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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
				589	this convention should allow arbitrary tail call optimization to be supported.
				590	This calling convention does not support varargs and requires the prototype of
				591	all callees to exactly match the prototype of the function definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	592	</dd>
				593
				594	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				595
				596	<dd>This calling convention attempts to make code in the caller as efficient
				597	as possible under the assumption that the call is not commonly executed. As
				598	such, these calls often preserve all registers so that the call does not break
				599	any live ranges in the caller side. This calling convention does not support
				600	varargs and requires the prototype of all callees to exactly match the
				601	prototype of the function definition.
				602	</dd>
				603
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	604	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	605
				606	<dd>Any calling convention may be specified by number, allowing
				607	target-specific calling conventions to be used. Target specific calling
				608	conventions start at 64.
				609	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	610	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	611
				612	<p>More calling conventions can be added/defined on an as-needed basis, to
				613	support pascal conventions or any other well-known target-independent
				614	convention.</p>
				615
				616	</div>
				617
				618	<!-- ======================================================================= -->
				619	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	620	<a name="visibility">Visibility Styles</a>
				621	</div>
				622
				623	<div class="doc_text">
				624
				625	<p>
				626	All Global Variables and Functions have one of the following visibility styles:
				627	</p>
				628
				629	<dl>
				630	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				631
				632	<dd>On ELF, default visibility means that the declaration is visible to other
				633	modules and, in shared libraries, means that the declared entity may be
				634	overridden. On Darwin, default visibility means that the declaration is
				635	visible to other modules. Default visibility corresponds to "external
				636	linkage" in the language.
				637	</dd>
				638
				639	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				640
				641	<dd>Two declarations of an object with hidden visibility refer to the same
				642	object if they are in the same shared object. Usually, hidden visibility
				643	indicates that the symbol will not be placed into the dynamic symbol table,
				644	so no other module (executable or shared library) can reference it
				645	directly.
				646	</dd>
				647
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	648	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				649
				650	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				651	the dynamic symbol table, but that references within the defining module will
				652	bind to the local symbol. That is, the symbol cannot be overridden by another
				653	module.
				654	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	655	</dl>
				656
				657	</div>
				658
				659	<!-- ======================================================================= -->
				660	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	661	<a name="globalvars">Global Variables</a>
				662	</div>
				663
				664	<div class="doc_text">
				665
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	666	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	667	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	668	an explicit section to be placed in, and may have an optional explicit alignment
				669	specified. A variable may be defined as "thread_local", which means that it
				670	will not be shared by threads (each thread will have a separated copy of the
				671	variable). A variable may be defined as a global "constant," which indicates
				672	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]	673	optimization, allowing the global data to be placed in the read-only section of
				674	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	675	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]	676
				677	<p>
				678	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				679	constant, even if the final definition of the global is not. This capability
				680	can be used to enable slightly better optimization of the program, but requires
				681	the language definition to guarantee that optimizations based on the
				682	'constantness' are valid for the translation units that do not include the
				683	definition.
				684	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	685
				686	<p>As SSA values, global variables define pointer values that are in
				687	scope (i.e. they dominate) all basic blocks in the program. Global
				688	variables always define a pointer to their "content" type because they
				689	describe a region of memory, and all memory objects in LLVM are
				690	accessed through pointers.</p>
				691
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	692	<p>A global variable may be declared to reside in a target-specifc numbered
				693	address space. For targets that support them, address spaces may affect how
				694	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	695	the variable. The default address space is zero. The address space qualifier
				696	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	697
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	698	<p>LLVM allows an explicit section to be specified for globals. If the target
				699	supports it, it will emit globals to the section specified.</p>
				700
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	701	<p>An explicit alignment may be specified for a global. If not present, or if
				702	the alignment is set to zero, the alignment of the global is set by the target
				703	to whatever it feels convenient. If an explicit alignment is specified, the
				704	global is forced to have at least that much alignment. All alignments must be
				705	a power of 2.</p>
				706
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	707	<p>For example, the following defines a global in a numbered address space with
				708	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	709
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	710	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	711	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	712	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	713	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	714	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	715
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	716	</div>
				717
				718
				719	<!-- ======================================================================= -->
				720	<div class="doc_subsection">
				721	<a name="functionstructure">Functions</a>
				722	</div>
				723
				724	<div class="doc_text">
				725
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	726	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				727	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	728	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	729	<a href="#callingconv">calling convention</a>, a return type, an optional
				730	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				731	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	732	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	733	optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	734	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]	735
				736	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				737	optional <a href="#linkage">linkage type</a>, an optional
				738	<a href="#visibility">visibility style</a>, an optional
				739	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	740	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	741	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]	742	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	743
				744	<p>A function definition contains a list of basic blocks, forming the CFG for
				745	the function. Each basic block may optionally start with a label (giving the
				746	basic block a symbol table entry), contains a list of instructions, and ends
				747	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				748	function return).</p>
				749
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	750	<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]	751	executed on entrance to the function, and it is not allowed to have predecessor
				752	basic blocks (i.e. there can not be any branches to the entry block of a
				753	function). Because the block can have no predecessors, it also cannot have any
				754	<a href="#i_phi">PHI nodes</a>.</p>
				755
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	756	<p>LLVM allows an explicit section to be specified for functions. If the target
				757	supports it, it will emit functions to the section specified.</p>
				758
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	759	<p>An explicit alignment may be specified for a function. If not present, or if
				760	the alignment is set to zero, the alignment of the function is set by the target
				761	to whatever it feels convenient. If an explicit alignment is specified, the
				762	function is forced to have at least that much alignment. All alignments must be
				763	a power of 2.</p>
				764
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	765	</div>
				766
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	767
				768	<!-- ======================================================================= -->
				769	<div class="doc_subsection">
				770	<a name="aliasstructure">Aliases</a>
				771	</div>
				772	<div class="doc_text">
				773	<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]	774	function, global variable, another alias or bitcast of global value). Aliases
				775	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	776	optional <a href="#visibility">visibility style</a>.</p>
				777
				778	<h5>Syntax:</h5>
				779
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	780	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	781	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	782	@<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
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	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	785
				786	</div>
				787
				788
				789
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	790	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	791	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				792	<div class="doc_text">
				793	<p>The return type and each parameter of a function type may have a set of
				794	<i>parameter attributes</i> associated with them. Parameter attributes are
				795	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	796	a function. Parameter attributes are considered to be part of the function,
				797	not of the function type, so functions with different parameter attributes
				798	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	799
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	800	<p>Parameter attributes are simple keywords that follow the type specified. If
				801	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	802	example:</p>
				803
				804	<div class="doc_code">
				805	<pre>
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	806	declare i32 @printf(i8* noalias , ...) nounwind
				807	declare i32 @atoi(i8*) nounwind readonly
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	808	</pre>
				809	</div>
				810
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	811	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				812	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	813
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	814	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	815	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	816	<dt><tt>zeroext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	817	<dd>This indicates that the parameter should be zero extended just before
				818	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	819
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	820	<dt><tt>signext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	821	<dd>This indicates that the parameter should be sign extended just before
				822	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	823
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	824	<dt><tt>inreg</tt></dt>
				825	<dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov	66a8c8c	2007-01-28 15:27:21 +0000	[diff] [blame]	826	possible) during assembling function call. Support for this attribute is
				827	target-specific</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	828
				829	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	830	<dd>This indicates that the pointer parameter should really be passed by
				831	value to the function. The attribute implies that a hidden copy of the
				832	pointee is made between the caller and the callee, so the callee is unable
				833	to modify the value in the callee. This attribute is only valid on llvm
				834	pointer arguments. It is generally used to pass structs and arrays by
				835	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]	836
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	837	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	838	<dd>This indicates that the pointer parameter specifies the address of a
				839	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]	840	Loads and stores to the structure are assumed not to trap.
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	841	May only be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	842
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	843	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	844	<dd>This indicates that the parameter does not alias any global or any other
				845	parameter. The caller is responsible for ensuring that this is the case,
				846	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	847
Reid Spencer	2dc5201	2007-03-22 02:18:56 +0000	[diff] [blame]	848	<dt><tt>noreturn</tt></dt>
				849	<dd>This function attribute indicates that the function never returns. This
				850	indicates to LLVM that every call to this function should be treated as if
				851	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	852
Reid Spencer	6760612	2007-03-22 02:02:11 +0000	[diff] [blame]	853	<dt><tt>nounwind</tt></dt>
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	854	<dd>This function attribute indicates that no exceptions unwind out of the
				855	function. Usually this is because the function makes no use of exceptions,
				856	but it may also be that the function catches any exceptions thrown when
				857	executing it.</dd>
				858
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	859	<dt><tt>nest</tt></dt>
				860	<dd>This indicates that the parameter can be excised using the
				861	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	862	<dt><tt>readonly</tt></dt>
Duncan Sands	f04d584	2007-11-14 21:14:02 +0000	[diff] [blame]	863	<dd>This function attribute indicates that the function has no side-effects
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	864	except for producing a return value or throwing an exception. The value
				865	returned must only depend on the function arguments and/or global variables.
				866	It may use values obtained by dereferencing pointers.</dd>
				867	<dt><tt>readnone</tt></dt>
				868	<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]	869	function, but in addition it is not allowed to dereference any pointer arguments
				870	or global variables.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	871	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	872
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	873	</div>
				874
				875	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	876	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	877	<a name="gc">Garbage Collector Names</a>
				878	</div>
				879
				880	<div class="doc_text">
				881	<p>Each function may specify a garbage collector name, which is simply a
				882	string.</p>
				883
				884	<div class="doc_code"><pre
				885	>define void @f() gc "name" { ...</pre></div>
				886
				887	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				888	collector which will cause the compiler to alter its output in order to support
				889	the named garbage collection algorithm.</p>
				890	</div>
				891
				892	<!-- ======================================================================= -->
				893	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	894	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	895	</div>
				896
				897	<div class="doc_text">
				898	<p>
				899	Modules may contain "module-level inline asm" blocks, which corresponds to the
				900	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				901	LLVM and treated as a single unit, but may be separated in the .ll file if
				902	desired. The syntax is very simple:
				903	</p>
				904
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	905	<div class="doc_code">
				906	<pre>
				907	module asm "inline asm code goes here"
				908	module asm "more can go here"
				909	</pre>
				910	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	911
				912	<p>The strings can contain any character by escaping non-printable characters.
				913	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				914	for the number.
				915	</p>
				916
				917	<p>
				918	The inline asm code is simply printed to the machine code .s file when
				919	assembly code is generated.
				920	</p>
				921	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	922
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	923	<!-- ======================================================================= -->
				924	<div class="doc_subsection">
				925	<a name="datalayout">Data Layout</a>
				926	</div>
				927
				928	<div class="doc_text">
				929	<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]	930	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				931	<pre> target datalayout = "<i>layout specification</i>"</pre>
				932	<p>The <i>layout specification</i> consists of a list of specifications
				933	separated by the minus sign character ('-'). Each specification starts with a
				934	letter and may include other information after the letter to define some
				935	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	936	<dl>
				937	<dt><tt>E</tt></dt>
				938	<dd>Specifies that the target lays out data in big-endian form. That is, the
				939	bits with the most significance have the lowest address location.</dd>
				940	<dt><tt>e</tt></dt>
				941	<dd>Specifies that hte target lays out data in little-endian form. That is,
				942	the bits with the least significance have the lowest address location.</dd>
				943	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				944	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				945	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				946	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				947	too.</dd>
				948	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				949	<dd>This specifies the alignment for an integer type of a given bit
				950	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				951	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				952	<dd>This specifies the alignment for a vector type of a given bit
				953	<i>size</i>.</dd>
				954	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				955	<dd>This specifies the alignment for a floating point type of a given bit
				956	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				957	(double).</dd>
				958	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				959	<dd>This specifies the alignment for an aggregate type of a given bit
				960	<i>size</i>.</dd>
				961	</dl>
				962	<p>When constructing the data layout for a given target, LLVM starts with a
				963	default set of specifications which are then (possibly) overriden by the
				964	specifications in the <tt>datalayout</tt> keyword. The default specifications
				965	are given in this list:</p>
				966	<ul>
				967	<li><tt>E</tt> - big endian</li>
				968	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				969	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				970	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				971	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				972	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
				973	<li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
				974	alignment of 64-bits</li>
				975	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				976	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				977	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				978	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				979	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				980	</ul>
				981	<p>When llvm is determining the alignment for a given type, it uses the
				982	following rules:
				983	<ol>
				984	<li>If the type sought is an exact match for one of the specifications, that
				985	specification is used.</li>
				986	<li>If no match is found, and the type sought is an integer type, then the
				987	smallest integer type that is larger than the bitwidth of the sought type is
				988	used. If none of the specifications are larger than the bitwidth then the the
				989	largest integer type is used. For example, given the default specifications
				990	above, the i7 type will use the alignment of i8 (next largest) while both
				991	i65 and i256 will use the alignment of i64 (largest specified).</li>
				992	<li>If no match is found, and the type sought is a vector type, then the
				993	largest vector type that is smaller than the sought vector type will be used
				994	as a fall back. This happens because <128 x double> can be implemented in
				995	terms of 64 <2 x double>, for example.</li>
				996	</ol>
				997	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	998
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	999	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1000	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1001	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1002
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1003	<div class="doc_text">
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	<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]	1006	intermediate representation. Being typed enables a number of
				1007	optimizations to be performed on the IR directly, without having to do
				1008	extra analyses on the side before the transformation. A strong type
				1009	system makes it easier to read the generated code and enables novel
				1010	analyses and transformations that are not feasible to perform on normal
				1011	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1012
				1013	</div>
				1014
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1015	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1016	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1017	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1018	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1019	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1020	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1021
				1022	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1023	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1024	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1025	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1026	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1027	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1028	</tr>
				1029	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1030	<td><a href="#t_floating">floating point</a></td>
				1031	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1032	</tr>
				1033	<tr>
				1034	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1035	<td><a href="#t_integer">integer</a>,
				1036	<a href="#t_floating">floating point</a>,
				1037	<a href="#t_pointer">pointer</a>,
				1038	<a href="#t_vector">vector</a>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1039	<a href="#t_struct">structure</a>,
				1040	<a href="#t_array">array</a>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1041	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1042	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1043	<tr>
				1044	<td><a href="#t_primitive">primitive</a></td>
				1045	<td><a href="#t_label">label</a>,
				1046	<a href="#t_void">void</a>,
				1047	<a href="#t_integer">integer</a>,
				1048	<a href="#t_floating">floating point</a>.</td>
				1049	</tr>
				1050	<tr>
				1051	<td><a href="#t_derived">derived</a></td>
				1052	<td><a href="#t_integer">integer</a>,
				1053	<a href="#t_array">array</a>,
				1054	<a href="#t_function">function</a>,
				1055	<a href="#t_pointer">pointer</a>,
				1056	<a href="#t_struct">structure</a>,
				1057	<a href="#t_pstruct">packed structure</a>,
				1058	<a href="#t_vector">vector</a>,
				1059	<a href="#t_opaque">opaque</a>.
				1060	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1061	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1062	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1063
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1064	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1065	most important. Values of these types are the only ones which can be
				1066	produced by instructions, passed as arguments, or used as operands to
				1067	instructions. This means that all structures and arrays must be
				1068	manipulated either by pointer or by component.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1069	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1070
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1071	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1072	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1073
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1074	<div class="doc_text">
				1075	<p>The primitive types are the fundamental building blocks of the LLVM
				1076	system.</p>
				1077
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1078	</div>
				1079
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1080	<!-- _______________________________________________________________________ -->
				1081	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1082
				1083	<div class="doc_text">
				1084	<table>
				1085	<tbody>
				1086	<tr><th>Type</th><th>Description</th></tr>
				1087	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1088	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1089	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1090	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1091	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1092	</tbody>
				1093	</table>
				1094	</div>
				1095
				1096	<!-- _______________________________________________________________________ -->
				1097	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1098
				1099	<div class="doc_text">
				1100	<h5>Overview:</h5>
				1101	<p>The void type does not represent any value and has no size.</p>
				1102
				1103	<h5>Syntax:</h5>
				1104
				1105	<pre>
				1106	void
				1107	</pre>
				1108	</div>
				1109
				1110	<!-- _______________________________________________________________________ -->
				1111	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1112
				1113	<div class="doc_text">
				1114	<h5>Overview:</h5>
				1115	<p>The label type represents code labels.</p>
				1116
				1117	<h5>Syntax:</h5>
				1118
				1119	<pre>
				1120	label
				1121	</pre>
				1122	</div>
				1123
				1124
				1125	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1126	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1127
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1128	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1129
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1130	<p>The real power in LLVM comes from the derived types in the system.
