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				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	cb84e43	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	7630785	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	6af02f3	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	25	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	26	<li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov	546ea7e	2007-04-29 18:02:48 +0000	[diff] [blame]	27	<li><a href="#aliasstructure">Aliases</a>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	28	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	29	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	30	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	31	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	32	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	33	</ol>
				34	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	35	<li><a href="#typesystem">Type System</a>
				36	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	37	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	38	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	39	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	40	<li><a href="#t_floating">Floating Point Types</a></li>
				41	<li><a href="#t_void">Void Type</a></li>
				42	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	43	</ol>
				44	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	45	<li><a href="#t_derived">Derived Types</a>
				46	<ol>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	47	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	48	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	49	<li><a href="#t_function">Function Type</a></li>
				50	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	51	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	52	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	53	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	54	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	55	</ol>
				56	</li>
				57	</ol>
				58	</li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	59	<li><a href="#constants">Constants</a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	60	<ol>
				61	<li><a href="#simpleconstants">Simple Constants</a>
				62	<li><a href="#aggregateconstants">Aggregate Constants</a>
				63	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				64	<li><a href="#undefvalues">Undefined Values</a>
				65	<li><a href="#constantexprs">Constant Expressions</a>
				66	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	67	</li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	68	<li><a href="#othervalues">Other Values</a>
				69	<ol>
				70	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				71	</ol>
				72	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	73	<li><a href="#instref">Instruction Reference</a>
				74	<ol>
				75	<li><a href="#terminators">Terminator Instructions</a>
				76	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	77	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				78	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	79	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				80	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	82	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	83	</ol>
				84	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	85	<li><a href="#binaryops">Binary Operations</a>
				86	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	87	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				88	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				89	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	90	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				91	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				92	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	93	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				94	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				95	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	96	</ol>
				97	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	98	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				99	<ol>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	100	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				101	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				102	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	103	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	104	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	106	</ol>
				107	</li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	108	<li><a href="#vectorops">Vector Operations</a>
				109	<ol>
				110	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				111	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				112	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	113	</ol>
				114	</li>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	115	<li><a href="#aggregateops">Aggregate Operations</a>
				116	<ol>
				117	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				118	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				119	</ol>
				120	</li>
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	121	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	122	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	123	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				124	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				125	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	126	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				127	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				128	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	129	</ol>
				130	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	131	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	132	<ol>
				133	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	138	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	142	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	144	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	145	</ol>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	146	<li><a href="#otherops">Other Operations</a>
				147	<ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	148	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				149	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	150	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				151	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	152	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	153	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	154	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	155	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	156	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	157	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	158	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	159	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	160	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				163	<ol>
Reid Spencer	96a5f02	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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	167	</ol>
				168	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	169	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				170	<ol>
Reid Spencer	96a5f02	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	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	174	</ol>
				175	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	176	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				177	<ol>
Reid Spencer	96a5f02	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	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	185	</ol>
				186	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	187	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				188	<ol>
Reid Spencer	96a5f02	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	b6324c1	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	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	197	</ol>
				198	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	199	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	200	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	201	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	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	5bf54c8	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	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	207	</ol>
				208	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	209	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	210	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	211	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	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	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	214	</ol>
				215	</li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	216	<li><a href="#int_atomics">Atomic intrinsics</a>
				217	<ol>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	218	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	219	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	220	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	221	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				222	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				223	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				224	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				225	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				226	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				227	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				228	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				229	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				230	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	231	</ol>
				232	</li>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	233	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	234	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	235	<li><a href="#int_var_annotation">
Tanya Lattner	08abc81	2007-09-22 00:01:26 +0000	[diff] [blame]	236	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	237	<li><a href="#int_annotation">
Tanya Lattner	08abc81	2007-09-22 00:01:26 +0000	[diff] [blame]	238	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	239	<li><a href="#int_trap">
				240	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	241	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	242	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	243	</ol>
				244	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	245	</ol>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	246
				247	<div class="doc_author">
				248	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				249	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	250	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	251
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	252	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	253	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				254	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	255
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	256	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	257	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	258	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	259	type safety, low-level operations, flexibility, and the capability of
				260	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	261	representation used throughout all phases of the LLVM compilation
				262	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	263	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	264
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	265	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	266	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				267	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	268
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	269	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	270
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	271	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	272	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	273	representation (suitable for fast loading by a Just-In-Time compiler),
				274	and as a human readable assembly language representation. This allows
				275	LLVM to provide a powerful intermediate representation for efficient
				276	compiler transformations and analysis, while providing a natural means
				277	to debug and visualize the transformations. The three different forms
				278	of LLVM are all equivalent. This document describes the human readable
				279	representation and notation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	280
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	281	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	282	while being expressive, typed, and extensible at the same time. It
				283	aims to be a "universal IR" of sorts, by being at a low enough level
				284	that high-level ideas may be cleanly mapped to it (similar to how
				285	microprocessors are "universal IR's", allowing many source languages to
				286	be mapped to them). By providing type information, LLVM can be used as
				287	the target of optimizations: for example, through pointer analysis, it
				288	can be proven that a C automatic variable is never accessed outside of
				289	the current function... allowing it to be promoted to a simple SSA
				290	value instead of a memory location.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	291
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	292	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	293
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	294	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	295	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	296
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	297	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	298
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	299	<p>It is important to note that this document describes 'well formed'
				300	LLVM assembly language. There is a difference between what the parser
				301	accepts and what is considered 'well formed'. For example, the
				302	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	303
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	304	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	305	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	306	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	307	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	308	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	310	<p>...because the definition of <tt>%x</tt> does not dominate all of
				311	its uses. The LLVM infrastructure provides a verification pass that may
				312	be used to verify that an LLVM module is well formed. This pass is
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	313	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	314	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	315	by the verifier pass indicate bugs in transformation passes or input to
				316	the parser.</p>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	317	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	319	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	320
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	321	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	322	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	323	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	324
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	325	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	326
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	327	<p>LLVM identifiers come in two basic types: global and local. Global
				328	identifiers (functions, global variables) begin with the @ character. Local
				329	identifiers (register names, types) begin with the % character. Additionally,
				330	there are three different formats for identifiers, for different purposes:
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	331
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	332	<ol>
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	333	<li>Named values are represented as a string of characters with their prefix.
				334	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				335	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	336	Identifiers which require other characters in their names can be surrounded
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	337	with quotes. In this way, anything except a <tt>"</tt> character can
				338	be used in a named value.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	339
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	340	<li>Unnamed values are represented as an unsigned numeric value with their
				341	prefix. For example, %12, @2, %44.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	342
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	343	<li>Constants, which are described in a <a href="#constants">section about
				344	constants</a>, below.</li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	345	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	346
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	347	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	348	don't need to worry about name clashes with reserved words, and the set of
				349	reserved words may be expanded in the future without penalty. Additionally,
				350	unnamed identifiers allow a compiler to quickly come up with a temporary
				351	variable without having to avoid symbol table conflicts.</p>
				352
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	353	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	354	languages. There are keywords for different opcodes
				355	('<tt><a href="#i_add">add</a></tt>',
				356	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				357	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	358	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	359	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	360	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	361
				362	<p>Here is an example of LLVM code to multiply the integer variable
				363	'<tt>%X</tt>' by 8:</p>
				364
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	365	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	366
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	367	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	368	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	369	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	370	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	371	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	372
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	373	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	374
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	375	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	376	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	377	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	378	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	379	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	380
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	381	<p>And the hard way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	382
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	383	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	384	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	385	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				386	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				387	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	388	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	389	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	390
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	391	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				392	important lexical features of LLVM:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	394	<ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	395
				396	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				397	line.</li>
				398
				399	<li>Unnamed temporaries are created when the result of a computation is not
				400	assigned to a named value.</li>
				401
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	402	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	403
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	404	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	405
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	406	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	407	demonstrating instructions, we will follow an instruction with a comment that
				408	defines the type and name of value produced. Comments are shown in italic
				409	text.</p>
				410
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	411	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	412
				413	<!-- *********************************************************************** -->
				414	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				415	<!-- *********************************************************************** -->
				416
				417	<!-- ======================================================================= -->
				418	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				419	</div>
				420
				421	<div class="doc_text">
				422
				423	<p>LLVM programs are composed of "Module"s, each of which is a
				424	translation unit of the input programs. Each module consists of
				425	functions, global variables, and symbol table entries. Modules may be
				426	combined together with the LLVM linker, which merges function (and
				427	global variable) definitions, resolves forward declarations, and merges
				428	symbol table entries. Here is an example of the "hello world" module:</p>
				429
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	430	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	431	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	432	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				433	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	434
				435	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	436	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	437
				438	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	439	define i32 @main() { <i>; i32()* </i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	440	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	441	%cast210 = <a
Chris Lattner	2150cde	2007-06-12 17:01:15 +0000	[diff] [blame]	442	href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	443
				444	<i>; Call puts function to write out the string to stdout...</i>
				445	<a
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	446	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	447	<a
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	448	href="#i_ret">ret</a> i32 0<br>}<br>
				449	</pre>
				450	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	451
				452	<p>This example is made up of a <a href="#globalvars">global variable</a>
				453	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				454	function, and a <a href="#functionstructure">function definition</a>
				455	for "<tt>main</tt>".</p>
				456
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	457	<p>In general, a module is made up of a list of global values,
				458	where both functions and global variables are global values. Global values are
				459	represented by a pointer to a memory location (in this case, a pointer to an
				460	array of char, and a pointer to a function), and have one of the following <a
				461	href="#linkage">linkage types</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	462
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	463	</div>
				464
				465	<!-- ======================================================================= -->
				466	<div class="doc_subsection">
				467	<a name="linkage">Linkage Types</a>
				468	</div>
				469
				470	<div class="doc_text">
				471
				472	<p>
				473	All Global Variables and Functions have one of the following types of linkage:
				474	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	475
				476	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	477
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	478	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	479
				480	<dd>Global values with internal linkage are only directly accessible by
				481	objects in the current module. In particular, linking code into a module with
				482	an internal global value may cause the internal to be renamed as necessary to
				483	avoid collisions. Because the symbol is internal to the module, all
				484	references can be updated. This corresponds to the notion of the
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	485	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	486	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	487
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	488	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	489
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	490	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				491	the same name when linkage occurs. This is typically used to implement
				492	inline functions, templates, or other code which must be generated in each
				493	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				494	allowed to be discarded.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	495	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	496
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	497	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				498
				499	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				500	linkage, except that unreferenced <tt>common</tt> globals may not be
				501	discarded. This is used for globals that may be emitted in multiple
				502	translation units, but that are not guaranteed to be emitted into every
				503	translation unit that uses them. One example of this is tentative
				504	definitions in C, such as "<tt>int X;</tt>" at global scope.
				505	</dd>
				506
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	507	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	508
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	509	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				510	that some targets may choose to emit different assembly sequences for them
				511	for target-dependent reasons. This is used for globals that are declared
				512	"weak" in C source code.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	513	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	514
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	515	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	516
				517	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				518	pointer to array type. When two global variables with appending linkage are
				519	linked together, the two global arrays are appended together. This is the
				520	LLVM, typesafe, equivalent of having the system linker append together
				521	"sections" with identical names when .o files are linked.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	522	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	523
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	524	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	525	<dd>The semantics of this linkage follow the ELF object file model: the
				526	symbol is weak until linked, if not linked, the symbol becomes null instead
				527	of being an undefined reference.
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	528	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	529
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	530	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	531
				532	<dd>If none of the above identifiers are used, the global is externally
				533	visible, meaning that it participates in linkage and can be used to resolve
				534	external symbol references.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	535	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	536	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	537
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	538	<p>
				539	The next two types of linkage are targeted for Microsoft Windows platform
				540	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	541	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	542	</p>
				543
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	544	<dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	545	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				546
				547	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				548	or variable via a global pointer to a pointer that is set up by the DLL
				549	exporting the symbol. On Microsoft Windows targets, the pointer name is
				550	formed by combining <code>_imp__</code> and the function or variable name.
				551	</dd>
				552
				553	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				554
				555	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				556	pointer to a pointer in a DLL, so that it can be referenced with the
				557	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				558	name is formed by combining <code>_imp__</code> and the function or variable
				559	name.
				560	</dd>
				561
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	562	</dl>
				563
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	564	<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	565	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				566	variable and was linked with this one, one of the two would be renamed,
				567	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				568	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	92c671e	2007-01-05 00:59:10 +0000	[diff] [blame]	569	outside of the current module.</p>
				570	<p>It is illegal for a function <i>declaration</i>
				571	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	572	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	573	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				574	linkages.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	575	</div>
				576
				577	<!-- ======================================================================= -->
				578	<div class="doc_subsection">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	579	<a name="callingconv">Calling Conventions</a>
				580	</div>
				581
				582	<div class="doc_text">
				583
				584	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				585	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				586	specified for the call. The calling convention of any pair of dynamic
				587	caller/callee must match, or the behavior of the program is undefined. The
				588	following calling conventions are supported by LLVM, and more may be added in
				589	the future:</p>
				590
				591	<dl>
				592	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				593
				594	<dd>This calling convention (the default if no other calling convention is
				595	specified) matches the target C calling conventions. This calling convention
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	596	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	597	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	598	</dd>
				599
				600	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				601
				602	<dd>This calling convention attempts to make calls as fast as possible
				603	(e.g. by passing things in registers). This calling convention allows the
				604	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	605	without having to conform to an externally specified ABI (Application Binary
				606	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	2c6b888	2008-05-14 09:17:12 +0000	[diff] [blame]	607	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				608	supported. This calling convention does not support varargs and requires the
				609	prototype of all callees to exactly match the prototype of the function
				610	definition.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	611	</dd>
				612
				613	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				614
				615	<dd>This calling convention attempts to make code in the caller as efficient
				616	as possible under the assumption that the call is not commonly executed. As
				617	such, these calls often preserve all registers so that the call does not break
				618	any live ranges in the caller side. This calling convention does not support
				619	varargs and requires the prototype of all callees to exactly match the
				620	prototype of the function definition.
				621	</dd>
				622
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	623	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	624
				625	<dd>Any calling convention may be specified by number, allowing
				626	target-specific calling conventions to be used. Target specific calling
				627	conventions start at 64.
				628	</dd>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	629	</dl>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	630
				631	<p>More calling conventions can be added/defined on an as-needed basis, to
				632	support pascal conventions or any other well-known target-independent
				633	convention.</p>
				634
				635	</div>
				636
				637	<!-- ======================================================================= -->
				638	<div class="doc_subsection">
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	639	<a name="visibility">Visibility Styles</a>
				640	</div>
				641
				642	<div class="doc_text">
				643
				644	<p>
				645	All Global Variables and Functions have one of the following visibility styles:
				646	</p>
				647
				648	<dl>
				649	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				650
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	651	<dd>On targets that use the ELF object file format, default visibility means
				652	that the declaration is visible to other
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	653	modules and, in shared libraries, means that the declared entity may be
				654	overridden. On Darwin, default visibility means that the declaration is
				655	visible to other modules. Default visibility corresponds to "external
				656	linkage" in the language.
				657	</dd>
				658
				659	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				660
				661	<dd>Two declarations of an object with hidden visibility refer to the same
				662	object if they are in the same shared object. Usually, hidden visibility
				663	indicates that the symbol will not be placed into the dynamic symbol table,
				664	so no other module (executable or shared library) can reference it
				665	directly.
				666	</dd>
				667
Anton Korobeynikov	39f3cff	2007-04-29 18:35:00 +0000	[diff] [blame]	668	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				669
				670	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				671	the dynamic symbol table, but that references within the defining module will
				672	bind to the local symbol. That is, the symbol cannot be overridden by another
				673	module.
				674	</dd>
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	675	</dl>
				676
				677	</div>
				678
				679	<!-- ======================================================================= -->
				680	<div class="doc_subsection">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	681	<a name="globalvars">Global Variables</a>
				682	</div>
				683
				684	<div class="doc_text">
				685
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	686	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	687	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	688	an explicit section to be placed in, and may have an optional explicit alignment
				689	specified. A variable may be defined as "thread_local", which means that it
				690	will not be shared by threads (each thread will have a separated copy of the
				691	variable). A variable may be defined as a global "constant," which indicates
				692	that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	693	optimization, allowing the global data to be placed in the read-only section of
				694	an executable, etc). Note that variables that need runtime initialization
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	695	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	696
				697	<p>
				698	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				699	constant, even if the final definition of the global is not. This capability
				700	can be used to enable slightly better optimization of the program, but requires
				701	the language definition to guarantee that optimizations based on the
				702	'constantness' are valid for the translation units that do not include the
				703	definition.
