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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
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	752	<a href="#paramattrs">parameter attributes</a>), optional
				753	<a href="#fnattrs">function attributes</a>, an optional section,
				754	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	755	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]	756
				757	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				758	optional <a href="#linkage">linkage type</a>, an optional
				759	<a href="#visibility">visibility style</a>, an optional
				760	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	761	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	762	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]	763	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	764
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	765	<p>A function definition contains a list of basic blocks, forming the CFG
				766	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	767	the function. Each basic block may optionally start with a label (giving the
				768	basic block a symbol table entry), contains a list of instructions, and ends
				769	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				770	function return).</p>
				771
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	772	<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]	773	executed on entrance to the function, and it is not allowed to have predecessor
				774	basic blocks (i.e. there can not be any branches to the entry block of a
				775	function). Because the block can have no predecessors, it also cannot have any
				776	<a href="#i_phi">PHI nodes</a>.</p>
				777
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	778	<p>LLVM allows an explicit section to be specified for functions. If the target
				779	supports it, it will emit functions to the section specified.</p>
				780
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	781	<p>An explicit alignment may be specified for a function. If not present, or if
				782	the alignment is set to zero, the alignment of the function is set by the target
				783	to whatever it feels convenient. If an explicit alignment is specified, the
				784	function is forced to have at least that much alignment. All alignments must be
				785	a power of 2.</p>
				786
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	787	<h5>Syntax:</h5>
				788
				789	<div class="doc_code">
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame^]	790	<tt>
				791	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				792	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				793	<ResultType> @<FunctionName> ([argument list])
				794	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				795	[<a href="#gc">gc</a>] { ... }
				796	</tt>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	797	</div>
				798
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	799	</div>
				800
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	801
				802	<!-- ======================================================================= -->
				803	<div class="doc_subsection">
				804	<a name="aliasstructure">Aliases</a>
				805	</div>
				806	<div class="doc_text">
				807	<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]	808	function, global variable, another alias or bitcast of global value). Aliases
				809	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	810	optional <a href="#visibility">visibility style</a>.</p>
				811
				812	<h5>Syntax:</h5>
				813
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	814	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	815	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	816	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	817	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	818	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	819
				820	</div>
				821
				822
				823
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	824	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	825	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				826	<div class="doc_text">
				827	<p>The return type and each parameter of a function type may have a set of
				828	<i>parameter attributes</i> associated with them. Parameter attributes are
				829	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	830	a function. Parameter attributes are considered to be part of the function,
				831	not of the function type, so functions with different parameter attributes
				832	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	833
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	834	<p>Parameter attributes are simple keywords that follow the type specified. If
				835	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	836	example:</p>
				837
				838	<div class="doc_code">
				839	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	840	declare i32 @printf(i8* noalias , ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	841	declare i32 @atoi(i8 zeroext)
				842	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	843	</pre>
				844	</div>
				845
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	846	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				847	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	848
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	849	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	850	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	851	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	852	<dd>This indicates to the code generator that the parameter or return value
				853	should be zero-extended to a 32-bit value by the caller (for a parameter)
				854	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	855
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	856	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	857	<dd>This indicates to the code generator that the parameter or return value
				858	should be sign-extended to a 32-bit value by the caller (for a parameter)
				859	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	860
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	861	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	862	<dd>This indicates that this parameter or return value should be treated
				863	in a special target-dependent fashion during while emitting code for a
				864	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]	865	to memory, though some targets use it to distinguish between two different
				866	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	867
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	868	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	869	<dd>This indicates that the pointer parameter should really be passed by
				870	value to the function. The attribute implies that a hidden copy of the
				871	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]	872	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]	873	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	874	value, but is also valid on pointers to scalars. The copy is considered to
				875	belong to the caller not the callee (for example,
				876	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	877	<tt>byval</tt> parameters). This is not a valid attribute for return
				878	values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	879