				1131	This is what allows a programmer to represent arrays, functions,
				1132	pointers, and other useful types. Note that these derived types may be
				1133	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]	1134
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1135	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1136
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1137	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1138	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1139
				1140	<div class="doc_text">
				1141
				1142	<h5>Overview:</h5>
				1143	<p>The integer type is a very simple derived type that simply specifies an
				1144	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1145	2^23-1 (about 8 million) can be specified.</p>
				1146
				1147	<h5>Syntax:</h5>
				1148
				1149	<pre>
				1150	iN
				1151	</pre>
				1152
				1153	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1154	value.</p>
				1155
				1156	<h5>Examples:</h5>
				1157	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1158	<tbody>
				1159	<tr>
				1160	<td><tt>i1</tt></td>
				1161	<td>a single-bit integer.</td>
				1162	</tr><tr>
				1163	<td><tt>i32</tt></td>
				1164	<td>a 32-bit integer.</td>
				1165	</tr><tr>
				1166	<td><tt>i1942652</tt></td>
				1167	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1168	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1169	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1170	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1171	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1172
				1173	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1174	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1175
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1176	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1177
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1178	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1179
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1180	<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]	1181	sequentially in memory. The array type requires a size (number of
				1182	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1183
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1184	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1185
				1186	<pre>
				1187	[<# elements> x <elementtype>]
				1188	</pre>
				1189
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1190	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1191	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1192
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1193	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1194	<table class="layout">
				1195	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1196	<td class="left"><tt>[40 x i32]</tt></td>
				1197	<td class="left">Array of 40 32-bit integer values.</td>
				1198	</tr>
				1199	<tr class="layout">
				1200	<td class="left"><tt>[41 x i32]</tt></td>
				1201	<td class="left">Array of 41 32-bit integer values.</td>
				1202	</tr>
				1203	<tr class="layout">
				1204	<td class="left"><tt>[4 x i8]</tt></td>
				1205	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1206	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1207	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1208	<p>Here are some examples of multidimensional arrays:</p>
				1209	<table class="layout">
				1210	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1211	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1212	<td class="left">3x4 array of 32-bit integer values.</td>
				1213	</tr>
				1214	<tr class="layout">
				1215	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1216	<td class="left">12x10 array of single precision floating point values.</td>
				1217	</tr>
				1218	<tr class="layout">
				1219	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1220	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1221	</tr>
				1222	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1223
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1224	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1225	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]	1226	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1227	As a special case, however, zero length arrays are recognized to be variable
				1228	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1229	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1230
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1231	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1232
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1233	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1234	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1235	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1236
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1237	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1238
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1239	<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]	1240	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]	1241	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]	1242	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]	1243	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1244
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1245	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1246
				1247	<pre>
				1248	<returntype list> (<parameter list>)
				1249	</pre>
				1250
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1251	<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]	1252	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1253	which indicates that the function takes a variable number of arguments.
				1254	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1255	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1256	'<tt><returntype list></tt>' is a comma-separated list of
				1257	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1258
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1259	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1260	<table class="layout">
				1261	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1262	<td class="left"><tt>i32 (i32)</tt></td>
				1263	<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]	1264	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1265	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1266	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1267	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1268	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1269	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1270	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1271	<tt>float</tt>.
				1272	</td>
				1273	</tr><tr class="layout">
				1274	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1275	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1276	<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]	1277	which returns an integer. This is the signature for <tt>printf</tt> in
				1278	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1279	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1280	</tr><tr class="layout">
				1281	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1282	<td class="left">A function taking an <tt>i32></tt>, returning two
				1283	<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]	1284	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1285	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1286	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1287
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1288	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1289	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1290	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1291	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1292	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1293	<p>The structure type is used to represent a collection of data members
				1294	together in memory. The packing of the field types is defined to match
				1295	the ABI of the underlying processor. The elements of a structure may
				1296	be any type that has a size.</p>
				1297	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1298	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1299	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1300	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1301	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1302	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1303	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1304	<table class="layout">
				1305	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1306	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1307	<td class="left">A triple of three <tt>i32</tt> values</td>
				1308	</tr><tr class="layout">
				1309	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1310	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1311	second element is a <a href="#t_pointer">pointer</a> to a
				1312	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1313	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1314	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1315	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1316	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1317
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1318	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1319	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1320	</div>
				1321	<div class="doc_text">
				1322	<h5>Overview:</h5>
				1323	<p>The packed structure type is used to represent a collection of data members
				1324	together in memory. There is no padding between fields. Further, the alignment
				1325	of a packed structure is 1 byte. The elements of a packed structure may
				1326	be any type that has a size.</p>
				1327	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1328	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1329	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1330	instruction.</p>
				1331	<h5>Syntax:</h5>
				1332	<pre> < { <type list> } > <br></pre>
				1333	<h5>Examples:</h5>
				1334	<table class="layout">
				1335	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1336	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1337	<td class="left">A triple of three <tt>i32</tt> values</td>
				1338	</tr><tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1339	<td class="left"><tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1340	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1341	second element is a <a href="#t_pointer">pointer</a> to a
				1342	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1343	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1344	</tr>
				1345	</table>
				1346	</div>
				1347
				1348	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1349	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1350	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1351	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1352	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1353	reference to another object, which must live in memory. Pointer types may have
				1354	an optional address space attribute defining the target-specific numbered
				1355	address space where the pointed-to object resides. The default address space is
				1356	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1357	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1358	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1359	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1360	<table class="layout">
				1361	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1362	<td class="left"><tt>[4x i32]*</tt></td>
				1363	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1364	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1365	</tr>
				1366	<tr class="layout">
				1367	<td class="left"><tt>i32 (i32 ) </tt></td>
				1368	<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]	1369	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]	1370	<tt>i32</tt>.</td>
				1371	</tr>
				1372	<tr class="layout">
				1373	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1374	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1375	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1376	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1377	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1378	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1379
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1380	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1381	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1382	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1383
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1384	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1385
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1386	<p>A vector type is a simple derived type that represents a vector
				1387	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1388	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1389	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1390	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1391	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1392	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1393
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1394	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1395
				1396	<pre>
				1397	< <# elements> x <elementtype> >
				1398	</pre>
				1399
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1400	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1401	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1402
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1403	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1404
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1405	<table class="layout">
				1406	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1407	<td class="left"><tt><4 x i32></tt></td>
				1408	<td class="left">Vector of 4 32-bit integer values.</td>
				1409	</tr>
				1410	<tr class="layout">
				1411	<td class="left"><tt><8 x float></tt></td>
				1412	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1413	</tr>
				1414	<tr class="layout">
				1415	<td class="left"><tt><2 x i64></tt></td>
				1416	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1417	</tr>
				1418	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1419	</div>
				1420
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1421	<!-- _______________________________________________________________________ -->
				1422	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1423	<div class="doc_text">
				1424
				1425	<h5>Overview:</h5>
				1426
				1427	<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]	1428	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]	1429	In LLVM, opaque types can eventually be resolved to any type (not just a
				1430	structure type).</p>
				1431
				1432	<h5>Syntax:</h5>
				1433
				1434	<pre>
				1435	opaque
				1436	</pre>
				1437
				1438	<h5>Examples:</h5>
				1439
				1440	<table class="layout">
				1441	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1442	<td class="left"><tt>opaque</tt></td>
				1443	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1444	</tr>
				1445	</table>
				1446	</div>
				1447
				1448
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1449	<!-- *********************************************************************** -->
				1450	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1451	<!-- *********************************************************************** -->
				1452
				1453	<div class="doc_text">
				1454
				1455	<p>LLVM has several different basic types of constants. This section describes
				1456	them all and their syntax.</p>
				1457
				1458	</div>
				1459
				1460	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1461	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1462
				1463	<div class="doc_text">
				1464
				1465	<dl>
				1466	<dt><b>Boolean constants</b></dt>
				1467
				1468	<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]	1469	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1470	</dd>
				1471
				1472	<dt><b>Integer constants</b></dt>
				1473
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1474	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1475	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1476	integer types.
				1477	</dd>
				1478
				1479	<dt><b>Floating point constants</b></dt>
				1480
				1481	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1482	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1483	notation (see below). The assembler requires the exact decimal value of
				1484	a floating-point constant. For example, the assembler accepts 1.25 but
				1485	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1486	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]	1487
				1488	<dt><b>Null pointer constants</b></dt>
				1489
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1490	<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]	1491	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1492
				1493	</dl>
				1494
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1495	<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]	1496	of floating point constants. For example, the form '<tt>double
				1497	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1498	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]	1499	(and the only time that they are generated by the disassembler) is when a
				1500	floating point constant must be emitted but it cannot be represented as a
				1501	decimal floating point number. For example, NaN's, infinities, and other
				1502	special values are represented in their IEEE hexadecimal format so that
				1503	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]	1504
				1505	</div>
				1506
				1507	<!-- ======================================================================= -->
				1508	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1509	</div>
				1510
				1511	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1512	<p>Aggregate constants arise from aggregation of simple constants
				1513	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1514
				1515	<dl>
				1516	<dt><b>Structure constants</b></dt>
				1517
				1518	<dd>Structure constants are represented with notation similar to structure
				1519	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1520	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1521	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]	1522	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]	1523	types of elements must match those specified by the type.
				1524	</dd>
				1525
				1526	<dt><b>Array constants</b></dt>
				1527
				1528	<dd>Array constants are represented with notation similar to array type
				1529	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1530	(<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]	1531	constants must have <a href="#t_array">array type</a>, and the number and
				1532	types of elements must match those specified by the type.
				1533	</dd>
				1534
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1535	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1536
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1537	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1538	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1539	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1540	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1541	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]	1542	match those specified by the type.
				1543	</dd>
				1544
				1545	<dt><b>Zero initialization</b></dt>
				1546
				1547	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1548	value to zero of <em>any</em> type, including scalar and aggregate types.
				1549	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]	1550	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1551	initializers.
				1552	</dd>
				1553	</dl>
				1554
				1555	</div>
				1556
				1557	<!-- ======================================================================= -->
				1558	<div class="doc_subsection">
				1559	<a name="globalconstants">Global Variable and Function Addresses</a>
				1560	</div>
				1561
				1562	<div class="doc_text">
				1563
				1564	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1565	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1566	constants. These constants are explicitly referenced when the <a
				1567	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]	1568	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1569	file:</p>
				1570
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1571	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1572	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1573	@X = global i32 17
				1574	@Y = global i32 42
				1575	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1576	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1577	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1578
				1579	</div>
				1580
				1581	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1582	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1583	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1584	<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]	1585	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]	1586	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1587
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1588	<p>Undefined values indicate to the compiler that the program is well defined
				1589	no matter what value is used, giving the compiler more freedom to optimize.
				1590	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1591	</div>
				1592
				1593	<!-- ======================================================================= -->
				1594	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1595	</div>
				1596
				1597	<div class="doc_text">
				1598
				1599	<p>Constant expressions are used to allow expressions involving other constants
				1600	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1601	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]	1602	that does not have side effects (e.g. load and call are not supported). The
				1603	following is the syntax for constant expressions:</p>
				1604
				1605	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1606	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1607	<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]	1608	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1609
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1610	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1611	<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]	1612	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]	1613
				1614	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1615	<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]	1616	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]	1617
				1618	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1619	<dd>Truncate a floating point constant to another floating point type. The
				1620	size of CST must be larger than the size of TYPE. Both types must be
				1621	floating point.</dd>
				1622
				1623	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1624	<dd>Floating point extend a constant to another type. The size of CST must be
				1625	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1626
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1627	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1628	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1629	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1630	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1631	of the same number of elements. If the value won't fit in the integer type,
				1632	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1633
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1634	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1635	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1636	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1637	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1638	of the same number of elements. If the value won't fit in the integer type,
				1639	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1640
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1641	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1642	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1643	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1644	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1645	of the same number of elements. If the value won't fit in the floating point
				1646	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1647
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1648	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1649	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1650	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1651	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1652	of the same number of elements. If the value won't fit in the floating point
				1653	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1654
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1655	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1656	<dd>Convert a pointer typed constant to the corresponding integer constant
				1657	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1658	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1659
				1660	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1661	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1662	pointer type. CST must be of integer type. The CST value is zero extended,
				1663	truncated, or unchanged to make it fit in a pointer size. This one is
				1664	<i>really</i> dangerous!</dd>
				1665
				1666	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1667	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1668	identical (same number of bits). The conversion is done as if the CST value
				1669	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]	1670	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]	1671	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]	1672	pointers it is only valid to cast to another pointer type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1673	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1674
				1675	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1676
				1677	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1678	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1679	instruction, the index list may have zero or more indexes, which are required
				1680	to make sense for the type of "CSTPTR".</dd>
				1681
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1682	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1683
				1684	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1685	constants.</dd>
				1686
				1687	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1688	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1689
				1690	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1691	<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]	1692
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1693	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1694	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1695
				1696	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1697	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1698
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1699	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1700
				1701	<dd>Perform the <a href="#i_extractelement">extractelement
				1702	operation</a> on constants.
				1703
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1704	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1705
				1706	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1707	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1708
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1709
				1710	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1711
				1712	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1713	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1714
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1715	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1716
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1717	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1718	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]	1719	binary</a> operations. The constraints on operands are the same as those for
				1720	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1721	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1722	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1723	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1724
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1725	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1726	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1727	<!-- *********************************************************************** -->
				1728
				1729	<!-- ======================================================================= -->
				1730	<div class="doc_subsection">
				1731	<a name="inlineasm">Inline Assembler Expressions</a>
				1732	</div>
				1733
				1734	<div class="doc_text">
				1735
				1736	<p>
				1737	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1738	Module-Level Inline Assembly</a>) through the use of a special value. This
				1739	value represents the inline assembler as a string (containing the instructions
				1740	to emit), a list of operand constraints (stored as a string), and a flag that
				1741	indicates whether or not the inline asm expression has side effects. An example
				1742	inline assembler expression is:
				1743	</p>
				1744
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1745	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1746	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1747	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1748	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1749	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1750
				1751	<p>
				1752	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1753	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1754	</p>
				1755
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1756	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1757	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1758	%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]	1759	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1760	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1761
				1762	<p>
				1763	Inline asms with side effects not visible in the constraint list must be marked
				1764	as having side effects. This is done through the use of the
				1765	'<tt>sideeffect</tt>' keyword, like so:
				1766	</p>
				1767
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1768	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1769	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1770	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1771	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1772	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1773
				1774	<p>TODO: The format of the asm and constraints string still need to be
				1775	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1776	need to be documented).