				704	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	705
				706	<p>As SSA values, global variables define pointer values that are in
				707	scope (i.e. they dominate) all basic blocks in the program. Global
				708	variables always define a pointer to their "content" type because they
				709	describe a region of memory, and all memory objects in LLVM are
				710	accessed through pointers.</p>
				711
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	712	<p>A global variable may be declared to reside in a target-specifc numbered
				713	address space. For targets that support them, address spaces may affect how
				714	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	25f5076	2007-12-12 08:44:39 +0000	[diff] [blame]	715	the variable. The default address space is zero. The address space qualifier
				716	must precede any other attributes.</p>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	717
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	718	<p>LLVM allows an explicit section to be specified for globals. If the target
				719	supports it, it will emit globals to the section specified.</p>
				720
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	721	<p>An explicit alignment may be specified for a global. If not present, or if
				722	the alignment is set to zero, the alignment of the global is set by the target
				723	to whatever it feels convenient. If an explicit alignment is specified, the
				724	global is forced to have at least that much alignment. All alignments must be
				725	a power of 2.</p>
				726
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	727	<p>For example, the following defines a global in a numbered address space with
				728	an initializer, section, and alignment:</p>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	729
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	730	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	731	<pre>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	732	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	733	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	734	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	735
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	736	</div>
				737
				738
				739	<!-- ======================================================================= -->
				740	<div class="doc_subsection">
				741	<a name="functionstructure">Functions</a>
				742	</div>
				743
				744	<div class="doc_text">
				745
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	746	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				747	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	748	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	749	<a href="#callingconv">calling convention</a>, a return type, an optional
				750	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				751	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	752	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	753	optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	754	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	755
				756	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				757	optional <a href="#linkage">linkage type</a>, an optional
				758	<a href="#visibility">visibility style</a>, an optional
				759	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	760	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	761	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	dc5cafb	2007-12-10 03:30:21 +0000	[diff] [blame]	762	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	763
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	764	<p>A function definition contains a list of basic blocks, forming the CFG
				765	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	766	the function. Each basic block may optionally start with a label (giving the
				767	basic block a symbol table entry), contains a list of instructions, and ends
				768	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				769	function return).</p>
				770
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	771	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	772	executed on entrance to the function, and it is not allowed to have predecessor
				773	basic blocks (i.e. there can not be any branches to the entry block of a
				774	function). Because the block can have no predecessors, it also cannot have any
				775	<a href="#i_phi">PHI nodes</a>.</p>
				776
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	777	<p>LLVM allows an explicit section to be specified for functions. If the target
				778	supports it, it will emit functions to the section specified.</p>
				779
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	780	<p>An explicit alignment may be specified for a function. If not present, or if
				781	the alignment is set to zero, the alignment of the function is set by the target
				782	to whatever it feels convenient. If an explicit alignment is specified, the
				783	function is forced to have at least that much alignment. All alignments must be
				784	a power of 2.</p>
				785
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	786	</div>
				787
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	788
				789	<!-- ======================================================================= -->
				790	<div class="doc_subsection">
				791	<a name="aliasstructure">Aliases</a>
				792	</div>
				793	<div class="doc_text">
				794	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	25b2e82	2008-03-22 08:36:14 +0000	[diff] [blame]	795	function, global variable, another alias or bitcast of global value). Aliases
				796	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	797	optional <a href="#visibility">visibility style</a>.</p>
				798
				799	<h5>Syntax:</h5>
				800
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	801	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	802	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	803	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	804	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	805	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	806
				807	</div>
				808
				809
				810
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	811	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	812	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				813	<div class="doc_text">
				814	<p>The return type and each parameter of a function type may have a set of
				815	<i>parameter attributes</i> associated with them. Parameter attributes are
				816	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	817	a function. Parameter attributes are considered to be part of the function,
				818	not of the function type, so functions with different parameter attributes
				819	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	820
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	821	<p>Parameter attributes are simple keywords that follow the type specified. If
				822	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	823	example:</p>
				824
				825	<div class="doc_code">
				826	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	827	declare i32 @printf(i8* noalias , ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	828	declare i32 @atoi(i8 zeroext)
				829	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	830	</pre>
				831	</div>
				832
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	833	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				834	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	835
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	836	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	837	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	838	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	839	<dd>This indicates to the code generator that the parameter or return value
				840	should be zero-extended to a 32-bit value by the caller (for a parameter)
				841	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	842
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	843	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	844	<dd>This indicates to the code generator that the parameter or return value
				845	should be sign-extended to a 32-bit value by the caller (for a parameter)
				846	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	847
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	848	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	849	<dd>This indicates that this parameter or return value should be treated
				850	in a special target-dependent fashion during while emitting code for a
				851	function call or return (usually, by putting it in a register as opposed
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	852	to memory, though some targets use it to distinguish between two different
				853	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	854
				855	<dt><tt>byval</tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	856	<dd>This indicates that the pointer parameter should really be passed by
				857	value to the function. The attribute implies that a hidden copy of the
				858	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	859	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	860	pointer arguments. It is generally used to pass structs and arrays by
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	861	value, but is also valid on pointers to scalars.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	862
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	863	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	864	<dd>This indicates that the pointer parameter specifies the address of a
				865	structure that is the return value of the function in the source program.
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	866	This pointer must be guaranteed by the caller to be valid: loads and stores
				867	to the structure may be assumed by the callee to not to trap. This may only
				868	be applied to the first parameter.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	869
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	870	<dt><tt>noalias</tt></dt>
Owen Anderson	6110128	2008-02-18 04:09:01 +0000	[diff] [blame]	871	<dd>This indicates that the parameter does not alias any global or any other
				872	parameter. The caller is responsible for ensuring that this is the case,
				873	usually by placing the value in a stack allocation.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	874
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	875	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	876	<dd>This indicates that the pointer parameter can be excised using the
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	877	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	878	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	879
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	880	</div>
				881
				882	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	883	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	884	<a name="gc">Garbage Collector Names</a>
				885	</div>
				886
				887	<div class="doc_text">
				888	<p>Each function may specify a garbage collector name, which is simply a
				889	string.</p>
				890
				891	<div class="doc_code"><pre
				892	>define void @f() gc "name" { ...</pre></div>
				893
				894	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				895	collector which will cause the compiler to alter its output in order to support
				896	the named garbage collection algorithm.</p>
				897	</div>
				898
				899	<!-- ======================================================================= -->
				900	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	901	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	902	</div>
				903
				904	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	905
				906	<p>Function attributes are set to communicate additional information about
				907	a function. Function attributes are considered to be part of the function,
				908	not of the function type, so functions with different parameter attributes
				909	can have the same function type.</p>
				910
				911	<p>Function attributes are simple keywords that follow the type specified. If
				912	multiple attributes are needed, they are space separated. For
				913	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	914
				915	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	916	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	917	define void @f() noinline { ... }
				918	define void @f() alwaysinline { ... }
				919	define void @f() alwaysinline optsize { ... }
				920	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	921	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	922	</div>
				923
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	924	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	925	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	926	<dd>This attribute indicates that the inliner should attempt to inline this
				927	function into callers whenever possible, ignoring any active inlining size
				928	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	929
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	930	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	931	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame^]	932	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	933	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	934
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	935	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	936	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	937	make choices that keep the code size of this function low, and otherwise do
				938	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	939
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	940	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	941	<dd>This function attribute indicates that the function never returns normally.
				942	This produces undefined behavior at runtime if the function ever does
				943	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	944
				945	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	946	<dd>This function attribute indicates that the function never returns with an
				947	unwind or exceptional control flow. If the function does unwind, its runtime
				948	behavior is undefined.</dd>
				949
				950	<dt><tt>readnone</tt></dt>
				951	<dd>This attribute indicates that the function computes its result (or its
				952	thrown exception) based strictly on its arguments. It does not read any global
				953	mutable state (e.g. memory, control registers, etc) visible to caller functions.
				954	Furthermore, <tt>readnone</tt> functions never change any state visible to their
				955	caller.
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	956
				957	<dt><tt>readonly</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	958	<dd>This function attribute indicates that the function has no side-effects on
				959	the calling function, but that it depends on state (memory state, control
				960	register state, etc) that may be set in the caller. A readonly function always
				961	returns the same value (or throws the same exception) whenever it is called with
				962	a particular set of arguments and global state.</dd>
				963
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	964	</dl>
				965
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	966	</div>
				967
				968	<!-- ======================================================================= -->
				969	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	970	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	971	</div>
				972
				973	<div class="doc_text">
				974	<p>
				975	Modules may contain "module-level inline asm" blocks, which corresponds to the
				976	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				977	LLVM and treated as a single unit, but may be separated in the .ll file if
				978	desired. The syntax is very simple:
				979	</p>
				980
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	981	<div class="doc_code">
				982	<pre>
				983	module asm "inline asm code goes here"
				984	module asm "more can go here"
				985	</pre>
				986	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	987
				988	<p>The strings can contain any character by escaping non-printable characters.
				989	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				990	for the number.
				991	</p>
				992
				993	<p>
				994	The inline asm code is simply printed to the machine code .s file when
				995	assembly code is generated.
				996	</p>
				997	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	998
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	999	<!-- ======================================================================= -->
				1000	<div class="doc_subsection">
				1001	<a name="datalayout">Data Layout</a>
				1002	</div>
				1003
				1004	<div class="doc_text">
				1005	<p>A module may specify a target specific data layout string that specifies how
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	1006	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1007	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1008	<p>The <i>layout specification</i> consists of a list of specifications
				1009	separated by the minus sign character ('-'). Each specification starts with a
				1010	letter and may include other information after the letter to define some
				1011	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1012	<dl>
				1013	<dt><tt>E</tt></dt>
				1014	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1015	bits with the most significance have the lowest address location.</dd>
				1016	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1017	<dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1018	the bits with the least significance have the lowest address location.</dd>
				1019	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1020	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1021	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1022	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1023	too.</dd>
				1024	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1025	<dd>This specifies the alignment for an integer type of a given bit
				1026	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1027	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1028	<dd>This specifies the alignment for a vector type of a given bit
				1029	<i>size</i>.</dd>
				1030	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1031	<dd>This specifies the alignment for a floating point type of a given bit
				1032	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1033	(double).</dd>
				1034	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1035	<dd>This specifies the alignment for an aggregate type of a given bit
				1036	<i>size</i>.</dd>
				1037	</dl>
				1038	<p>When constructing the data layout for a given target, LLVM starts with a
				1039	default set of specifications which are then (possibly) overriden by the
				1040	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1041	are given in this list:</p>
				1042	<ul>
				1043	<li><tt>E</tt> - big endian</li>
				1044	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1045	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1046	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1047	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1048	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1049	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1050	alignment of 64-bits</li>
				1051	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1052	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1053	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1054	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1055	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1056	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1057	<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1058	following rules:
				1059	<ol>
				1060	<li>If the type sought is an exact match for one of the specifications, that
				1061	specification is used.</li>
				1062	<li>If no match is found, and the type sought is an integer type, then the
				1063	smallest integer type that is larger than the bitwidth of the sought type is
				1064	used. If none of the specifications are larger than the bitwidth then the the
				1065	largest integer type is used. For example, given the default specifications
				1066	above, the i7 type will use the alignment of i8 (next largest) while both
				1067	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1068	<li>If no match is found, and the type sought is a vector type, then the
				1069	largest vector type that is smaller than the sought vector type will be used
				1070	as a fall back. This happens because <128 x double> can be implemented in
				1071	terms of 64 <2 x double>, for example.</li>
				1072	</ol>
				1073	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1074
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1075	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1076	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1077	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1078
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1079	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1080
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1081	<p>The LLVM type system is one of the most important features of the
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1082	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1083	optimizations to be performed on the intermediate representation directly,
				1084	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1085	extra analyses on the side before the transformation. A strong type
				1086	system makes it easier to read the generated code and enables novel
				1087	analyses and transformations that are not feasible to perform on normal
				1088	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1089
				1090	</div>
				1091
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1092	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1093	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1094	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1095	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1096	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1097	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1098
				1099	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1100	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1101	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1102	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1103	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1104	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1105	</tr>
				1106	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1107	<td><a href="#t_floating">floating point</a></td>
				1108	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1109	</tr>
				1110	<tr>
				1111	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1112	<td><a href="#t_integer">integer</a>,
				1113	<a href="#t_floating">floating point</a>,
				1114	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1115	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1116	<a href="#t_struct">structure</a>,
				1117	<a href="#t_array">array</a>,
Dan Gohman	da52d21	2008-05-23 22:50:26 +0000	[diff] [blame]	1118	<a href="#t_label">label</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1119	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1120	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1121	<tr>
				1122	<td><a href="#t_primitive">primitive</a></td>
				1123	<td><a href="#t_label">label</a>,
				1124	<a href="#t_void">void</a>,
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1125	<a href="#t_floating">floating point</a>.</td>
				1126	</tr>
				1127	<tr>
				1128	<td><a href="#t_derived">derived</a></td>
				1129	<td><a href="#t_integer">integer</a>,
				1130	<a href="#t_array">array</a>,
				1131	<a href="#t_function">function</a>,
				1132	<a href="#t_pointer">pointer</a>,
				1133	<a href="#t_struct">structure</a>,
				1134	<a href="#t_pstruct">packed structure</a>,
				1135	<a href="#t_vector">vector</a>,
				1136	<a href="#t_opaque">opaque</a>.
				1137	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1138	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1139	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1140
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1141	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1142	most important. Values of these types are the only ones which can be
				1143	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1144	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1145	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1146
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1147	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1148	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1149
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1150	<div class="doc_text">
				1151	<p>The primitive types are the fundamental building blocks of the LLVM
				1152	system.</p>
				1153
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1154	</div>
				1155
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1156	<!-- _______________________________________________________________________ -->
				1157	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1158
				1159	<div class="doc_text">
				1160	<table>
				1161	<tbody>
				1162	<tr><th>Type</th><th>Description</th></tr>
				1163	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1164	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1165	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1166	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1167	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1168	</tbody>
				1169	</table>
				1170	</div>
				1171
				1172	<!-- _______________________________________________________________________ -->
				1173	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1174
				1175	<div class="doc_text">
				1176	<h5>Overview:</h5>
				1177	<p>The void type does not represent any value and has no size.</p>
				1178
				1179	<h5>Syntax:</h5>
				1180
				1181	<pre>
				1182	void
				1183	</pre>
				1184	</div>
				1185
				1186	<!-- _______________________________________________________________________ -->
				1187	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1188
				1189	<div class="doc_text">
				1190	<h5>Overview:</h5>
				1191	<p>The label type represents code labels.</p>
				1192
				1193	<h5>Syntax:</h5>
				1194
				1195	<pre>
				1196	label
				1197	</pre>
				1198	</div>
				1199
				1200
				1201	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1202	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1203
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1204	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1205
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1206	<p>The real power in LLVM comes from the derived types in the system.
				1207	This is what allows a programmer to represent arrays, functions,
				1208	pointers, and other useful types. Note that these derived types may be
				1209	recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1210
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1211	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1212
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1213	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1214	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1215
				1216	<div class="doc_text">
				1217
				1218	<h5>Overview:</h5>
				1219	<p>The integer type is a very simple derived type that simply specifies an
				1220	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1221	2^23-1 (about 8 million) can be specified.</p>
				1222
				1223	<h5>Syntax:</h5>
				1224
				1225	<pre>
				1226	iN
				1227	</pre>
				1228
				1229	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1230	value.</p>
				1231
				1232	<h5>Examples:</h5>
				1233	<table class="layout">
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1234	<tbody>
				1235	<tr>
				1236	<td><tt>i1</tt></td>
				1237	<td>a single-bit integer.</td>
				1238	</tr><tr>
				1239	<td><tt>i32</tt></td>
				1240	<td>a 32-bit integer.</td>
				1241	</tr><tr>
				1242	<td><tt>i1942652</tt></td>
				1243	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1244	</tr>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1245	</tbody>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1246	</table>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1247	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1248
				1249	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1250	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1251
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1252	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1253
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1254	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1255
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1256	<p>The array type is a very simple derived type that arranges elements
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1257	sequentially in memory. The array type requires a size (number of
				1258	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1259
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1260	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1261
				1262	<pre>
				1263	[<# elements> x <elementtype>]
				1264	</pre>
				1265
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1266	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1267	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1268
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1269	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1270	<table class="layout">
				1271	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1272	<td class="left"><tt>[40 x i32]</tt></td>
				1273	<td class="left">Array of 40 32-bit integer values.</td>
				1274	</tr>
				1275	<tr class="layout">
				1276	<td class="left"><tt>[41 x i32]</tt></td>
				1277	<td class="left">Array of 41 32-bit integer values.</td>
				1278	</tr>
				1279	<tr class="layout">
				1280	<td class="left"><tt>[4 x i8]</tt></td>
				1281	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1282	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1283	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1284	<p>Here are some examples of multidimensional arrays:</p>
				1285	<table class="layout">
				1286	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1287	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1288	<td class="left">3x4 array of 32-bit integer values.</td>
				1289	</tr>
				1290	<tr class="layout">
				1291	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1292	<td class="left">12x10 array of single precision floating point values.</td>
				1293	</tr>
				1294	<tr class="layout">
				1295	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1296	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1297	</tr>
				1298	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1299
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1300	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1301	length array. Normally, accesses past the end of an array are undefined in
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1302	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1303	As a special case, however, zero length arrays are recognized to be variable
				1304	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1305	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1306
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1307	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1308
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1309	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1310	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1311	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1312
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1313	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1314
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1315	<p>The function type can be thought of as a function signature. It
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1316	consists of a return type and a list of formal parameter types. The
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1317	return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel	9c1f8b1	2008-03-24 20:52:42 +0000	[diff] [blame]	1318	If the return type is a struct type then all struct elements must be of first
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1319	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1320
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1321	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1322
				1323	<pre>
				1324	<returntype list> (<parameter list>)
				1325	</pre>
				1326
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1327	<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
Misha Brukman	20f9a62	2004-08-12 20:16:08 +0000	[diff] [blame]	1328	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1329	which indicates that the function takes a variable number of arguments.
				1330	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1331	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1332	'<tt><returntype list></tt>' is a comma-separated list of
				1333	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1334
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1335	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1336	<table class="layout">
				1337	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1338	<td class="left"><tt>i32 (i32)</tt></td>
				1339	<td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1340	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1341	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1342	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1343	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1344	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1345	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1346	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1347	<tt>float</tt>.
