 @foo() <i>; yields i32</i>
				4196	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4197	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4198
				4199	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4200	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4201	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4202	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4203	</pre>
				4204
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4205	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4206
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4207	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4208	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4209	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4210	</div>
				4211
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4212	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4213
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4214	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4215
				4216	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4217	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4218	</pre>
				4219
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4220	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4221
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4222	<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]	4223	the "variable argument" area of a function call. It is used to implement the
				4224	<tt>va_arg</tt> macro in C.</p>
				4225
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4226	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4227
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4228	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4229	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4230	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]	4231	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4232
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4233	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4234
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4235	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4236	type from the specified <tt>va_list</tt> and causes the
				4237	<tt>va_list</tt> to point to the next argument. For more information,
				4238	see the variable argument handling <a href="#int_varargs">Intrinsic
				4239	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4240
				4241	<p>It is legal for this instruction to be called in a function which does not
				4242	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4243	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4244
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4245	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4246	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4247	argument.</p>
				4248
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4249	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4250
				4251	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4252
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4253	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4254
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4255	<!-- _______________________________________________________________________ -->
				4256	<div class="doc_subsubsection">
				4257	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4258	</div>
				4259
				4260	<div class="doc_text">
				4261
				4262	<h5>Syntax:</h5>
				4263	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4264	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4265	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4266
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4267	<h5>Overview:</h5>
				4268
				4269	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4270	from a '<tt><a href="#i_call">call</a></tt>'
				4271	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4272	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4273
				4274	<h5>Arguments:</h5>
				4275
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4276	<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]	4277	first argument, or an undef value. The value must have <a
				4278	href="#t_struct">structure type</a>. The second argument is a constant
				4279	unsigned index value which must be in range for the number of values returned
				4280	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4281
				4282	<h5>Semantics:</h5>
				4283
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4284	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4285	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4286
				4287	<h5>Example:</h5>
				4288
				4289	<pre>
				4290	%struct.A = type { i32, i8 }
				4291
				4292	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4293	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4294	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4295	add i32 %gr, 42
				4296	add i8 %gr1, 41
				4297	</pre>
				4298
				4299	</div>
				4300
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4301	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4302	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4303	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4304
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4305	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4306
				4307	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4308	well known names and semantics and are required to follow certain restrictions.
				4309	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4310	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]	4311	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]	4312
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4313	<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]	4314	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4315	begin with this prefix. Intrinsic functions must always be external functions:
				4316	you cannot define the body of intrinsic functions. Intrinsic functions may
				4317	only be used in call or invoke instructions: it is illegal to take the address
				4318	of an intrinsic function. Additionally, because intrinsic functions are part
				4319	of the LLVM language, it is required if any are added that they be documented
				4320	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4321
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4322	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4323	a family of functions that perform the same operation but on different data
				4324	types. Because LLVM can represent over 8 million different integer types,
				4325	overloading is used commonly to allow an intrinsic function to operate on any
				4326	integer type. One or more of the argument types or the result type can be
				4327	overloaded to accept any integer type. Argument types may also be defined as
				4328	exactly matching a previous argument's type or the result type. This allows an
				4329	intrinsic function which accepts multiple arguments, but needs all of them to
				4330	be of the same type, to only be overloaded with respect to a single argument or
				4331	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4332
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4333	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4334	encoded into its function name, each preceded by a period. Only those types
				4335	which are overloaded result in a name suffix. Arguments whose type is matched
				4336	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4337	take an integer of any width and returns an integer of exactly the same integer
				4338	width. This leads to a family of functions such as
				4339	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4340	Only one type, the return type, is overloaded, and only one type suffix is
				4341	required. Because the argument's type is matched against the return type, it
				4342	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4343
				4344	<p>To learn how to add an intrinsic function, please see the
				4345	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4346	</p>
				4347
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4348	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4349
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4350	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4351	<div class="doc_subsection">
				4352	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4353	</div>
				4354
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4355	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4356
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4357	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4358	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]	4359	intrinsic functions. These functions are related to the similarly
				4360	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4361
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4362	<p>All of these functions operate on arguments that use a
				4363	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4364	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4365	transformations should be prepared to handle these functions regardless of
				4366	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4367
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4368	<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]	4369	instruction and the variable argument handling intrinsic functions are
				4370	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4371
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4372	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4373	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4374	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4375	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4376	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4377	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4378	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4379
				4380	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4381	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4382
				4383	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4384	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4385	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4386	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4387	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4388
				4389	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4390	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4391	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4392	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4393
				4394	declare void @llvm.va_start(i8*)
				4395	declare void @llvm.va_copy(i8, i8)
				4396	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4397	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4398	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4399
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4400	</div>
				4401
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4402	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4403	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4404	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4405	</div>
				4406
				4407
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4408	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4409	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4410	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4411	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4412	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4413	<tt>*<arglist></tt> for subsequent use by <tt><a
				4414	href="#i_va_arg">va_arg</a></tt>.</p>
				4415
				4416	<h5>Arguments:</h5>
				4417
				4418	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4419
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4420	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4421
				4422	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4423	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4424	<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]	4425	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4426	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]	4427	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]	4428
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4429	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4430
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4431	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4432	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4433	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4434	</div>