				1777	</p>
				1778
				1779	</div>
				1780
				1781	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1782	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1783	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1784
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1785	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1786
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1787	<p>The LLVM instruction set consists of several different
				1788	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1789	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1790	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1791	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1792	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1793
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1794	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1795
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1796	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1797	<div class="doc_subsection"> <a name="terminators">Terminator
				1798	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1799
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1800	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1801
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1802	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1803	basic block in a program ends with a "Terminator" instruction, which
				1804	indicates which block should be executed after the current block is
				1805	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1806	value: they produce control flow, not values (the one exception being
				1807	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1808	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1809	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1810	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1811	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1812	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1813	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1814
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1815	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1816
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1817	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1818	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1819	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1820	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1821	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1822	<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]	1823	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1824	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]	1825	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1826
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1827	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1828
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1829	<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]	1830	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1831	<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]	1832	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]	1833	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1834
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1835	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1836
				1837	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1838	The type of each return value must be a '<a href="#t_firstclass">first
				1839	class</a>' type. Note that a function is not <a href="#wellformed">well
				1840	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1841	function that returns values that do not match the return type of the
				1842	function.</p>
				1843
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1844	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1845
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1846	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1847	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]	1848	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1849	the instruction after the call. If the caller was an "<a
				1850	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1851	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1852	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]	1853	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1854	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1855	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1856
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1857	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1858
				1859	<pre>
				1860	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1861	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1862	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]	1863	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1864	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1865	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1866	<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]	1867	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1868	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1869	<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]	1870	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1871	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1872	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1873	transfer to a different basic block in the current function. There are
				1874	two forms of this instruction, corresponding to a conditional branch
				1875	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1876	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1877	<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]	1878	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1879	unconditional form of the '<tt>br</tt>' instruction takes a single
				1880	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1881	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1882	<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]	1883	argument is evaluated. If the value is <tt>true</tt>, control flows
				1884	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1885	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1886	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1887	<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]	1888	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]	1889	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1890	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1891	<div class="doc_subsubsection">
				1892	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1893	</div>
				1894
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1895	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1896	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1897
				1898	<pre>
				1899	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1900	</pre>
				1901
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1902	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1903
				1904	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1905	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1906	instruction, allowing a branch to occur to one of many possible
				1907	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1908
				1909
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1910	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1911
				1912	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1913	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1914	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1915	table is not allowed to contain duplicate constant entries.</p>
				1916
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1917	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1918
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1919	<p>The <tt>switch</tt> instruction specifies a table of values and
				1920	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1921	table is searched for the given value. If the value is found, control flow is
				1922	transfered to the corresponding destination; otherwise, control flow is
				1923	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1924
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1925	<h5>Implementation:</h5>
				1926
				1927	<p>Depending on properties of the target machine and the particular
				1928	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1929	ways. For example, it could be generated as a series of chained conditional
				1930	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1931
				1932	<h5>Example:</h5>
				1933
				1934	<pre>
				1935	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1936	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1937	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1938
				1939	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1940	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1941
				1942	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1943	switch i32 %val, label %otherwise [ i32 0, label %onzero
				1944	i32 1, label %onone
				1945	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1946	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1947	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1948
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1949	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1950	<div class="doc_subsubsection">
				1951	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				1952	</div>
				1953
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1954	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1955
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1956	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1957
				1958	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	1959	<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]	1960	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1961	</pre>
				1962
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	1963	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1964
				1965	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				1966	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1967	'<tt>normal</tt>' label or the
				1968	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1969	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				1970	"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]	1971	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1972	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1973	returns multiple values then individual return values are only accessible through
				1974	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1975
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1976	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1977
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1978	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1979
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1980	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1981	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	1982	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1983	convention</a> the call should use. If none is specified, the call defaults
				1984	to using C calling conventions.
				1985	</li>
				1986	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				1987	function value being invoked. In most cases, this is a direct function
				1988	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				1989	an arbitrary pointer to function value.
				1990	</li>
				1991
				1992	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				1993	function to be invoked. </li>
				1994
				1995	<li>'<tt>function args</tt>': argument list whose types match the function
				1996	signature argument types. If the function signature indicates the function
				1997	accepts a variable number of arguments, the extra arguments can be
				1998	specified. </li>
				1999
				2000	<li>'<tt>normal label</tt>': the label reached when the called function
				2001	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2002
				2003	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2004	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2005
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2006	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2007
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2008	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2009
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2010	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2011	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2012	difference is that it establishes an association with a label, which is used by
				2013	the runtime library to unwind the stack.</p>
				2014
				2015	<p>This instruction is used in languages with destructors to ensure that proper
				2016	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2017	exception. Additionally, this is important for implementation of
				2018	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2019
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2020	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2021	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2022	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2023	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2024	%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]	2025	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2026	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2027	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2028
				2029
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2030	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2031
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2032	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2033	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2034
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2035	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2036
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2037	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2038	<pre>
				2039	unwind
				2040	</pre>
				2041
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2042	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2043
				2044	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2045	at the first callee in the dynamic call stack which used an <a
				2046	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2047	primarily used to implement exception handling.</p>
				2048
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2049	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2050
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2051	<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]	2052	immediately halt. The dynamic call stack is then searched for the first <a
				2053	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2054	execution continues at the "exceptional" destination block specified by the
				2055	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2056	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2057	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2058
				2059	<!-- _______________________________________________________________________ -->
				2060
				2061	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2062	Instruction</a> </div>
				2063
				2064	<div class="doc_text">
				2065
				2066	<h5>Syntax:</h5>
				2067	<pre>
				2068	unreachable
				2069	</pre>
				2070
				2071	<h5>Overview:</h5>
				2072
				2073	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2074	instruction is used to inform the optimizer that a particular portion of the
				2075	code is not reachable. This can be used to indicate that the code after a
				2076	no-return function cannot be reached, and other facts.</p>
				2077
				2078	<h5>Semantics:</h5>
				2079
				2080	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2081	</div>
				2082
				2083
				2084
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2085	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2086	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2087	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2088	<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]	2089	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]	2090	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2091	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]	2092	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2093	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2094	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2095	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2096	<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
				2097	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2098	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2099	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2100	<pre> <result> = add <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2101	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2102	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2103	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2104	<h5>Arguments:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2105	<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	2106	href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2107	This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	2108	Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2109	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2110	<p>The value produced is the integer or floating point sum of the two
				2111	operands.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2112	<p>If an integer sum has unsigned overflow, the result returned is the
				2113	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2114	the result.</p>
				2115	<p>Because LLVM integers use a two's complement representation, this
				2116	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2117	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2118	<pre> <result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2119	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2120	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2121	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2122	<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
				2123	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2124	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2125	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2126	<pre> <result> = sub <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2127	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2128	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2129	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2130	operands.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2131	<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
				2132	instruction present in most other intermediate representations.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2133	<h5>Arguments:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2134	<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2135	href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	2136	values.
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2137	This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	2138	Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2139	<h5>Semantics:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2140	<p>The value produced is the integer or floating point difference of
				2141	the two operands.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2142	<p>If an integer difference has unsigned overflow, the result returned is the
				2143	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2144	the result.</p>
				2145	<p>Because LLVM integers use a two's complement representation, this
				2146	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2147	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2148	<pre>
				2149	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2150	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2151	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2152	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2153	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2154	<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
				2155	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2156	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2157	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2158	<pre> <result> = mul <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2159	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2160	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2161	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2162	operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2163	<h5>Arguments:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2164	<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2165	href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	2166	values.
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2167	This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	2168	Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2169	<h5>Semantics:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2170	<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]	2171	two operands.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2172	<p>If the result of an integer multiplication has unsigned overflow,
				2173	the result returned is the mathematical result modulo
				2174	2<sup>n</sup>, where n is the bit width of the result.</p>
				2175	<p>Because LLVM integers use a two's complement representation, and the
				2176	result is the same width as the operands, this instruction returns the
				2177	correct result for both signed and unsigned integers. If a full product
				2178	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2179	should be sign-extended or zero-extended as appropriate to the
				2180	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2181	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2182	<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]	2183	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2184	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2185	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2186	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2187	</a></div>
				2188	<div class="doc_text">
				2189	<h5>Syntax:</h5>
				2190	<pre> <result> = udiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2191	</pre>
				2192	<h5>Overview:</h5>
				2193	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2194	operands.</p>
				2195	<h5>Arguments:</h5>
				2196	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
				2197	<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2198	types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2199	of the values in which case the elements must be integers.</p>
				2200	<h5>Semantics:</h5>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2201	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2202	<p>Note that unsigned integer division and signed integer division are distinct
				2203	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2204	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2205	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2206	<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]	2207	</pre>
				2208	</div>
				2209	<!-- _______________________________________________________________________ -->
				2210	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2211	</a> </div>
				2212	<div class="doc_text">
				2213	<h5>Syntax:</h5>
				2214	<pre> <result> = sdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2215	</pre>
				2216	<h5>Overview:</h5>
				2217	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2218	operands.</p>
				2219	<h5>Arguments:</h5>
				2220	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2221	<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2222	types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2223	of the values in which case the elements must be integers.</p>
				2224	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2225	<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]	2226	<p>Note that signed integer division and unsigned integer division are distinct
				2227	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2228	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2229	undefined behavior; this is a rare case, but can occur, for example,
				2230	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2231	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2232	<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]	2233	</pre>
				2234	</div>
				2235	<!-- _______________________________________________________________________ -->
				2236	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2237	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2238	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2239	<h5>Syntax:</h5>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2240	<pre> <result> = fdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2241	</pre>
				2242	<h5>Overview:</h5>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2243	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2244	operands.</p>
				2245	<h5>Arguments:</h5>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2246	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2247	<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2248	identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2249	versions of floating point values.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2250	<h5>Semantics:</h5>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2251	<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2252	<h5>Example:</h5>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2253	<pre> <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]	2254	</pre>
				2255	</div>
				2256	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2257	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2258	</div>
				2259	<div class="doc_text">
				2260	<h5>Syntax:</h5>
				2261	<pre> <result> = urem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2262	</pre>
				2263	<h5>Overview:</h5>
				2264	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2265	unsigned division of its two arguments.</p>
				2266	<h5>Arguments:</h5>
				2267	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2268	<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2269	types. This instruction can also take <a href="#t_vector">vector</a> versions
				2270	of the values in which case the elements must be integers.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2271	<h5>Semantics:</h5>
				2272	<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]	2273	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2274	<p>Note that unsigned integer remainder and signed integer remainder are
				2275	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2276	<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]	2277	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2278	<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]	2279	</pre>
				2280
				2281	</div>
				2282	<!-- _______________________________________________________________________ -->
				2283	<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2284	Instruction</a> </div>
				2285	<div class="doc_text">
				2286	<h5>Syntax:</h5>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2287	<pre> <result> = srem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2288	</pre>
				2289	<h5>Overview:</h5>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2290	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2291	signed division of its two operands. This instruction can also take
				2292	<a href="#t_vector">vector</a> versions of the values in which case
				2293	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2294
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2295	<h5>Arguments:</h5>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2296	<p>The two arguments to the '<tt>srem</tt>' instruction must be
				2297	<a href="#t_integer">integer</a> values. Both arguments must have identical
				2298	types.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2299	<h5>Semantics:</h5>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2300	<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]	2301	has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
				2302	operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
				2303	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2304	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]	2305	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]	2306	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2307	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2308	<p>Note that signed integer remainder and unsigned integer remainder are
				2309	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2310	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2311	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2312	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2313	(The remainder doesn't actually overflow, but this rule lets srem be
				2314	implemented using instructions that return both the result of the division
				2315	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2316	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2317	<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]	2318	</pre>
				2319
				2320	</div>
				2321	<!-- _______________________________________________________________________ -->
				2322	<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
				2323	Instruction</a> </div>
				2324	<div class="doc_text">
				2325	<h5>Syntax:</h5>
				2326	<pre> <result> = frem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2327	</pre>
				2328	<h5>Overview:</h5>
				2329	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2330	division of its two operands.</p>
				2331	<h5>Arguments:</h5>
				2332	<p>The two arguments to the '<tt>frem</tt>' instruction must be
				2333	<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2334	identical types. This instruction can also take <a href="#t_vector">vector</a>
				2335	versions of floating point values.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2336	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2337	<p>This instruction returns the <i>remainder</i> of a division.
				2338	The remainder has the same sign as the dividend.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2339	<h5>Example:</h5>
				2340	<pre> <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]	2341	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2342	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2343
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2344	<!-- ======================================================================= -->
				2345	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2346	Operations</a> </div>
				2347	<div class="doc_text">
				2348	<p>Bitwise binary operators are used to do various forms of
				2349	bit-twiddling in a program. They are generally very efficient
				2350	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2351	instructions. They require two operands of the same type, execute an operation on them,
				2352	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]	2353	</div>
				2354
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2355	<!-- _______________________________________________________________________ -->
				2356	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2357	Instruction</a> </div>
				2358	<div class="doc_text">
				2359	<h5>Syntax:</h5>
				2360	<pre> <result> = shl <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2361	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2362
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2363	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2364
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2365	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2366	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2367
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2368	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2369
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2370	<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]	2371	href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
				2372	unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2373
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2374	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2375
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2376	<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup> mod 2<sup>n</sup>,
				2377	where n is the width of the result. If <tt>var2</tt> is (statically or dynamically) negative or
				2378	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]	2379
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2380	<h5>Example:</h5><pre>
				2381	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2382	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2383	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2384	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2385	</pre>
				2386	</div>
				2387	<!-- _______________________________________________________________________ -->
				2388	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2389	Instruction</a> </div>
				2390	<div class="doc_text">
				2391	<h5>Syntax:</h5>
				2392	<pre> <result> = lshr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2393	</pre>
				2394
				2395	<h5>Overview:</h5>
				2396	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2397	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]	2398
				2399	<h5>Arguments:</h5>
				2400	<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]	2401	<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
				2402	unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2403
				2404	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2405
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2406	<p>This instruction always performs a logical shift right operation. The most
				2407	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]	2408	shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
				2409	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]	2410
				2411	<h5>Example:</h5>
				2412	<pre>
				2413	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2414	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2415	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2416	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2417	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2418	</pre>
				2419	</div>
				2420
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2421	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2422	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2423	Instruction</a> </div>
				2424	<div class="doc_text">
				2425
				2426	<h5>Syntax:</h5>
				2427	<pre> <result> = ashr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2428	</pre>
				2429
				2430	<h5>Overview:</h5>
				2431	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2432	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]	2433
				2434	<h5>Arguments:</h5>
				2435	<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]	2436	<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
				2437	unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2438
				2439	<h5>Semantics:</h5>
				2440	<p>This instruction always performs an arithmetic shift right operation,
				2441	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]	2442	of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
				2443	larger than the number of bits in <tt>var1</tt>, the result is undefined.
				2444	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2445
				2446	<h5>Example:</h5>
				2447	<pre>
				2448	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2449	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2450	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2451	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2452	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2453	</pre>
				2454	</div>
				2455
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2456	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2457	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2458	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2459	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2460	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2461	<pre> <result> = and <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2462	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2463	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2464	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2465	its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2466	<h5>Arguments:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2467	<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	2468	href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2469	identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2470	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2471	<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]	2472	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2473	<div style="align: center">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2474	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2475	<tbody>
				2476	<tr>
				2477	<td>In0</td>
				2478	<td>In1</td>
				2479	<td>Out</td>
				2480	</tr>
				2481	<tr>
				2482	<td>0</td>
				2483	<td>0</td>
				2484	<td>0</td>
				2485	</tr>
				2486	<tr>
				2487	<td>0</td>
				2488	<td>1</td>
				2489	<td>0</td>
				2490	</tr>
				2491	<tr>
				2492	<td>1</td>
				2493	<td>0</td>
				2494	<td>0</td>
				2495	</tr>
				2496	<tr>
				2497	<td>1</td>
				2498	<td>1</td>
				2499	<td>1</td>
				2500	</tr>
				2501	</tbody>
				2502	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2503	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2504	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2505	<pre> <result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
				2506	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2507	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2508	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2509	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2510	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2511	<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]	2512	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2513	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2514	<pre> <result> = or <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2515	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2516	<h5>Overview:</h5>
				2517	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2518	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2519	<h5>Arguments:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2520	<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	2521	href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2522	identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2523	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2524	<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]	2525	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2526	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2527	<table border="1" cellspacing="0" cellpadding="4">
				2528	<tbody>
				2529	<tr>
				2530	<td>In0</td>
				2531	<td>In1</td>
				2532	<td>Out</td>
				2533	</tr>
				2534	<tr>
				2535	<td>0</td>
				2536	<td>0</td>
				2537	<td>0</td>
				2538	</tr>
				2539	<tr>
				2540	<td>0</td>
				2541	<td>1</td>
				2542	<td>1</td>
				2543	</tr>
				2544	<tr>
				2545	<td>1</td>
				2546	<td>0</td>
				2547	<td>1</td>
				2548	</tr>
				2549	<tr>
				2550	<td>1</td>
				2551	<td>1</td>
				2552	<td>1</td>
				2553	</tr>
				2554	</tbody>
				2555	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2556	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2557	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2558	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2559	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2560	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2561	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2562	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2563	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2564	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2565	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2566	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2567	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2568	<pre> <result> = xor <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2569	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2570	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2571	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2572	or of its two operands. The <tt>xor</tt> is used to implement the
				2573	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2574	<h5>Arguments:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2575	<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	2576	href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2577	identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2578	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2579	<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]	2580	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2581	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2582	<table border="1" cellspacing="0" cellpadding="4">
				2583	<tbody>
				2584	<tr>
				2585	<td>In0</td>
				2586	<td>In1</td>
				2587	<td>Out</td>
				2588	</tr>
				2589	<tr>
				2590	<td>0</td>
				2591	<td>0</td>
				2592	<td>0</td>
				2593	</tr>
				2594	<tr>
				2595	<td>0</td>
				2596	<td>1</td>
				2597	<td>1</td>
				2598	</tr>
				2599	<tr>
				2600	<td>1</td>
				2601	<td>0</td>
				2602	<td>1</td>
				2603	</tr>
				2604	<tr>
				2605	<td>1</td>
				2606	<td>1</td>
				2607	<td>0</td>
				2608	</tr>
				2609	</tbody>
				2610	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2611	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2612	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2613	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2614	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2615	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2616	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2617	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2618	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2619	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2620
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2621	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2622	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2623	<a name="vectorops">Vector Operations</a>
				2624	</div>
				2625
				2626	<div class="doc_text">
				2627
				2628	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2629	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2630	vector-specific operations needed to process vectors effectively. While LLVM
				2631	does directly support these vector operations, many sophisticated algorithms
				2632	will want to use target-specific intrinsics to take full advantage of a specific
				2633	target.</p>
				2634
				2635	</div>
				2636
				2637	<!-- _______________________________________________________________________ -->
				2638	<div class="doc_subsubsection">
				2639	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2640	</div>
				2641
				2642	<div class="doc_text">
				2643
				2644	<h5>Syntax:</h5>
				2645
				2646	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2647	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2648	</pre>
				2649
				2650	<h5>Overview:</h5>
				2651
				2652	<p>
				2653	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2654	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2655	</p>
				2656
				2657
				2658	<h5>Arguments:</h5>
				2659
				2660	<p>
				2661	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2662	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]	2663	an index indicating the position from which to extract the element.