				1348	</td>
				1349	</tr><tr class="layout">
				1350	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1351	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1352	<a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1353	which returns an integer. This is the signature for <tt>printf</tt> in
				1354	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1355	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1356	</tr><tr class="layout">
				1357	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	8dec6c2	2008-03-24 18:10:52 +0000	[diff] [blame]	1358	<td class="left">A function taking an <tt>i32></tt>, returning two
				1359	<tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1360	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1361	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1362	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1363
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1364	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1365	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1366	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1367	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1368	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1369	<p>The structure type is used to represent a collection of data members
				1370	together in memory. The packing of the field types is defined to match
				1371	the ABI of the underlying processor. The elements of a structure may
				1372	be any type that has a size.</p>
				1373	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1374	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1375	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1376	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1377	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1378	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1379	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1380	<table class="layout">
				1381	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1382	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1383	<td class="left">A triple of three <tt>i32</tt> values</td>
				1384	</tr><tr class="layout">
				1385	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1386	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1387	second element is a <a href="#t_pointer">pointer</a> to a
				1388	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1389	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1390	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1391	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1392	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1393
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1394	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1395	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1396	</div>
				1397	<div class="doc_text">
				1398	<h5>Overview:</h5>
				1399	<p>The packed structure type is used to represent a collection of data members
				1400	together in memory. There is no padding between fields. Further, the alignment
				1401	of a packed structure is 1 byte. The elements of a packed structure may
				1402	be any type that has a size.</p>
				1403	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1404	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1405	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1406	instruction.</p>
				1407	<h5>Syntax:</h5>
				1408	<pre> < { <type list> } > <br></pre>
				1409	<h5>Examples:</h5>
				1410	<table class="layout">
				1411	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1412	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1413	<td class="left">A triple of three <tt>i32</tt> values</td>
				1414	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1415	<td class="left">
				1416	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1417	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1418	second element is a <a href="#t_pointer">pointer</a> to a
				1419	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1420	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1421	</tr>
				1422	</table>
				1423	</div>
				1424
				1425	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1426	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1427	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1428	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1429	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1430	reference to another object, which must live in memory. Pointer types may have
				1431	an optional address space attribute defining the target-specific numbered
				1432	address space where the pointed-to object resides. The default address space is
				1433	zero.</p>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1434	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1435	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1436	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1437	<table class="layout">
				1438	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1439	<td class="left"><tt>[4x i32]*</tt></td>
				1440	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1441	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1442	</tr>
				1443	<tr class="layout">
				1444	<td class="left"><tt>i32 (i32 ) </tt></td>
				1445	<td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1446	href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1447	<tt>i32</tt>.</td>
				1448	</tr>
				1449	<tr class="layout">
				1450	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1451	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1452	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1453	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1454	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1455	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1456
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1457	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1458	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1459	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1460
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1461	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1462
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1463	<p>A vector type is a simple derived type that represents a vector
				1464	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1465	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1466	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1467	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1468	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1469	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1470
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1471	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1472
				1473	<pre>
				1474	< <# elements> x <elementtype> >
				1475	</pre>
				1476
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1477	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1478	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1479
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1480	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1481
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1482	<table class="layout">
				1483	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1484	<td class="left"><tt><4 x i32></tt></td>
				1485	<td class="left">Vector of 4 32-bit integer values.</td>
				1486	</tr>
				1487	<tr class="layout">
				1488	<td class="left"><tt><8 x float></tt></td>
				1489	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1490	</tr>
				1491	<tr class="layout">
				1492	<td class="left"><tt><2 x i64></tt></td>
				1493	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1494	</tr>
				1495	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1496	</div>
				1497
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1498	<!-- _______________________________________________________________________ -->
				1499	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1500	<div class="doc_text">
				1501
				1502	<h5>Overview:</h5>
				1503
				1504	<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen	a699c4d	2007-10-14 00:34:53 +0000	[diff] [blame]	1505	corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1506	In LLVM, opaque types can eventually be resolved to any type (not just a
				1507	structure type).</p>
				1508
				1509	<h5>Syntax:</h5>
				1510
				1511	<pre>
				1512	opaque
				1513	</pre>
				1514
				1515	<h5>Examples:</h5>
				1516
				1517	<table class="layout">
				1518	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1519	<td class="left"><tt>opaque</tt></td>
				1520	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1521	</tr>
				1522	</table>
				1523	</div>
				1524
				1525
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1526	<!-- *********************************************************************** -->
				1527	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1528	<!-- *********************************************************************** -->
				1529
				1530	<div class="doc_text">
				1531
				1532	<p>LLVM has several different basic types of constants. This section describes
				1533	them all and their syntax.</p>
				1534
				1535	</div>
				1536
				1537	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1538	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1539
				1540	<div class="doc_text">
				1541
				1542	<dl>
				1543	<dt><b>Boolean constants</b></dt>
				1544
				1545	<dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1546	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1547	</dd>
				1548
				1549	<dt><b>Integer constants</b></dt>
				1550
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1551	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1552	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1553	integer types.
				1554	</dd>
				1555
				1556	<dt><b>Floating point constants</b></dt>
				1557
				1558	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1559	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1560	notation (see below). The assembler requires the exact decimal value of
				1561	a floating-point constant. For example, the assembler accepts 1.25 but
				1562	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1563	constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1564
				1565	<dt><b>Null pointer constants</b></dt>
				1566
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1567	<dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1568	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1569
				1570	</dl>
				1571
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1572	<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1573	of floating point constants. For example, the form '<tt>double
				1574	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1575	4.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1576	(and the only time that they are generated by the disassembler) is when a
				1577	floating point constant must be emitted but it cannot be represented as a
				1578	decimal floating point number. For example, NaN's, infinities, and other
				1579	special values are represented in their IEEE hexadecimal format so that
				1580	assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1581
				1582	</div>
				1583
				1584	<!-- ======================================================================= -->
				1585	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1586	</div>
				1587
				1588	<div class="doc_text">
Chris Lattner	455fc8c	2005-03-07 22:13:59 +0000	[diff] [blame]	1589	<p>Aggregate constants arise from aggregation of simple constants
				1590	and smaller aggregate constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1591
				1592	<dl>
				1593	<dt><b>Structure constants</b></dt>
				1594
				1595	<dd>Structure constants are represented with notation similar to structure
				1596	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1597	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1598	where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner	455fc8c	2005-03-07 22:13:59 +0000	[diff] [blame]	1599	must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1600	types of elements must match those specified by the type.
				1601	</dd>
				1602
				1603	<dt><b>Array constants</b></dt>
				1604
				1605	<dd>Array constants are represented with notation similar to array type
				1606	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1607	(<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1608	constants must have <a href="#t_array">array type</a>, and the number and
				1609	types of elements must match those specified by the type.
				1610	</dd>
				1611
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1612	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1613
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1614	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1615	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1616	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1617	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1618	href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1619	match those specified by the type.
				1620	</dd>
				1621
				1622	<dt><b>Zero initialization</b></dt>
				1623
				1624	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1625	value to zero of <em>any</em> type, including scalar and aggregate types.
				1626	This is often used to avoid having to print large zero initializers (e.g. for
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1627	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1628	initializers.
				1629	</dd>
				1630	</dl>
				1631
				1632	</div>
				1633
				1634	<!-- ======================================================================= -->
				1635	<div class="doc_subsection">
				1636	<a name="globalconstants">Global Variable and Function Addresses</a>
				1637	</div>
				1638
				1639	<div class="doc_text">
				1640
				1641	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1642	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1643	constants. These constants are explicitly referenced when the <a
				1644	href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1645	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1646	file:</p>
				1647
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1648	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1649	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1650	@X = global i32 17
				1651	@Y = global i32 42
				1652	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1653	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1654	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1655
				1656	</div>
				1657
				1658	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1659	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1660	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1661	<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1662	no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1663	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1664
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1665	<p>Undefined values indicate to the compiler that the program is well defined
				1666	no matter what value is used, giving the compiler more freedom to optimize.
				1667	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1668	</div>
				1669
				1670	<!-- ======================================================================= -->
				1671	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1672	</div>
				1673
				1674	<div class="doc_text">
				1675
				1676	<p>Constant expressions are used to allow expressions involving other constants
				1677	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1678	href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1679	that does not have side effects (e.g. load and call are not supported). The
				1680	following is the syntax for constant expressions:</p>
				1681
				1682	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1683	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1684	<dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1685	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1686
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1687	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1688	<dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1689	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1690
				1691	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1692	<dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1693	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1694
				1695	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1696	<dd>Truncate a floating point constant to another floating point type. The
				1697	size of CST must be larger than the size of TYPE. Both types must be
				1698	floating point.</dd>
				1699
				1700	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1701	<dd>Floating point extend a constant to another type. The size of CST must be
				1702	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1703
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1704	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1705	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1706	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1707	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1708	of the same number of elements. If the value won't fit in the integer type,
				1709	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1710
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1711	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1712	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1713	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1714	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1715	of the same number of elements. If the value won't fit in the integer type,
				1716	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1717
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1718	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1719	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1720	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1721	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1722	of the same number of elements. If the value won't fit in the floating point
				1723	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1724
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1725	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1726	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1727	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1728	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1729	of the same number of elements. If the value won't fit in the floating point
				1730	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1731
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1732	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1733	<dd>Convert a pointer typed constant to the corresponding integer constant
				1734	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1735	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1736
				1737	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1738	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1739	pointer type. CST must be of integer type. The CST value is zero extended,
				1740	truncated, or unchanged to make it fit in a pointer size. This one is
				1741	<i>really</i> dangerous!</dd>
				1742
				1743	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1744	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1745	identical (same number of bits). The conversion is done as if the CST value
				1746	was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1747	with this operator, just the type. This can be used for conversion of
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1748	vector types to any other type, as long as they have the same bit width. For
Dan Gohman	c05dca9	2008-09-08 16:45:59 +0000	[diff] [blame]	1749	pointers it is only valid to cast to another pointer type. It is not valid
				1750	to bitcast to or from an aggregate type.
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1751	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1752
				1753	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1754
				1755	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1756	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1757	instruction, the index list may have zero or more indexes, which are required
				1758	to make sense for the type of "CSTPTR".</dd>
				1759
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1760	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1761
				1762	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1763	constants.</dd>
				1764
				1765	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1766	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1767
				1768	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1769	<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1770
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	1771	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1772	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1773
				1774	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1775	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1776
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1777	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1778
				1779	<dd>Perform the <a href="#i_extractelement">extractelement
				1780	operation</a> on constants.
				1781
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	1782	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1783
				1784	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1785	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	1786
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	1787
				1788	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1789
				1790	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1791	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	1792
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1793	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1794
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1795	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1796	be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1797	binary</a> operations. The constraints on operands are the same as those for
				1798	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1799	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1800	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1801	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	1802
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1803	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1804	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1805	<!-- *********************************************************************** -->
				1806
				1807	<!-- ======================================================================= -->
				1808	<div class="doc_subsection">
				1809	<a name="inlineasm">Inline Assembler Expressions</a>
				1810	</div>
				1811
				1812	<div class="doc_text">
				1813
				1814	<p>
				1815	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1816	Module-Level Inline Assembly</a>) through the use of a special value. This
				1817	value represents the inline assembler as a string (containing the instructions
				1818	to emit), a list of operand constraints (stored as a string), and a flag that
				1819	indicates whether or not the inline asm expression has side effects. An example
				1820	inline assembler expression is:
				1821	</p>
				1822
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1823	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1824	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1825	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1826	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1827	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1828
				1829	<p>
				1830	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1831	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1832	</p>
				1833
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1834	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1835	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1836	%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1837	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1838	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1839
				1840	<p>
				1841	Inline asms with side effects not visible in the constraint list must be marked
				1842	as having side effects. This is done through the use of the
				1843	'<tt>sideeffect</tt>' keyword, like so:
				1844	</p>
				1845
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1846	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1847	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1848	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1849	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1850	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1851
				1852	<p>TODO: The format of the asm and constraints string still need to be
				1853	documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner	d552826	2008-10-04 18:36:02 +0000	[diff] [blame]	1854	need to be documented). This is probably best done by reference to another
				1855	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1856	</p>
				1857
				1858	</div>
				1859
				1860	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1861	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1862	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1863
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1864	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1865
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1866	<p>The LLVM instruction set consists of several different
				1867	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1868	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1869	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1870	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1871	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1872
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1873	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1874
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1875	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1876	<div class="doc_subsection"> <a name="terminators">Terminator
				1877	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1878
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1879	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1880
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1881	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1882	basic block in a program ends with a "Terminator" instruction, which
				1883	indicates which block should be executed after the current block is
				1884	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1885	value: they produce control flow, not values (the one exception being
				1886	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1887	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1888	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1889	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	1890	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1891	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1892	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1893
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1894	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1895
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1896	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1897	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1898	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1899	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1900	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1901	<pre>
				1902	ret <type> <value> <i>; Return a value from a non-void function</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1903	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1904	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1905
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1906	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1907
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1908	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				1909	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	1910	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1911	returns a value and then causes control flow, and one that just causes
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1912	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1913
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1914	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1915
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1916	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				1917	the return value. The type of the return value must be a
				1918	'<a href="#t_firstclass">first class</a>' type.</p>
				1919
				1920	<p>A function is not <a href="#wellformed">well formed</a> if
				1921	it it has a non-void return type and contains a '<tt>ret</tt>'
				1922	instruction with no return value or a return value with a type that
				1923	does not match its type, or if it has a void return type and contains
				1924	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1925
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1926	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1927
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1928	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1929	returns back to the calling function's context. If the caller is a "<a
John Criswell	40db33f	2004-06-25 15:16:57 +0000	[diff] [blame]	1930	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1931	the instruction after the call. If the caller was an "<a
				1932	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1933	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1934	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1935	return value.
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1936
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1937	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1938
				1939	<pre>
				1940	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1941	ret void <i>; Return from a void function</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1942	ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1943	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1944	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1945	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1946	<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1947	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1948	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1949	<pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1950	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1951	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1952	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1953	transfer to a different basic block in the current function. There are
				1954	two forms of this instruction, corresponding to a conditional branch
				1955	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1956	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1957	<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1958	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1959	unconditional form of the '<tt>br</tt>' instruction takes a single
				1960	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1961	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1962	<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1963	argument is evaluated. If the value is <tt>true</tt>, control flows
				1964	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1965	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1966	<h5>Example:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1967	<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	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1968	href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1969	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1970	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1971	<div class="doc_subsubsection">
				1972	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1973	</div>
				1974
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1975	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1976	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1977
				1978	<pre>
				1979	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1980	</pre>
				1981
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1982	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1983
				1984	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1985	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1986	instruction, allowing a branch to occur to one of many possible
				1987	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1988
				1989
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1990	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1991
				1992	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1993	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1994	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1995	table is not allowed to contain duplicate constant entries.</p>
				1996
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1997	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1998
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1999	<p>The <tt>switch</tt> instruction specifies a table of values and
				2000	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2001	table is searched for the given value. If the value is found, control flow is
				2002	transfered to the corresponding destination; otherwise, control flow is
				2003	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2004
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2005	<h5>Implementation:</h5>
				2006
				2007	<p>Depending on properties of the target machine and the particular
				2008	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2009	ways. For example, it could be generated as a series of chained conditional
				2010	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2011
				2012	<h5>Example:</h5>
				2013
				2014	<pre>
				2015	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2016	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2017	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2018
				2019	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2020	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2021
				2022	<i>; Implement a jump table:</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2023	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2024	i32 1, label %onone
				2025	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2026	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2027	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2028
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2029	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2030	<div class="doc_subsubsection">
				2031	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2032	</div>
				2033
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2034	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2035
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2036	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2037
				2038	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2039	<result> = invoke [<a href="#callingconv">cconv</a>] <ptr to function ty> <function ptr val>(<function args>)
Chris Lattner	6b7a008	2006-05-14 18:23:06 +0000	[diff] [blame]	2040	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2041	</pre>
				2042
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2043	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2044
				2045	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2046	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2047	'<tt>normal</tt>' label or the
				2048	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2049	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2050	"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2051	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2052	continued at the dynamically nearest "exception" label.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2053
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2054	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2055
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2056	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2057
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2058	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2059	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2060	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2061	convention</a> the call should use. If none is specified, the call defaults
				2062	to using C calling conventions.
				2063	</li>
				2064	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2065	function value being invoked. In most cases, this is a direct function
				2066	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2067	an arbitrary pointer to function value.