				4435
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4436	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4437	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4438	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4439	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4440
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4441	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4442	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]	4443	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]	4444
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4445	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4446
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4447	<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]	4448
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4449	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4450
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4451	<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]	4452	macro available in C. In a target-dependent way, it destroys the
				4453	<tt>va_list</tt> element to which the argument points. Calls to <a
				4454	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4455	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4456	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4457
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4458	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4459
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4460	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4461	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4462	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4463	</div>
				4464
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4465	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4466
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4467	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4468
				4469	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4470	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4471	</pre>
				4472
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4473	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4474
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4475	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4476	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4477
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4478	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4479
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4480	<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]	4481	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]	4482
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4483
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4484	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4485
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4486	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4487	macro available in C. In a target-dependent way, it copies the source
				4488	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4489	intrinsic is necessary because the <tt><a href="#int_va_start">
				4490	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4491	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4492
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4493	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4494
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4495	<!-- ======================================================================= -->
				4496	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4497	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4498	</div>
				4499
				4500	<div class="doc_text">
				4501
				4502	<p>
				4503	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
				4504	Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4505	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]	4506	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4507	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]	4508	Front-ends for type-safe garbage collected languages should generate these
				4509	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4510	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4511	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4512
				4513	<p>The garbage collection intrinsics only operate on objects in the generic
				4514	address space (address space zero).</p>
				4515
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4516	</div>
				4517
				4518	<!-- _______________________________________________________________________ -->
				4519	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4520	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4521	</div>
				4522
				4523	<div class="doc_text">
				4524
				4525	<h5>Syntax:</h5>
				4526
				4527	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4528	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4529	</pre>
				4530
				4531	<h5>Overview:</h5>
				4532
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4533	<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]	4534	the code generator, and allows some metadata to be associated with it.</p>
				4535
				4536	<h5>Arguments:</h5>
				4537
				4538	<p>The first argument specifies the address of a stack object that contains the
				4539	root pointer. The second pointer (which must be either a constant or a global
				4540	value address) contains the meta-data to be associated with the root.</p>
				4541
				4542	<h5>Semantics:</h5>
				4543
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4544	<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]	4545	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4546	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4547	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4548	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4549
				4550	</div>
				4551
				4552
				4553	<!-- _______________________________________________________________________ -->
				4554	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4555	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4556	</div>
				4557
				4558	<div class="doc_text">
				4559
				4560	<h5>Syntax:</h5>
				4561
				4562	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4563	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4564	</pre>
				4565
				4566	<h5>Overview:</h5>
				4567
				4568	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4569	locations, allowing garbage collector implementations that require read
				4570	barriers.</p>
				4571
				4572	<h5>Arguments:</h5>
				4573
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4574	<p>The second argument is the address to read from, which should be an address
				4575	allocated from the garbage collector. The first object is a pointer to the
				4576	start of the referenced object, if needed by the language runtime (otherwise
				4577	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4578
				4579	<h5>Semantics:</h5>
				4580
				4581	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4582	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4583	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4584	may only be used in a function which <a href="#gc">specifies a GC
				4585	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4586
				4587	</div>
				4588
				4589
				4590	<!-- _______________________________________________________________________ -->
				4591	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4592	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4593	</div>
				4594
				4595	<div class="doc_text">
				4596
				4597	<h5>Syntax:</h5>
				4598
				4599	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4600	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4601	</pre>
				4602
				4603	<h5>Overview:</h5>
				4604
				4605	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4606	locations, allowing garbage collector implementations that require write
				4607	barriers (such as generational or reference counting collectors).</p>
				4608
				4609	<h5>Arguments:</h5>
				4610
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4611	<p>The first argument is the reference to store, the second is the start of the
				4612	object to store it to, and the third is the address of the field of Obj to
				4613	store to. If the runtime does not require a pointer to the object, Obj may be
				4614	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4615
				4616	<h5>Semantics:</h5>
				4617
				4618	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4619	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4620	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4621	may only be used in a function which <a href="#gc">specifies a GC
				4622	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4623
				4624	</div>
				4625
				4626
				4627
				4628	<!-- ======================================================================= -->
				4629	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4630	<a name="int_codegen">Code Generator Intrinsics</a>
				4631	</div>
				4632
				4633	<div class="doc_text">
				4634	<p>
				4635	These intrinsics are provided by LLVM to expose special features that may only
				4636	be implemented with code generator support.
				4637	</p>
				4638
				4639	</div>
				4640
				4641	<!-- _______________________________________________________________________ -->
				4642	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4643	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4644	</div>
				4645
				4646	<div class="doc_text">
				4647
				4648	<h5>Syntax:</h5>
				4649	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4650	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4651	</pre>
				4652
				4653	<h5>Overview:</h5>
				4654
				4655	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4656	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4657	target-specific value indicating the return address of the current function
				4658	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4659	</p>
				4660
				4661	<h5>Arguments:</h5>
				4662
				4663	<p>
				4664	The argument to this intrinsic indicates which function to return the address
				4665	for. Zero indicates the calling function, one indicates its caller, etc. The
				4666	argument is <b>required</b> to be a constant integer value.
				4667	</p>
				4668
				4669	<h5>Semantics:</h5>
				4670
				4671	<p>
				4672	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4673	the return address of the specified call frame, or zero if it cannot be
				4674	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4675	for arguments other than zero, so it should only be used for debugging purposes.
				4676	</p>
				4677
				4678	<p>
				4679	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4680	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]	4681	source-language caller.
				4682	</p>
				4683	</div>
				4684
				4685
				4686	<!-- _______________________________________________________________________ -->
				4687	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4688	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4689	</div>
				4690
				4691	<div class="doc_text">
				4692
				4693	<h5>Syntax:</h5>
				4694	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4695	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4696	</pre>
				4697
				4698	<h5>Overview:</h5>
				4699
				4700	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4701	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4702	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4703	</p>
				4704
				4705	<h5>Arguments:</h5>
				4706
				4707	<p>
				4708	The argument to this intrinsic indicates which function to return the frame
				4709	pointer for. Zero indicates the calling function, one indicates its caller,
				4710	etc. The argument is <b>required</b> to be a constant integer value.
				4711	</p>
				4712
				4713	<h5>Semantics:</h5>
				4714
				4715	<p>
				4716	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4717	the frame address of the specified call frame, or zero if it cannot be
				4718	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4719	for arguments other than zero, so it should only be used for debugging purposes.
				4720	</p>
				4721
				4722	<p>
				4723	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4724	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]	4725	source-language caller.