				2664	The index may be a variable.</p>
				2665
				2666	<h5>Semantics:</h5>
				2667
				2668	<p>
				2669	The result is a scalar of the same type as the element type of
				2670	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2671	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2672	results are undefined.
				2673	</p>
				2674
				2675	<h5>Example:</h5>
				2676
				2677	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2678	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2679	</pre>
				2680	</div>
				2681
				2682
				2683	<!-- _______________________________________________________________________ -->
				2684	<div class="doc_subsubsection">
				2685	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2686	</div>
				2687
				2688	<div class="doc_text">
				2689
				2690	<h5>Syntax:</h5>
				2691
				2692	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2693	<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]	2694	</pre>
				2695
				2696	<h5>Overview:</h5>
				2697
				2698	<p>
				2699	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2700	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2701	</p>
				2702
				2703
				2704	<h5>Arguments:</h5>
				2705
				2706	<p>
				2707	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2708	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]	2709	scalar value whose type must equal the element type of the first
				2710	operand. The third operand is an index indicating the position at
				2711	which to insert the value. The index may be a variable.</p>
				2712
				2713	<h5>Semantics:</h5>
				2714
				2715	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2716	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]	2717	element values are those of <tt>val</tt> except at position
				2718	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2719	exceeds the length of <tt>val</tt>, the results are undefined.
				2720	</p>
				2721
				2722	<h5>Example:</h5>
				2723
				2724	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2725	%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]	2726	</pre>
				2727	</div>
				2728
				2729	<!-- _______________________________________________________________________ -->
				2730	<div class="doc_subsubsection">
				2731	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2732	</div>
				2733
				2734	<div class="doc_text">
				2735
				2736	<h5>Syntax:</h5>
				2737
				2738	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2739	<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]	2740	</pre>
				2741
				2742	<h5>Overview:</h5>
				2743
				2744	<p>
				2745	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2746	from two input vectors, returning a vector of the same type.
				2747	</p>
				2748
				2749	<h5>Arguments:</h5>
				2750
				2751	<p>
				2752	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2753	with types that match each other and types that match the result of the
				2754	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]	2755	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]	2756	</p>
				2757
				2758	<p>
				2759	The shuffle mask operand is required to be a constant vector with either
				2760	constant integer or undef values.
				2761	</p>
				2762
				2763	<h5>Semantics:</h5>
				2764
				2765	<p>
				2766	The elements of the two input vectors are numbered from left to right across
				2767	both of the vectors. The shuffle mask operand specifies, for each element of
				2768	the result vector, which element of the two input registers the result element
				2769	gets. The element selector may be undef (meaning "don't care") and the second
				2770	operand may be undef if performing a shuffle from only one vector.
				2771	</p>
				2772
				2773	<h5>Example:</h5>
				2774
				2775	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2776	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2777	<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]	2778	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2779	<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]	2780	</pre>
				2781	</div>
				2782
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2783
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2784	<!-- ======================================================================= -->
				2785	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2786	<a name="aggregateops">Aggregate Operations</a>
				2787	</div>
				2788
				2789	<div class="doc_text">
				2790
				2791	<p>LLVM supports several instructions for working with aggregate values.
				2792	</p>
				2793
				2794	</div>
				2795
				2796	<!-- _______________________________________________________________________ -->
				2797	<div class="doc_subsubsection">
				2798	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2799	</div>
				2800
				2801	<div class="doc_text">
				2802
				2803	<h5>Syntax:</h5>
				2804
				2805	<pre>
				2806	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2807	</pre>
				2808
				2809	<h5>Overview:</h5>
				2810
				2811	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame^]	2812	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2813	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2814	</p>
				2815
				2816
				2817	<h5>Arguments:</h5>
				2818
				2819	<p>
				2820	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2821	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^]	2822	type. The operands are constant indices to specify which value to extract
				2823	in the same manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2824	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2825	</p>
				2826
				2827	<h5>Semantics:</h5>
				2828
				2829	<p>
				2830	The result is the value at the position in the aggregate specified by
				2831	the index operands.
				2832	</p>
				2833
				2834	<h5>Example:</h5>
				2835
				2836	<pre>
				2837	%result = extractvalue {i32, float} %agg, i32 0 <i>; yields i32</i>
				2838	</pre>
				2839	</div>
				2840
				2841
				2842	<!-- _______________________________________________________________________ -->
				2843	<div class="doc_subsubsection">
				2844	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				2845	</div>
				2846
				2847	<div class="doc_text">
				2848
				2849	<h5>Syntax:</h5>
				2850
				2851	<pre>
				2852	<result> = insertvalue <aggregate type> <val>, <ty> <val>, i32 <idx> <i>; yields <n x <ty>></i>
				2853	</pre>
				2854
				2855	<h5>Overview:</h5>
				2856
				2857	<p>
				2858	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame^]	2859	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2860	</p>
				2861
				2862
				2863	<h5>Arguments:</h5>
				2864
				2865	<p>
				2866	The first operand of an '<tt>insertvalue</tt>' instruction is a
				2867	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				2868	The second operand is a first-class value to insert.
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame^]	2869	type of the first operand. The following operands are constant indices
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2870	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^]	2871	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2872	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2873	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^]	2874	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2875
				2876	<h5>Semantics:</h5>
				2877
				2878	<p>
				2879	The result is an aggregate of the same type as <tt>val</tt>. Its
				2880	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^]	2881	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2882	</p>
				2883
				2884	<h5>Example:</h5>
				2885
				2886	<pre>
				2887	%result = insertvalue {i32, float} %agg, i32 1, i32 0 <i>; yields {i32, float}</i>
				2888	</pre>
				2889	</div>
				2890
				2891
				2892	<!-- ======================================================================= -->
				2893	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	2894	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2895	</div>
				2896
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2897	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2898
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2899	<p>A key design point of an SSA-based representation is how it
				2900	represents memory. In LLVM, no memory locations are in SSA form, which
				2901	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2902	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2903
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2904	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2905
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2906	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2907	<div class="doc_subsubsection">
				2908	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				2909	</div>
				2910
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2911	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2912
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2913	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2914
				2915	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2916	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2917	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2918
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2919	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2920
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2921	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	2922	heap and returns a pointer to it. The object is always allocated in the generic
				2923	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2924
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2925	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2926
				2927	<p>The '<tt>malloc</tt>' instruction allocates
				2928	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	2929	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]	2930	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	2931	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	2932	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]	2933	be aligned to at least that boundary. If not specified, or if zero, the target can
				2934	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2935
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2936	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2937
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2938	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2939
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2940	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2941	a pointer is returned. The result of a zero byte allocattion is undefined. The
				2942	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2943
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2944	<h5>Example:</h5>
				2945
				2946	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2947	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2948
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2949	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				2950	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				2951	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				2952	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				2953	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2954	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2955	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2956
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2957	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2958	<div class="doc_subsubsection">
				2959	<a name="i_free">'<tt>free</tt>' Instruction</a>
				2960	</div>
				2961
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2962	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2963
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2964	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2965
				2966	<pre>
				2967	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2968	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2969
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2970	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2971
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2972	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2973	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2974
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2975	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2976
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2977	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				2978	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				2979	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2980
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2981	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2982
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2983	<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]	2984	after this instruction executes. If the pointer is null, the operation
				2985	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2986
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2987	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2988
				2989	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2990	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				2991	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2992	</pre>
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_alloca">'<tt>alloca</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> = alloca <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
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3010	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3011	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3012	returns to its caller. The object is always allocated in the generic address
				3013	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3014
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3015	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3016
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3017	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3018	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3019	appropriate type to the program. If "NumElements" is specified, it is the
				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
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3022	to be aligned to at least that boundary. If not specified, or if zero, the target
				3023	can 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>' may be any 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	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3029	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3030	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3031	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3032	instruction is commonly used to represent automatic variables that must
				3033	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]	3034	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]	3035	instructions), the memory is reclaimed. Allocating zero bytes
				3036	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3037
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3038	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3039
				3040	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3041	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3042	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3043	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3044	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3045	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3046	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3047
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3048	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3049	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3050	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3051	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3052	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3053	<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]	3054	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3055	<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]	3056	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3057	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3058	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3059	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]	3060	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]	3061	the number or order of execution of this <tt>load</tt> with other
				3062	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3063	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3064	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3065	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3066	(that is, the alignment of the memory address). A value of 0 or an
				3067	omitted "align" argument means that the operation has the preferential
				3068	alignment for the target. It is the responsibility of the code emitter
				3069	to ensure that the alignment information is correct. Overestimating
				3070	the alignment results in an undefined behavior. Underestimating the
				3071	alignment may produce less efficient code. An alignment of 1 is always
				3072	safe.
				3073	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3074	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3075	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3076	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3077	<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]	3078	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3079	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3080	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3081	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3082	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3083	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3084	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3085	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3086	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3087	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3088	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3089	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3090	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3091	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3092	<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]	3093	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3094	<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]	3095	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]	3096	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3097	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3098	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]	3099	optimizer is not allowed to modify the number or order of execution of
				3100	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3101	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3102	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3103	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3104	(that is, the alignment of the memory address). A value of 0 or an
				3105	omitted "align" argument means that the operation has the preferential
				3106	alignment for the target. It is the responsibility of the code emitter
				3107	to ensure that the alignment information is correct. Overestimating
				3108	the alignment results in an undefined behavior. Underestimating the
				3109	alignment may produce less efficient code. An alignment of 1 is always
				3110	safe.
				3111	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3112	<h5>Semantics:</h5>
				3113	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3114	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3115	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3116	<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]	3117	store i32 3, i32* %ptr <i>; yields {void}</i>
				3118	%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]	3119	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3120	</div>
				3121
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3122	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3123	<div class="doc_subsubsection">
				3124	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3125	</div>
				3126
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3127	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3128	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3129	<pre>
				3130	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3131	</pre>
				3132
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3133	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3134
				3135	<p>
				3136	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3137	subelement of an aggregate data structure.</p>
				3138
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3139	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3140
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3141	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3142	elements of the aggregate object to index to. The actual types of the arguments
				3143	provided depend on the type of the first pointer argument. The
				3144	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3145	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]	3146	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3147	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3148	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3149
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3150	<p>For example, let's consider a C code fragment and how it gets
				3151	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3152
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3153	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3154	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3155	struct RT {
				3156	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3157	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3158	char C;
				3159	};
				3160	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3161	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3162	double Y;
				3163	struct RT Z;
				3164	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3165
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3166	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3167	return &s[1].Z.B[5][13];
				3168	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3169	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3170	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3171
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3172	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3173
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3174	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3175	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3176	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3177	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3178
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3179	define i32* %foo(%ST* %s) {
				3180	entry:
				3181	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3182	ret i32* %reg
				3183	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3184	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3185	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3186
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3187	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3188
				3189	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3190	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]	3191	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]	3192	<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]	3193	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3194	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3195
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3196	<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]	3197	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]	3198	}</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]	3199	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3200	i8 }</tt>' type, another structure. The third index indexes into the second
				3201	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]	3202	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3203	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3204	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]	3205
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3206	<p>Note that it is perfectly legal to index partially through a
				3207	structure, returning a pointer to an inner element. Because of this,
				3208	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3209
				3210	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3211	define i32* %foo(%ST* %s) {
				3212	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3213	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3214	%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]	3215	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3216	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3217	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3218	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3219	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3220
				3221	<p>Note that it is undefined to access an array out of bounds: array and
				3222	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]	3223	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]	3224	defined to be accessible as variable length arrays, which requires access
				3225	beyond the zero'th element.</p>
				3226
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3227	<p>The getelementptr instruction is often confusing. For some more insight
				3228	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3229	FAQ</a>.</p>
				3230
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3231	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3232
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3233	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3234	<i>; yields [12 x i8]*:aptr</i>
				3235	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3236	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3237	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3238
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3239	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3240	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3241	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3242	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3243	<p>The instructions in this category are the conversion instructions (casting)
				3244	which all take a single operand and a type. They perform various bit conversions
				3245	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3246	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3247
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3248	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3249	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3250	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3251	</div>
				3252	<div class="doc_text">
				3253
				3254	<h5>Syntax:</h5>
				3255	<pre>
				3256	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3257	</pre>
				3258
				3259	<h5>Overview:</h5>
				3260	<p>
				3261	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3262	</p>
				3263
				3264	<h5>Arguments:</h5>
				3265	<p>
				3266	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3267	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]	3268	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]	3269	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3270	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3271
				3272	<h5>Semantics:</h5>
				3273	<p>
				3274	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]	3275	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3276	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3277	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3278
				3279	<h5>Example:</h5>
				3280	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3281	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3282	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3283	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3284	</pre>
				3285	</div>
				3286
				3287	<!-- _______________________________________________________________________ -->
				3288	<div class="doc_subsubsection">
				3289	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3290	</div>
				3291	<div class="doc_text">
				3292
				3293	<h5>Syntax:</h5>
				3294	<pre>
				3295	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3296	</pre>
				3297
				3298	<h5>Overview:</h5>
				3299	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3300	<tt>ty2</tt>.</p>
				3301
				3302
				3303	<h5>Arguments:</h5>
				3304	<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]	3305	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3306	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]	3307	<tt>value</tt> must be smaller than the bit size of the destination type,
				3308	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3309
				3310	<h5>Semantics:</h5>
				3311	<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]	3312	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]	3313
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3314	<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]	3315
				3316	<h5>Example:</h5>
				3317	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3318	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3319	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3320	</pre>
				3321	</div>
				3322
				3323	<!-- _______________________________________________________________________ -->
				3324	<div class="doc_subsubsection">
				3325	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3326	</div>
				3327	<div class="doc_text">
				3328
				3329	<h5>Syntax:</h5>
				3330	<pre>
				3331	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3332	</pre>
				3333
				3334	<h5>Overview:</h5>
				3335	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3336
				3337	<h5>Arguments:</h5>
				3338	<p>
				3339	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]	3340	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3341	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]	3342	<tt>value</tt> must be smaller than the bit size of the destination type,
				3343	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3344
				3345	<h5>Semantics:</h5>
				3346	<p>
				3347	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3348	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]	3349	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3350
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3351	<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]	3352
				3353	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3354	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3355	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3356	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3357	</pre>
				3358	</div>
				3359
				3360	<!-- _______________________________________________________________________ -->
				3361	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3362	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3363	</div>
				3364
				3365	<div class="doc_text">
				3366
				3367	<h5>Syntax:</h5>
				3368
				3369	<pre>
				3370	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3371	</pre>
				3372
				3373	<h5>Overview:</h5>
				3374	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3375	<tt>ty2</tt>.</p>
				3376
				3377
				3378	<h5>Arguments:</h5>
				3379	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3380	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3381	cast it to. The size of <tt>value</tt> must be larger than the size of
				3382	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3383	<i>no-op cast</i>.</p>
				3384
				3385	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3386	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3387	<a href="#t_floating">floating point</a> type to a smaller
				3388	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3389	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3390
				3391	<h5>Example:</h5>
				3392	<pre>
				3393	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3394	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3395	</pre>
				3396	</div>
				3397
				3398	<!-- _______________________________________________________________________ -->
				3399	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3400	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3401	</div>
				3402	<div class="doc_text">
				3403
				3404	<h5>Syntax:</h5>
				3405	<pre>
				3406	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3407	</pre>
				3408
				3409	<h5>Overview:</h5>
				3410	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3411	floating point value.</p>
				3412
				3413	<h5>Arguments:</h5>
				3414	<p>The '<tt>fpext</tt>' instruction takes a
				3415	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3416	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3417	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3418
				3419	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3420	<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]	3421	<a href="#t_floating">floating point</a> type to a larger
				3422	<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]	3423	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]	3424	<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]	3425
				3426	<h5>Example:</h5>
				3427	<pre>
				3428	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3429	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3430	</pre>
				3431	</div>
				3432
				3433	<!-- _______________________________________________________________________ -->
				3434	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3435	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3436	</div>
				3437	<div class="doc_text">
				3438
				3439	<h5>Syntax:</h5>
				3440	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3441	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3442	</pre>
				3443
				3444	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3445	<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]	3446	unsigned integer equivalent of type <tt>ty2</tt>.