				2068	</li>
				2069
				2070	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2071	function to be invoked. </li>
				2072
				2073	<li>'<tt>function args</tt>': argument list whose types match the function
				2074	signature argument types. If the function signature indicates the function
				2075	accepts a variable number of arguments, the extra arguments can be
				2076	specified. </li>
				2077
				2078	<li>'<tt>normal label</tt>': the label reached when the called function
				2079	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2080
				2081	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2082	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2083
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2084	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2085
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2086	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2087
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2088	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2089	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2090	difference is that it establishes an association with a label, which is used by
				2091	the runtime library to unwind the stack.</p>
				2092
				2093	<p>This instruction is used in languages with destructors to ensure that proper
				2094	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2095	exception. Additionally, this is important for implementation of
				2096	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2097
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2098	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2099	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2100	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2101	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2102	%retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2103	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2104	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2105	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2106
				2107
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2108	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2109
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2110	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2111	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2112
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2113	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2114
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2115	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2116	<pre>
				2117	unwind
				2118	</pre>
				2119
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2120	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2121
				2122	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2123	at the first callee in the dynamic call stack which used an <a
				2124	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2125	primarily used to implement exception handling.</p>
				2126
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2127	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2128
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2129	<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2130	immediately halt. The dynamic call stack is then searched for the first <a
				2131	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2132	execution continues at the "exceptional" destination block specified by the
				2133	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2134	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2135	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2136
				2137	<!-- _______________________________________________________________________ -->
				2138
				2139	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2140	Instruction</a> </div>
				2141
				2142	<div class="doc_text">
				2143
				2144	<h5>Syntax:</h5>
				2145	<pre>
				2146	unreachable
				2147	</pre>
				2148
				2149	<h5>Overview:</h5>
				2150
				2151	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2152	instruction is used to inform the optimizer that a particular portion of the
				2153	code is not reachable. This can be used to indicate that the code after a
				2154	no-return function cannot be reached, and other facts.</p>
				2155
				2156	<h5>Semantics:</h5>
				2157
				2158	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2159	</div>
				2160
				2161
				2162
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2163	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2164	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2165	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2166	<p>Binary operators are used to do most of the computation in a
Chris Lattner	81f9297	2008-04-01 18:47:32 +0000	[diff] [blame]	2167	program. They require two operands of the same type, execute an operation on them, and
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2168	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2169	multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner	81f9297	2008-04-01 18:47:32 +0000	[diff] [blame]	2170	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2171	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2172	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2173	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2174	<div class="doc_subsubsection">
				2175	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2176	</div>
				2177
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2178	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2179
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2180	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2181
				2182	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2183	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2184	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2185
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2186	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2187
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2188	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2189
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2190	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2191
				2192	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2193	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2194	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2195	types.</p>
				2196
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2197	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2198
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2199	<p>The value produced is the integer or floating point sum of the two
				2200	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2201
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2202	<p>If an integer sum has unsigned overflow, the result returned is the
				2203	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2204	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2205
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2206	<p>Because LLVM integers use a two's complement representation, this
				2207	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2208
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2209	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2210
				2211	<pre>
				2212	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2213	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2214	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2215	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2216	<div class="doc_subsubsection">
				2217	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2218	</div>
				2219
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2220	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2221
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2222	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2223
				2224	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2225	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2226	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2227
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2228	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2229
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2230	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2231	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2232
				2233	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2234	'<tt>neg</tt>' instruction present in most other intermediate
				2235	representations.</p>
				2236
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2237	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2238
				2239	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2240	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2241	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2242	types.</p>
				2243
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2244	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2245
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2246	<p>The value produced is the integer or floating point difference of
				2247	the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2248
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2249	<p>If an integer difference has unsigned overflow, the result returned is the
				2250	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2251	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2252
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2253	<p>Because LLVM integers use a two's complement representation, this
				2254	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2255
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2256	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2257	<pre>
				2258	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2259	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2260	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2261	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2262
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2263	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2264	<div class="doc_subsubsection">
				2265	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2266	</div>
				2267
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2268	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2269
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2270	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2271	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2272	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2273	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2274	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2275	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2276
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2277	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2278
				2279	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2280	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2281	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2282	types.</p>
				2283
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2284	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2285
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2286	<p>The value produced is the integer or floating point product of the
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2287	two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2288
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2289	<p>If the result of an integer multiplication has unsigned overflow,
				2290	the result returned is the mathematical result modulo
				2291	2<sup>n</sup>, where n is the bit width of the result.</p>
				2292	<p>Because LLVM integers use a two's complement representation, and the
				2293	result is the same width as the operands, this instruction returns the
				2294	correct result for both signed and unsigned integers. If a full product
				2295	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2296	should be sign-extended or zero-extended as appropriate to the
				2297	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2298	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2299	<pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2300	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2301	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2302
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2303	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2304	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2305	</a></div>
				2306	<div class="doc_text">
				2307	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2308	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2309	</pre>
				2310	<h5>Overview:</h5>
				2311	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2312	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2313
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2314	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2315
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2316	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2317	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2318	values. Both arguments must have identical types.</p>
				2319
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2320	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2321
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2322	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2323	<p>Note that unsigned integer division and signed integer division are distinct
				2324	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2325	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2326	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2327	<pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2328	</pre>
				2329	</div>
				2330	<!-- _______________________________________________________________________ -->
				2331	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2332	</a> </div>
				2333	<div class="doc_text">
				2334	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2335	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2336	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2337	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2338
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2339	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2340
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2341	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2342	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2343
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2344	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2345
				2346	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2347	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2348	values. Both arguments must have identical types.</p>
				2349
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2350	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2351	<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2352	<p>Note that signed integer division and unsigned integer division are distinct
				2353	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2354	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2355	undefined behavior; this is a rare case, but can occur, for example,
				2356	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2357	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2358	<pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2359	</pre>
				2360	</div>
				2361	<!-- _______________________________________________________________________ -->
				2362	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2363	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2364	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2365	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2366	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2367	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2368	</pre>
				2369	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2370
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2371	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2372	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2373
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2374	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2375
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2376	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2377	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2378	of floating point values. Both arguments must have identical types.</p>
				2379
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2380	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2381
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2382	<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2383
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2384	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2385
				2386	<pre>
				2387	<result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2388	</pre>
				2389	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2390
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2391	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2392	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2393	</div>
				2394	<div class="doc_text">
				2395	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2396	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2397	</pre>
				2398	<h5>Overview:</h5>
				2399	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2400	unsigned division of its two arguments.</p>
				2401	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2402	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2403	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2404	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2405	<h5>Semantics:</h5>
				2406	<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2407	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2408	<p>Note that unsigned integer remainder and signed integer remainder are
				2409	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2410	<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2411	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2412	<pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2413	</pre>
				2414
				2415	</div>
				2416	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2417	<div class="doc_subsubsection">
				2418	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2419	</div>
				2420
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2421	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2422
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2423	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2424
				2425	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2426	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2427	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2428
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2429	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2430
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2431	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2432	signed division of its two operands. This instruction can also take
				2433	<a href="#t_vector">vector</a> versions of the values in which case
				2434	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2435
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2436	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2437
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2438	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2439	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2440	values. Both arguments must have identical types.</p>
				2441
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2442	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2443
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2444	<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2445	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2446	operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2447	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2448	href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2449	Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer	db3b93b	2007-03-24 22:40:44 +0000	[diff] [blame]	2450	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2451	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2452	<p>Note that signed integer remainder and unsigned integer remainder are
				2453	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2454	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2455	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2456	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2457	(The remainder doesn't actually overflow, but this rule lets srem be
				2458	implemented using instructions that return both the result of the division
				2459	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2460	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2461	<pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2462	</pre>
				2463
				2464	</div>
				2465	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2466	<div class="doc_subsubsection">
				2467	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2468
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2469	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2470
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2471	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2472	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2473	</pre>
				2474	<h5>Overview:</h5>
				2475	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2476	division of its two operands.</p>
				2477	<h5>Arguments:</h5>
				2478	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2479	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2480	of floating point values. Both arguments must have identical types.</p>
				2481
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2482	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2483
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2484	<p>This instruction returns the <i>remainder</i> of a division.
				2485	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2486
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2487	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2488
				2489	<pre>
				2490	<result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2491	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2492	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2493
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2494	<!-- ======================================================================= -->
				2495	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2496	Operations</a> </div>
				2497	<div class="doc_text">
				2498	<p>Bitwise binary operators are used to do various forms of
				2499	bit-twiddling in a program. They are generally very efficient
				2500	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2501	instructions. They require two operands of the same type, execute an operation on them,
				2502	and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2503	</div>
				2504
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2505	<!-- _______________________________________________________________________ -->
				2506	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2507	Instruction</a> </div>
				2508	<div class="doc_text">
				2509	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2510	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2511	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2512
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2513	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2514
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2515	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2516	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2517
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2518	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2519
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2520	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	2521	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2522	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2523
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2524	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2525
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2526	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2527	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2528	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2529
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2530	<h5>Example:</h5><pre>
				2531	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2532	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2533	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2534	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2535	</pre>
				2536	</div>
				2537	<!-- _______________________________________________________________________ -->
				2538	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2539	Instruction</a> </div>
				2540	<div class="doc_text">
				2541	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2542	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2543	</pre>
				2544
				2545	<h5>Overview:</h5>
				2546	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2547	operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2548
				2549	<h5>Arguments:</h5>
				2550	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	2551	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2552	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2553
				2554	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2555
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2556	<p>This instruction always performs a logical shift right operation. The most
				2557	significant bits of the result will be filled with zero bits after the
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2558	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2559	the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2560
				2561	<h5>Example:</h5>
				2562	<pre>
				2563	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2564	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2565	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2566	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2567	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2568	</pre>
				2569	</div>
				2570
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2571	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2572	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2573	Instruction</a> </div>
				2574	<div class="doc_text">
				2575
				2576	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2577	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2578	</pre>
				2579
				2580	<h5>Overview:</h5>
				2581	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2582	operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2583
				2584	<h5>Arguments:</h5>
				2585	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	2586	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2587	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2588
				2589	<h5>Semantics:</h5>
				2590	<p>This instruction always performs an arithmetic shift right operation,
				2591	The most significant bits of the result will be filled with the sign bit
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2592	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2593	larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2594	</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2595
				2596	<h5>Example:</h5>
				2597	<pre>
				2598	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2599	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2600	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2601	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2602	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2603	</pre>
				2604	</div>
				2605
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2606	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2607	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2608	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2609
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2610	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2611
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2612	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2613
				2614	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2615	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2616	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2617
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2618	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2619
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2620	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2621	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2622
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2623	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2624
				2625	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2626	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2627	values. Both arguments must have identical types.</p>
				2628
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2629	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2630	<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2631	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2632	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2633	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2634	<tbody>
				2635	<tr>
				2636	<td>In0</td>
				2637	<td>In1</td>
				2638	<td>Out</td>
				2639	</tr>
				2640	<tr>
				2641	<td>0</td>
				2642	<td>0</td>
				2643	<td>0</td>
				2644	</tr>
				2645	<tr>
				2646	<td>0</td>
				2647	<td>1</td>
				2648	<td>0</td>
				2649	</tr>
				2650	<tr>
				2651	<td>1</td>
				2652	<td>0</td>
				2653	<td>0</td>
				2654	</tr>
				2655	<tr>
				2656	<td>1</td>
				2657	<td>1</td>
				2658	<td>1</td>
				2659	</tr>
				2660	</tbody>
				2661	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2662	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2663	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2664	<pre>
				2665	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2666	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2667	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2668	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2669	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2670	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2671	<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2672	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2673	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2674	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2675	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2676	<h5>Overview:</h5>
				2677	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2678	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2679	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2680
				2681	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2682	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2683	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2684	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2685	<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2686	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2687	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2688	<table border="1" cellspacing="0" cellpadding="4">
				2689	<tbody>
				2690	<tr>
				2691	<td>In0</td>
				2692	<td>In1</td>
				2693	<td>Out</td>
				2694	</tr>
				2695	<tr>
				2696	<td>0</td>
				2697	<td>0</td>
				2698	<td>0</td>
				2699	</tr>
				2700	<tr>
				2701	<td>0</td>
				2702	<td>1</td>
				2703	<td>1</td>
				2704	</tr>
				2705	<tr>
				2706	<td>1</td>
				2707	<td>0</td>
				2708	<td>1</td>
				2709	</tr>
				2710	<tr>
				2711	<td>1</td>
				2712	<td>1</td>
				2713	<td>1</td>
				2714	</tr>
				2715	</tbody>
				2716	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2717	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2718	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2719	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2720	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2721	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2722	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2723	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2724	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2725	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2726	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2727	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2728	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2729	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2730	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2731	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2732	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2733	or of its two operands. The <tt>xor</tt> is used to implement the
				2734	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2735	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2736	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2737	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2738	values. Both arguments must have identical types.</p>
				2739
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2740	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2741
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2742	<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2743	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2744	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2745	<table border="1" cellspacing="0" cellpadding="4">
				2746	<tbody>
				2747	<tr>
				2748	<td>In0</td>
				2749	<td>In1</td>
				2750	<td>Out</td>
				2751	</tr>
				2752	<tr>
				2753	<td>0</td>
				2754	<td>0</td>
				2755	<td>0</td>
				2756	</tr>
				2757	<tr>
				2758	<td>0</td>
				2759	<td>1</td>
				2760	<td>1</td>
				2761	</tr>
				2762	<tr>
				2763	<td>1</td>
				2764	<td>0</td>
				2765	<td>1</td>
				2766	</tr>
				2767	<tr>
				2768	<td>1</td>
				2769	<td>1</td>
				2770	<td>0</td>
				2771	</tr>
				2772	</tbody>
				2773	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2774	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2775	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2776	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2777	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2778	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2779	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2780	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2781	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2782	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	2783
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2784	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	2785	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2786	<a name="vectorops">Vector Operations</a>
				2787	</div>
				2788
				2789	<div class="doc_text">
				2790
				2791	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2792	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2793	vector-specific operations needed to process vectors effectively. While LLVM
				2794	does directly support these vector operations, many sophisticated algorithms
				2795	will want to use target-specific intrinsics to take full advantage of a specific
				2796	target.</p>
				2797
				2798	</div>
				2799
				2800	<!-- _______________________________________________________________________ -->
				2801	<div class="doc_subsubsection">
				2802	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2803	</div>
				2804
				2805	<div class="doc_text">
				2806
				2807	<h5>Syntax:</h5>
				2808
				2809	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2810	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2811	</pre>
				2812
				2813	<h5>Overview:</h5>
				2814
				2815	<p>
				2816	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2817	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2818	</p>
				2819
				2820
				2821	<h5>Arguments:</h5>
				2822
				2823	<p>
				2824	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2825	value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2826	an index indicating the position from which to extract the element.
				2827	The index may be a variable.</p>
				2828
				2829	<h5>Semantics:</h5>
				2830
				2831	<p>
				2832	The result is a scalar of the same type as the element type of
				2833	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2834	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2835	results are undefined.
				2836	</p>
				2837
				2838	<h5>Example:</h5>
				2839
				2840	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2841	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2842	</pre>
				2843	</div>
				2844
				2845
				2846	<!-- _______________________________________________________________________ -->
				2847	<div class="doc_subsubsection">
				2848	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2849	</div>
				2850
				2851	<div class="doc_text">
				2852
				2853	<h5>Syntax:</h5>
				2854
				2855	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	2856	<result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2857	</pre>
				2858
				2859	<h5>Overview:</h5>
				2860
				2861	<p>
				2862	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2863	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2864	</p>
				2865
				2866
				2867	<h5>Arguments:</h5>
				2868
				2869	<p>
				2870	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2871	value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2872	scalar value whose type must equal the element type of the first
				2873	operand. The third operand is an index indicating the position at
				2874	which to insert the value. The index may be a variable.</p>
				2875
				2876	<h5>Semantics:</h5>
				2877
				2878	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2879	The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2880	element values are those of <tt>val</tt> except at position
				2881	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2882	exceeds the length of <tt>val</tt>, the results are undefined.
				2883	</p>
				2884
				2885	<h5>Example:</h5>
				2886
				2887	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2888	%result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2889	</pre>
				2890	</div>
				2891
				2892	<!-- _______________________________________________________________________ -->
				2893	<div class="doc_subsubsection">
				2894	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2895	</div>
				2896
				2897	<div class="doc_text">
				2898
				2899	<h5>Syntax:</h5>
				2900
				2901	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2902	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2903	</pre>
				2904
				2905	<h5>Overview:</h5>
				2906
				2907	<p>
				2908	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2909	from two input vectors, returning a vector of the same type.
				2910	</p>
				2911
				2912	<h5>Arguments:</h5>
				2913
				2914	<p>
				2915	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2916	with types that match each other and types that match the result of the
				2917	instruction. The third argument is a shuffle mask, which has the same number
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2918	of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2919	</p>
				2920
				2921	<p>
				2922	The shuffle mask operand is required to be a constant vector with either
				2923	constant integer or undef values.
				2924	</p>
				2925
				2926	<h5>Semantics:</h5>
				2927
				2928	<p>
				2929	The elements of the two input vectors are numbered from left to right across
				2930	both of the vectors. The shuffle mask operand specifies, for each element of
				2931	the result vector, which element of the two input registers the result element
				2932	gets. The element selector may be undef (meaning "don't care") and the second
				2933	operand may be undef if performing a shuffle from only one vector.
				2934	</p>
				2935
				2936	<h5>Example:</h5>
				2937
				2938	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2939	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2940	<4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2941	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2942	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2943	</pre>
				2944	</div>
				2945
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	2946
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2947	<!-- ======================================================================= -->
				2948	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2949	<a name="aggregateops">Aggregate Operations</a>
				2950	</div>
				2951
				2952	<div class="doc_text">
				2953
				2954	<p>LLVM supports several instructions for working with aggregate values.
				2955	</p>
				2956
				2957	</div>
				2958
				2959	<!-- _______________________________________________________________________ -->
				2960	<div class="doc_subsubsection">
				2961	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2962	</div>
				2963
				2964	<div class="doc_text">
				2965
				2966	<h5>Syntax:</h5>
				2967
				2968	<pre>
				2969	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2970	</pre>
				2971
				2972	<h5>Overview:</h5>
				2973
				2974	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	2975	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2976	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2977	</p>
				2978
				2979
				2980	<h5>Arguments:</h5>
				2981
				2982	<p>
				2983	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2984	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	2985	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	2986	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2987	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2988	</p>
				2989
				2990	<h5>Semantics:</h5>
				2991
				2992	<p>
				2993	The result is the value at the position in the aggregate specified by
				2994	the index operands.
				2995	</p>
				2996
				2997	<h5>Example:</h5>
				2998
				2999	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3000	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3001	</pre>
				3002	</div>
				3003
				3004
				3005	<!-- _______________________________________________________________________ -->
				3006	<div class="doc_subsubsection">
				3007	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3008	</div>
				3009
				3010	<div class="doc_text">
				3011
				3012	<h5>Syntax:</h5>
				3013
				3014	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3015	<result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3016	</pre>
				3017
				3018	<h5>Overview:</h5>
				3019
				3020	<p>
				3021	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3022	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3023	</p>
				3024
				3025
				3026	<h5>Arguments:</h5>
				3027
				3028	<p>
				3029	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3030	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3031	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3032	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3033	indicating the position at which to insert the value in a similar manner as
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3034	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3035	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3036	The value to insert must have the same type as the value identified
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3037	by the indices.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3038
				3039	<h5>Semantics:</h5>
				3040
				3041	<p>
				3042	The result is an aggregate of the same type as <tt>val</tt>. Its
				3043	value is that of <tt>val</tt> except that the value at the position
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3044	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3045	</p>
				3046
				3047	<h5>Example:</h5>
				3048
				3049	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3050	%result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3051	</pre>
				3052	</div>
				3053
				3054
				3055	<!-- ======================================================================= -->
				3056	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3057	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3058	</div>
				3059
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3060	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3061
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3062	<p>A key design point of an SSA-based representation is how it
				3063	represents memory. In LLVM, no memory locations are in SSA form, which
				3064	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3065	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3066
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3067	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3068
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3069	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3070	<div class="doc_subsubsection">
				3071	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3072	</div>
				3073
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3074	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3075
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3076	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3077
				3078	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3079	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3080	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3081
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3082	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3083
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3084	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3085	heap and returns a pointer to it. The object is always allocated in the generic
				3086	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3087
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3088	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3089
				3090	<p>The '<tt>malloc</tt>' instruction allocates
				3091	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3092	bytes of memory from the operating system and returns a pointer of the
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3093	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3094	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3095	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3096	be aligned to at least that boundary. If not specified, or if zero, the target can
				3097	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3098
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3099	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3100
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3101	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3102
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3103	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3104	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3105	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3106
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3107	<h5>Example:</h5>
				3108
				3109	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3110	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3111
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3112	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3113	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3114	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3115	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3116	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3117	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3118	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3119
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3120	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3121	<div class="doc_subsubsection">
				3122	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3123	</div>
				3124
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3125	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3126
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3127	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3128
				3129	<pre>
				3130	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3131	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3132
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3133	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3134
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3135	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3136	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3137
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3138	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3139
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3140	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3141	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3142	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3143
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3144	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3145
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3146	<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner	0f103e1	2008-04-19 22:41:32 +0000	[diff] [blame]	3147	after this instruction executes. If the pointer is null, the operation
				3148	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3149
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3150	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3151
				3152	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3153	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3154	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3155	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3156	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3157
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3158	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3159	<div class="doc_subsubsection">
				3160	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3161	</div>
				3162
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3163	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3164
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3165	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3166
				3167	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3168	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3169	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3170
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3171	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3172
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3173	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3174	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3175	returns to its caller. The object is always allocated in the generic address
				3176	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3177
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3178	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3179
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3180	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3181	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3182	appropriate type to the program. If "NumElements" is specified, it is the
				3183	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3184	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3185	to be aligned to at least that boundary. If not specified, or if zero, the target
				3186	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3187
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3188	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3189
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3190	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3191
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3192	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3193	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3194	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3195	instruction is commonly used to represent automatic variables that must
				3196	have an address available. When the function returns (either with the <tt><a
John Criswell	c932bef	2005-05-12 16:55:34 +0000	[diff] [blame]	3197	href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3198	instructions), the memory is reclaimed. Allocating zero bytes
				3199	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3200
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3201	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3202
				3203	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3204	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3205	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3206	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3207	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3208	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3209	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3210
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3211	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3212	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3213	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3214	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3215	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3216	<pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3217	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3218	<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3219	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3220	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3221	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3222	href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3223	marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3224	the number or order of execution of this <tt>load</tt> with other
				3225	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3226	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3227	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3228	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3229	(that is, the alignment of the memory address). A value of 0 or an
				3230	omitted "align" argument means that the operation has the preferential
				3231	alignment for the target. It is the responsibility of the code emitter
				3232	to ensure that the alignment information is correct. Overestimating
				3233	the alignment results in an undefined behavior. Underestimating the
				3234	alignment may produce less efficient code. An alignment of 1 is always
				3235	safe.