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	880	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	881	<dd>This indicates that the pointer parameter specifies the address of a
				882	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]	883	This pointer must be guaranteed by the caller to be valid: loads and stores
				884	to the structure may be assumed by the callee to not to trap. This may only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	885	be applied to the first parameter. This is not a valid attribute for
				886	return values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	887
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	888	<dt><tt>noalias</tt></dt>
Owen Anderson	6110128	2008-02-18 04:09:01 +0000	[diff] [blame]	889	<dd>This indicates that the parameter does not alias any global or any other
				890	parameter. The caller is responsible for ensuring that this is the case,
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	891	usually by placing the value in a stack allocation. This is not a valid
				892	attribute for return values.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	893
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	894	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	895	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	896	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				897	attribute for return values.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	898	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	899
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	900	</div>
				901
				902	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	903	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	904	<a name="gc">Garbage Collector Names</a>
				905	</div>
				906
				907	<div class="doc_text">
				908	<p>Each function may specify a garbage collector name, which is simply a
				909	string.</p>
				910
				911	<div class="doc_code"><pre
				912	>define void @f() gc "name" { ...</pre></div>
				913
				914	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				915	collector which will cause the compiler to alter its output in order to support
				916	the named garbage collection algorithm.</p>
				917	</div>
				918
				919	<!-- ======================================================================= -->
				920	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	921	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	922	</div>
				923
				924	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	925
				926	<p>Function attributes are set to communicate additional information about
				927	a function. Function attributes are considered to be part of the function,
				928	not of the function type, so functions with different parameter attributes
				929	can have the same function type.</p>
				930
				931	<p>Function attributes are simple keywords that follow the type specified. If
				932	multiple attributes are needed, they are space separated. For
				933	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	934
				935	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	936	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	937	define void @f() noinline { ... }
				938	define void @f() alwaysinline { ... }
				939	define void @f() alwaysinline optsize { ... }
				940	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	941	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	942	</div>
				943
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	944	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	945	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	946	<dd>This attribute indicates that the inliner should attempt to inline this
				947	function into callers whenever possible, ignoring any active inlining size
				948	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	949
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	950	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	951	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame]	952	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	953	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	954
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	955	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	956	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	957	make choices that keep the code size of this function low, and otherwise do
				958	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	959
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	960	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	961	<dd>This function attribute indicates that the function never returns normally.
				962	This produces undefined behavior at runtime if the function ever does
				963	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	964
				965	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	966	<dd>This function attribute indicates that the function never returns with an
				967	unwind or exceptional control flow. If the function does unwind, its runtime
				968	behavior is undefined.</dd>
				969
				970	<dt><tt>readnone</tt></dt>
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	971	<dd>This attribute indicates that the function computes its result (or the
				972	exception it throws) based strictly on its arguments, without dereferencing any
				973	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				974	registers, etc) visible to caller functions. It does not write through any
				975	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
				976	never changes any state visible to callers.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	977
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	978	<dt><tt><a name="readonly">readonly</a></tt></dt>
				979	<dd>This attribute indicates that the function does not write through any
				980	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				981	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				982	caller functions. It may dereference pointer arguments and read state that may
				983	be set in the caller. A readonly function always returns the same value (or
				984	throws the same exception) when called with the same set of arguments and global
				985	state.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	986	</dl>
				987
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	988	</div>
				989
				990	<!-- ======================================================================= -->
				991	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	992	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	993	</div>
				994
				995	<div class="doc_text">
				996	<p>
				997	Modules may contain "module-level inline asm" blocks, which corresponds to the
				998	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				999	LLVM and treated as a single unit, but may be separated in the .ll file if
				1000	desired. The syntax is very simple:
				1001	</p>
				1002
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1003	<div class="doc_code">
				1004	<pre>
				1005	module asm "inline asm code goes here"
				1006	module asm "more can go here"
				1007	</pre>
				1008	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1009
				1010	<p>The strings can contain any character by escaping non-printable characters.
				1011	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1012	for the number.
				1013	</p>
				1014
				1015	<p>
				1016	The inline asm code is simply printed to the machine code .s file when
				1017	assembly code is generated.