				3447	</p>
				3448
				3449	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3450	<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]	3451	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3452	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3453	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3454	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]	3455
				3456	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3457	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3458	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3459	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3460	the results are undefined.</p>
				3461
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3462	<h5>Example:</h5>
				3463	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3464	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3465	%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]	3466	%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]	3467	</pre>
				3468	</div>
				3469
				3470	<!-- _______________________________________________________________________ -->
				3471	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3472	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3473	</div>
				3474	<div class="doc_text">
				3475
				3476	<h5>Syntax:</h5>
				3477	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3478	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3479	</pre>
				3480
				3481	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3482	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3483	<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]	3484	</p>
				3485
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3486	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3487	<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]	3488	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3489	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3490	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3491	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]	3492
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3493	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3494	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3495	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3496	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3497	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3498
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3499	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3500	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3501	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3502	%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]	3503	%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]	3504	</pre>
				3505	</div>
				3506
				3507	<!-- _______________________________________________________________________ -->
				3508	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3509	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3510	</div>
				3511	<div class="doc_text">
				3512
				3513	<h5>Syntax:</h5>
				3514	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3515	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3516	</pre>
				3517
				3518	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3519	<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]	3520	integer and converts that value to the <tt>ty2</tt> type.</p>
				3521
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3522	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3523	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3524	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3525	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3526	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3527	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]	3528
				3529	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3530	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3531	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3532	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]	3533
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3534	<h5>Example:</h5>
				3535	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3536	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3537	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3538	</pre>
				3539	</div>
				3540
				3541	<!-- _______________________________________________________________________ -->
				3542	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3543	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3544	</div>
				3545	<div class="doc_text">
				3546
				3547	<h5>Syntax:</h5>
				3548	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3549	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3550	</pre>
				3551
				3552	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3553	<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]	3554	integer and converts that value to the <tt>ty2</tt> type.</p>
				3555
				3556	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3557	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3558	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3559	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3560	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3561	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]	3562
				3563	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3564	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3565	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3566	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]	3567
				3568	<h5>Example:</h5>
				3569	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3570	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3571	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3572	</pre>
				3573	</div>
				3574
				3575	<!-- _______________________________________________________________________ -->
				3576	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3577	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3578	</div>
				3579	<div class="doc_text">
				3580
				3581	<h5>Syntax:</h5>
				3582	<pre>
				3583	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3584	</pre>
				3585
				3586	<h5>Overview:</h5>
				3587	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3588	the integer type <tt>ty2</tt>.</p>
				3589
				3590	<h5>Arguments:</h5>
				3591	<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]	3592	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]	3593	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3594
				3595	<h5>Semantics:</h5>
				3596	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3597	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3598	truncating or zero extending that value to the size of the integer type. If
				3599	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3600	<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]	3601	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3602	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3603
				3604	<h5>Example:</h5>
				3605	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3606	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3607	%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]	3608	</pre>
				3609	</div>
				3610
				3611	<!-- _______________________________________________________________________ -->
				3612	<div class="doc_subsubsection">
				3613	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3614	</div>
				3615	<div class="doc_text">
				3616
				3617	<h5>Syntax:</h5>
				3618	<pre>
				3619	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3620	</pre>
				3621
				3622	<h5>Overview:</h5>
				3623	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3624	a pointer type, <tt>ty2</tt>.</p>
				3625
				3626	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3627	<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]	3628	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]	3629	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3630
				3631	<h5>Semantics:</h5>
				3632	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3633	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3634	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3635	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3636	the size of a pointer then a zero extension is done. If they are the same size,
				3637	nothing is done (<i>no-op cast</i>).</p>
				3638
				3639	<h5>Example:</h5>
				3640	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3641	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3642	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3643	%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]	3644	</pre>
				3645	</div>
				3646
				3647	<!-- _______________________________________________________________________ -->
				3648	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3649	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3650	</div>
				3651	<div class="doc_text">
				3652
				3653	<h5>Syntax:</h5>
				3654	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3655	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3656	</pre>
				3657
				3658	<h5>Overview:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3659	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3660	<tt>ty2</tt> without changing any bits.</p>
				3661
				3662	<h5>Arguments:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3663	<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]	3664	a first class value, and a type to cast it to, which must also be a <a
				3665	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]	3666	and the destination type, <tt>ty2</tt>, must be identical. If the source
				3667	type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3668
				3669	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3670	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3671	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3672	this conversion. The conversion is done as if the <tt>value</tt> had been
				3673	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3674	converted to other pointer types with this instruction. To convert pointers to
				3675	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3676	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3677
				3678	<h5>Example:</h5>
				3679	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3680	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3681	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3682	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3683	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3684	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3685
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3686	<!-- ======================================================================= -->
				3687	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3688	<div class="doc_text">
				3689	<p>The instructions in this category are the "miscellaneous"
				3690	instructions, which defy better classification.</p>
				3691	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3692
				3693	<!-- _______________________________________________________________________ -->
				3694	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3695	</div>
				3696	<div class="doc_text">
				3697	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3698	<pre> <result> = icmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3699	</pre>
				3700	<h5>Overview:</h5>
				3701	<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]	3702	of its two integer or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3703	<h5>Arguments:</h5>
				3704	<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]	3705	the condition code indicating the kind of comparison to perform. It is not
				3706	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3707	<ol>
				3708	<li><tt>eq</tt>: equal</li>
				3709	<li><tt>ne</tt>: not equal </li>
				3710	<li><tt>ugt</tt>: unsigned greater than</li>
				3711	<li><tt>uge</tt>: unsigned greater or equal</li>
				3712	<li><tt>ult</tt>: unsigned less than</li>
				3713	<li><tt>ule</tt>: unsigned less or equal</li>
				3714	<li><tt>sgt</tt>: signed greater than</li>
				3715	<li><tt>sge</tt>: signed greater or equal</li>
				3716	<li><tt>slt</tt>: signed less than</li>
				3717	<li><tt>sle</tt>: signed less or equal</li>
				3718	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3719	<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]	3720	<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]	3721	<h5>Semantics:</h5>
				3722	<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
				3723	the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3724	yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3725	<ol>
				3726	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3727	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3728	</li>
				3729	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3730	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3731	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
				3732	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3733	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
				3734	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3735	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
				3736	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3737	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
				3738	<tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
				3739	<li><tt>sgt</tt>: interprets the operands as signed values and yields
				3740	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3741	<li><tt>sge</tt>: interprets the operands as signed values and yields
				3742	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3743	<li><tt>slt</tt>: interprets the operands as signed values and yields
				3744	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3745	<li><tt>sle</tt>: interprets the operands as signed values and yields
				3746	<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]	3747	</ol>
				3748	<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]	3749	values are compared as if they were integers.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3750
				3751	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3752	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3753	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3754	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3755	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3756	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3757	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3758	</pre>
				3759	</div>
				3760
				3761	<!-- _______________________________________________________________________ -->
				3762	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3763	</div>
				3764	<div class="doc_text">
				3765	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3766	<pre> <result> = fcmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3767	</pre>
				3768	<h5>Overview:</h5>
				3769	<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
				3770	of its floating point operands.</p>
				3771	<h5>Arguments:</h5>
				3772	<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]	3773	the condition code indicating the kind of comparison to perform. It is not
				3774	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3775	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3776	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3777	<li><tt>oeq</tt>: ordered and equal</li>
				3778	<li><tt>ogt</tt>: ordered and greater than </li>
				3779	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3780	<li><tt>olt</tt>: ordered and less than </li>
				3781	<li><tt>ole</tt>: ordered and less than or equal</li>
				3782	<li><tt>one</tt>: ordered and not equal</li>
				3783	<li><tt>ord</tt>: ordered (no nans)</li>
				3784	<li><tt>ueq</tt>: unordered or equal</li>
				3785	<li><tt>ugt</tt>: unordered or greater than </li>
				3786	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3787	<li><tt>ult</tt>: unordered or less than </li>
				3788	<li><tt>ule</tt>: unordered or less than or equal</li>
				3789	<li><tt>une</tt>: unordered or not equal</li>
				3790	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3791	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3792	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3793	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3794	<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer	350f8aa	2007-01-04 05:19:58 +0000	[diff] [blame]	3795	<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
				3796	<a href="#t_floating">floating point</a> typed. They must have identical
				3797	types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3798	<h5>Semantics:</h5>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3799	<p>The '<tt>fcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3800	according to the condition code given as <tt>cond</tt>. The comparison performed
				3801	always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3802	<ol>
				3803	<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]	3804	<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]	3805	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3806	<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]	3807	<tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3808	<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]	3809	<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]	3810	<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]	3811	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3812	<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]	3813	<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]	3814	<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]	3815	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3816	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3817	<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]	3818	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3819	<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]	3820	<tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3821	<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]	3822	<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]	3823	<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]	3824	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3825	<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]	3826	<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]	3827	<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]	3828	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3829	<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]	3830	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				3831	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3832
				3833	<h5>Example:</h5>
				3834	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
				3835	<result> = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
				3836	<result> = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				3837	<result> = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
				3838	</pre>
				3839	</div>
				3840
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3841	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3842	<div class="doc_subsubsection">
				3843	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				3844	</div>
				3845	<div class="doc_text">
				3846	<h5>Syntax:</h5>
				3847	<pre> <result> = vicmp <cond> <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				3848	</pre>
				3849	<h5>Overview:</h5>
				3850	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				3851	element-wise comparison of its two integer vector operands.</p>
				3852	<h5>Arguments:</h5>
				3853	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				3854	the condition code indicating the kind of comparison to perform. It is not
				3855	a value, just a keyword. The possible condition code are:
				3856	<ol>
				3857	<li><tt>eq</tt>: equal</li>
				3858	<li><tt>ne</tt>: not equal </li>
				3859	<li><tt>ugt</tt>: unsigned greater than</li>
				3860	<li><tt>uge</tt>: unsigned greater or equal</li>
				3861	<li><tt>ult</tt>: unsigned less than</li>
				3862	<li><tt>ule</tt>: unsigned less or equal</li>
				3863	<li><tt>sgt</tt>: signed greater than</li>
				3864	<li><tt>sge</tt>: signed greater or equal</li>
				3865	<li><tt>slt</tt>: signed less than</li>
				3866	<li><tt>sle</tt>: signed less or equal</li>
				3867	</ol>
				3868	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				3869	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				3870	<h5>Semantics:</h5>
				3871	<p>The '<tt>vicmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3872	according to the condition code given as <tt>cond</tt>. The comparison yields a
				3873	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				3874	identical type as the values being compared. The most significant bit in each
				3875	element is 1 if the element-wise comparison evaluates to true, and is 0
				3876	otherwise. All other bits of the result are undefined. The condition codes
				3877	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				3878	instruction</a>.
				3879
				3880	<h5>Example:</h5>
				3881	<pre>
				3882	<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>
				3883	<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>
				3884	</pre>
				3885	</div>
				3886
				3887	<!-- _______________________________________________________________________ -->
				3888	<div class="doc_subsubsection">
				3889	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				3890	</div>
				3891	<div class="doc_text">
				3892	<h5>Syntax:</h5>
				3893	<pre> <result> = vfcmp <cond> <ty> <var1>, <var2></pre>
				3894	<h5>Overview:</h5>
				3895	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				3896	element-wise comparison of its two floating point vector operands. The output
				3897	elements have the same width as the input elements.</p>
				3898	<h5>Arguments:</h5>
				3899	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				3900	the condition code indicating the kind of comparison to perform. It is not
				3901	a value, just a keyword. The possible condition code are:
				3902	<ol>
				3903	<li><tt>false</tt>: no comparison, always returns false</li>
				3904	<li><tt>oeq</tt>: ordered and equal</li>
				3905	<li><tt>ogt</tt>: ordered and greater than </li>
				3906	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3907	<li><tt>olt</tt>: ordered and less than </li>
				3908	<li><tt>ole</tt>: ordered and less than or equal</li>
				3909	<li><tt>one</tt>: ordered and not equal</li>
				3910	<li><tt>ord</tt>: ordered (no nans)</li>
				3911	<li><tt>ueq</tt>: unordered or equal</li>
				3912	<li><tt>ugt</tt>: unordered or greater than </li>
				3913	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3914	<li><tt>ult</tt>: unordered or less than </li>
				3915	<li><tt>ule</tt>: unordered or less than or equal</li>
				3916	<li><tt>une</tt>: unordered or not equal</li>
				3917	<li><tt>uno</tt>: unordered (either nans)</li>
				3918	<li><tt>true</tt>: no comparison, always returns true</li>
				3919	</ol>
				3920	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				3921	<a href="#t_floating">floating point</a> typed. They must also be identical
				3922	types.</p>
				3923	<h5>Semantics:</h5>
				3924	<p>The '<tt>vfcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3925	according to the condition code given as <tt>cond</tt>. The comparison yields a
				3926	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				3927	an identical number of elements as the values being compared, and each element
				3928	having identical with to the width of the floating point elements. The most
				3929	significant bit in each element is 1 if the element-wise comparison evaluates to
				3930	true, and is 0 otherwise. All other bits of the result are undefined. The
				3931	condition codes are evaluated identically to the
				3932	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				3933
				3934	<h5>Example:</h5>
				3935	<pre>
				3936	<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>
				3937	<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>
				3938	</pre>
				3939	</div>
				3940
				3941	<!-- _______________________________________________________________________ -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3942	<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
				3943	Instruction</a> </div>
				3944	<div class="doc_text">
				3945	<h5>Syntax:</h5>
				3946	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				3947	<h5>Overview:</h5>
				3948	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				3949	the SSA graph representing the function.</p>
				3950	<h5>Arguments:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3951	<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]	3952	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				3953	as arguments, with one pair for each predecessor basic block of the
				3954	current block. Only values of <a href="#t_firstclass">first class</a>
				3955	type may be used as the value arguments to the PHI node. Only labels
				3956	may be used as the label arguments.</p>
				3957	<p>There must be no non-phi instructions between the start of a basic
				3958	block and the PHI instructions: i.e. PHI instructions must be first in
				3959	a basic block.</p>
				3960	<h5>Semantics:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3961	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				3962	specified by the pair corresponding to the predecessor basic block that executed
				3963	just prior to the current block.</p>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3964	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3965	<pre>Loop: ; Infinite loop that counts from 0 on up...<br> %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]<br> %nextindvar = add i32 %indvar, 1<br> br label %Loop<br></pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3966	</div>
				3967
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3968	<!-- _______________________________________________________________________ -->
				3969	<div class="doc_subsubsection">
				3970	<a name="i_select">'<tt>select</tt>' Instruction</a>
				3971	</div>
				3972
				3973	<div class="doc_text">
				3974
				3975	<h5>Syntax:</h5>
				3976
				3977	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3978	<result> = select i1 <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3979	</pre>
				3980
				3981	<h5>Overview:</h5>
				3982
				3983	<p>
				3984	The '<tt>select</tt>' instruction is used to choose one value based on a
				3985	condition, without branching.