				3236	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3237	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3238	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3239	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3240	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3241	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3242	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3243	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3244	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3245	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3246	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3247	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3248	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3249	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3250	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3251	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3252	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3253	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3254	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3255	<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3256	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3257	<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3258	to store and an address at which to store it. The type of the '<tt><pointer></tt>'
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3259	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3260	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3261	operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3262	optimizer is not allowed to modify the number or order of execution of
				3263	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3264	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3265	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3266	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3267	(that is, the alignment of the memory address). A value of 0 or an
				3268	omitted "align" argument means that the operation has the preferential
				3269	alignment for the target. It is the responsibility of the code emitter
				3270	to ensure that the alignment information is correct. Overestimating
				3271	the alignment results in an undefined behavior. Underestimating the
				3272	alignment may produce less efficient code. An alignment of 1 is always
				3273	safe.
				3274	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3275	<h5>Semantics:</h5>
				3276	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3277	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3278	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3279	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	8830ffe	2007-10-22 05:10:05 +0000	[diff] [blame]	3280	store i32 3, i32* %ptr <i>; yields {void}</i>
				3281	%val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3282	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3283	</div>
				3284
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3285	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3286	<div class="doc_subsubsection">
				3287	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3288	</div>
				3289
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3290	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3291	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3292	<pre>
				3293	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3294	</pre>
				3295
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3296	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3297
				3298	<p>
				3299	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3300	subelement of an aggregate data structure.</p>
				3301
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3302	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3303
Reid Spencer	cee005c	2006-12-04 21:29:24 +0000	[diff] [blame]	3304	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3305	elements of the aggregate object to index to. The actual types of the arguments
				3306	provided depend on the type of the first pointer argument. The
				3307	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	3308	levels of a structure or to a specific index in an array. When indexing into a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3309	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	3310	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3311	values will be sign extended to 64-bits if required.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3312
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3313	<p>For example, let's consider a C code fragment and how it gets
				3314	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3315
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3316	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3317	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3318	struct RT {
				3319	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3320	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3321	char C;
				3322	};
				3323	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3324	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3325	double Y;
				3326	struct RT Z;
				3327	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3328
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3329	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3330	return &s[1].Z.B[5][13];
				3331	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3332	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3333	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3334
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3335	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3336
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3337	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3338	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3339	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3340	%ST = type { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3341
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3342	define i32* %foo(%ST* %s) {
				3343	entry:
				3344	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3345	ret i32* %reg
				3346	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3347	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3348	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3349
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3350	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3351
				3352	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3353	on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer	cee005c	2006-12-04 21:29:24 +0000	[diff] [blame]	3354	and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer	c031269	2006-12-03 16:53:48 +0000	[diff] [blame]	3355	<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3356	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3357	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3358
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3359	<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3360	type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3361	}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3362	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3363	i8 }</tt>' type, another structure. The third index indexes into the second
				3364	element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3365	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3366	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3367	to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3368
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3369	<p>Note that it is perfectly legal to index partially through a
				3370	structure, returning a pointer to an inner element. Because of this,
				3371	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3372
				3373	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3374	define i32* %foo(%ST* %s) {
				3375	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3376	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3377	%t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3378	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3379	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3380	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3381	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3382	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3383
				3384	<p>Note that it is undefined to access an array out of bounds: array and
				3385	pointer indexes must always be within the defined bounds of the array type.
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	3386	The one exception for this rule is zero length arrays. These arrays are
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3387	defined to be accessible as variable length arrays, which requires access
				3388	beyond the zero'th element.</p>
				3389
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3390	<p>The getelementptr instruction is often confusing. For some more insight
				3391	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3392	FAQ</a>.</p>
				3393
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3394	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3395
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3396	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3397	<i>; yields [12 x i8]*:aptr</i>
				3398	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3399	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3400	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3401
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3402	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3403	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3404	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3405	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3406	<p>The instructions in this category are the conversion instructions (casting)
				3407	which all take a single operand and a type. They perform various bit conversions
				3408	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3409	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3410
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3411	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3412	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3413	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3414	</div>
				3415	<div class="doc_text">
				3416
				3417	<h5>Syntax:</h5>
				3418	<pre>
				3419	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3420	</pre>
				3421
				3422	<h5>Overview:</h5>
				3423	<p>
				3424	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3425	</p>
				3426
				3427	<h5>Arguments:</h5>
				3428	<p>
				3429	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3430	be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3431	and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3432	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3433	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3434
				3435	<h5>Semantics:</h5>
				3436	<p>
				3437	The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3438	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3439	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3440	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3441
				3442	<h5>Example:</h5>
				3443	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3444	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3445	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3446	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3447	</pre>
				3448	</div>
				3449
				3450	<!-- _______________________________________________________________________ -->
				3451	<div class="doc_subsubsection">
				3452	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3453	</div>
				3454	<div class="doc_text">
				3455
				3456	<h5>Syntax:</h5>
				3457	<pre>
				3458	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3459	</pre>
				3460
				3461	<h5>Overview:</h5>
				3462	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3463	<tt>ty2</tt>.</p>
				3464
				3465
				3466	<h5>Arguments:</h5>
				3467	<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3468	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3469	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3470	<tt>value</tt> must be smaller than the bit size of the destination type,
				3471	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3472
				3473	<h5>Semantics:</h5>
				3474	<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattner	c87f3df	2007-05-24 19:13:27 +0000	[diff] [blame]	3475	bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3476
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3477	<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3478
				3479	<h5>Example:</h5>
				3480	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3481	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3482	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3483	</pre>
				3484	</div>
				3485
				3486	<!-- _______________________________________________________________________ -->
				3487	<div class="doc_subsubsection">
				3488	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3489	</div>
				3490	<div class="doc_text">
				3491
				3492	<h5>Syntax:</h5>
				3493	<pre>
				3494	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3495	</pre>
				3496
				3497	<h5>Overview:</h5>
				3498	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3499
				3500	<h5>Arguments:</h5>
				3501	<p>
				3502	The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3503	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3504	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3505	<tt>value</tt> must be smaller than the bit size of the destination type,
				3506	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3507
				3508	<h5>Semantics:</h5>
				3509	<p>
				3510	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3511	bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattner	c87f3df	2007-05-24 19:13:27 +0000	[diff] [blame]	3512	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3513
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3514	<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3515
				3516	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3517	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3518	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3519	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3520	</pre>
				3521	</div>
				3522
				3523	<!-- _______________________________________________________________________ -->
				3524	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3525	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3526	</div>
				3527
				3528	<div class="doc_text">
				3529
				3530	<h5>Syntax:</h5>
				3531
				3532	<pre>
				3533	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3534	</pre>
				3535
				3536	<h5>Overview:</h5>
				3537	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3538	<tt>ty2</tt>.</p>
				3539
				3540
				3541	<h5>Arguments:</h5>
				3542	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3543	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3544	cast it to. The size of <tt>value</tt> must be larger than the size of
				3545	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3546	<i>no-op cast</i>.</p>
				3547
				3548	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3549	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3550	<a href="#t_floating">floating point</a> type to a smaller
				3551	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3552	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3553
				3554	<h5>Example:</h5>
				3555	<pre>
				3556	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3557	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3558	</pre>
				3559	</div>
				3560
				3561	<!-- _______________________________________________________________________ -->
				3562	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3563	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3564	</div>
				3565	<div class="doc_text">
				3566
				3567	<h5>Syntax:</h5>
				3568	<pre>
				3569	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3570	</pre>
				3571
				3572	<h5>Overview:</h5>
				3573	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3574	floating point value.</p>
				3575
				3576	<h5>Arguments:</h5>
				3577	<p>The '<tt>fpext</tt>' instruction takes a
				3578	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3579	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3580	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3581
				3582	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3583	<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	3584	<a href="#t_floating">floating point</a> type to a larger
				3585	<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3586	used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3587	<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3588
				3589	<h5>Example:</h5>
				3590	<pre>
				3591	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3592	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3593	</pre>
				3594	</div>
				3595
				3596	<!-- _______________________________________________________________________ -->
				3597	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	3598	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3599	</div>
				3600	<div class="doc_text">
				3601
				3602	<h5>Syntax:</h5>
				3603	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3604	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3605	</pre>
				3606
				3607	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3608	<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3609	unsigned integer equivalent of type <tt>ty2</tt>.
				3610	</p>
				3611
				3612	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3613	<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3614	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3615	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3616	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3617	vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3618
				3619	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3620	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3621	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3622	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3623	the results are undefined.</p>
				3624
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3625	<h5>Example:</h5>
				3626	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3627	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3628	%Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3629	%X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3630	</pre>
				3631	</div>
				3632
				3633	<!-- _______________________________________________________________________ -->
				3634	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3635	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3636	</div>
				3637	<div class="doc_text">
				3638
				3639	<h5>Syntax:</h5>
				3640	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3641	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3642	</pre>
				3643
				3644	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3645	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3646	<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3647	</p>
				3648
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3649	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3650	<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3651	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3652	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3653	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3654	vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3655
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3656	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3657	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3658	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3659	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3660	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3661
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3662	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3663	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3664	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3665	%Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3666	%X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3667	</pre>
				3668	</div>
				3669
				3670	<!-- _______________________________________________________________________ -->
				3671	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3672	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3673	</div>
				3674	<div class="doc_text">
				3675
				3676	<h5>Syntax:</h5>
				3677	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3678	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3679	</pre>
				3680
				3681	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3682	<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3683	integer and converts that value to the <tt>ty2</tt> type.</p>
				3684
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3685	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3686	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3687	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3688	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3689	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3690	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3691
				3692	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3693	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3694	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3695	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3696
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3697	<h5>Example:</h5>
				3698	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3699	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3700	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3701	</pre>
				3702	</div>
				3703
				3704	<!-- _______________________________________________________________________ -->
				3705	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3706	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3707	</div>
				3708	<div class="doc_text">
				3709
				3710	<h5>Syntax:</h5>
				3711	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3712	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3713	</pre>
				3714
				3715	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3716	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3717	integer and converts that value to the <tt>ty2</tt> type.</p>
				3718
				3719	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3720	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3721	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3722	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3723	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3724	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3725
				3726	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3727	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3728	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3729	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3730
				3731	<h5>Example:</h5>
				3732	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3733	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3734	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3735	</pre>
				3736	</div>
				3737
				3738	<!-- _______________________________________________________________________ -->
				3739	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3740	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3741	</div>
				3742	<div class="doc_text">
				3743
				3744	<h5>Syntax:</h5>
				3745	<pre>
				3746	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3747	</pre>
				3748
				3749	<h5>Overview:</h5>
				3750	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3751	the integer type <tt>ty2</tt>.</p>
				3752
				3753	<h5>Arguments:</h5>
				3754	<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	3755	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3756	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3757
				3758	<h5>Semantics:</h5>
				3759	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3760	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3761	truncating or zero extending that value to the size of the integer type. If
				3762	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3763	<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3764	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3765	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3766
				3767	<h5>Example:</h5>
				3768	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3769	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3770	%Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3771	</pre>
				3772	</div>
				3773
				3774	<!-- _______________________________________________________________________ -->
				3775	<div class="doc_subsubsection">
				3776	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3777	</div>
				3778	<div class="doc_text">
				3779
				3780	<h5>Syntax:</h5>
				3781	<pre>
				3782	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3783	</pre>
				3784
				3785	<h5>Overview:</h5>
				3786	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3787	a pointer type, <tt>ty2</tt>.</p>
				3788
				3789	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	3790	<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3791	value to cast, and a type to cast it to, which must be a
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	3792	<a href="#t_pointer">pointer</a> type.
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3793
				3794	<h5>Semantics:</h5>
				3795	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3796	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3797	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3798	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3799	the size of a pointer then a zero extension is done. If they are the same size,
				3800	nothing is done (<i>no-op cast</i>).</p>
				3801
				3802	<h5>Example:</h5>
				3803	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3804	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3805	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3806	%Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3807	</pre>
				3808	</div>
				3809
				3810	<!-- _______________________________________________________________________ -->
				3811	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3812	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3813	</div>
				3814	<div class="doc_text">
				3815
				3816	<h5>Syntax:</h5>
				3817	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3818	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3819	</pre>
				3820
				3821	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3822
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3823	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3824	<tt>ty2</tt> without changing any bits.</p>
				3825
				3826	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3827
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3828	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	c05dca9	2008-09-08 16:45:59 +0000	[diff] [blame]	3829	a non-aggregate first class value, and a type to cast it to, which must also be
				3830	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3831	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	3832	and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3833	type is a pointer, the destination type must also be a pointer. This
				3834	instruction supports bitwise conversion of vectors to integers and to vectors
				3835	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3836
				3837	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3838	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3839	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3840	this conversion. The conversion is done as if the <tt>value</tt> had been
				3841	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3842	converted to other pointer types with this instruction. To convert pointers to
				3843	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3844	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3845
				3846	<h5>Example:</h5>
				3847	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3848	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3849	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3850	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3851	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3852	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3853
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3854	<!-- ======================================================================= -->
				3855	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3856	<div class="doc_text">
				3857	<p>The instructions in this category are the "miscellaneous"
				3858	instructions, which defy better classification.</p>
				3859	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3860
				3861	<!-- _______________________________________________________________________ -->
				3862	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3863	</div>
				3864	<div class="doc_text">
				3865	<h5>Syntax:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3866	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3867	</pre>
				3868	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3869	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3870	a vector of boolean values based on comparison
				3871	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3872	<h5>Arguments:</h5>
				3873	<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3874	the condition code indicating the kind of comparison to perform. It is not
				3875	a value, just a keyword. The possible condition code are:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3876	<ol>
				3877	<li><tt>eq</tt>: equal</li>
				3878	<li><tt>ne</tt>: not equal </li>
				3879	<li><tt>ugt</tt>: unsigned greater than</li>
				3880	<li><tt>uge</tt>: unsigned greater or equal</li>
				3881	<li><tt>ult</tt>: unsigned less than</li>
				3882	<li><tt>ule</tt>: unsigned less or equal</li>
				3883	<li><tt>sgt</tt>: signed greater than</li>
				3884	<li><tt>sge</tt>: signed greater or equal</li>
				3885	<li><tt>slt</tt>: signed less than</li>
				3886	<li><tt>sle</tt>: signed less or equal</li>
				3887	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3888	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3889	<a href="#t_pointer">pointer</a>
				3890	or integer <a href="#t_vector">vector</a> typed.
				3891	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3892	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3893	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3894	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3895	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3896	<ol>
				3897	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3898	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3899	</li>
				3900	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3901	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3902	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3903	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3904	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3905	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3906	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3907	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3908	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3909	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3910	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3911	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3912	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3913	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3914	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3915	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3916	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3917	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3918	</ol>
				3919	<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3920	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3921	<p>If the operands are integer vectors, then they are compared
				3922	element by element. The result is an <tt>i1</tt> vector with
				3923	the same number of elements as the values being compared.
				3924	Otherwise, the result is an <tt>i1</tt>.
				3925	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3926
				3927	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3928	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3929	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3930	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3931	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3932	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3933	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3934	</pre>
				3935	</div>
				3936
				3937	<!-- _______________________________________________________________________ -->
				3938	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3939	</div>
				3940	<div class="doc_text">
				3941	<h5>Syntax:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3942	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3943	</pre>
				3944	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3945	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3946	or vector of boolean values based on comparison
				3947	of its operands.
				3948	<p>
				3949	If the operands are floating point scalars, then the result
				3950	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3951	</p>
				3952	<p>If the operands are floating point vectors, then the result type
				3953	is a vector of boolean with the same number of elements as the
				3954	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3955	<h5>Arguments:</h5>
				3956	<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3957	the condition code indicating the kind of comparison to perform. It is not
				3958	a value, just a keyword. The possible condition code are:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3959	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3960	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3961	<li><tt>oeq</tt>: ordered and equal</li>
				3962	<li><tt>ogt</tt>: ordered and greater than </li>
				3963	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3964	<li><tt>olt</tt>: ordered and less than </li>
				3965	<li><tt>ole</tt>: ordered and less than or equal</li>
				3966	<li><tt>one</tt>: ordered and not equal</li>
				3967	<li><tt>ord</tt>: ordered (no nans)</li>
				3968	<li><tt>ueq</tt>: unordered or equal</li>
				3969	<li><tt>ugt</tt>: unordered or greater than </li>
				3970	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3971	<li><tt>ult</tt>: unordered or less than </li>
				3972	<li><tt>ule</tt>: unordered or less than or equal</li>
				3973	<li><tt>une</tt>: unordered or not equal</li>
				3974	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3975	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3976	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3977	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	3978	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3979	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				3980	either a <a href="#t_floating">floating point</a> type
				3981	or a <a href="#t_vector">vector</a> of floating point type.
				3982	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3983	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3984	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3985	according to the condition code given as <tt>cond</tt>.
				3986	If the operands are vectors, then the vectors are compared
				3987	element by element.