				1018	</p>
				1019	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1020
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1021	<!-- ======================================================================= -->
				1022	<div class="doc_subsection">
				1023	<a name="datalayout">Data Layout</a>
				1024	</div>
				1025
				1026	<div class="doc_text">
				1027	<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]	1028	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1029	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1030	<p>The <i>layout specification</i> consists of a list of specifications
				1031	separated by the minus sign character ('-'). Each specification starts with a
				1032	letter and may include other information after the letter to define some
				1033	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1034	<dl>
				1035	<dt><tt>E</tt></dt>
				1036	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1037	bits with the most significance have the lowest address location.</dd>
				1038	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1039	<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]	1040	the bits with the least significance have the lowest address location.</dd>
				1041	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1042	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1043	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1044	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1045	too.</dd>
				1046	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1047	<dd>This specifies the alignment for an integer type of a given bit
				1048	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1049	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1050	<dd>This specifies the alignment for a vector type of a given bit
				1051	<i>size</i>.</dd>
				1052	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1053	<dd>This specifies the alignment for a floating point type of a given bit
				1054	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1055	(double).</dd>
				1056	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1057	<dd>This specifies the alignment for an aggregate type of a given bit
				1058	<i>size</i>.</dd>
				1059	</dl>
				1060	<p>When constructing the data layout for a given target, LLVM starts with a
				1061	default set of specifications which are then (possibly) overriden by the
				1062	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1063	are given in this list:</p>
				1064	<ul>
				1065	<li><tt>E</tt> - big endian</li>
				1066	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1067	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1068	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1069	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1070	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1071	<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]	1072	alignment of 64-bits</li>
				1073	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1074	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1075	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1076	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1077	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1078	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1079	<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]	1080	following rules:
				1081	<ol>
				1082	<li>If the type sought is an exact match for one of the specifications, that
				1083	specification is used.</li>
				1084	<li>If no match is found, and the type sought is an integer type, then the
				1085	smallest integer type that is larger than the bitwidth of the sought type is
				1086	used. If none of the specifications are larger than the bitwidth then the the
				1087	largest integer type is used. For example, given the default specifications
				1088	above, the i7 type will use the alignment of i8 (next largest) while both
				1089	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1090	<li>If no match is found, and the type sought is a vector type, then the
				1091	largest vector type that is smaller than the sought vector type will be used
				1092	as a fall back. This happens because <128 x double> can be implemented in
				1093	terms of 64 <2 x double>, for example.</li>
				1094	</ol>
				1095	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1096
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1097	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1098	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1099	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1100
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1101	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1102
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1103	<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]	1104	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1105	optimizations to be performed on the intermediate representation directly,
				1106	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1107	extra analyses on the side before the transformation. A strong type
				1108	system makes it easier to read the generated code and enables novel
				1109	analyses and transformations that are not feasible to perform on normal
				1110	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1111
				1112	</div>
				1113
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1114	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1115	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1116	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1117	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1118	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1119	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1120
				1121	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1122	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1123	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1124	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1125	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1126	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1127	</tr>
				1128	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1129	<td><a href="#t_floating">floating point</a></td>
				1130	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1131	</tr>
				1132	<tr>
				1133	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1134	<td><a href="#t_integer">integer</a>,
				1135	<a href="#t_floating">floating point</a>,
				1136	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1137	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1138	<a href="#t_struct">structure</a>,
				1139	<a href="#t_array">array</a>,
Dan Gohman	da52d21	2008-05-23 22:50:26 +0000	[diff] [blame]	1140	<a href="#t_label">label</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1141	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1142	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1143	<tr>
				1144	<td><a href="#t_primitive">primitive</a></td>
				1145	<td><a href="#t_label">label</a>,
				1146	<a href="#t_void">void</a>,
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1147	<a href="#t_floating">floating point</a>.</td>
				1148	</tr>
				1149	<tr>
				1150	<td><a href="#t_derived">derived</a></td>
				1151	<td><a href="#t_integer">integer</a>,
				1152	<a href="#t_array">array</a>,
				1153	<a href="#t_function">function</a>,
				1154	<a href="#t_pointer">pointer</a>,
				1155	<a href="#t_struct">structure</a>,
				1156	<a href="#t_pstruct">packed structure</a>,
				1157	<a href="#t_vector">vector</a>,
				1158	<a href="#t_opaque">opaque</a>.