				4726	</p>
				4727	</div>
				4728
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4729	<!-- _______________________________________________________________________ -->
				4730	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4731	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4732	</div>
				4733
				4734	<div class="doc_text">
				4735
				4736	<h5>Syntax:</h5>
				4737	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4738	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4739	</pre>
				4740
				4741	<h5>Overview:</h5>
				4742
				4743	<p>
				4744	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]	4745	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4746	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4747	features like scoped automatic variable sized arrays in C99.
				4748	</p>
				4749
				4750	<h5>Semantics:</h5>
				4751
				4752	<p>
				4753	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]	4754	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4755	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4756	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4757	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4758	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4759	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4760	</p>
				4761
				4762	</div>
				4763
				4764	<!-- _______________________________________________________________________ -->
				4765	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4766	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4767	</div>
				4768
				4769	<div class="doc_text">
				4770
				4771	<h5>Syntax:</h5>
				4772	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4773	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4774	</pre>
				4775
				4776	<h5>Overview:</h5>
				4777
				4778	<p>
				4779	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4780	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]	4781	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4782	useful for implementing language features like scoped automatic variable sized
				4783	arrays in C99.
				4784	</p>
				4785
				4786	<h5>Semantics:</h5>
				4787
				4788	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4789	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]	4790	</p>
				4791
				4792	</div>
				4793
				4794
				4795	<!-- _______________________________________________________________________ -->
				4796	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4797	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4798	</div>
				4799
				4800	<div class="doc_text">
				4801
				4802	<h5>Syntax:</h5>
				4803	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4804	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4805	</pre>
				4806
				4807	<h5>Overview:</h5>
				4808
				4809
				4810	<p>
				4811	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]	4812	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4813	no
				4814	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4815	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4816	</p>
				4817
				4818	<h5>Arguments:</h5>
				4819
				4820	<p>
				4821	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4822	determining if the fetch should be for a read (0) or write (1), and
				4823	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4824	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]	4825	<tt>locality</tt> arguments must be constant integers.
				4826	</p>
				4827
				4828	<h5>Semantics:</h5>
				4829
				4830	<p>
				4831	This intrinsic does not modify the behavior of the program. In particular,
				4832	prefetches cannot trap and do not produce a value. On targets that support this
				4833	intrinsic, the prefetch can provide hints to the processor cache for better
				4834	performance.
				4835	</p>
				4836
				4837	</div>
				4838
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4839	<!-- _______________________________________________________________________ -->
				4840	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4841	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4842	</div>
				4843
				4844	<div class="doc_text">
				4845
				4846	<h5>Syntax:</h5>
				4847	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4848	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4849	</pre>
				4850
				4851	<h5>Overview:</h5>
				4852
				4853
				4854	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4855	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
				4856	(PC) in a region of
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4857	code to simulators and other tools. The method is target specific, but it is
				4858	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]	4859	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]	4860	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]	4861	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4862	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4863	</p>
				4864
				4865	<h5>Arguments:</h5>
				4866
				4867	<p>
				4868	<tt>id</tt> is a numerical id identifying the marker.
				4869	</p>
				4870
				4871	<h5>Semantics:</h5>
				4872
				4873	<p>
				4874	This intrinsic does not modify the behavior of the program. Backends that do not
				4875	support this intrinisic may ignore it.
				4876	</p>
				4877
				4878	</div>
				4879
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4880	<!-- _______________________________________________________________________ -->
				4881	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4882	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4883	</div>
				4884
				4885	<div class="doc_text">
				4886
				4887	<h5>Syntax:</h5>
				4888	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4889	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4890	</pre>
				4891
				4892	<h5>Overview:</h5>
				4893
				4894
				4895	<p>
				4896	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4897	counter register (or similar low latency, high accuracy clocks) on those targets
				4898	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4899	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4900	should only be used for small timings.
				4901	</p>
				4902
				4903	<h5>Semantics:</h5>
				4904
				4905	<p>
				4906	When directly supported, reading the cycle counter should not modify any memory.
				4907	Implementations are allowed to either return a application specific value or a
				4908	system wide value. On backends without support, this is lowered to a constant 0.
				4909	</p>
				4910
				4911	</div>
				4912
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4913	<!-- ======================================================================= -->
				4914	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4915	<a name="int_libc">Standard C Library Intrinsics</a>
				4916	</div>
				4917
				4918	<div class="doc_text">
				4919	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4920	LLVM provides intrinsics for a few important standard C library functions.
				4921	These intrinsics allow source-language front-ends to pass information about the
				4922	alignment of the pointer arguments to the code generator, providing opportunity
				4923	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4924	</p>
				4925
				4926	</div>
				4927
				4928	<!-- _______________________________________________________________________ -->
				4929	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4930	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4931	</div>
				4932
				4933	<div class="doc_text">
				4934
				4935	<h5>Syntax:</h5>
				4936	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4937	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4938	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4939	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4940	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4941	</pre>
				4942
				4943	<h5>Overview:</h5>
				4944
				4945	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4946	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]	4947	location to the destination location.
				4948	</p>
				4949
				4950	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4951	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				4952	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4953	</p>
				4954
				4955	<h5>Arguments:</h5>
				4956
				4957	<p>
				4958	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]	4959	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4960	specifying the number of bytes to copy, and the fourth argument is the alignment
				4961	of the source and destination locations.
				4962	</p>
				4963
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4964	<p>
				4965	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]	4966	the caller guarantees that both the source and destination pointers are aligned
				4967	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4968	</p>
				4969
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4970	<h5>Semantics:</h5>
				4971
				4972	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4973	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]	4974	location to the destination location, which are not allowed to overlap. It
				4975	copies "len" bytes of memory over. If the argument is known to be aligned to
				4976	some boundary, this can be specified as the fourth argument, otherwise it should
				4977	be set to 0 or 1.