				3988	Each comparison performed
				3989	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3990	<ol>
				3991	<li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3992	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3993	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3994	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3995	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3996	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3997	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3998	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3999	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4000	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4001	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4002	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4003	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4004	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4005	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4006	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4007	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4008	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4009	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4010	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4011	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4012	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4013	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4014	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4015	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4016	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4017	<li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4018	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4019	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4020
				4021	<h5>Example:</h5>
				4022	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4023	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4024	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4025	<result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4026	</pre>
				4027	</div>
				4028
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4029	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4030	<div class="doc_subsubsection">
				4031	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4032	</div>
				4033	<div class="doc_text">
				4034	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4035	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4036	</pre>
				4037	<h5>Overview:</h5>
				4038	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4039	element-wise comparison of its two integer vector operands.</p>
				4040	<h5>Arguments:</h5>
				4041	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4042	the condition code indicating the kind of comparison to perform. It is not
				4043	a value, just a keyword. The possible condition code are:
				4044	<ol>
				4045	<li><tt>eq</tt>: equal</li>
				4046	<li><tt>ne</tt>: not equal </li>
				4047	<li><tt>ugt</tt>: unsigned greater than</li>
				4048	<li><tt>uge</tt>: unsigned greater or equal</li>
				4049	<li><tt>ult</tt>: unsigned less than</li>
				4050	<li><tt>ule</tt>: unsigned less or equal</li>
				4051	<li><tt>sgt</tt>: signed greater than</li>
				4052	<li><tt>sge</tt>: signed greater or equal</li>
				4053	<li><tt>slt</tt>: signed less than</li>
				4054	<li><tt>sle</tt>: signed less or equal</li>
				4055	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4056	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4057	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4058	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4059	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4060	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4061	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4062	identical type as the values being compared. The most significant bit in each
				4063	element is 1 if the element-wise comparison evaluates to true, and is 0
				4064	otherwise. All other bits of the result are undefined. The condition codes
				4065	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4066	instruction</a>.
				4067
				4068	<h5>Example:</h5>
				4069	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4070	<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>
				4071	<result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4072	</pre>
				4073	</div>
				4074
				4075	<!-- _______________________________________________________________________ -->
				4076	<div class="doc_subsubsection">
				4077	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4078	</div>
				4079	<div class="doc_text">
				4080	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4081	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4082	<h5>Overview:</h5>
				4083	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4084	element-wise comparison of its two floating point vector operands. The output
				4085	elements have the same width as the input elements.</p>
				4086	<h5>Arguments:</h5>
				4087	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4088	the condition code indicating the kind of comparison to perform. It is not
				4089	a value, just a keyword. The possible condition code are:
				4090	<ol>
				4091	<li><tt>false</tt>: no comparison, always returns false</li>
				4092	<li><tt>oeq</tt>: ordered and equal</li>
				4093	<li><tt>ogt</tt>: ordered and greater than </li>
				4094	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4095	<li><tt>olt</tt>: ordered and less than </li>
				4096	<li><tt>ole</tt>: ordered and less than or equal</li>
				4097	<li><tt>one</tt>: ordered and not equal</li>
				4098	<li><tt>ord</tt>: ordered (no nans)</li>
				4099	<li><tt>ueq</tt>: unordered or equal</li>
				4100	<li><tt>ugt</tt>: unordered or greater than </li>
				4101	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4102	<li><tt>ult</tt>: unordered or less than </li>
				4103	<li><tt>ule</tt>: unordered or less than or equal</li>
				4104	<li><tt>une</tt>: unordered or not equal</li>
				4105	<li><tt>uno</tt>: unordered (either nans)</li>
				4106	<li><tt>true</tt>: no comparison, always returns true</li>
				4107	</ol>
				4108	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4109	<a href="#t_floating">floating point</a> typed. They must also be identical
				4110	types.</p>
				4111	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4112	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4113	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4114	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4115	an identical number of elements as the values being compared, and each element
				4116	having identical with to the width of the floating point elements. The most
				4117	significant bit in each element is 1 if the element-wise comparison evaluates to
				4118	true, and is 0 otherwise. All other bits of the result are undefined. The
				4119	condition codes are evaluated identically to the
				4120	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4121
				4122	<h5>Example:</h5>
				4123	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4124	<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>
				4125	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2> <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4126	</pre>
				4127	</div>
				4128
				4129	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4130	<div class="doc_subsubsection">
				4131	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4132	</div>
				4133
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4134	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4135
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4136	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4137
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4138	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4139	<h5>Overview:</h5>
				4140	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4141	the SSA graph representing the function.</p>
				4142	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4143
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4144	<p>The type of the incoming values is specified with the first type
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4145	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4146	as arguments, with one pair for each predecessor basic block of the
				4147	current block. Only values of <a href="#t_firstclass">first class</a>
				4148	type may be used as the value arguments to the PHI node. Only labels
				4149	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4150
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4151	<p>There must be no non-phi instructions between the start of a basic
				4152	block and the PHI instructions: i.e. PHI instructions must be first in
				4153	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4154
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4155	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4156
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4157	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4158	specified by the pair corresponding to the predecessor basic block that executed
				4159	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4160
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4161	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4162	<pre>
				4163	Loop: ; Infinite loop that counts from 0 on up...
				4164	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4165	%nextindvar = add i32 %indvar, 1
				4166	br label %Loop
				4167	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4168	</div>
				4169
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4170	<!-- _______________________________________________________________________ -->
				4171	<div class="doc_subsubsection">
				4172	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4173	</div>
				4174
				4175	<div class="doc_text">
				4176
				4177	<h5>Syntax:</h5>
				4178
				4179	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4180	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4181
				4182	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4183	</pre>
				4184
				4185	<h5>Overview:</h5>
				4186
				4187	<p>
				4188	The '<tt>select</tt>' instruction is used to choose one value based on a
				4189	condition, without branching.
				4190	</p>
				4191
				4192
				4193	<h5>Arguments:</h5>
				4194
				4195	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4196	The '<tt>select</tt>' instruction requires an 'i1' value or
				4197	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4198	condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4199	type. If the val1/val2 are vectors and
				4200	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4201	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4202	</p>
				4203
				4204	<h5>Semantics:</h5>
				4205
				4206	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4207	If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4208	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4209	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4210	<p>
				4211	If the condition is a vector of i1, then the value arguments must
				4212	be vectors of the same size, and the selection is done element
				4213	by element.
				4214	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4215
				4216	<h5>Example:</h5>
				4217
				4218	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4219	%X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4220	</pre>
				4221	</div>
				4222
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4223
				4224	<!-- _______________________________________________________________________ -->
				4225	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4226	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4227	</div>
				4228
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4229	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4230
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4231	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4232	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4233	<result> = [tail] call [<a href="#callingconv">cconv</a>] <ty> [<fnty>*] <fnptrval>(<param list>)
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4234	</pre>
				4235
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4236	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4237
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4238	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4239
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4240	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4241
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4242	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4243
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4244	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4245	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4246	<p>The optional "tail" marker indicates whether the callee function accesses
				4247	any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4248	function call is eligible for tail call optimization. Note that calls may
				4249	be marked "tail" even if they do not occur before a <a
				4250	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4251	</li>
				4252	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4253	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4254	convention</a> the call should use. If none is specified, the call defaults
				4255	to using C calling conventions.
				4256	</li>
				4257	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4258	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4259	the type of the return value. Functions that return no value are marked
				4260	<tt><a href="#t_void">void</a></tt>.</p>
				4261	</li>
				4262	<li>
				4263	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4264	value being invoked. The argument types must match the types implied by
				4265	this signature. This type can be omitted if the function is not varargs
				4266	and if the function type does not return a pointer to a function.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4267	</li>
				4268	<li>
				4269	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4270	be invoked. In most cases, this is a direct function invocation, but
				4271	indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4272	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4273	</li>
				4274	<li>
				4275	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4276	function signature argument types. All arguments must be of
				4277	<a href="#t_firstclass">first class</a> type. If the function signature
				4278	indicates the function accepts a variable number of arguments, the extra
				4279	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4280	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4281	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4282
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4283	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4284
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4285	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4286	transfer to a specified function, with its incoming arguments bound to
				4287	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4288	instruction in the called function, control flow continues with the
				4289	instruction after the function call, and the return value of the
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4290	function is bound to the result argument.
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4291
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4292	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4293
				4294	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4295	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4296	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4297	%X = tail call i32 @foo() <i>; yields i32</i>
				4298	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4299	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4300
				4301	%struct.A = type { i32, i8 }
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4302	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4303	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4304	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4305	</pre>
				4306
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4307	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4308
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4309	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4310	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4311	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4312	</div>
				4313
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4314	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4315
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4316	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4317
				4318	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4319	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4320	</pre>
				4321
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4322	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4323
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4324	<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4325	the "variable argument" area of a function call. It is used to implement the
				4326	<tt>va_arg</tt> macro in C.</p>
				4327
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4328	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4329
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4330	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4331	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4332	increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4333	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4334
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4335	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4336
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4337	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4338	type from the specified <tt>va_list</tt> and causes the
				4339	<tt>va_list</tt> to point to the next argument. For more information,
				4340	see the variable argument handling <a href="#int_varargs">Intrinsic
				4341	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4342
				4343	<p>It is legal for this instruction to be called in a function which does not
				4344	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4345	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4346
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4347	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4348	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4349	argument.</p>
				4350
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4351	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4352
				4353	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4354
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4355	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4356
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4357	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4358	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4359	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4360
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4361	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4362
				4363	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4364	well known names and semantics and are required to follow certain restrictions.
				4365	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4366	language that does not require changing all of the transformations in LLVM when
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	4367	adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4368
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4369	<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4370	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4371	begin with this prefix. Intrinsic functions must always be external functions:
				4372	you cannot define the body of intrinsic functions. Intrinsic functions may
				4373	only be used in call or invoke instructions: it is illegal to take the address
				4374	of an intrinsic function. Additionally, because intrinsic functions are part
				4375	of the LLVM language, it is required if any are added that they be documented
				4376	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4377
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4378	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4379	a family of functions that perform the same operation but on different data
				4380	types. Because LLVM can represent over 8 million different integer types,
				4381	overloading is used commonly to allow an intrinsic function to operate on any
				4382	integer type. One or more of the argument types or the result type can be
				4383	overloaded to accept any integer type. Argument types may also be defined as
				4384	exactly matching a previous argument's type or the result type. This allows an
				4385	intrinsic function which accepts multiple arguments, but needs all of them to
				4386	be of the same type, to only be overloaded with respect to a single argument or
				4387	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4388
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4389	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4390	encoded into its function name, each preceded by a period. Only those types
				4391	which are overloaded result in a name suffix. Arguments whose type is matched
				4392	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4393	take an integer of any width and returns an integer of exactly the same integer
				4394	width. This leads to a family of functions such as
				4395	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4396	Only one type, the return type, is overloaded, and only one type suffix is
				4397	required. Because the argument's type is matched against the return type, it
				4398	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4399
				4400	<p>To learn how to add an intrinsic function, please see the
				4401	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4402	</p>
				4403
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4404	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4405
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4406	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4407	<div class="doc_subsection">
				4408	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4409	</div>
				4410
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4411	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4412
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4413	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4414	href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4415	intrinsic functions. These functions are related to the similarly
				4416	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4417
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4418	<p>All of these functions operate on arguments that use a
				4419	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4420	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4421	transformations should be prepared to handle these functions regardless of
				4422	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4423
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4424	<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4425	instruction and the variable argument handling intrinsic functions are
				4426	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4427
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4428	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4429	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4430	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4431	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4432	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4433	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4434	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4435
				4436	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4437	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4438
				4439	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4440	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4441	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4442	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4443	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4444
				4445	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4446	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4447	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4448	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4449
				4450	declare void @llvm.va_start(i8*)
				4451	declare void @llvm.va_copy(i8, i8)
				4452	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4453	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4454	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4455
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4456	</div>
				4457
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4458	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4459	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4460	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4461	</div>
				4462
				4463
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4464	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4465	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4466	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4467	<h5>Overview:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4468	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4469	<tt>*<arglist></tt> for subsequent use by <tt><a
				4470	href="#i_va_arg">va_arg</a></tt>.</p>
				4471
				4472	<h5>Arguments:</h5>
				4473
				4474	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4475
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4476	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4477
				4478	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4479	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4480	<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4481	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4482	Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4483	last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4484
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4485	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4486
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4487	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4488	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4489	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4490	</div>
				4491
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4492	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4493	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4494	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4495	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4496
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4497	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4498	which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4499	or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4500
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4501	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4502
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4503	<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4504
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4505	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4506
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4507	<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4508	macro available in C. In a target-dependent way, it destroys the
				4509	<tt>va_list</tt> element to which the argument points. Calls to <a
				4510	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4511	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4512	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4513
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4514	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4515
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4516	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4517	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4518	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4519	</div>
				4520
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4521	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4522
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4523	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4524
				4525	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4526	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4527	</pre>
				4528
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4529	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4530
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4531	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4532	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4533
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4534	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4535
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4536	<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth	5305ea5	2005-06-22 20:38:11 +0000	[diff] [blame]	4537	The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4538
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4539
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4540	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4541
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4542	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4543	macro available in C. In a target-dependent way, it copies the source
				4544	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4545	intrinsic is necessary because the <tt><a href="#int_va_start">
				4546	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4547	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4548
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4549	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4550
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4551	<!-- ======================================================================= -->
				4552	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4553	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4554	</div>
				4555
				4556	<div class="doc_text">
				4557
				4558	<p>
				4559	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4560	Collection</a> (GC) requires the implementation and generation of these
				4561	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4562	These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4563	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4564	href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4565	Front-ends for type-safe garbage collected languages should generate these
				4566	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4567	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4568	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	4569
				4570	<p>The garbage collection intrinsics only operate on objects in the generic
				4571	address space (address space zero).</p>
				4572
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4573	</div>
				4574
				4575	<!-- _______________________________________________________________________ -->
				4576	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4577	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4578	</div>
				4579
				4580	<div class="doc_text">
				4581
				4582	<h5>Syntax:</h5>
				4583
				4584	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4585	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4586	</pre>
				4587
				4588	<h5>Overview:</h5>
				4589
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	4590	<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4591	the code generator, and allows some metadata to be associated with it.</p>
				4592
				4593	<h5>Arguments:</h5>
				4594
				4595	<p>The first argument specifies the address of a stack object that contains the
				4596	root pointer. The second pointer (which must be either a constant or a global
				4597	value address) contains the meta-data to be associated with the root.</p>
				4598
				4599	<h5>Semantics:</h5>
				4600
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	4601	<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4602	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4603	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4604	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4605	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4606
				4607	</div>
				4608
				4609
				4610	<!-- _______________________________________________________________________ -->
				4611	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4612	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4613	</div>
				4614
				4615	<div class="doc_text">
				4616
				4617	<h5>Syntax:</h5>
				4618
				4619	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4620	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4621	</pre>
				4622
				4623	<h5>Overview:</h5>
				4624
				4625	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4626	locations, allowing garbage collector implementations that require read
				4627	barriers.</p>
				4628
				4629	<h5>Arguments:</h5>
				4630
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4631	<p>The second argument is the address to read from, which should be an address
				4632	allocated from the garbage collector. The first object is a pointer to the
				4633	start of the referenced object, if needed by the language runtime (otherwise
				4634	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4635
				4636	<h5>Semantics:</h5>
				4637
				4638	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4639	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4640	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4641	may only be used in a function which <a href="#gc">specifies a GC
				4642	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4643
				4644	</div>
				4645
				4646
				4647	<!-- _______________________________________________________________________ -->
				4648	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4649	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4650	</div>
				4651
				4652	<div class="doc_text">
				4653
				4654	<h5>Syntax:</h5>
				4655
				4656	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4657	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4658	</pre>
				4659
				4660	<h5>Overview:</h5>
				4661
				4662	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4663	locations, allowing garbage collector implementations that require write
				4664	barriers (such as generational or reference counting collectors).</p>
				4665
				4666	<h5>Arguments:</h5>
				4667
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4668	<p>The first argument is the reference to store, the second is the start of the
				4669	object to store it to, and the third is the address of the field of Obj to
				4670	store to. If the runtime does not require a pointer to the object, Obj may be
				4671	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4672
				4673	<h5>Semantics:</h5>
				4674
				4675	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4676	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4677	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4678	may only be used in a function which <a href="#gc">specifies a GC
				4679	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4680
				4681	</div>
				4682
				4683
				4684
				4685	<!-- ======================================================================= -->
				4686	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4687	<a name="int_codegen">Code Generator Intrinsics</a>
				4688	</div>
				4689
				4690	<div class="doc_text">
				4691	<p>
				4692	These intrinsics are provided by LLVM to expose special features that may only
				4693	be implemented with code generator support.
				4694	</p>
				4695
				4696	</div>
				4697
				4698	<!-- _______________________________________________________________________ -->
				4699	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4700	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4701	</div>
				4702
				4703	<div class="doc_text">
				4704
				4705	<h5>Syntax:</h5>
				4706	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4707	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4708	</pre>
				4709
				4710	<h5>Overview:</h5>
				4711
				4712	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	4713	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4714	target-specific value indicating the return address of the current function
				4715	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4716	</p>
				4717
				4718	<h5>Arguments:</h5>
				4719
				4720	<p>
				4721	The argument to this intrinsic indicates which function to return the address
				4722	for. Zero indicates the calling function, one indicates its caller, etc. The
				4723	argument is <b>required</b> to be a constant integer value.
				4724	</p>
				4725
				4726	<h5>Semantics:</h5>
				4727
				4728	<p>
				4729	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4730	the return address of the specified call frame, or zero if it cannot be
				4731	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4732	for arguments other than zero, so it should only be used for debugging purposes.
				4733	</p>
				4734
				4735	<p>
				4736	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	4737	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4738	source-language caller.
				4739	</p>
				4740	</div>
				4741
				4742
				4743	<!-- _______________________________________________________________________ -->
				4744	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4745	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4746	</div>
				4747
				4748	<div class="doc_text">
				4749
				4750	<h5>Syntax:</h5>
				4751	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4752	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4753	</pre>
				4754
				4755	<h5>Overview:</h5>
				4756
				4757	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	4758	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4759	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4760	</p>
				4761
				4762	<h5>Arguments:</h5>
				4763
				4764	<p>
				4765	The argument to this intrinsic indicates which function to return the frame
				4766	pointer for. Zero indicates the calling function, one indicates its caller,
				4767	etc. The argument is <b>required</b> to be a constant integer value.
				4768	</p>
				4769
				4770	<h5>Semantics:</h5>
				4771
				4772	<p>
				4773	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4774	the frame address of the specified call frame, or zero if it cannot be
				4775	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4776	for arguments other than zero, so it should only be used for debugging purposes.
				4777	</p>
				4778
				4779	<p>
				4780	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	4781	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4782	source-language caller.
				4783	</p>
				4784	</div>
				4785
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4786	<!-- _______________________________________________________________________ -->
				4787	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4788	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4789	</div>
				4790
				4791	<div class="doc_text">
				4792
				4793	<h5>Syntax:</h5>
				4794	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4795	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4796	</pre>
				4797
				4798	<h5>Overview:</h5>
				4799
				4800	<p>
				4801	The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4802	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4803	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4804	features like scoped automatic variable sized arrays in C99.