				1159	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1160	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1161	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1162
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1163	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1164	most important. Values of these types are the only ones which can be
				1165	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1166	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1167	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1168
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1169	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1170	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1171
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1172	<div class="doc_text">
				1173	<p>The primitive types are the fundamental building blocks of the LLVM
				1174	system.</p>
				1175
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1176	</div>
				1177
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1178	<!-- _______________________________________________________________________ -->
				1179	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1180
				1181	<div class="doc_text">
				1182	<table>
				1183	<tbody>
				1184	<tr><th>Type</th><th>Description</th></tr>
				1185	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1186	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1187	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1188	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1189	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1190	</tbody>
				1191	</table>
				1192	</div>
				1193
				1194	<!-- _______________________________________________________________________ -->
				1195	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1196
				1197	<div class="doc_text">
				1198	<h5>Overview:</h5>
				1199	<p>The void type does not represent any value and has no size.</p>
				1200
				1201	<h5>Syntax:</h5>
				1202
				1203	<pre>
				1204	void
				1205	</pre>
				1206	</div>
				1207
				1208	<!-- _______________________________________________________________________ -->
				1209	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1210
				1211	<div class="doc_text">
				1212	<h5>Overview:</h5>
				1213	<p>The label type represents code labels.</p>
				1214
				1215	<h5>Syntax:</h5>
				1216
				1217	<pre>
				1218	label
				1219	</pre>
				1220	</div>
				1221
				1222
				1223	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1224	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1225
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1226	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1227
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1228	<p>The real power in LLVM comes from the derived types in the system.
				1229	This is what allows a programmer to represent arrays, functions,
				1230	pointers, and other useful types. Note that these derived types may be
				1231	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]	1232
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1233	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1234
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1235	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1236	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1237
				1238	<div class="doc_text">
				1239
				1240	<h5>Overview:</h5>
				1241	<p>The integer type is a very simple derived type that simply specifies an
				1242	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1243	2^23-1 (about 8 million) can be specified.</p>
				1244
				1245	<h5>Syntax:</h5>
				1246
				1247	<pre>
				1248	iN
				1249	</pre>
				1250
				1251	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1252	value.</p>
				1253
				1254	<h5>Examples:</h5>
				1255	<table class="layout">
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1256	<tbody>
				1257	<tr>
				1258	<td><tt>i1</tt></td>
				1259	<td>a single-bit integer.</td>
				1260	</tr><tr>
				1261	<td><tt>i32</tt></td>
				1262	<td>a 32-bit integer.</td>
				1263	</tr><tr>
				1264	<td><tt>i1942652</tt></td>
				1265	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1266	</tr>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1267	</tbody>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1268	</table>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1269	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1270
				1271	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1272	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1273
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1274	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1275
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1276	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1277
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1278	<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]	1279	sequentially in memory. The array type requires a size (number of
				1280	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1281
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1282	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1283
				1284	<pre>
				1285	[<# elements> x <elementtype>]
				1286	</pre>
				1287
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1288	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1289	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1290
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1291	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1292	<table class="layout">
				1293	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1294	<td class="left"><tt>[40 x i32]</tt></td>
				1295	<td class="left">Array of 40 32-bit integer values.</td>
				1296	</tr>
				1297	<tr class="layout">
				1298	<td class="left"><tt>[41 x i32]</tt></td>
				1299	<td class="left">Array of 41 32-bit integer values.</td>
				1300	</tr>
				1301	<tr class="layout">
				1302	<td class="left"><tt>[4 x i8]</tt></td>
				1303	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1304	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1305	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1306	<p>Here are some examples of multidimensional arrays:</p>
				1307	<table class="layout">
				1308	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1309	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1310	<td class="left">3x4 array of 32-bit integer values.</td>
				1311	</tr>
				1312	<tr class="layout">
				1313	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1314	<td class="left">12x10 array of single precision floating point values.</td>
				1315	</tr>
				1316	<tr class="layout">
				1317	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1318	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1319	</tr>
				1320	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1321
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1322	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1323	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]	1324	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1325	As a special case, however, zero length arrays are recognized to be variable
				1326	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1327	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1328
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1329	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1330
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1331	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1332	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1333	<div class="doc_text">
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>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1336
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1337	<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]	1338	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]	1339	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]	1340	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]	1341	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1342
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1343	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1344
				1345	<pre>
				1346	<returntype list> (<parameter list>)
				1347	</pre>
				1348
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1349	<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]	1350	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1351	which indicates that the function takes a variable number of arguments.