				4978	</p>
				4979	</div>
				4980
				4981
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4982	<!-- _______________________________________________________________________ -->
				4983	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4984	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4985	</div>
				4986
				4987	<div class="doc_text">
				4988
				4989	<h5>Syntax:</h5>
				4990	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4991	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4992	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4993	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4994	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4995	</pre>
				4996
				4997	<h5>Overview:</h5>
				4998
				4999	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5000	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5001	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5002	'<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]	5003	</p>
				5004
				5005	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5006	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5007	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5008	</p>
				5009
				5010	<h5>Arguments:</h5>
				5011
				5012	<p>
				5013	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]	5014	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5015	specifying the number of bytes to copy, and the fourth argument is the alignment
				5016	of the source and destination locations.
				5017	</p>
				5018
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5019	<p>
				5020	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]	5021	the caller guarantees that the source and destination pointers are aligned to
				5022	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5023	</p>
				5024
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5025	<h5>Semantics:</h5>
				5026
				5027	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5028	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]	5029	location to the destination location, which may overlap. It
				5030	copies "len" bytes of memory over. If the argument is known to be aligned to
				5031	some boundary, this can be specified as the fourth argument, otherwise it should
				5032	be set to 0 or 1.
				5033	</p>
				5034	</div>
				5035
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5036
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5037	<!-- _______________________________________________________________________ -->
				5038	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5039	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5040	</div>
				5041
				5042	<div class="doc_text">
				5043
				5044	<h5>Syntax:</h5>
				5045	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5046	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5047	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5048	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5049	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5050	</pre>
				5051
				5052	<h5>Overview:</h5>
				5053
				5054	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5055	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]	5056	byte value.
				5057	</p>
				5058
				5059	<p>
				5060	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5061	does not return a value, and takes an extra alignment argument.
				5062	</p>
				5063
				5064	<h5>Arguments:</h5>
				5065
				5066	<p>
				5067	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]	5068	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5069	argument specifying the number of bytes to fill, and the fourth argument is the
				5070	known alignment of destination location.
				5071	</p>
				5072
				5073	<p>
				5074	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]	5075	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5076	</p>
				5077
				5078	<h5>Semantics:</h5>
				5079
				5080	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5081	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5082	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5083	destination location. If the argument is known to be aligned to some boundary,
				5084	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5085	1.
				5086	</p>
				5087	</div>
				5088
				5089
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5090	<!-- _______________________________________________________________________ -->
				5091	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5092	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5093	</div>
				5094
				5095	<div class="doc_text">
				5096
				5097	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5098	<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]	5099	floating point or vector of floating point type. Not all targets support all
				5100	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5101	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5102	declare float @llvm.sqrt.f32(float %Val)
				5103	declare double @llvm.sqrt.f64(double %Val)
				5104	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5105	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5106	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5107	</pre>
				5108
				5109	<h5>Overview:</h5>
				5110
				5111	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5112	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]	5113	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]	5114	<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]	5115	negative numbers other than -0.0 (which allows for better optimization, because
				5116	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5117	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5118	</p>
				5119
				5120	<h5>Arguments:</h5>
				5121
				5122	<p>
				5123	The argument and return value are floating point numbers of the same type.
				5124	</p>
				5125
				5126	<h5>Semantics:</h5>
				5127
				5128	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5129	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]	5130	floating point number.
				5131	</p>
				5132	</div>
				5133
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5134	<!-- _______________________________________________________________________ -->
				5135	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5136	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5137	</div>
				5138
				5139	<div class="doc_text">
				5140
				5141	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5142	<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]	5143	floating point or vector of floating point type. Not all targets support all
				5144	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5145	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5146	declare float @llvm.powi.f32(float %Val, i32 %power)
				5147	declare double @llvm.powi.f64(double %Val, i32 %power)
				5148	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5149	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5150	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5151	</pre>
				5152
				5153	<h5>Overview:</h5>
				5154
				5155	<p>
				5156	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5157	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5158	multiplications is not defined. When a vector of floating point type is
				5159	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5160	</p>
				5161
				5162	<h5>Arguments:</h5>
				5163
				5164	<p>
				5165	The second argument is an integer power, and the first is a value to raise to
				5166	that power.
				5167	</p>
				5168
				5169	<h5>Semantics:</h5>
				5170
				5171	<p>
				5172	This function returns the first value raised to the second power with an
				5173	unspecified sequence of rounding operations.</p>
				5174	</div>
				5175
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5176	<!-- _______________________________________________________________________ -->
				5177	<div class="doc_subsubsection">
				5178	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5179	</div>
				5180
				5181	<div class="doc_text">
				5182
				5183	<h5>Syntax:</h5>
				5184	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5185	floating point or vector of floating point type. Not all targets support all
				5186	types however.
				5187	<pre>
				5188	declare float @llvm.sin.f32(float %Val)
				5189	declare double @llvm.sin.f64(double %Val)
				5190	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5191	declare fp128 @llvm.sin.f128(fp128 %Val)
				5192	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5193	</pre>
				5194
				5195	<h5>Overview:</h5>
				5196
				5197	<p>
				5198	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5199	</p>
				5200
				5201	<h5>Arguments:</h5>
				5202
				5203	<p>
				5204	The argument and return value are floating point numbers of the same type.
				5205	</p>
				5206
				5207	<h5>Semantics:</h5>
				5208
				5209	<p>
				5210	This function returns the sine of the specified operand, returning the
				5211	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]	5212	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5213	</div>
				5214
				5215	<!-- _______________________________________________________________________ -->
				5216	<div class="doc_subsubsection">
				5217	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5218	</div>
				5219
				5220	<div class="doc_text">
				5221
				5222	<h5>Syntax:</h5>
				5223	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5224	floating point or vector of floating point type. Not all targets support all
				5225	types however.