				4805	</p>
				4806
				4807	<h5>Semantics:</h5>
				4808
				4809	<p>
				4810	This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4811	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4812	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4813	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4814	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4815	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4816	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4817	</p>
				4818
				4819	</div>
				4820
				4821	<!-- _______________________________________________________________________ -->
				4822	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4823	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4824	</div>
				4825
				4826	<div class="doc_text">
				4827
				4828	<h5>Syntax:</h5>
				4829	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4830	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4831	</pre>
				4832
				4833	<h5>Overview:</h5>
				4834
				4835	<p>
				4836	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4837	the function stack to the state it was in when the corresponding <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4838	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4839	useful for implementing language features like scoped automatic variable sized
				4840	arrays in C99.
				4841	</p>
				4842
				4843	<h5>Semantics:</h5>
				4844
				4845	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4846	See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4847	</p>
				4848
				4849	</div>
				4850
				4851
				4852	<!-- _______________________________________________________________________ -->
				4853	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4854	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4855	</div>
				4856
				4857	<div class="doc_text">
				4858
				4859	<h5>Syntax:</h5>
				4860	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4861	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4862	</pre>
				4863
				4864	<h5>Overview:</h5>
				4865
				4866
				4867	<p>
				4868	The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4869	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4870	no
				4871	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	4872	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4873	</p>
				4874
				4875	<h5>Arguments:</h5>
				4876
				4877	<p>
				4878	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4879	determining if the fetch should be for a read (0) or write (1), and
				4880	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	4881	locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4882	<tt>locality</tt> arguments must be constant integers.
				4883	</p>
				4884
				4885	<h5>Semantics:</h5>
				4886
				4887	<p>
				4888	This intrinsic does not modify the behavior of the program. In particular,
				4889	prefetches cannot trap and do not produce a value. On targets that support this
				4890	intrinsic, the prefetch can provide hints to the processor cache for better
				4891	performance.
				4892	</p>
				4893
				4894	</div>
				4895
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4896	<!-- _______________________________________________________________________ -->
				4897	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4898	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4899	</div>
				4900
				4901	<div class="doc_text">
				4902
				4903	<h5>Syntax:</h5>
				4904	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4905	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4906	</pre>
				4907
				4908	<h5>Overview:</h5>
				4909
				4910
				4911	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4912	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4913	(PC) in a region of
				4914	code to simulators and other tools. The method is target specific, but it is
				4915	expected that the marker will use exported symbols to transmit the PC of the
				4916	marker.
				4917	The marker makes no guarantees that it will remain with any specific instruction
				4918	after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattner	b40261e	2006-03-24 07:16:10 +0000	[diff] [blame]	4919	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4920	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4921	</p>
				4922
				4923	<h5>Arguments:</h5>
				4924
				4925	<p>
				4926	<tt>id</tt> is a numerical id identifying the marker.
				4927	</p>
				4928
				4929	<h5>Semantics:</h5>
				4930
				4931	<p>
				4932	This intrinsic does not modify the behavior of the program. Backends that do not
				4933	support this intrinisic may ignore it.
				4934	</p>
				4935
				4936	</div>
				4937
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4938	<!-- _______________________________________________________________________ -->
				4939	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4940	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4941	</div>
				4942
				4943	<div class="doc_text">
				4944
				4945	<h5>Syntax:</h5>
				4946	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4947	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4948	</pre>
				4949
				4950	<h5>Overview:</h5>
				4951
				4952
				4953	<p>
				4954	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4955	counter register (or similar low latency, high accuracy clocks) on those targets
				4956	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4957	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4958	should only be used for small timings.
				4959	</p>
				4960
				4961	<h5>Semantics:</h5>
				4962
				4963	<p>
				4964	When directly supported, reading the cycle counter should not modify any memory.
				4965	Implementations are allowed to either return a application specific value or a
				4966	system wide value. On backends without support, this is lowered to a constant 0.
				4967	</p>
				4968
				4969	</div>
				4970
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4971	<!-- ======================================================================= -->
				4972	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4973	<a name="int_libc">Standard C Library Intrinsics</a>
				4974	</div>
				4975
				4976	<div class="doc_text">
				4977	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4978	LLVM provides intrinsics for a few important standard C library functions.
				4979	These intrinsics allow source-language front-ends to pass information about the
				4980	alignment of the pointer arguments to the code generator, providing opportunity
				4981	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4982	</p>
				4983
				4984	</div>
				4985
				4986	<!-- _______________________________________________________________________ -->
				4987	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4988	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4989	</div>
				4990
				4991	<div class="doc_text">
				4992
				4993	<h5>Syntax:</h5>
				4994	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4995	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4996	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4997	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4998	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4999	</pre>
				5000
				5001	<h5>Overview:</h5>
				5002
				5003	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5004	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5005	location to the destination location.
				5006	</p>
				5007
				5008	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5009	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5010	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5011	</p>
				5012
				5013	<h5>Arguments:</h5>
				5014
				5015	<p>
				5016	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5017	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5018	specifying the number of bytes to copy, and the fourth argument is the alignment
				5019	of the source and destination locations.
				5020	</p>
				5021
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5022	<p>
				5023	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5024	the caller guarantees that both the source and destination pointers are aligned
				5025	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5026	</p>
				5027
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5028	<h5>Semantics:</h5>
				5029
				5030	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5031	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5032	location to the destination location, which are not allowed to overlap. It
				5033	copies "len" bytes of memory over. If the argument is known to be aligned to
				5034	some boundary, this can be specified as the fourth argument, otherwise it should
				5035	be set to 0 or 1.
				5036	</p>
				5037	</div>
				5038
				5039
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5040	<!-- _______________________________________________________________________ -->
				5041	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5042	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5043	</div>
				5044
				5045	<div class="doc_text">
				5046
				5047	<h5>Syntax:</h5>
				5048	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5049	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5050	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5051	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5052	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5053	</pre>
				5054
				5055	<h5>Overview:</h5>
				5056
				5057	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5058	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5059	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5060	'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5061	</p>
				5062
				5063	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5064	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5065	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5066	</p>
				5067
				5068	<h5>Arguments:</h5>
				5069
				5070	<p>
				5071	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5072	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5073	specifying the number of bytes to copy, and the fourth argument is the alignment
				5074	of the source and destination locations.
				5075	</p>
				5076
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5077	<p>
				5078	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5079	the caller guarantees that the source and destination pointers are aligned to
				5080	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5081	</p>
				5082
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5083	<h5>Semantics:</h5>
				5084
				5085	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5086	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5087	location to the destination location, which may overlap. It
				5088	copies "len" bytes of memory over. If the argument is known to be aligned to
				5089	some boundary, this can be specified as the fourth argument, otherwise it should
				5090	be set to 0 or 1.
				5091	</p>
				5092	</div>
				5093
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5094
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5095	<!-- _______________________________________________________________________ -->
				5096	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5097	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5098	</div>
				5099
				5100	<div class="doc_text">
				5101
				5102	<h5>Syntax:</h5>
				5103	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5104	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5105	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5106	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5107	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5108	</pre>
				5109
				5110	<h5>Overview:</h5>
				5111
				5112	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5113	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5114	byte value.
				5115	</p>
				5116
				5117	<p>
				5118	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5119	does not return a value, and takes an extra alignment argument.
				5120	</p>
				5121
				5122	<h5>Arguments:</h5>
				5123
				5124	<p>
				5125	The first argument is a pointer to the destination to fill, the second is the
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5126	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5127	argument specifying the number of bytes to fill, and the fourth argument is the
				5128	known alignment of destination location.
				5129	</p>
				5130
				5131	<p>
				5132	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5133	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5134	</p>
				5135
				5136	<h5>Semantics:</h5>
				5137
				5138	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5139	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5140	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5141	destination location. If the argument is known to be aligned to some boundary,
				5142	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5143	1.
				5144	</p>
				5145	</div>
				5146
				5147
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5148	<!-- _______________________________________________________________________ -->
				5149	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5150	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5151	</div>
				5152
				5153	<div class="doc_text">
				5154
				5155	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5156	<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5157	floating point or vector of floating point type. Not all targets support all
				5158	types however.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5159	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5160	declare float @llvm.sqrt.f32(float %Val)
				5161	declare double @llvm.sqrt.f64(double %Val)
				5162	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5163	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5164	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5165	</pre>
				5166
				5167	<h5>Overview:</h5>
				5168
				5169	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5170	The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5171	returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5172	<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner	00d7cb9	2008-01-29 07:00:44 +0000	[diff] [blame]	5173	negative numbers other than -0.0 (which allows for better optimization, because
				5174	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5175	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5176	</p>
				5177
				5178	<h5>Arguments:</h5>
				5179
				5180	<p>
				5181	The argument and return value are floating point numbers of the same type.
				5182	</p>
				5183
				5184	<h5>Semantics:</h5>
				5185
				5186	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5187	This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5188	floating point number.
				5189	</p>
				5190	</div>
				5191
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5192	<!-- _______________________________________________________________________ -->
				5193	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5194	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5195	</div>
				5196
				5197	<div class="doc_text">
				5198
				5199	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5200	<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5201	floating point or vector of floating point type. Not all targets support all
				5202	types however.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5203	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5204	declare float @llvm.powi.f32(float %Val, i32 %power)
				5205	declare double @llvm.powi.f64(double %Val, i32 %power)
				5206	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5207	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5208	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5209	</pre>
				5210
				5211	<h5>Overview:</h5>
				5212
				5213	<p>
				5214	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5215	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5216	multiplications is not defined. When a vector of floating point type is
				5217	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5218	</p>
				5219
				5220	<h5>Arguments:</h5>
				5221
				5222	<p>
				5223	The second argument is an integer power, and the first is a value to raise to
				5224	that power.
				5225	</p>
				5226
				5227	<h5>Semantics:</h5>
				5228
				5229	<p>
				5230	This function returns the first value raised to the second power with an
				5231	unspecified sequence of rounding operations.</p>
				5232	</div>
				5233
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5234	<!-- _______________________________________________________________________ -->
				5235	<div class="doc_subsubsection">
				5236	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5237	</div>
				5238
				5239	<div class="doc_text">
				5240
				5241	<h5>Syntax:</h5>
				5242	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5243	floating point or vector of floating point type. Not all targets support all
				5244	types however.
				5245	<pre>
				5246	declare float @llvm.sin.f32(float %Val)
				5247	declare double @llvm.sin.f64(double %Val)
				5248	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5249	declare fp128 @llvm.sin.f128(fp128 %Val)
				5250	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5251	</pre>
				5252
				5253	<h5>Overview:</h5>
				5254
				5255	<p>
				5256	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5257	</p>
				5258
				5259	<h5>Arguments:</h5>
				5260
				5261	<p>
				5262	The argument and return value are floating point numbers of the same type.
				5263	</p>
				5264
				5265	<h5>Semantics:</h5>
				5266
				5267	<p>
				5268	This function returns the sine of the specified operand, returning the
				5269	same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5270	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5271	</div>
				5272
				5273	<!-- _______________________________________________________________________ -->
				5274	<div class="doc_subsubsection">
				5275	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5276	</div>
				5277
				5278	<div class="doc_text">
				5279
				5280	<h5>Syntax:</h5>
				5281	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5282	floating point or vector of floating point type. Not all targets support all
				5283	types however.
				5284	<pre>
				5285	declare float @llvm.cos.f32(float %Val)
				5286	declare double @llvm.cos.f64(double %Val)
				5287	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5288	declare fp128 @llvm.cos.f128(fp128 %Val)
				5289	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5290	</pre>
				5291
				5292	<h5>Overview:</h5>
				5293
				5294	<p>
				5295	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5296	</p>
				5297
				5298	<h5>Arguments:</h5>
				5299
				5300	<p>
				5301	The argument and return value are floating point numbers of the same type.
				5302	</p>
				5303
				5304	<h5>Semantics:</h5>
				5305
				5306	<p>
				5307	This function returns the cosine of the specified operand, returning the
				5308	same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5309	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5310	</div>
				5311
				5312	<!-- _______________________________________________________________________ -->
				5313	<div class="doc_subsubsection">
				5314	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5315	</div>
				5316
				5317	<div class="doc_text">
				5318
				5319	<h5>Syntax:</h5>
				5320	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5321	floating point or vector of floating point type. Not all targets support all
				5322	types however.
				5323	<pre>
				5324	declare float @llvm.pow.f32(float %Val, float %Power)
				5325	declare double @llvm.pow.f64(double %Val, double %Power)
				5326	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5327	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5328	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5329	</pre>
				5330
				5331	<h5>Overview:</h5>
				5332
				5333	<p>
				5334	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5335	specified (positive or negative) power.
				5336	</p>
				5337
				5338	<h5>Arguments:</h5>
				5339
				5340	<p>
				5341	The second argument is a floating point power, and the first is a value to
				5342	raise to that power.
				5343	</p>
				5344
				5345	<h5>Semantics:</h5>
				5346
				5347	<p>
				5348	This function returns the first value raised to the second power,
				5349	returning the
				5350	same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5351	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5352	</div>
				5353
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5354
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5355	<!-- ======================================================================= -->
				5356	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5357	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5358	</div>
				5359
				5360	<div class="doc_text">
				5361	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5362	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5363	These allow efficient code generation for some algorithms.
				5364	</p>
				5365
				5366	</div>
				5367
				5368	<!-- _______________________________________________________________________ -->
				5369	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5370	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5371	</div>
				5372
				5373	<div class="doc_text">
				5374
				5375	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5376	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5377	type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5378	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5379	declare i16 @llvm.bswap.i16(i16 <id>)
				5380	declare i32 @llvm.bswap.i32(i32 <id>)
				5381	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5382	</pre>
				5383
				5384	<h5>Overview:</h5>
				5385
				5386	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5387	The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5388	values with an even number of bytes (positive multiple of 16 bits). These are
				5389	useful for performing operations on data that is not in the target's native
				5390	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5391	</p>
				5392
				5393	<h5>Semantics:</h5>
				5394
				5395	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5396	The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5397	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5398	intrinsic returns an i32 value that has the four bytes of the input i32
				5399	swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5400	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5401	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5402	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5403	</p>
				5404
				5405	</div>
				5406
				5407	<!-- _______________________________________________________________________ -->
				5408	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5409	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5410	</div>
				5411
				5412	<div class="doc_text">
				5413
				5414	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5415	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5416	width. Not all targets support all bit widths however.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5417	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5418	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5419	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5420	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5421	declare i64 @llvm.ctpop.i64(i64 <src>)
				5422	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5423	</pre>
				5424
				5425	<h5>Overview:</h5>
				5426
				5427	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5428	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5429	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5430	</p>
				5431
				5432	<h5>Arguments:</h5>
				5433
				5434	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5435	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	5436	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5437	</p>
				5438
				5439	<h5>Semantics:</h5>
				5440
				5441	<p>
				5442	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5443	</p>
				5444	</div>
				5445
				5446	<!-- _______________________________________________________________________ -->
				5447	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5448	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5449	</div>
				5450
				5451	<div class="doc_text">
				5452
				5453	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5454	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5455	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5456	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5457	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5458	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5459	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5460	declare i64 @llvm.ctlz.i64(i64 <src>)
				5461	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5462	</pre>
				5463
				5464	<h5>Overview:</h5>
				5465
				5466	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5467	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5468	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5469	</p>
				5470
				5471	<h5>Arguments:</h5>
				5472
				5473	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5474	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	5475	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5476	</p>
				5477
				5478	<h5>Semantics:</h5>
				5479
				5480	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5481	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5482	in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5483	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5484	</p>
				5485	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5486
				5487
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5488
				5489	<!-- _______________________________________________________________________ -->
				5490	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5491	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5492	</div>
				5493
				5494	<div class="doc_text">
				5495
				5496	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5497	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5498	integer bit width. Not all targets support all bit widths however.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5499	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5500	declare i8 @llvm.cttz.i8 (i8 <src>)
				5501	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5502	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5503	declare i64 @llvm.cttz.i64(i64 <src>)
				5504	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5505	</pre>
				5506
				5507	<h5>Overview:</h5>
				5508
				5509	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5510	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5511	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5512	</p>
				5513
				5514	<h5>Arguments:</h5>
				5515
				5516	<p>
				5517	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	5518	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5519	</p>
				5520
				5521	<h5>Semantics:</h5>
				5522
				5523	<p>
				5524	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5525	in a variable. If the src == 0 then the result is the size in bits of the type
				5526	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5527	</p>
				5528	</div>
				5529
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	5530	<!-- _______________________________________________________________________ -->
				5531	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5532	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5533	</div>
				5534
				5535	<div class="doc_text">
				5536
				5537	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5538	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5539	on any integer bit width.
				5540	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5541	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5542	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5543	</pre>
				5544
				5545	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5546	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5547	range of bits from an integer value and returns them in the same bit width as
				5548	the original value.</p>
				5549
				5550	<h5>Arguments:</h5>
				5551	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5552	any bit width but they must have the same bit width. The second and third
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5553	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5554
				5555	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5556	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5557	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5558	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5559	operates in forward mode.</p>
				5560	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5561	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5562	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5563	<ol>
				5564	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5565	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5566	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5567	to determine the number of bits to retain.</li>
				5568	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5569	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5570	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	5571	<p>In reverse mode, a similar computation is made except that the bits are
				5572	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5573	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5574	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5575	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5576	</div>
				5577
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5578	<div class="doc_subsubsection">
				5579	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5580	</div>
				5581
				5582	<div class="doc_text">
				5583
				5584	<h5>Syntax:</h5>
				5585	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5586	on any integer bit width.
				5587	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5588	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5589	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5590	</pre>
				5591
				5592	<h5>Overview:</h5>
				5593	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5594	of bits in an integer value with another integer value. It returns the integer
				5595	with the replaced bits.</p>
				5596
				5597	<h5>Arguments:</h5>
				5598	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5599	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5600	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5601	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5602	type since they specify only a bit index.</p>
				5603
				5604	<h5>Semantics:</h5>
				5605	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5606	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5607	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5608	operates in forward mode.</p>
				5609	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5610	truncating it down to the size of the replacement area or zero extending it
				5611	up to that size.</p>
				5612	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5613	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5614	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5615	to the <tt>%hi</tt>th bit.