				1352	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1353	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1354	'<tt><returntype list></tt>' is a comma-separated list of
				1355	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1356
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1357	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1358	<table class="layout">
				1359	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1360	<td class="left"><tt>i32 (i32)</tt></td>
				1361	<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]	1362	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1363	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1364	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1365	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1366	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1367	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1368	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1369	<tt>float</tt>.
				1370	</td>
				1371	</tr><tr class="layout">
				1372	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1373	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1374	<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]	1375	which returns an integer. This is the signature for <tt>printf</tt> in
				1376	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1377	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1378	</tr><tr class="layout">
				1379	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	8dec6c2	2008-03-24 18:10:52 +0000	[diff] [blame]	1380	<td class="left">A function taking an <tt>i32></tt>, returning two
				1381	<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]	1382	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1383	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1384	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1385
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1386	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1387	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1388	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1389	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1390	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1391	<p>The structure type is used to represent a collection of data members
				1392	together in memory. The packing of the field types is defined to match
				1393	the ABI of the underlying processor. The elements of a structure may
				1394	be any type that has a size.</p>
				1395	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1396	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1397	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1398	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1399	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1400	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1401	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1402	<table class="layout">
				1403	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1404	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1405	<td class="left">A triple of three <tt>i32</tt> values</td>
				1406	</tr><tr class="layout">
				1407	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1408	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1409	second element is a <a href="#t_pointer">pointer</a> to a
				1410	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1411	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1412	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1413	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1414	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1415
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1416	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1417	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1418	</div>
				1419	<div class="doc_text">
				1420	<h5>Overview:</h5>
				1421	<p>The packed structure type is used to represent a collection of data members
				1422	together in memory. There is no padding between fields. Further, the alignment
				1423	of a packed structure is 1 byte. The elements of a packed structure may
				1424	be any type that has a size.</p>
				1425	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1426	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1427	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1428	instruction.</p>
				1429	<h5>Syntax:</h5>
				1430	<pre> < { <type list> } > <br></pre>
				1431	<h5>Examples:</h5>
				1432	<table class="layout">
				1433	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1434	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1435	<td class="left">A triple of three <tt>i32</tt> values</td>
				1436	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1437	<td class="left">
				1438	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1439	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1440	second element is a <a href="#t_pointer">pointer</a> to a
				1441	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1442	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1443	</tr>
				1444	</table>
				1445	</div>
				1446
				1447	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1448	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1449	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1450	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1451	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1452	reference to another object, which must live in memory. Pointer types may have
				1453	an optional address space attribute defining the target-specific numbered
				1454	address space where the pointed-to object resides. The default address space is
				1455	zero.</p>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1456	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1457	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1458	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1459	<table class="layout">
				1460	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1461	<td class="left"><tt>[4x i32]*</tt></td>
				1462	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1463	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1464	</tr>
				1465	<tr class="layout">
				1466	<td class="left"><tt>i32 (i32 ) </tt></td>
				1467	<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]	1468	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]	1469	<tt>i32</tt>.</td>
				1470	</tr>
				1471	<tr class="layout">
				1472	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1473	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1474	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1475	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1476	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1477	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1478
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1479	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1480	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1481	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1482
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1483	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1484
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1485	<p>A vector type is a simple derived type that represents a vector
				1486	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1487	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1488	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1489	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1490	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1491	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1492
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1493	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1494
				1495	<pre>
				1496	< <# elements> x <elementtype> >
				1497	</pre>
				1498
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1499	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1500	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1501
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1502	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1503
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1504	<table class="layout">
				1505	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1506	<td class="left"><tt><4 x i32></tt></td>
				1507	<td class="left">Vector of 4 32-bit integer values.</td>
				1508	</tr>
				1509	<tr class="layout">
				1510	<td class="left"><tt><8 x float></tt></td>
				1511	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1512	</tr>
				1513	<tr class="layout">
				1514	<td class="left"><tt><2 x i64></tt></td>
				1515	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1516	</tr>
				1517	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1518	</div>
				1519
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1520	<!-- _______________________________________________________________________ -->
				1521	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1522	<div class="doc_text">
				1523
				1524	<h5>Overview:</h5>
				1525
				1526	<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]	1527	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]	1528	In LLVM, opaque types can eventually be resolved to any type (not just a
				1529	structure type).</p>
				1530
				1531	<h5>Syntax:</h5>
				1532
				1533	<pre>
				1534	opaque
				1535	</pre>
				1536
				1537	<h5>Examples:</h5>
				1538
				1539	<table class="layout">
				1540	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1541	<td class="left"><tt>opaque</tt></td>
				1542	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1543	</tr>
				1544	</table>
				1545	</div>
				1546
				1547
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1548	<!-- *********************************************************************** -->
				1549	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1550	<!-- *********************************************************************** -->
				1551
				1552	<div class="doc_text">
				1553
				1554	<p>LLVM has several different basic types of constants. This section describes
				1555	them all and their syntax.</p>
				1556
				1557	</div>
				1558
				1559	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1560	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1561
				1562	<div class="doc_text">
				1563
				1564	<dl>
				1565	<dt><b>Boolean constants</b></dt>
				1566
				1567	<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]	1568	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1569	</dd>
				1570
				1571	<dt><b>Integer constants</b></dt>
				1572
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1573	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1574	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1575	integer types.