				5226	<pre>
				5227	declare float @llvm.cos.f32(float %Val)
				5228	declare double @llvm.cos.f64(double %Val)
				5229	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5230	declare fp128 @llvm.cos.f128(fp128 %Val)
				5231	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5232	</pre>
				5233
				5234	<h5>Overview:</h5>
				5235
				5236	<p>
				5237	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5238	</p>
				5239
				5240	<h5>Arguments:</h5>
				5241
				5242	<p>
				5243	The argument and return value are floating point numbers of the same type.
				5244	</p>
				5245
				5246	<h5>Semantics:</h5>
				5247
				5248	<p>
				5249	This function returns the cosine of the specified operand, returning the
				5250	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]	5251	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5252	</div>
				5253
				5254	<!-- _______________________________________________________________________ -->
				5255	<div class="doc_subsubsection">
				5256	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5257	</div>
				5258
				5259	<div class="doc_text">
				5260
				5261	<h5>Syntax:</h5>
				5262	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5263	floating point or vector of floating point type. Not all targets support all
				5264	types however.
				5265	<pre>
				5266	declare float @llvm.pow.f32(float %Val, float %Power)
				5267	declare double @llvm.pow.f64(double %Val, double %Power)
				5268	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5269	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5270	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5271	</pre>
				5272
				5273	<h5>Overview:</h5>
				5274
				5275	<p>
				5276	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5277	specified (positive or negative) power.
				5278	</p>
				5279
				5280	<h5>Arguments:</h5>
				5281
				5282	<p>
				5283	The second argument is a floating point power, and the first is a value to
				5284	raise to that power.
				5285	</p>
				5286
				5287	<h5>Semantics:</h5>
				5288
				5289	<p>
				5290	This function returns the first value raised to the second power,
				5291	returning the
				5292	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]	5293	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5294	</div>
				5295
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5296
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5297	<!-- ======================================================================= -->
				5298	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5299	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5300	</div>
				5301
				5302	<div class="doc_text">
				5303	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5304	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5305	These allow efficient code generation for some algorithms.
				5306	</p>
				5307
				5308	</div>
				5309
				5310	<!-- _______________________________________________________________________ -->
				5311	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5312	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5313	</div>
				5314
				5315	<div class="doc_text">
				5316
				5317	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5318	<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]	5319	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]	5320	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5321	declare i16 @llvm.bswap.i16(i16 <id>)
				5322	declare i32 @llvm.bswap.i32(i32 <id>)
				5323	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5324	</pre>
				5325
				5326	<h5>Overview:</h5>
				5327
				5328	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5329	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]	5330	values with an even number of bytes (positive multiple of 16 bits). These are
				5331	useful for performing operations on data that is not in the target's native
				5332	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5333	</p>
				5334
				5335	<h5>Semantics:</h5>
				5336
				5337	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5338	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]	5339	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5340	intrinsic returns an i32 value that has the four bytes of the input i32
				5341	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]	5342	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5343	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5344	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5345	</p>
				5346
				5347	</div>
				5348
				5349	<!-- _______________________________________________________________________ -->
				5350	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5351	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5352	</div>
				5353
				5354	<div class="doc_text">
				5355
				5356	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5357	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5358	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5359	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5360	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5361	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5362	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5363	declare i64 @llvm.ctpop.i64(i64 <src>)
				5364	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5365	</pre>
				5366
				5367	<h5>Overview:</h5>
				5368
				5369	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5370	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5371	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5372	</p>
				5373
				5374	<h5>Arguments:</h5>
				5375
				5376	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5377	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]	5378	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5379	</p>
				5380
				5381	<h5>Semantics:</h5>
				5382
				5383	<p>
				5384	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5385	</p>
				5386	</div>
				5387
				5388	<!-- _______________________________________________________________________ -->
				5389	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5390	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5391	</div>
				5392
				5393	<div class="doc_text">
				5394
				5395	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5396	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5397	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5398	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5399	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5400	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5401	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5402	declare i64 @llvm.ctlz.i64(i64 <src>)
				5403	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5404	</pre>
				5405
				5406	<h5>Overview:</h5>
				5407
				5408	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5409	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5410	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5411	</p>
				5412
				5413	<h5>Arguments:</h5>
				5414
				5415	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5416	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]	5417	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5418	</p>
				5419
				5420	<h5>Semantics:</h5>
				5421
				5422	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5423	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5424	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]	5425	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5426	</p>
				5427	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5428
				5429
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5430
				5431	<!-- _______________________________________________________________________ -->
				5432	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5433	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5434	</div>
				5435
				5436	<div class="doc_text">
				5437
				5438	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5439	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5440	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5441	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5442	declare i8 @llvm.cttz.i8 (i8 <src>)
				5443	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5444	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5445	declare i64 @llvm.cttz.i64(i64 <src>)
				5446	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5447	</pre>
				5448
				5449	<h5>Overview:</h5>
				5450
				5451	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5452	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5453	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5454	</p>
				5455
				5456	<h5>Arguments:</h5>
				5457
				5458	<p>
				5459	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]	5460	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5461	</p>
				5462
				5463	<h5>Semantics:</h5>
				5464
				5465	<p>
				5466	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5467	in a variable. If the src == 0 then the result is the size in bits of the type
				5468	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5469	</p>
				5470	</div>
				5471
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5472	<!-- _______________________________________________________________________ -->
				5473	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5474	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5475	</div>
				5476
				5477	<div class="doc_text">
				5478
				5479	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5480	<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]	5481	on any integer bit width.