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5616	<p>In reverse mode, a similar computation is made except that the bits are
				5617	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5618	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5619	<h5>Examples:</h5>
				5620	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5621	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5622	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5623	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5624	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5625	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	5626	</pre>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5627	</div>
				5628
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5629	<!-- ======================================================================= -->
				5630	<div class="doc_subsection">
				5631	<a name="int_debugger">Debugger Intrinsics</a>
				5632	</div>
				5633
				5634	<div class="doc_text">
				5635	<p>
				5636	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5637	are described in the <a
				5638	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5639	Debugging</a> document.
				5640	</p>
				5641	</div>
				5642
				5643
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	5644	<!-- ======================================================================= -->
				5645	<div class="doc_subsection">
				5646	<a name="int_eh">Exception Handling Intrinsics</a>
				5647	</div>
				5648
				5649	<div class="doc_text">
				5650	<p> The LLVM exception handling intrinsics (which all start with
				5651	<tt>llvm.eh.</tt> prefix), are described in the <a
				5652	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5653	Handling</a> document. </p>
				5654	</div>
				5655
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	5656	<!-- ======================================================================= -->
				5657	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5658	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5659	</div>
				5660
				5661	<div class="doc_text">
				5662	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5663	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5664	the <tt>nest</tt> attribute, from a function. The result is a callable
				5665	function pointer lacking the nest parameter - the caller does not need
				5666	to provide a value for it. Instead, the value to use is stored in
				5667	advance in a "trampoline", a block of memory usually allocated
				5668	on the stack, which also contains code to splice the nest value into the
				5669	argument list. This is used to implement the GCC nested function address
				5670	extension.
				5671	</p>
				5672	<p>
				5673	For example, if the function is
				5674	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	5675	pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5676	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5677	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5678	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5679	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5680	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5681	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	5682	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5683	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5684	</div>
				5685
				5686	<!-- _______________________________________________________________________ -->
				5687	<div class="doc_subsubsection">
				5688	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5689	</div>
				5690	<div class="doc_text">
				5691	<h5>Syntax:</h5>
				5692	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5693	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5694	</pre>
				5695	<h5>Overview:</h5>
				5696	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5697	This fills the memory pointed to by <tt>tramp</tt> with code
				5698	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5699	</p>
				5700	<h5>Arguments:</h5>
				5701	<p>
				5702	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5703	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5704	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	f2bcd37	2007-08-22 23:39:54 +0000	[diff] [blame]	5705	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5706	currently provides no portable way of determining them, so a front-end that
				5707	generates this intrinsic needs to have some target-specific knowledge.
				5708	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5709	</p>
				5710	<h5>Semantics:</h5>
				5711	<p>
				5712	The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5713	dependent code, turning it into a function. A pointer to this function is
				5714	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5715	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5716	before being called. The new function's signature is the same as that of
				5717	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5718	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5719	of pointer type. Calling the new function is equivalent to calling
				5720	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5721	missing <tt>nest</tt> argument. If, after calling
				5722	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5723	modified, then the effect of any later call to the returned function pointer is
				5724	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5725	</p>
				5726	</div>
				5727
				5728	<!-- ======================================================================= -->
				5729	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	5730	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5731	</div>
				5732
				5733	<div class="doc_text">
				5734	<p>
				5735	These intrinsic functions expand the "universal IR" of LLVM to represent
				5736	hardware constructs for atomic operations and memory synchronization. This
				5737	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	5738	is aimed at a low enough level to allow any programming models or APIs
				5739	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	5740	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5741	hardware behavior. Just as hardware provides a "universal IR" for source
				5742	languages, it also provides a starting point for developing a "universal"
				5743	atomic operation and synchronization IR.
				5744	</p>
				5745	<p>
				5746	These do <em>not</em> form an API such as high-level threading libraries,
				5747	software transaction memory systems, atomic primitives, and intrinsic
				5748	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5749	application libraries. The hardware interface provided by LLVM should allow
				5750	a clean implementation of all of these APIs and parallel programming models.
				5751	No one model or paradigm should be selected above others unless the hardware
				5752	itself ubiquitously does so.
				5753
				5754	</p>
				5755	</div>
				5756
				5757	<!-- _______________________________________________________________________ -->
				5758	<div class="doc_subsubsection">
				5759	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5760	</div>
				5761	<div class="doc_text">
				5762	<h5>Syntax:</h5>
				5763	<pre>
				5764	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5765	i1 <device> )
				5766
				5767	</pre>
				5768	<h5>Overview:</h5>
				5769	<p>
				5770	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5771	specific pairs of memory access types.
				5772	</p>
				5773	<h5>Arguments:</h5>
				5774	<p>
				5775	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5776	The first four arguments enables a specific barrier as listed below. The fith
				5777	argument specifies that the barrier applies to io or device or uncached memory.
				5778
				5779	</p>
				5780	<ul>
				5781	<li><tt>ll</tt>: load-load barrier</li>
				5782	<li><tt>ls</tt>: load-store barrier</li>
				5783	<li><tt>sl</tt>: store-load barrier</li>
				5784	<li><tt>ss</tt>: store-store barrier</li>
				5785	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5786	</ul>
				5787	<h5>Semantics:</h5>
				5788	<p>
				5789	This intrinsic causes the system to enforce some ordering constraints upon
				5790	the loads and stores of the program. This barrier does not indicate
				5791	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5792	which they occur. For any of the specified pairs of load and store operations
				5793	(f.ex. load-load, or store-load), all of the first operations preceding the
				5794	barrier will complete before any of the second operations succeeding the
				5795	barrier begin. Specifically the semantics for each pairing is as follows:
				5796	</p>
				5797	<ul>
				5798	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5799	after the barrier begins.</li>
				5800
				5801	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5802	store after the barrier begins.</li>
				5803	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5804	store after the barrier begins.</li>
				5805	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5806	load after the barrier begins.</li>
				5807	</ul>
				5808	<p>
				5809	These semantics are applied with a logical "and" behavior when more than one
				5810	is enabled in a single memory barrier intrinsic.
				5811	</p>
				5812	<p>
				5813	Backends may implement stronger barriers than those requested when they do not
				5814	support as fine grained a barrier as requested. Some architectures do not
				5815	need all types of barriers and on such architectures, these become noops.
				5816	</p>
				5817	<h5>Example:</h5>
				5818	<pre>
				5819	%ptr = malloc i32
				5820	store i32 4, %ptr
				5821
				5822	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5823	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5824	<i>; guarantee the above finishes</i>
				5825	store i32 8, %ptr <i>; before this begins</i>
				5826	</pre>
				5827	</div>
				5828
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5829	<!-- _______________________________________________________________________ -->
				5830	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5831	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5832	</div>
				5833	<div class="doc_text">
				5834	<h5>Syntax:</h5>
				5835	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5836	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5837	any integer bit width and for different address spaces. Not all targets
				5838	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5839
				5840	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5841	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5842	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5843	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5844	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5845
				5846	</pre>
				5847	<h5>Overview:</h5>
				5848	<p>
				5849	This loads a value in memory and compares it to a given value. If they are
				5850	equal, it stores a new value into the memory.
				5851	</p>
				5852	<h5>Arguments:</h5>
				5853	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5854	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5855	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5856	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5857	this integer type. While any bit width integer may be used, targets may only
				5858	lower representations they support in hardware.
				5859
				5860	</p>
				5861	<h5>Semantics:</h5>
				5862	<p>
				5863	This entire intrinsic must be executed atomically. It first loads the value
				5864	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5865	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5866	loaded value is yielded in all cases. This provides the equivalent of an
				5867	atomic compare-and-swap operation within the SSA framework.
				5868	</p>
				5869	<h5>Examples:</h5>
				5870
				5871	<pre>
				5872	%ptr = malloc i32
				5873	store i32 4, %ptr
				5874
				5875	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5876	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5877	<i>; yields {i32}:result1 = 4</i>
				5878	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5879	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5880
				5881	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5882	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5883	<i>; yields {i32}:result2 = 8</i>
				5884	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5885
				5886	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5887	</pre>
				5888	</div>
				5889
				5890	<!-- _______________________________________________________________________ -->
				5891	<div class="doc_subsubsection">
				5892	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5893	</div>
				5894	<div class="doc_text">
				5895	<h5>Syntax:</h5>
				5896
				5897	<p>
				5898	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5899	integer bit width. Not all targets support all bit widths however.</p>
				5900	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5901	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5902	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5903	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5904	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5905
				5906	</pre>
				5907	<h5>Overview:</h5>
				5908	<p>
				5909	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5910	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5911	at <tt>ptr</tt>.
				5912	</p>
				5913	<h5>Arguments:</h5>
				5914
				5915	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5916	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5917	<tt>val</tt> argument and the result must be integers of the same bit width.
				5918	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5919	integer type. The targets may only lower integer representations they
				5920	support.
				5921	</p>
				5922	<h5>Semantics:</h5>
				5923	<p>
				5924	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5925	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5926	equivalent of an atomic swap operation within the SSA framework.
				5927
				5928	</p>
				5929	<h5>Examples:</h5>
				5930	<pre>
				5931	%ptr = malloc i32
				5932	store i32 4, %ptr
				5933
				5934	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5935	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5936	<i>; yields {i32}:result1 = 4</i>
				5937	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5938	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5939
				5940	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5941	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5942	<i>; yields {i32}:result2 = 8</i>
				5943
				5944	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5945	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5946	</pre>
				5947	</div>
				5948
				5949	<!-- _______________________________________________________________________ -->
				5950	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5951	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5952
				5953	</div>
				5954	<div class="doc_text">
				5955	<h5>Syntax:</h5>
				5956	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5957	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5958	integer bit width. Not all targets support all bit widths however.</p>
				5959	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5960	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				5961	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				5962	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				5963	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5964
				5965	</pre>
				5966	<h5>Overview:</h5>
				5967	<p>
				5968	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5969	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5970	</p>
				5971	<h5>Arguments:</h5>
				5972	<p>
				5973
				5974	The intrinsic takes two arguments, the first a pointer to an integer value
				5975	and the second an integer value. The result is also an integer value. These
				5976	integer types can have any bit width, but they must all have the same bit
				5977	width. The targets may only lower integer representations they support.
				5978	</p>
				5979	<h5>Semantics:</h5>
				5980	<p>
				5981	This intrinsic does a series of operations atomically. It first loads the
				5982	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5983	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5984	</p>
				5985
				5986	<h5>Examples:</h5>
				5987	<pre>
				5988	%ptr = malloc i32
				5989	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5990	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5991	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5992	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5993	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5994	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5995	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5996	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5997	</pre>
				5998	</div>
				5999
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6000	<!-- _______________________________________________________________________ -->
				6001	<div class="doc_subsubsection">
				6002	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6003
				6004	</div>
				6005	<div class="doc_text">
				6006	<h5>Syntax:</h5>
				6007	<p>
				6008	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6009	any integer bit width and for different address spaces. Not all targets
				6010	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6011	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6012	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6013	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6014	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6015	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6016
				6017	</pre>
				6018	<h5>Overview:</h5>
				6019	<p>
				6020	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6021	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6022	</p>
				6023	<h5>Arguments:</h5>
				6024	<p>
				6025
				6026	The intrinsic takes two arguments, the first a pointer to an integer value
				6027	and the second an integer value. The result is also an integer value. These
				6028	integer types can have any bit width, but they must all have the same bit
				6029	width. The targets may only lower integer representations they support.
				6030	</p>
				6031	<h5>Semantics:</h5>
				6032	<p>
				6033	This intrinsic does a series of operations atomically. It first loads the
				6034	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6035	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6036	</p>
				6037
				6038	<h5>Examples:</h5>
				6039	<pre>
				6040	%ptr = malloc i32
				6041	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6042	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6043	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6044	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6045	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6046	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6047	<i>; yields {i32}:result3 = 2</i>
				6048	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6049	</pre>
				6050	</div>
				6051
				6052	<!-- _______________________________________________________________________ -->
				6053	<div class="doc_subsubsection">
				6054	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6055	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6056	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6057	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6058
				6059	</div>
				6060	<div class="doc_text">
				6061	<h5>Syntax:</h5>
				6062	<p>
				6063	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6064	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6065	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6066	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6067	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6068	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6069	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6070	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6071	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6072
				6073	</pre>
				6074
				6075	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6076	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6077	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6078	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6079	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6080
				6081	</pre>
				6082
				6083	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6084	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6085	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6086	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6087	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6088
				6089	</pre>
				6090
				6091	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6092	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6093	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6094	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6095	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6096
				6097	</pre>
				6098	<h5>Overview:</h5>
				6099	<p>
				6100	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6101	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6102	at <tt>ptr</tt>.
				6103	</p>
				6104	<h5>Arguments:</h5>
				6105	<p>
				6106
				6107	These intrinsics take two arguments, the first a pointer to an integer value
				6108	and the second an integer value. The result is also an integer value. These
				6109	integer types can have any bit width, but they must all have the same bit
				6110	width. The targets may only lower integer representations they support.
				6111	</p>
				6112	<h5>Semantics:</h5>
				6113	<p>
				6114	These intrinsics does a series of operations atomically. They first load the
				6115	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6116	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6117	value stored at <tt>ptr</tt>.
				6118	</p>
				6119
				6120	<h5>Examples:</h5>
				6121	<pre>
				6122	%ptr = malloc i32
				6123	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6124	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6125	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6126	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6127	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6128	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6129	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6130	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6131	<i>; yields {i32}:result3 = FF</i>
				6132	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6133	</pre>
				6134	</div>
				6135
				6136
				6137	<!-- _______________________________________________________________________ -->
				6138	<div class="doc_subsubsection">
				6139	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6140	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6141	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6142	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6143
				6144	</div>
				6145	<div class="doc_text">
				6146	<h5>Syntax:</h5>
				6147	<p>
				6148	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6149	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6150	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6151	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6152	support all bit widths however.</p>
				6153	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6154	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6155	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6156	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6157	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6158
				6159	</pre>
				6160
				6161	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6162	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6163	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6164	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6165	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6166
				6167	</pre>
				6168
				6169	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6170	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6171	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6172	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6173	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6174
				6175	</pre>
				6176
				6177	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6178	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6179	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6180	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6181	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6182
				6183	</pre>
				6184	<h5>Overview:</h5>
				6185	<p>
				6186	These intrinsics takes the signed or unsigned minimum or maximum of
				6187	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6188	original value at <tt>ptr</tt>.
				6189	</p>
				6190	<h5>Arguments:</h5>
				6191	<p>
				6192
				6193	These intrinsics take two arguments, the first a pointer to an integer value
				6194	and the second an integer value. The result is also an integer value. These
				6195	integer types can have any bit width, but they must all have the same bit
				6196	width. The targets may only lower integer representations they support.
				6197	</p>
				6198	<h5>Semantics:</h5>
				6199	<p>
				6200	These intrinsics does a series of operations atomically. They first load the
				6201	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6202	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6203	the original value stored at <tt>ptr</tt>.
				6204	</p>
				6205
				6206	<h5>Examples:</h5>
				6207	<pre>
				6208	%ptr = malloc i32
				6209	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6210	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6211	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6212	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6213	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6214	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6215	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6216	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6217	<i>; yields {i32}:result3 = 8</i>
				6218	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6219	</pre>
				6220	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6221
				6222	<!-- ======================================================================= -->
				6223	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6224	<a name="int_general">General Intrinsics</a>
				6225	</div>
				6226
				6227	<div class="doc_text">
				6228	<p> This class of intrinsics is designed to be generic and has
				6229	no specific purpose. </p>
				6230	</div>
				6231
				6232	<!-- _______________________________________________________________________ -->
				6233	<div class="doc_subsubsection">
				6234	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6235	</div>
				6236
				6237	<div class="doc_text">
				6238
				6239	<h5>Syntax:</h5>
				6240	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6241	declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6242	</pre>
				6243
				6244	<h5>Overview:</h5>
				6245
				6246	<p>
				6247	The '<tt>llvm.var.annotation</tt>' intrinsic
				6248	</p>
				6249
				6250	<h5>Arguments:</h5>
				6251
				6252	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6253	The first argument is a pointer to a value, the second is a pointer to a
				6254	global string, the third is a pointer to a global string which is the source
				6255	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6256	</p>
				6257
				6258	<h5>Semantics:</h5>
				6259
				6260	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6261	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6262	This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6263	annotations. These have no other defined use, they are ignored by code
				6264	generation and optimization.
				6265	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6266	</div>
				6267
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6268	<!-- _______________________________________________________________________ -->
				6269	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	6270	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6271	</div>
				6272
				6273	<div class="doc_text">
				6274
				6275	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6276	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6277	any integer bit width.
				6278	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6279	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	6280	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6281	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6282	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6283	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6284	declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6285	</pre>
				6286
				6287	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6288
				6289	<p>
				6290	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6291	</p>
				6292
				6293	<h5>Arguments:</h5>
				6294
				6295	<p>
				6296	The first argument is an integer value (result of some expression),
				6297	the second is a pointer to a global string, the third is a pointer to a global
				6298	string which is the source file name, and the last argument is the line number.
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6299	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6300	</p>
				6301
				6302	<h5>Semantics:</h5>
				6303
				6304	<p>
				6305	This intrinsic allows annotations to be put on arbitrary expressions
				6306	with arbitrary strings. This can be useful for special purpose optimizations
				6307	that want to look for these annotations. These have no other defined use, they
				6308	are ignored by code generation and optimization.
				6309	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6310
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6311	<!-- _______________________________________________________________________ -->
				6312	<div class="doc_subsubsection">
				6313	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6314	</div>
				6315
				6316	<div class="doc_text">
				6317
				6318	<h5>Syntax:</h5>
				6319	<pre>
				6320	declare void @llvm.trap()
				6321	</pre>
				6322
				6323	<h5>Overview:</h5>
				6324
				6325	<p>
				6326	The '<tt>llvm.trap</tt>' intrinsic
				6327	</p>
				6328
				6329	<h5>Arguments:</h5>
				6330
				6331	<p>
				6332	None
				6333	</p>
				6334
				6335	<h5>Semantics:</h5>
				6336
				6337	<p>
				6338	This intrinsics is lowered to the target dependent trap instruction. If the
				6339	target does not have a trap instruction, this intrinsic will be lowered to the
				6340	call of the abort() function.
				6341	</p>
				6342	</div>
				6343
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	6344	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	6345	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6346	<address>
				6347	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6348	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6349	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	6350	src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6351
				6352	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	6353	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6354	Last modified: $Date$
				6355	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	6356
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	6357	</body>
				6358	</html>