				1576	</dd>
				1577
				1578	<dt><b>Floating point constants</b></dt>
				1579
				1580	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1581	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1582	notation (see below). The assembler requires the exact decimal value of
				1583	a floating-point constant. For example, the assembler accepts 1.25 but
				1584	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1585	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]	1586
				1587	<dt><b>Null pointer constants</b></dt>
				1588
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1589	<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]	1590	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1591
				1592	</dl>
				1593
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1594	<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]	1595	of floating point constants. For example, the form '<tt>double
				1596	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1597	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]	1598	(and the only time that they are generated by the disassembler) is when a
				1599	floating point constant must be emitted but it cannot be represented as a
				1600	decimal floating point number. For example, NaN's, infinities, and other
				1601	special values are represented in their IEEE hexadecimal format so that
				1602	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]	1603
				1604	</div>
				1605
				1606	<!-- ======================================================================= -->
				1607	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1608	</div>
				1609
				1610	<div class="doc_text">
Chris Lattner	455fc8c	2005-03-07 22:13:59 +0000	[diff] [blame]	1611	<p>Aggregate constants arise from aggregation of simple constants
				1612	and smaller aggregate constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1613
				1614	<dl>
				1615	<dt><b>Structure constants</b></dt>
				1616
				1617	<dd>Structure constants are represented with notation similar to structure
				1618	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1619	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1620	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]	1621	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]	1622	types of elements must match those specified by the type.
				1623	</dd>
				1624
				1625	<dt><b>Array constants</b></dt>
				1626
				1627	<dd>Array constants are represented with notation similar to array type
				1628	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1629	(<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]	1630	constants must have <a href="#t_array">array type</a>, and the number and
				1631	types of elements must match those specified by the type.
				1632	</dd>
				1633
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1634	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1635
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1636	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1637	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1638	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1639	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1640	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]	1641	match those specified by the type.
				1642	</dd>
				1643
				1644	<dt><b>Zero initialization</b></dt>
				1645
				1646	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1647	value to zero of <em>any</em> type, including scalar and aggregate types.
				1648	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]	1649	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1650	initializers.
				1651	</dd>
				1652	</dl>
				1653
				1654	</div>
				1655
				1656	<!-- ======================================================================= -->
				1657	<div class="doc_subsection">
				1658	<a name="globalconstants">Global Variable and Function Addresses</a>
				1659	</div>
				1660
				1661	<div class="doc_text">
				1662
				1663	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1664	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1665	constants. These constants are explicitly referenced when the <a
				1666	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]	1667	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1668	file:</p>
				1669
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1670	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1671	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1672	@X = global i32 17
				1673	@Y = global i32 42
				1674	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1675	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1676	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1677
				1678	</div>
				1679
				1680	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1681	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1682	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1683	<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]	1684	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]	1685	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1686
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1687	<p>Undefined values indicate to the compiler that the program is well defined
				1688	no matter what value is used, giving the compiler more freedom to optimize.