				5482	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5483	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5484	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5485	</pre>
				5486
				5487	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5488	<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]	5489	range of bits from an integer value and returns them in the same bit width as
				5490	the original value.</p>
				5491
				5492	<h5>Arguments:</h5>
				5493	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5494	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]	5495	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]	5496
				5497	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5498	<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]	5499	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5500	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5501	operates in forward mode.</p>
				5502	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5503	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]	5504	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5505	<ol>
				5506	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5507	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5508	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5509	to determine the number of bits to retain.</li>
				5510	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5511	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5512	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5513	<p>In reverse mode, a similar computation is made except that the bits are
				5514	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5515	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5516	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5517	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5518	</div>
				5519
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5520	<div class="doc_subsubsection">
				5521	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5522	</div>
				5523
				5524	<div class="doc_text">
				5525
				5526	<h5>Syntax:</h5>
				5527	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5528	on any integer bit width.
				5529	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5530	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5531	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]	5532	</pre>
				5533
				5534	<h5>Overview:</h5>
				5535	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5536	of bits in an integer value with another integer value. It returns the integer
				5537	with the replaced bits.</p>
				5538
				5539	<h5>Arguments:</h5>
				5540	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5541	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5542	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5543	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5544	type since they specify only a bit index.</p>
				5545
				5546	<h5>Semantics:</h5>
				5547	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5548	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5549	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5550	operates in forward mode.</p>
				5551	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5552	truncating it down to the size of the replacement area or zero extending it
				5553	up to that size.</p>
				5554	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5555	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5556	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5557	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5558	<p>In reverse mode, a similar computation is made except that the bits are
				5559	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5560	<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]	5561	<h5>Examples:</h5>
				5562	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5563	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5564	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5565	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5566	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5567	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5568	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5569	</div>
				5570
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5571	<!-- ======================================================================= -->
				5572	<div class="doc_subsection">
				5573	<a name="int_debugger">Debugger Intrinsics</a>
				5574	</div>
				5575
				5576	<div class="doc_text">
				5577	<p>
				5578	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5579	are described in the <a
				5580	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5581	Debugging</a> document.
				5582	</p>
				5583	</div>
				5584
				5585
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5586	<!-- ======================================================================= -->
				5587	<div class="doc_subsection">
				5588	<a name="int_eh">Exception Handling Intrinsics</a>
				5589	</div>
				5590
				5591	<div class="doc_text">
				5592	<p> The LLVM exception handling intrinsics (which all start with
				5593	<tt>llvm.eh.</tt> prefix), are described in the <a
				5594	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5595	Handling</a> document. </p>
				5596	</div>
				5597
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5598	<!-- ======================================================================= -->
				5599	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5600	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5601	</div>
				5602
				5603	<div class="doc_text">
				5604	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5605	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5606	the <tt>nest</tt> attribute, from a function. The result is a callable
				5607	function pointer lacking the nest parameter - the caller does not need
				5608	to provide a value for it. Instead, the value to use is stored in
				5609	advance in a "trampoline", a block of memory usually allocated
				5610	on the stack, which also contains code to splice the nest value into the
				5611	argument list. This is used to implement the GCC nested function address
				5612	extension.
				5613	</p>
				5614	<p>
				5615	For example, if the function is
				5616	<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]	5617	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]	5618	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5619	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5620	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5621	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5622	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5623	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5624	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5625	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]	5626	</div>
				5627
				5628	<!-- _______________________________________________________________________ -->
				5629	<div class="doc_subsubsection">
				5630	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5631	</div>
				5632	<div class="doc_text">
				5633	<h5>Syntax:</h5>
				5634	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5635	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5636	</pre>
				5637	<h5>Overview:</h5>
				5638	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5639	This fills the memory pointed to by <tt>tramp</tt> with code
				5640	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5641	</p>
				5642	<h5>Arguments:</h5>
				5643	<p>
				5644	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5645	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5646	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]	5647	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5648	currently provides no portable way of determining them, so a front-end that
				5649	generates this intrinsic needs to have some target-specific knowledge.
				5650	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]	5651	</p>
				5652	<h5>Semantics:</h5>
				5653	<p>
				5654	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]	5655	dependent code, turning it into a function. A pointer to this function is
				5656	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5657	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5658	before being called. The new function's signature is the same as that of
				5659	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5660	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5661	of pointer type. Calling the new function is equivalent to calling
				5662	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5663	missing <tt>nest</tt> argument. If, after calling
				5664	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5665	modified, then the effect of any later call to the returned function pointer is
				5666	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5667	</p>
				5668	</div>
				5669
				5670	<!-- ======================================================================= -->
				5671	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5672	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5673	</div>
				5674
				5675	<div class="doc_text">
				5676	<p>
				5677	These intrinsic functions expand the "universal IR" of LLVM to represent
				5678	hardware constructs for atomic operations and memory synchronization. This
				5679	provides an interface to the hardware, not an interface to the programmer. It
				5680	is aimed at a low enough level to allow any programming models or APIs which
				5681	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5682	hardware behavior. Just as hardware provides a "universal IR" for source
				5683	languages, it also provides a starting point for developing a "universal"
				5684	atomic operation and synchronization IR.
				5685	</p>
				5686	<p>
				5687	These do <em>not</em> form an API such as high-level threading libraries,
				5688	software transaction memory systems, atomic primitives, and intrinsic
				5689	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5690	application libraries. The hardware interface provided by LLVM should allow
				5691	a clean implementation of all of these APIs and parallel programming models.
				5692	No one model or paradigm should be selected above others unless the hardware
				5693	itself ubiquitously does so.
				5694
				5695	</p>
				5696	</div>
				5697
				5698	<!-- _______________________________________________________________________ -->
				5699	<div class="doc_subsubsection">
				5700	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5701	</div>
				5702	<div class="doc_text">
				5703	<h5>Syntax:</h5>
				5704	<pre>
				5705	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5706	i1 <device> )
				5707
				5708	</pre>
				5709	<h5>Overview:</h5>
				5710	<p>
				5711	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5712	specific pairs of memory access types.
				5713	</p>
				5714	<h5>Arguments:</h5>
				5715	<p>
				5716	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5717	The first four arguments enables a specific barrier as listed below. The fith
				5718	argument specifies that the barrier applies to io or device or uncached memory.