				3986	</p>
				3987
				3988
				3989	<h5>Arguments:</h5>
				3990
				3991	<p>
				3992	The '<tt>select</tt>' instruction requires a boolean value indicating the condition, and two values of the same <a href="#t_firstclass">first class</a> type.
				3993	</p>
				3994
				3995	<h5>Semantics:</h5>
				3996
				3997	<p>
				3998	If the boolean condition evaluates to true, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3999	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4000	</p>
				4001
				4002	<h5>Example:</h5>
				4003
				4004	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4005	%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]	4006	</pre>
				4007	</div>
				4008
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4009
				4010	<!-- _______________________________________________________________________ -->
				4011	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4012	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4013	</div>
				4014
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4015	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4016
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4017	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4018	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4019	<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]	4020	</pre>
				4021
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4022	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4023
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4024	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4025
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4026	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4027
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4028	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4029
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4030	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4031	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4032	<p>The optional "tail" marker indicates whether the callee function accesses
				4033	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]	4034	function call is eligible for tail call optimization. Note that calls may
				4035	be marked "tail" even if they do not occur before a <a
				4036	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4037	</li>
				4038	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4039	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4040	convention</a> the call should use. If none is specified, the call defaults
				4041	to using C calling conventions.
				4042	</li>
				4043	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4044	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4045	the type of the return value. Functions that return no value are marked
				4046	<tt><a href="#t_void">void</a></tt>.</p>
				4047	</li>
				4048	<li>
				4049	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4050	value being invoked. The argument types must match the types implied by
				4051	this signature. This type can be omitted if the function is not varargs
				4052	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]	4053	</li>
				4054	<li>
				4055	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4056	be invoked. In most cases, this is a direct function invocation, but
				4057	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]	4058	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4059	</li>
				4060	<li>
				4061	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4062	function signature argument types. All arguments must be of
				4063	<a href="#t_firstclass">first class</a> type. If the function signature
				4064	indicates the function accepts a variable number of arguments, the extra
				4065	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4066	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4067	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4068
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4069	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4070
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4071	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4072	transfer to a specified function, with its incoming arguments bound to
				4073	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4074	instruction in the called function, control flow continues with the
				4075	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4076	function is bound to the result argument. If the callee returns multiple
				4077	values then the return values of the function are only accessible through
				4078	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4079
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4080	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4081
				4082	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4083	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4084	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4085	%X = tail call i32 @foo() <i>; yields i32</i>
				4086	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4087	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4088
				4089	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4090	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4091	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4092	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4093	</pre>
				4094
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4095	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4096
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4097	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4098	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4099	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4100	</div>
				4101
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4102	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4103
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4104	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4105
				4106	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4107	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4108	</pre>
				4109
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4110	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4111
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4112	<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]	4113	the "variable argument" area of a function call. It is used to implement the
				4114	<tt>va_arg</tt> macro in C.</p>
				4115
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4116	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4117
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4118	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4119	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4120	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]	4121	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4122
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4123	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4124
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4125	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4126	type from the specified <tt>va_list</tt> and causes the
				4127	<tt>va_list</tt> to point to the next argument. For more information,
				4128	see the variable argument handling <a href="#int_varargs">Intrinsic
				4129	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4130
				4131	<p>It is legal for this instruction to be called in a function which does not
				4132	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4133	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4134
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4135	<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]	4136	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4137	argument.</p>
				4138
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4139	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4140
				4141	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4142
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4143	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4144
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4145	<!-- _______________________________________________________________________ -->
				4146	<div class="doc_subsubsection">
				4147	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4148	</div>
				4149
				4150	<div class="doc_text">
				4151
				4152	<h5>Syntax:</h5>
				4153	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4154	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4155	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4156
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4157	<h5>Overview:</h5>
				4158
				4159	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4160	from a '<tt><a href="#i_call">call</a></tt>'
				4161	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4162	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4163
				4164	<h5>Arguments:</h5>
				4165
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4166	<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]	4167	first argument, or an undef value. The value must have <a
				4168	href="#t_struct">structure type</a>. The second argument is a constant
				4169	unsigned index value which must be in range for the number of values returned
				4170	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4171
				4172	<h5>Semantics:</h5>
				4173
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4174	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4175	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4176
				4177	<h5>Example:</h5>
				4178
				4179	<pre>
				4180	%struct.A = type { i32, i8 }
				4181
				4182	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4183	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4184	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4185	add i32 %gr, 42
				4186	add i8 %gr1, 41
				4187	</pre>
				4188
				4189	</div>
				4190
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4191	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4192	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4193	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4194
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4195	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4196
				4197	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4198	well known names and semantics and are required to follow certain restrictions.
				4199	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4200	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]	4201	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]	4202
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4203	<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]	4204	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4205	begin with this prefix. Intrinsic functions must always be external functions:
				4206	you cannot define the body of intrinsic functions. Intrinsic functions may
				4207	only be used in call or invoke instructions: it is illegal to take the address
				4208	of an intrinsic function. Additionally, because intrinsic functions are part
				4209	of the LLVM language, it is required if any are added that they be documented
				4210	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4211
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4212	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4213	a family of functions that perform the same operation but on different data
				4214	types. Because LLVM can represent over 8 million different integer types,
				4215	overloading is used commonly to allow an intrinsic function to operate on any
				4216	integer type. One or more of the argument types or the result type can be
				4217	overloaded to accept any integer type. Argument types may also be defined as
				4218	exactly matching a previous argument's type or the result type. This allows an
				4219	intrinsic function which accepts multiple arguments, but needs all of them to
				4220	be of the same type, to only be overloaded with respect to a single argument or
				4221	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4222
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4223	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4224	encoded into its function name, each preceded by a period. Only those types
				4225	which are overloaded result in a name suffix. Arguments whose type is matched
				4226	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4227	take an integer of any width and returns an integer of exactly the same integer
				4228	width. This leads to a family of functions such as
				4229	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4230	Only one type, the return type, is overloaded, and only one type suffix is
				4231	required. Because the argument's type is matched against the return type, it
				4232	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4233
				4234	<p>To learn how to add an intrinsic function, please see the
				4235	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4236	</p>
				4237
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4238	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4239
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4240	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4241	<div class="doc_subsection">
				4242	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4243	</div>
				4244
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4245	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4246
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4247	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4248	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]	4249	intrinsic functions. These functions are related to the similarly
				4250	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4251
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4252	<p>All of these functions operate on arguments that use a
				4253	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4254	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4255	transformations should be prepared to handle these functions regardless of
				4256	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4257
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4258	<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]	4259	instruction and the variable argument handling intrinsic functions are
				4260	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4261
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4262	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4263	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4264	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4265	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4266	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4267	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4268	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4269
				4270	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4271	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4272
				4273	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4274	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4275	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4276	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4277	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4278
				4279	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4280	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4281	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4282	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4283
				4284	declare void @llvm.va_start(i8*)
				4285	declare void @llvm.va_copy(i8, i8)
				4286	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4287	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4288	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4289
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4290	</div>
				4291
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4292	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4293	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4294	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4295	</div>
				4296
				4297
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4298	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4299	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4300	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4301	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4302	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4303	<tt>*<arglist></tt> for subsequent use by <tt><a
				4304	href="#i_va_arg">va_arg</a></tt>.</p>
				4305
				4306	<h5>Arguments:</h5>
				4307
				4308	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4309
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4310	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4311
				4312	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4313	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4314	<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]	4315	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4316	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]	4317	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]	4318
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4319	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4320
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4321	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4322	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4323	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4324	</div>
				4325
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4326	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4327	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4328	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4329	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4330
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4331	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4332	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]	4333	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]	4334
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4335	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4336
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4337	<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]	4338
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4339	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4340
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4341	<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]	4342	macro available in C. In a target-dependent way, it destroys the
				4343	<tt>va_list</tt> element to which the argument points. Calls to <a
				4344	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4345	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4346	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	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_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4352	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	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
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4357	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4358
				4359	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4360	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4361	</pre>
				4362
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4363	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4364
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4365	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4366	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4367
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4368	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4369
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4370	<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]	4371	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]	4372
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4373
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4374	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4375
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4376	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4377	macro available in C. In a target-dependent way, it copies the source
				4378	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4379	intrinsic is necessary because the <tt><a href="#int_va_start">
				4380	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4381	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4382
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4383	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4384
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4385	<!-- ======================================================================= -->
				4386	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4387	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4388	</div>
				4389
				4390	<div class="doc_text">
				4391
				4392	<p>
				4393	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
				4394	Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4395	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]	4396	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4397	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]	4398	Front-ends for type-safe garbage collected languages should generate these
				4399	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4400	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4401	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4402
				4403	<p>The garbage collection intrinsics only operate on objects in the generic
				4404	address space (address space zero).</p>
				4405
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4406	</div>
				4407
				4408	<!-- _______________________________________________________________________ -->
				4409	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4410	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4411	</div>
				4412
				4413	<div class="doc_text">
				4414
				4415	<h5>Syntax:</h5>
				4416
				4417	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4418	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4419	</pre>
				4420
				4421	<h5>Overview:</h5>
				4422
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4423	<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]	4424	the code generator, and allows some metadata to be associated with it.</p>
				4425
				4426	<h5>Arguments:</h5>
				4427
				4428	<p>The first argument specifies the address of a stack object that contains the
				4429	root pointer. The second pointer (which must be either a constant or a global
				4430	value address) contains the meta-data to be associated with the root.</p>
				4431
				4432	<h5>Semantics:</h5>
				4433
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4434	<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]	4435	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4436	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4437	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4438	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4439
				4440	</div>
				4441
				4442
				4443	<!-- _______________________________________________________________________ -->
				4444	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4445	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4446	</div>
				4447
				4448	<div class="doc_text">
				4449
				4450	<h5>Syntax:</h5>
				4451
				4452	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4453	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4454	</pre>
				4455
				4456	<h5>Overview:</h5>
				4457
				4458	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4459	locations, allowing garbage collector implementations that require read
				4460	barriers.</p>
				4461
				4462	<h5>Arguments:</h5>
				4463
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4464	<p>The second argument is the address to read from, which should be an address
				4465	allocated from the garbage collector. The first object is a pointer to the
				4466	start of the referenced object, if needed by the language runtime (otherwise
				4467	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4468
				4469	<h5>Semantics:</h5>
				4470
				4471	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4472	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4473	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4474	may only be used in a function which <a href="#gc">specifies a GC
				4475	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4476
				4477	</div>
				4478
				4479
				4480	<!-- _______________________________________________________________________ -->
				4481	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4482	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4483	</div>
				4484
				4485	<div class="doc_text">
				4486
				4487	<h5>Syntax:</h5>
				4488
				4489	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4490	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4491	</pre>
				4492
				4493	<h5>Overview:</h5>
				4494
				4495	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4496	locations, allowing garbage collector implementations that require write
				4497	barriers (such as generational or reference counting collectors).</p>
				4498
				4499	<h5>Arguments:</h5>
				4500
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4501	<p>The first argument is the reference to store, the second is the start of the
				4502	object to store it to, and the third is the address of the field of Obj to
				4503	store to. If the runtime does not require a pointer to the object, Obj may be
				4504	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4505
				4506	<h5>Semantics:</h5>
				4507
				4508	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4509	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4510	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4511	may only be used in a function which <a href="#gc">specifies a GC
				4512	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4513
				4514	</div>
				4515
				4516
				4517
				4518	<!-- ======================================================================= -->
				4519	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4520	<a name="int_codegen">Code Generator Intrinsics</a>
				4521	</div>
				4522
				4523	<div class="doc_text">
				4524	<p>
				4525	These intrinsics are provided by LLVM to expose special features that may only
				4526	be implemented with code generator support.
				4527	</p>
				4528
				4529	</div>
				4530
				4531	<!-- _______________________________________________________________________ -->
				4532	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4533	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4534	</div>
				4535
				4536	<div class="doc_text">
				4537
				4538	<h5>Syntax:</h5>
				4539	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4540	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4541	</pre>
				4542
				4543	<h5>Overview:</h5>
				4544
				4545	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4546	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4547	target-specific value indicating the return address of the current function
				4548	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4549	</p>
				4550
				4551	<h5>Arguments:</h5>
				4552
				4553	<p>
				4554	The argument to this intrinsic indicates which function to return the address
				4555	for. Zero indicates the calling function, one indicates its caller, etc. The
				4556	argument is <b>required</b> to be a constant integer value.
				4557	</p>
				4558
				4559	<h5>Semantics:</h5>
				4560
				4561	<p>
				4562	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4563	the return address of the specified call frame, or zero if it cannot be
				4564	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4565	for arguments other than zero, so it should only be used for debugging purposes.
				4566	</p>
				4567
				4568	<p>
				4569	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4570	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]	4571	source-language caller.
				4572	</p>
				4573	</div>
				4574
				4575
				4576	<!-- _______________________________________________________________________ -->
				4577	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4578	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4579	</div>
				4580
				4581	<div class="doc_text">
				4582
				4583	<h5>Syntax:</h5>
				4584	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4585	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4586	</pre>
				4587
				4588	<h5>Overview:</h5>
				4589
				4590	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4591	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4592	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4593	</p>
				4594
				4595	<h5>Arguments:</h5>
				4596
				4597	<p>
				4598	The argument to this intrinsic indicates which function to return the frame
				4599	pointer for. Zero indicates the calling function, one indicates its caller,
				4600	etc. The argument is <b>required</b> to be a constant integer value.
				4601	</p>
				4602
				4603	<h5>Semantics:</h5>
				4604
				4605	<p>
				4606	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4607	the frame address of the specified call frame, or zero if it cannot be
				4608	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4609	for arguments other than zero, so it should only be used for debugging purposes.
				4610	</p>
				4611
				4612	<p>
				4613	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4614	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]	4615	source-language caller.
				4616	</p>
				4617	</div>
				4618
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4619	<!-- _______________________________________________________________________ -->
				4620	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4621	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4622	</div>
				4623
				4624	<div class="doc_text">
				4625
				4626	<h5>Syntax:</h5>
				4627	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4628	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4629	</pre>
				4630
				4631	<h5>Overview:</h5>
				4632
				4633	<p>
				4634	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]	4635	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4636	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4637	features like scoped automatic variable sized arrays in C99.
				4638	</p>
				4639
				4640	<h5>Semantics:</h5>
				4641
				4642	<p>
				4643	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]	4644	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4645	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4646	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4647	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4648	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4649	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4650	</p>
				4651
				4652	</div>
				4653
				4654	<!-- _______________________________________________________________________ -->
				4655	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4656	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4657	</div>
				4658
				4659	<div class="doc_text">
				4660
				4661	<h5>Syntax:</h5>
				4662	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4663	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4664	</pre>
				4665
				4666	<h5>Overview:</h5>
				4667
				4668	<p>
				4669	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4670	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]	4671	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4672	useful for implementing language features like scoped automatic variable sized
				4673	arrays in C99.
				4674	</p>
				4675
				4676	<h5>Semantics:</h5>
				4677
				4678	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4679	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]	4680	</p>
				4681
				4682	</div>
				4683
				4684
				4685	<!-- _______________________________________________________________________ -->
				4686	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4687	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4688	</div>
				4689
				4690	<div class="doc_text">
				4691
				4692	<h5>Syntax:</h5>
				4693	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4694	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4695	</pre>
				4696
				4697	<h5>Overview:</h5>
				4698
				4699
				4700	<p>
				4701	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]	4702	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4703	no
				4704	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4705	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4706	</p>
				4707
				4708	<h5>Arguments:</h5>
				4709
				4710	<p>
				4711	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4712	determining if the fetch should be for a read (0) or write (1), and
				4713	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4714	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]	4715	<tt>locality</tt> arguments must be constant integers.