				5719
				5720	</p>
				5721	<ul>
				5722	<li><tt>ll</tt>: load-load barrier</li>
				5723	<li><tt>ls</tt>: load-store barrier</li>
				5724	<li><tt>sl</tt>: store-load barrier</li>
				5725	<li><tt>ss</tt>: store-store barrier</li>
				5726	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5727	</ul>
				5728	<h5>Semantics:</h5>
				5729	<p>
				5730	This intrinsic causes the system to enforce some ordering constraints upon
				5731	the loads and stores of the program. This barrier does not indicate
				5732	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5733	which they occur. For any of the specified pairs of load and store operations
				5734	(f.ex. load-load, or store-load), all of the first operations preceding the
				5735	barrier will complete before any of the second operations succeeding the
				5736	barrier begin. Specifically the semantics for each pairing is as follows:
				5737	</p>
				5738	<ul>
				5739	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5740	after the barrier begins.</li>
				5741
				5742	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5743	store after the barrier begins.</li>
				5744	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5745	store after the barrier begins.</li>
				5746	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5747	load after the barrier begins.</li>
				5748	</ul>
				5749	<p>
				5750	These semantics are applied with a logical "and" behavior when more than one
				5751	is enabled in a single memory barrier intrinsic.
				5752	</p>
				5753	<p>
				5754	Backends may implement stronger barriers than those requested when they do not
				5755	support as fine grained a barrier as requested. Some architectures do not
				5756	need all types of barriers and on such architectures, these become noops.
				5757	</p>
				5758	<h5>Example:</h5>
				5759	<pre>
				5760	%ptr = malloc i32
				5761	store i32 4, %ptr
				5762
				5763	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5764	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5765	<i>; guarantee the above finishes</i>
				5766	store i32 8, %ptr <i>; before this begins</i>
				5767	</pre>
				5768	</div>
				5769
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5770	<!-- _______________________________________________________________________ -->
				5771	<div class="doc_subsubsection">
				5772	<a name="int_atomic_lcs">'<tt>llvm.atomic.lcs.*</tt>' Intrinsic</a>
				5773	</div>
				5774	<div class="doc_text">
				5775	<h5>Syntax:</h5>
				5776	<p>
				5777	This is an overloaded intrinsic. You can use <tt>llvm.atomic.lcs</tt> on any
				5778	integer bit width. Not all targets support all bit widths however.</p>
				5779
				5780	<pre>
				5781	declare i8 @llvm.atomic.lcs.i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5782	declare i16 @llvm.atomic.lcs.i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5783	declare i32 @llvm.atomic.lcs.i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5784	declare i64 @llvm.atomic.lcs.i64( i64* <ptr>, i64 <cmp>, i64 <val> )
				5785
				5786	</pre>
				5787	<h5>Overview:</h5>
				5788	<p>
				5789	This loads a value in memory and compares it to a given value. If they are
				5790	equal, it stores a new value into the memory.
				5791	</p>
				5792	<h5>Arguments:</h5>
				5793	<p>
				5794	The <tt>llvm.atomic.lcs</tt> intrinsic takes three arguments. The result as
				5795	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5796	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5797	this integer type. While any bit width integer may be used, targets may only
				5798	lower representations they support in hardware.
				5799
				5800	</p>
				5801	<h5>Semantics:</h5>
				5802	<p>
				5803	This entire intrinsic must be executed atomically. It first loads the value
				5804	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5805	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5806	loaded value is yielded in all cases. This provides the equivalent of an
				5807	atomic compare-and-swap operation within the SSA framework.
				5808	</p>
				5809	<h5>Examples:</h5>
				5810
				5811	<pre>
				5812	%ptr = malloc i32
				5813	store i32 4, %ptr
				5814
				5815	%val1 = add i32 4, 4
				5816	%result1 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 4, %val1 )
				5817	<i>; yields {i32}:result1 = 4</i>
				5818	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5819	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5820
				5821	%val2 = add i32 1, 1
				5822	%result2 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 5, %val2 )
				5823	<i>; yields {i32}:result2 = 8</i>
				5824	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5825
				5826	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5827	</pre>
				5828	</div>
				5829
				5830	<!-- _______________________________________________________________________ -->
				5831	<div class="doc_subsubsection">
				5832	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5833	</div>
				5834	<div class="doc_text">
				5835	<h5>Syntax:</h5>
				5836
				5837	<p>
				5838	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5839	integer bit width. Not all targets support all bit widths however.</p>
				5840	<pre>
				5841	declare i8 @llvm.atomic.swap.i8( i8* <ptr>, i8 <val> )
				5842	declare i16 @llvm.atomic.swap.i16( i16* <ptr>, i16 <val> )
				5843	declare i32 @llvm.atomic.swap.i32( i32* <ptr>, i32 <val> )
				5844	declare i64 @llvm.atomic.swap.i64( i64* <ptr>, i64 <val> )
				5845
				5846	</pre>
				5847	<h5>Overview:</h5>
				5848	<p>
				5849	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5850	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5851	at <tt>ptr</tt>.
				5852	</p>
				5853	<h5>Arguments:</h5>
				5854
				5855	<p>
				5856	The <tt>llvm.atomic.ls</tt> intrinsic takes two arguments. Both the
				5857	<tt>val</tt> argument and the result must be integers of the same bit width.
				5858	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5859	integer type. The targets may only lower integer representations they
				5860	support.
				5861	</p>
				5862	<h5>Semantics:</h5>
				5863	<p>
				5864	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5865	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5866	equivalent of an atomic swap operation within the SSA framework.
				5867
				5868	</p>
				5869	<h5>Examples:</h5>
				5870	<pre>
				5871	%ptr = malloc i32
				5872	store i32 4, %ptr
				5873
				5874	%val1 = add i32 4, 4
				5875	%result1 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val1 )
				5876	<i>; yields {i32}:result1 = 4</i>
				5877	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5878	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5879
				5880	%val2 = add i32 1, 1
				5881	%result2 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val2 )
				5882	<i>; yields {i32}:result2 = 8</i>
				5883
				5884	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5885	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5886	</pre>
				5887	</div>
				5888
				5889	<!-- _______________________________________________________________________ -->
				5890	<div class="doc_subsubsection">
				5891	<a name="int_atomic_las">'<tt>llvm.atomic.las.*</tt>' Intrinsic</a>
				5892
				5893	</div>
				5894	<div class="doc_text">
				5895	<h5>Syntax:</h5>
				5896	<p>
				5897	This is an overloaded intrinsic. You can use <tt>llvm.atomic.las</tt> on any
				5898	integer bit width. Not all targets support all bit widths however.</p>
				5899	<pre>
				5900	declare i8 @llvm.atomic.las.i8.( i8* <ptr>, i8 <delta> )
				5901	declare i16 @llvm.atomic.las.i16.( i16* <ptr>, i16 <delta> )
				5902	declare i32 @llvm.atomic.las.i32.( i32* <ptr>, i32 <delta> )
				5903	declare i64 @llvm.atomic.las.i64.( i64* <ptr>, i64 <delta> )
				5904
				5905	</pre>
				5906	<h5>Overview:</h5>
				5907	<p>
				5908	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5909	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5910	</p>
				5911	<h5>Arguments:</h5>
				5912	<p>
				5913
				5914	The intrinsic takes two arguments, the first a pointer to an integer value
				5915	and the second an integer value. The result is also an integer value. These
				5916	integer types can have any bit width, but they must all have the same bit
				5917	width. The targets may only lower integer representations they support.
				5918	</p>
				5919	<h5>Semantics:</h5>
				5920	<p>
				5921	This intrinsic does a series of operations atomically. It first loads the
				5922	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5923	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5924	</p>
				5925
				5926	<h5>Examples:</h5>
				5927	<pre>
				5928	%ptr = malloc i32
				5929	store i32 4, %ptr
				5930	%result1 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 4 )
				5931	<i>; yields {i32}:result1 = 4</i>
				5932	%result2 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 2 )
				5933	<i>; yields {i32}:result2 = 8</i>
				5934	%result3 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 5 )
				5935	<i>; yields {i32}:result3 = 10</i>
				5936	%memval = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
				5937	</pre>
				5938	</div>
				5939
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5940
				5941	<!-- ======================================================================= -->
				5942	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5943	<a name="int_general">General Intrinsics</a>
				5944	</div>
				5945
				5946	<div class="doc_text">
				5947	<p> This class of intrinsics is designed to be generic and has
				5948	no specific purpose. </p>
				5949	</div>
				5950
				5951	<!-- _______________________________________________________________________ -->
				5952	<div class="doc_subsubsection">
				5953	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				5954	</div>
				5955
				5956	<div class="doc_text">
				5957
				5958	<h5>Syntax:</h5>
				5959	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5960	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]	5961	</pre>
				5962
				5963	<h5>Overview:</h5>
				5964
				5965	<p>
				5966	The '<tt>llvm.var.annotation</tt>' intrinsic
				5967	</p>
				5968
				5969	<h5>Arguments:</h5>
				5970
				5971	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5972	The first argument is a pointer to a value, the second is a pointer to a
				5973	global string, the third is a pointer to a global string which is the source
				5974	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5975	</p>
				5976
				5977	<h5>Semantics:</h5>
				5978
				5979	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	5980	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5981	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]	5982	annotations. These have no other defined use, they are ignored by code
				5983	generation and optimization.
				5984	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5985	</div>
				5986
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5987	<!-- _______________________________________________________________________ -->
				5988	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	5989	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5990	</div>
				5991
				5992	<div class="doc_text">
				5993
				5994	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	5995	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				5996	any integer bit width.
				5997	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5998	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	5999	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6000	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6001	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6002	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6003	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]	6004	</pre>
				6005
				6006	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6007
				6008	<p>
				6009	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6010	</p>
				6011
				6012	<h5>Arguments:</h5>
				6013
				6014	<p>
				6015	The first argument is an integer value (result of some expression),
				6016	the second is a pointer to a global string, the third is a pointer to a global
				6017	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]	6018	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6019	</p>
				6020
				6021	<h5>Semantics:</h5>
				6022
				6023	<p>
				6024	This intrinsic allows annotations to be put on arbitrary expressions
				6025	with arbitrary strings. This can be useful for special purpose optimizations
				6026	that want to look for these annotations. These have no other defined use, they
				6027	are ignored by code generation and optimization.
				6028	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6029
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6030	<!-- _______________________________________________________________________ -->
				6031	<div class="doc_subsubsection">
				6032	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6033	</div>
				6034
				6035	<div class="doc_text">
				6036
				6037	<h5>Syntax:</h5>
				6038	<pre>
				6039	declare void @llvm.trap()
				6040	</pre>
				6041
				6042	<h5>Overview:</h5>
				6043
				6044	<p>
				6045	The '<tt>llvm.trap</tt>' intrinsic
				6046	</p>
				6047
				6048	<h5>Arguments:</h5>
				6049
				6050	<p>
				6051	None
				6052	</p>
				6053
				6054	<h5>Semantics:</h5>
				6055
				6056	<p>
				6057	This intrinsics is lowered to the target dependent trap instruction. If the
				6058	target does not have a trap instruction, this intrinsic will be lowered to the
				6059	call of the abort() function.
				6060	</p>
				6061	</div>
				6062
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6063	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6064	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6065	<address>
				6066	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6067	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6069	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]	6070
				6071	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6072	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6073	Last modified: $Date$
				6074	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6075
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6076	</body>
				6077	</html>