				4716	</p>
				4717
				4718	<h5>Semantics:</h5>
				4719
				4720	<p>
				4721	This intrinsic does not modify the behavior of the program. In particular,
				4722	prefetches cannot trap and do not produce a value. On targets that support this
				4723	intrinsic, the prefetch can provide hints to the processor cache for better
				4724	performance.
				4725	</p>
				4726
				4727	</div>
				4728
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +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_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +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 void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4739	</pre>
				4740
				4741	<h5>Overview:</h5>
				4742
				4743
				4744	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4745	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
				4746	(PC) in a region of
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4747	code to simulators and other tools. The method is target specific, but it is
				4748	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]	4749	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]	4750	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]	4751	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4752	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4753	</p>
				4754
				4755	<h5>Arguments:</h5>
				4756
				4757	<p>
				4758	<tt>id</tt> is a numerical id identifying the marker.
				4759	</p>
				4760
				4761	<h5>Semantics:</h5>
				4762
				4763	<p>
				4764	This intrinsic does not modify the behavior of the program. Backends that do not
				4765	support this intrinisic may ignore it.
				4766	</p>
				4767
				4768	</div>
				4769
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4770	<!-- _______________________________________________________________________ -->
				4771	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4772	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4773	</div>
				4774
				4775	<div class="doc_text">
				4776
				4777	<h5>Syntax:</h5>
				4778	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4779	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4780	</pre>
				4781
				4782	<h5>Overview:</h5>
				4783
				4784
				4785	<p>
				4786	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4787	counter register (or similar low latency, high accuracy clocks) on those targets
				4788	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4789	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4790	should only be used for small timings.
				4791	</p>
				4792
				4793	<h5>Semantics:</h5>
				4794
				4795	<p>
				4796	When directly supported, reading the cycle counter should not modify any memory.
				4797	Implementations are allowed to either return a application specific value or a
				4798	system wide value. On backends without support, this is lowered to a constant 0.
				4799	</p>
				4800
				4801	</div>
				4802
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4803	<!-- ======================================================================= -->
				4804	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4805	<a name="int_libc">Standard C Library Intrinsics</a>
				4806	</div>
				4807
				4808	<div class="doc_text">
				4809	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4810	LLVM provides intrinsics for a few important standard C library functions.
				4811	These intrinsics allow source-language front-ends to pass information about the
				4812	alignment of the pointer arguments to the code generator, providing opportunity
				4813	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4814	</p>
				4815
				4816	</div>
				4817
				4818	<!-- _______________________________________________________________________ -->
				4819	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4820	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4821	</div>
				4822
				4823	<div class="doc_text">
				4824
				4825	<h5>Syntax:</h5>
				4826	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4827	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4828	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4829	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4830	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4831	</pre>
				4832
				4833	<h5>Overview:</h5>
				4834
				4835	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4836	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]	4837	location to the destination location.
				4838	</p>
				4839
				4840	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4841	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				4842	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4843	</p>
				4844
				4845	<h5>Arguments:</h5>
				4846
				4847	<p>
				4848	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]	4849	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4850	specifying the number of bytes to copy, and the fourth argument is the alignment
				4851	of the source and destination locations.
				4852	</p>
				4853
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4854	<p>
				4855	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]	4856	the caller guarantees that both the source and destination pointers are aligned
				4857	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4858	</p>
				4859
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4860	<h5>Semantics:</h5>
				4861
				4862	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4863	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]	4864	location to the destination location, which are not allowed to overlap. It
				4865	copies "len" bytes of memory over. If the argument is known to be aligned to
				4866	some boundary, this can be specified as the fourth argument, otherwise it should
				4867	be set to 0 or 1.
				4868	</p>
				4869	</div>
				4870
				4871
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4872	<!-- _______________________________________________________________________ -->
				4873	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4874	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4875	</div>
				4876
				4877	<div class="doc_text">
				4878
				4879	<h5>Syntax:</h5>
				4880	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4881	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4882	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4883	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4884	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4885	</pre>
				4886
				4887	<h5>Overview:</h5>
				4888
				4889	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4890	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				4891	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	4892	'<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]	4893	</p>
				4894
				4895	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4896	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				4897	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4898	</p>
				4899
				4900	<h5>Arguments:</h5>
				4901
				4902	<p>
				4903	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]	4904	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4905	specifying the number of bytes to copy, and the fourth argument is the alignment
				4906	of the source and destination locations.
				4907	</p>
				4908
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4909	<p>
				4910	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]	4911	the caller guarantees that the source and destination pointers are aligned to
				4912	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4913	</p>
				4914
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4915	<h5>Semantics:</h5>
				4916
				4917	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4918	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]	4919	location to the destination location, which may overlap. It
				4920	copies "len" bytes of memory over. If the argument is known to be aligned to
				4921	some boundary, this can be specified as the fourth argument, otherwise it should
				4922	be set to 0 or 1.
				4923	</p>
				4924	</div>
				4925
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4926
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4927	<!-- _______________________________________________________________________ -->
				4928	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4929	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4930	</div>
				4931
				4932	<div class="doc_text">
				4933
				4934	<h5>Syntax:</h5>
				4935	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4936	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4937	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4938	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4939	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4940	</pre>
				4941
				4942	<h5>Overview:</h5>
				4943
				4944	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4945	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]	4946	byte value.
				4947	</p>
				4948
				4949	<p>
				4950	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				4951	does not return a value, and takes an extra alignment argument.
				4952	</p>
				4953
				4954	<h5>Arguments:</h5>
				4955
				4956	<p>
				4957	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]	4958	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4959	argument specifying the number of bytes to fill, and the fourth argument is the
				4960	known alignment of destination location.
				4961	</p>
				4962
				4963	<p>
				4964	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]	4965	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4966	</p>
				4967
				4968	<h5>Semantics:</h5>
				4969
				4970	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4971	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				4972	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4973	destination location. If the argument is known to be aligned to some boundary,
				4974	this can be specified as the fourth argument, otherwise it should be set to 0 or
				4975	1.
				4976	</p>
				4977	</div>
				4978
				4979
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	4980	<!-- _______________________________________________________________________ -->
				4981	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4982	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	4983	</div>
				4984
				4985	<div class="doc_text">
				4986
				4987	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	4988	<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]	4989	floating point or vector of floating point type. Not all targets support all
				4990	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	4991	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	4992	declare float @llvm.sqrt.f32(float %Val)
				4993	declare double @llvm.sqrt.f64(double %Val)
				4994	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				4995	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				4996	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	4997	</pre>
				4998
				4999	<h5>Overview:</h5>
				5000
				5001	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5002	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]	5003	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]	5004	<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]	5005	negative numbers other than -0.0 (which allows for better optimization, because
				5006	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5007	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5008	</p>
				5009
				5010	<h5>Arguments:</h5>
				5011
				5012	<p>
				5013	The argument and return value are floating point numbers of the same type.
				5014	</p>
				5015
				5016	<h5>Semantics:</h5>
				5017
				5018	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5019	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]	5020	floating point number.
				5021	</p>
				5022	</div>
				5023
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5024	<!-- _______________________________________________________________________ -->
				5025	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5026	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5027	</div>
				5028
				5029	<div class="doc_text">
				5030
				5031	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5032	<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]	5033	floating point or vector of floating point type. Not all targets support all
				5034	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5035	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5036	declare float @llvm.powi.f32(float %Val, i32 %power)
				5037	declare double @llvm.powi.f64(double %Val, i32 %power)
				5038	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5039	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5040	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5041	</pre>
				5042
				5043	<h5>Overview:</h5>
				5044
				5045	<p>
				5046	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5047	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5048	multiplications is not defined. When a vector of floating point type is
				5049	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5050	</p>
				5051
				5052	<h5>Arguments:</h5>
				5053
				5054	<p>
				5055	The second argument is an integer power, and the first is a value to raise to
				5056	that power.
				5057	</p>
				5058
				5059	<h5>Semantics:</h5>
				5060
				5061	<p>
				5062	This function returns the first value raised to the second power with an
				5063	unspecified sequence of rounding operations.</p>
				5064	</div>
				5065
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5066	<!-- _______________________________________________________________________ -->
				5067	<div class="doc_subsubsection">
				5068	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5069	</div>
				5070
				5071	<div class="doc_text">
				5072
				5073	<h5>Syntax:</h5>
				5074	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5075	floating point or vector of floating point type. Not all targets support all
				5076	types however.
				5077	<pre>
				5078	declare float @llvm.sin.f32(float %Val)
				5079	declare double @llvm.sin.f64(double %Val)
				5080	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5081	declare fp128 @llvm.sin.f128(fp128 %Val)
				5082	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5083	</pre>
				5084
				5085	<h5>Overview:</h5>
				5086
				5087	<p>
				5088	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5089	</p>
				5090
				5091	<h5>Arguments:</h5>
				5092
				5093	<p>
				5094	The argument and return value are floating point numbers of the same type.
				5095	</p>
				5096
				5097	<h5>Semantics:</h5>
				5098
				5099	<p>
				5100	This function returns the sine of the specified operand, returning the
				5101	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]	5102	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5103	</div>
				5104
				5105	<!-- _______________________________________________________________________ -->
				5106	<div class="doc_subsubsection">
				5107	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5108	</div>
				5109
				5110	<div class="doc_text">
				5111
				5112	<h5>Syntax:</h5>
				5113	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5114	floating point or vector of floating point type. Not all targets support all
				5115	types however.
				5116	<pre>
				5117	declare float @llvm.cos.f32(float %Val)
				5118	declare double @llvm.cos.f64(double %Val)
				5119	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5120	declare fp128 @llvm.cos.f128(fp128 %Val)
				5121	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5122	</pre>
				5123
				5124	<h5>Overview:</h5>
				5125
				5126	<p>
				5127	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5128	</p>
				5129
				5130	<h5>Arguments:</h5>
				5131
				5132	<p>
				5133	The argument and return value are floating point numbers of the same type.
				5134	</p>
				5135
				5136	<h5>Semantics:</h5>
				5137
				5138	<p>
				5139	This function returns the cosine of the specified operand, returning the
				5140	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]	5141	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5142	</div>
				5143
				5144	<!-- _______________________________________________________________________ -->
				5145	<div class="doc_subsubsection">
				5146	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5147	</div>
				5148
				5149	<div class="doc_text">
				5150
				5151	<h5>Syntax:</h5>
				5152	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5153	floating point or vector of floating point type. Not all targets support all
				5154	types however.
				5155	<pre>
				5156	declare float @llvm.pow.f32(float %Val, float %Power)
				5157	declare double @llvm.pow.f64(double %Val, double %Power)
				5158	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5159	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5160	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5161	</pre>
				5162
				5163	<h5>Overview:</h5>
				5164
				5165	<p>
				5166	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5167	specified (positive or negative) power.
				5168	</p>
				5169
				5170	<h5>Arguments:</h5>
				5171
				5172	<p>
				5173	The second argument is a floating point power, and the first is a value to
				5174	raise to that power.
				5175	</p>
				5176
				5177	<h5>Semantics:</h5>
				5178
				5179	<p>
				5180	This function returns the first value raised to the second power,
				5181	returning the
				5182	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]	5183	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5184	</div>
				5185
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5186
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5187	<!-- ======================================================================= -->
				5188	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5189	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5190	</div>
				5191
				5192	<div class="doc_text">
				5193	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5194	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5195	These allow efficient code generation for some algorithms.
				5196	</p>
				5197
				5198	</div>
				5199
				5200	<!-- _______________________________________________________________________ -->
				5201	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5202	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5203	</div>
				5204
				5205	<div class="doc_text">
				5206
				5207	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5208	<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]	5209	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]	5210	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5211	declare i16 @llvm.bswap.i16(i16 <id>)
				5212	declare i32 @llvm.bswap.i32(i32 <id>)
				5213	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5214	</pre>
				5215
				5216	<h5>Overview:</h5>
				5217
				5218	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5219	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]	5220	values with an even number of bytes (positive multiple of 16 bits). These are
				5221	useful for performing operations on data that is not in the target's native
				5222	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5223	</p>
				5224
				5225	<h5>Semantics:</h5>
				5226
				5227	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5228	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]	5229	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5230	intrinsic returns an i32 value that has the four bytes of the input i32
				5231	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]	5232	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5233	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5234	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5235	</p>
				5236
				5237	</div>
				5238
				5239	<!-- _______________________________________________________________________ -->
				5240	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5241	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5242	</div>
				5243
				5244	<div class="doc_text">
				5245
				5246	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5247	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5248	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5249	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5250	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5251	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5252	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5253	declare i64 @llvm.ctpop.i64(i64 <src>)
				5254	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5255	</pre>
				5256
				5257	<h5>Overview:</h5>
				5258
				5259	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5260	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5261	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5262	</p>
				5263
				5264	<h5>Arguments:</h5>
				5265
				5266	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5267	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]	5268	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5269	</p>
				5270
				5271	<h5>Semantics:</h5>
				5272
				5273	<p>
				5274	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5275	</p>
				5276	</div>
				5277
				5278	<!-- _______________________________________________________________________ -->
				5279	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5280	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5281	</div>
				5282
				5283	<div class="doc_text">
				5284
				5285	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5286	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5287	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5288	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5289	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5290	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5291	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5292	declare i64 @llvm.ctlz.i64(i64 <src>)
				5293	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5294	</pre>
				5295
				5296	<h5>Overview:</h5>
				5297
				5298	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5299	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5300	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5301	</p>
				5302
				5303	<h5>Arguments:</h5>
				5304
				5305	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5306	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]	5307	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5308	</p>
				5309
				5310	<h5>Semantics:</h5>
				5311
				5312	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5313	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5314	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]	5315	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5316	</p>
				5317	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5318
				5319
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5320
				5321	<!-- _______________________________________________________________________ -->
				5322	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5323	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5324	</div>
				5325
				5326	<div class="doc_text">
				5327
				5328	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5329	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5330	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5331	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5332	declare i8 @llvm.cttz.i8 (i8 <src>)
				5333	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5334	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5335	declare i64 @llvm.cttz.i64(i64 <src>)
				5336	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5337	</pre>
				5338
				5339	<h5>Overview:</h5>
				5340
				5341	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5342	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5343	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5344	</p>
				5345
				5346	<h5>Arguments:</h5>
				5347
				5348	<p>
				5349	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]	5350	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5351	</p>
				5352
				5353	<h5>Semantics:</h5>
				5354
				5355	<p>
				5356	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5357	in a variable. If the src == 0 then the result is the size in bits of the type
				5358	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5359	</p>
				5360	</div>
				5361
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5362	<!-- _______________________________________________________________________ -->
				5363	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5364	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5365	</div>
				5366
				5367	<div class="doc_text">
				5368
				5369	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5370	<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]	5371	on any integer bit width.
				5372	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5373	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5374	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5375	</pre>
				5376
				5377	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5378	<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]	5379	range of bits from an integer value and returns them in the same bit width as
				5380	the original value.</p>
				5381
				5382	<h5>Arguments:</h5>
				5383	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5384	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]	5385	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]	5386
				5387	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5388	<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]	5389	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5390	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5391	operates in forward mode.</p>
				5392	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5393	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]	5394	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5395	<ol>
				5396	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5397	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5398	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5399	to determine the number of bits to retain.</li>
				5400	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5401	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5402	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5403	<p>In reverse mode, a similar computation is made except that the bits are
				5404	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5405	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5406	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5407	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5408	</div>
				5409
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5410	<div class="doc_subsubsection">
				5411	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5412	</div>
				5413
				5414	<div class="doc_text">
				5415
				5416	<h5>Syntax:</h5>
				5417	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5418	on any integer bit width.
				5419	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5420	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5421	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]	5422	</pre>
				5423
				5424	<h5>Overview:</h5>
				5425	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5426	of bits in an integer value with another integer value. It returns the integer
				5427	with the replaced bits.</p>
				5428
				5429	<h5>Arguments:</h5>
				5430	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5431	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5432	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5433	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5434	type since they specify only a bit index.</p>
				5435
				5436	<h5>Semantics:</h5>
				5437	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5438	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5439	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5440	operates in forward mode.</p>
				5441	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5442	truncating it down to the size of the replacement area or zero extending it
				5443	up to that size.</p>
				5444	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5445	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5446	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5447	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5448	<p>In reverse mode, a similar computation is made except that the bits are
				5449	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5450	<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]	5451	<h5>Examples:</h5>
				5452	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5453	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5454	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5455	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5456	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5457	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5458	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5459	</div>
				5460
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5461	<!-- ======================================================================= -->
				5462	<div class="doc_subsection">
				5463	<a name="int_debugger">Debugger Intrinsics</a>
				5464	</div>
				5465
				5466	<div class="doc_text">
				5467	<p>
				5468	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5469	are described in the <a
				5470	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5471	Debugging</a> document.
				5472	</p>
				5473	</div>
				5474
				5475
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5476	<!-- ======================================================================= -->
				5477	<div class="doc_subsection">
				5478	<a name="int_eh">Exception Handling Intrinsics</a>
				5479	</div>
				5480
				5481	<div class="doc_text">
				5482	<p> The LLVM exception handling intrinsics (which all start with
				5483	<tt>llvm.eh.</tt> prefix), are described in the <a
				5484	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5485	Handling</a> document. </p>
				5486	</div>
				5487
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5488	<!-- ======================================================================= -->
				5489	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5490	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5491	</div>
				5492
				5493	<div class="doc_text">
				5494	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5495	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5496	the <tt>nest</tt> attribute, from a function. The result is a callable
				5497	function pointer lacking the nest parameter - the caller does not need
				5498	to provide a value for it. Instead, the value to use is stored in
				5499	advance in a "trampoline", a block of memory usually allocated
				5500	on the stack, which also contains code to splice the nest value into the
				5501	argument list. This is used to implement the GCC nested function address
				5502	extension.
				5503	</p>
				5504	<p>
				5505	For example, if the function is
				5506	<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]	5507	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]	5508	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5509	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5510	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5511	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5512	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5513	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5514	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5515	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]	5516	</div>
				5517
				5518	<!-- _______________________________________________________________________ -->
				5519	<div class="doc_subsubsection">
				5520	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5521	</div>
				5522	<div class="doc_text">
				5523	<h5>Syntax:</h5>
				5524	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5525	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5526	</pre>
				5527	<h5>Overview:</h5>
				5528	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5529	This fills the memory pointed to by <tt>tramp</tt> with code
				5530	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5531	</p>
				5532	<h5>Arguments:</h5>
				5533	<p>
				5534	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5535	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5536	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]	5537	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5538	currently provides no portable way of determining them, so a front-end that
				5539	generates this intrinsic needs to have some target-specific knowledge.
				5540	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]	5541	</p>
				5542	<h5>Semantics:</h5>
				5543	<p>
				5544	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]	5545	dependent code, turning it into a function. A pointer to this function is
				5546	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5547	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5548	before being called. The new function's signature is the same as that of
				5549	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5550	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5551	of pointer type. Calling the new function is equivalent to calling
				5552	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5553	missing <tt>nest</tt> argument. If, after calling
				5554	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5555	modified, then the effect of any later call to the returned function pointer is
				5556	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5557	</p>
				5558	</div>
				5559
				5560	<!-- ======================================================================= -->
				5561	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5562	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5563	</div>
				5564
				5565	<div class="doc_text">
				5566	<p>
				5567	These intrinsic functions expand the "universal IR" of LLVM to represent
				5568	hardware constructs for atomic operations and memory synchronization. This
				5569	provides an interface to the hardware, not an interface to the programmer. It
				5570	is aimed at a low enough level to allow any programming models or APIs which
				5571	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5572	hardware behavior. Just as hardware provides a "universal IR" for source
				5573	languages, it also provides a starting point for developing a "universal"
				5574	atomic operation and synchronization IR.
				5575	</p>
				5576	<p>
				5577	These do <em>not</em> form an API such as high-level threading libraries,
				5578	software transaction memory systems, atomic primitives, and intrinsic
				5579	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5580	application libraries. The hardware interface provided by LLVM should allow
				5581	a clean implementation of all of these APIs and parallel programming models.
				5582	No one model or paradigm should be selected above others unless the hardware
				5583	itself ubiquitously does so.
				5584
				5585	</p>
				5586	</div>
				5587
				5588	<!-- _______________________________________________________________________ -->
				5589	<div class="doc_subsubsection">
				5590	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5591	</div>
				5592	<div class="doc_text">
				5593	<h5>Syntax:</h5>
				5594	<pre>
				5595	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5596	i1 <device> )
				5597
				5598	</pre>
				5599	<h5>Overview:</h5>
				5600	<p>
				5601	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5602	specific pairs of memory access types.
				5603	</p>
				5604	<h5>Arguments:</h5>
				5605	<p>
				5606	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5607	The first four arguments enables a specific barrier as listed below. The fith
				5608	argument specifies that the barrier applies to io or device or uncached memory.
				5609
				5610	</p>
				5611	<ul>
				5612	<li><tt>ll</tt>: load-load barrier</li>
				5613	<li><tt>ls</tt>: load-store barrier</li>
				5614	<li><tt>sl</tt>: store-load barrier</li>
				5615	<li><tt>ss</tt>: store-store barrier</li>
				5616	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5617	</ul>
				5618	<h5>Semantics:</h5>
				5619	<p>
				5620	This intrinsic causes the system to enforce some ordering constraints upon
				5621	the loads and stores of the program. This barrier does not indicate
				5622	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5623	which they occur. For any of the specified pairs of load and store operations
				5624	(f.ex. load-load, or store-load), all of the first operations preceding the
				5625	barrier will complete before any of the second operations succeeding the
				5626	barrier begin. Specifically the semantics for each pairing is as follows:
				5627	</p>
				5628	<ul>
				5629	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5630	after the barrier begins.</li>
				5631
				5632	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5633	store after the barrier begins.</li>
				5634	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5635	store after the barrier begins.</li>
				5636	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5637	load after the barrier begins.</li>
				5638	</ul>
				5639	<p>
				5640	These semantics are applied with a logical "and" behavior when more than one
				5641	is enabled in a single memory barrier intrinsic.
				5642	</p>
				5643	<p>
				5644	Backends may implement stronger barriers than those requested when they do not
				5645	support as fine grained a barrier as requested. Some architectures do not
				5646	need all types of barriers and on such architectures, these become noops.
				5647	</p>
				5648	<h5>Example:</h5>
				5649	<pre>
				5650	%ptr = malloc i32
				5651	store i32 4, %ptr
				5652
				5653	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5654	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5655	<i>; guarantee the above finishes</i>
				5656	store i32 8, %ptr <i>; before this begins</i>
				5657	</pre>
				5658	</div>
				5659
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5660	<!-- _______________________________________________________________________ -->
				5661	<div class="doc_subsubsection">
				5662	<a name="int_atomic_lcs">'<tt>llvm.atomic.lcs.*</tt>' Intrinsic</a>
				5663	</div>
				5664	<div class="doc_text">
				5665	<h5>Syntax:</h5>
				5666	<p>
				5667	This is an overloaded intrinsic. You can use <tt>llvm.atomic.lcs</tt> on any
				5668	integer bit width. Not all targets support all bit widths however.</p>
				5669
				5670	<pre>
				5671	declare i8 @llvm.atomic.lcs.i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5672	declare i16 @llvm.atomic.lcs.i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5673	declare i32 @llvm.atomic.lcs.i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5674	declare i64 @llvm.atomic.lcs.i64( i64* <ptr>, i64 <cmp>, i64 <val> )
				5675
				5676	</pre>
				5677	<h5>Overview:</h5>
				5678	<p>
				5679	This loads a value in memory and compares it to a given value. If they are
				5680	equal, it stores a new value into the memory.
				5681	</p>
				5682	<h5>Arguments:</h5>
				5683	<p>
				5684	The <tt>llvm.atomic.lcs</tt> intrinsic takes three arguments. The result as
				5685	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5686	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5687	this integer type. While any bit width integer may be used, targets may only
				5688	lower representations they support in hardware.
				5689
				5690	</p>
				5691	<h5>Semantics:</h5>
				5692	<p>
				5693	This entire intrinsic must be executed atomically. It first loads the value
				5694	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5695	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5696	loaded value is yielded in all cases. This provides the equivalent of an
				5697	atomic compare-and-swap operation within the SSA framework.
				5698	</p>
				5699	<h5>Examples:</h5>
				5700
				5701	<pre>
				5702	%ptr = malloc i32
				5703	store i32 4, %ptr
				5704
				5705	%val1 = add i32 4, 4
				5706	%result1 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 4, %val1 )
				5707	<i>; yields {i32}:result1 = 4</i>
				5708	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5709	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5710
				5711	%val2 = add i32 1, 1
				5712	%result2 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 5, %val2 )
				5713	<i>; yields {i32}:result2 = 8</i>
				5714	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5715
				5716	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5717	</pre>
				5718	</div>
				5719
				5720	<!-- _______________________________________________________________________ -->
				5721	<div class="doc_subsubsection">
				5722	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5723	</div>
				5724	<div class="doc_text">
				5725	<h5>Syntax:</h5>
				5726
				5727	<p>
				5728	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5729	integer bit width. Not all targets support all bit widths however.</p>
				5730	<pre>
				5731	declare i8 @llvm.atomic.swap.i8( i8* <ptr>, i8 <val> )
				5732	declare i16 @llvm.atomic.swap.i16( i16* <ptr>, i16 <val> )
				5733	declare i32 @llvm.atomic.swap.i32( i32* <ptr>, i32 <val> )
				5734	declare i64 @llvm.atomic.swap.i64( i64* <ptr>, i64 <val> )
				5735
				5736	</pre>
				5737	<h5>Overview:</h5>
				5738	<p>
				5739	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5740	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5741	at <tt>ptr</tt>.
				5742	</p>
				5743	<h5>Arguments:</h5>
				5744
				5745	<p>
				5746	The <tt>llvm.atomic.ls</tt> intrinsic takes two arguments. Both the
				5747	<tt>val</tt> argument and the result must be integers of the same bit width.
				5748	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5749	integer type. The targets may only lower integer representations they
				5750	support.
				5751	</p>
				5752	<h5>Semantics:</h5>
				5753	<p>
				5754	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5755	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5756	equivalent of an atomic swap operation within the SSA framework.
				5757
				5758	</p>
				5759	<h5>Examples:</h5>
				5760	<pre>
				5761	%ptr = malloc i32
				5762	store i32 4, %ptr
				5763
				5764	%val1 = add i32 4, 4
				5765	%result1 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val1 )
				5766	<i>; yields {i32}:result1 = 4</i>
				5767	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5768	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5769
				5770	%val2 = add i32 1, 1
				5771	%result2 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val2 )
				5772	<i>; yields {i32}:result2 = 8</i>
				5773
				5774	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5775	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5776	</pre>
				5777	</div>
				5778
				5779	<!-- _______________________________________________________________________ -->
				5780	<div class="doc_subsubsection">
				5781	<a name="int_atomic_las">'<tt>llvm.atomic.las.*</tt>' Intrinsic</a>
				5782
				5783	</div>
				5784	<div class="doc_text">
				5785	<h5>Syntax:</h5>
				5786	<p>
				5787	This is an overloaded intrinsic. You can use <tt>llvm.atomic.las</tt> on any
				5788	integer bit width. Not all targets support all bit widths however.</p>
				5789	<pre>
				5790	declare i8 @llvm.atomic.las.i8.( i8* <ptr>, i8 <delta> )
				5791	declare i16 @llvm.atomic.las.i16.( i16* <ptr>, i16 <delta> )
				5792	declare i32 @llvm.atomic.las.i32.( i32* <ptr>, i32 <delta> )
				5793	declare i64 @llvm.atomic.las.i64.( i64* <ptr>, i64 <delta> )
				5794
				5795	</pre>
				5796	<h5>Overview:</h5>
				5797	<p>
				5798	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5799	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5800	</p>
				5801	<h5>Arguments:</h5>
				5802	<p>
				5803
				5804	The intrinsic takes two arguments, the first a pointer to an integer value
				5805	and the second an integer value. The result is also an integer value. These
				5806	integer types can have any bit width, but they must all have the same bit
				5807	width. The targets may only lower integer representations they support.
				5808	</p>
				5809	<h5>Semantics:</h5>
				5810	<p>
				5811	This intrinsic does a series of operations atomically. It first loads the
				5812	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5813	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5814	</p>
				5815
				5816	<h5>Examples:</h5>
				5817	<pre>
				5818	%ptr = malloc i32
				5819	store i32 4, %ptr
				5820	%result1 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 4 )
				5821	<i>; yields {i32}:result1 = 4</i>
				5822	%result2 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 2 )
				5823	<i>; yields {i32}:result2 = 8</i>
				5824	%result3 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 5 )
				5825	<i>; yields {i32}:result3 = 10</i>
				5826	%memval = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
				5827	</pre>
				5828	</div>
				5829
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5830
				5831	<!-- ======================================================================= -->
				5832	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5833	<a name="int_general">General Intrinsics</a>
				5834	</div>
				5835
				5836	<div class="doc_text">
				5837	<p> This class of intrinsics is designed to be generic and has
				5838	no specific purpose. </p>
				5839	</div>
				5840
				5841	<!-- _______________________________________________________________________ -->
				5842	<div class="doc_subsubsection">
				5843	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				5844	</div>
				5845
				5846	<div class="doc_text">
				5847
				5848	<h5>Syntax:</h5>
				5849	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5850	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]	5851	</pre>
				5852
				5853	<h5>Overview:</h5>
				5854
				5855	<p>
				5856	The '<tt>llvm.var.annotation</tt>' intrinsic
				5857	</p>
				5858
				5859	<h5>Arguments:</h5>
				5860
				5861	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5862	The first argument is a pointer to a value, the second is a pointer to a
				5863	global string, the third is a pointer to a global string which is the source
				5864	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5865	</p>
				5866
				5867	<h5>Semantics:</h5>
				5868
				5869	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	5870	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5871	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]	5872	annotations. These have no other defined use, they are ignored by code
				5873	generation and optimization.
				5874	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5875	</div>
				5876
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5877	<!-- _______________________________________________________________________ -->
				5878	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	5879	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5880	</div>
				5881
				5882	<div class="doc_text">
				5883
				5884	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	5885	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				5886	any integer bit width.
				5887	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5888	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	5889	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				5890	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				5891	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				5892	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				5893	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]	5894	</pre>
				5895
				5896	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	5897
				5898	<p>
				5899	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5900	</p>
				5901
				5902	<h5>Arguments:</h5>
				5903
				5904	<p>
				5905	The first argument is an integer value (result of some expression),
				5906	the second is a pointer to a global string, the third is a pointer to a global
				5907	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]	5908	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5909	</p>
				5910
				5911	<h5>Semantics:</h5>
				5912
				5913	<p>
				5914	This intrinsic allows annotations to be put on arbitrary expressions
				5915	with arbitrary strings. This can be useful for special purpose optimizations
				5916	that want to look for these annotations. These have no other defined use, they
				5917	are ignored by code generation and optimization.
				5918	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5919
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	5920	<!-- _______________________________________________________________________ -->
				5921	<div class="doc_subsubsection">
				5922	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				5923	</div>
				5924
				5925	<div class="doc_text">
				5926
				5927	<h5>Syntax:</h5>
				5928	<pre>
				5929	declare void @llvm.trap()
				5930	</pre>
				5931
				5932	<h5>Overview:</h5>
				5933
				5934	<p>
				5935	The '<tt>llvm.trap</tt>' intrinsic
				5936	</p>
				5937
				5938	<h5>Arguments:</h5>
				5939
				5940	<p>
				5941	None
				5942	</p>
				5943
				5944	<h5>Semantics:</h5>
				5945
				5946	<p>
				5947	This intrinsics is lowered to the target dependent trap instruction. If the
				5948	target does not have a trap instruction, this intrinsic will be lowered to the
				5949	call of the abort() function.
				5950	</p>
				5951	</div>
				5952
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	5953	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	5954	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	5955	<address>
				5956	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				5957	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				5958	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	5959	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]	5960
				5961	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	5962	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	5963	Last modified: $Date$
				5964	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	5965
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5966	</body>
				5967	</html>