				1689	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1690	</div>
				1691
				1692	<!-- ======================================================================= -->
				1693	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1694	</div>
				1695
				1696	<div class="doc_text">
				1697
				1698	<p>Constant expressions are used to allow expressions involving other constants
				1699	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1700	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]	1701	that does not have side effects (e.g. load and call are not supported). The
				1702	following is the syntax for constant expressions:</p>
				1703
				1704	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1705	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1706	<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]	1707	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1708
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1709	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1710	<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]	1711	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]	1712
				1713	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1714	<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]	1715	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]	1716
				1717	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1718	<dd>Truncate a floating point constant to another floating point type. The
				1719	size of CST must be larger than the size of TYPE. Both types must be
				1720	floating point.</dd>
				1721
				1722	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1723	<dd>Floating point extend a constant to another type. The size of CST must be
				1724	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1725
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1726	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1727	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1728	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1729	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1730	of the same number of elements. If the value won't fit in the integer type,
				1731	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1732
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1733	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1734	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1735	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1736	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1737	of the same number of elements. If the value won't fit in the integer type,
				1738	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1739
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1740	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1741	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1742	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1743	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1744	of the same number of elements. If the value won't fit in the floating point
				1745	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1746
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1747	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1748	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1749	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1750	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1751	of the same number of elements. If the value won't fit in the floating point
				1752	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1753
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1754	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1755	<dd>Convert a pointer typed constant to the corresponding integer constant
				1756	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1757	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1758
				1759	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1760	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1761	pointer type. CST must be of integer type. The CST value is zero extended,
				1762	truncated, or unchanged to make it fit in a pointer size. This one is
				1763	<i>really</i> dangerous!</dd>
				1764
				1765	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1766	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1767	identical (same number of bits). The conversion is done as if the CST value
				1768	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]	1769	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]	1770	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]	1771	pointers it is only valid to cast to another pointer type. It is not valid
				1772	to bitcast to or from an aggregate type.
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1773	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1774
				1775	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1776
				1777	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1778	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1779	instruction, the index list may have zero or more indexes, which are required
				1780	to make sense for the type of "CSTPTR".</dd>
				1781
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1782	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1783
				1784	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1785	constants.</dd>
				1786
				1787	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1788	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1789
				1790	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1791	<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]	1792
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	1793	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1794	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1795
				1796	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1797	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1798
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1799	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1800
				1801	<dd>Perform the <a href="#i_extractelement">extractelement
				1802	operation</a> on constants.
				1803
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	1804	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1805
				1806	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1807	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	1808
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	1809
				1810	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1811
				1812	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1813	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	1814
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1815	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1816
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1817	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1818	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]	1819	binary</a> operations. The constraints on operands are the same as those for
				1820	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1821	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1822	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1823	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	1824
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1825	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1826	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1827	<!-- *********************************************************************** -->
				1828
				1829	<!-- ======================================================================= -->
				1830	<div class="doc_subsection">
				1831	<a name="inlineasm">Inline Assembler Expressions</a>
				1832	</div>
				1833
				1834	<div class="doc_text">
				1835
				1836	<p>
				1837	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1838	Module-Level Inline Assembly</a>) through the use of a special value. This
				1839	value represents the inline assembler as a string (containing the instructions
				1840	to emit), a list of operand constraints (stored as a string), and a flag that
				1841	indicates whether or not the inline asm expression has side effects. An example
				1842	inline assembler expression is:
				1843	</p>
				1844
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1845	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1846	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1847	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1848	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1849	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1850
				1851	<p>
				1852	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1853	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1854	</p>
				1855
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1856	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1857	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1858	%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]	1859	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1860	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1861
				1862	<p>
				1863	Inline asms with side effects not visible in the constraint list must be marked
				1864	as having side effects. This is done through the use of the
				1865	'<tt>sideeffect</tt>' keyword, like so:
				1866	</p>
				1867
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1868	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1869	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1870	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1871	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1872	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1873
				1874	<p>TODO: The format of the asm and constraints string still need to be
				1875	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]	1876	need to be documented). This is probably best done by reference to another
				1877	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1878	</p>
				1879
				1880	</div>
				1881
				1882	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1883	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1884	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1885
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1886	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1887
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1888	<p>The LLVM instruction set consists of several different
				1889	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1890	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1891	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1892	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1893	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1894
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1895	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1896
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1897	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1898	<div class="doc_subsection"> <a name="terminators">Terminator
				1899	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1900
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1901	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1902
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1903	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1904	basic block in a program ends with a "Terminator" instruction, which
				1905	indicates which block should be executed after the current block is
				1906	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1907	value: they produce control flow, not values (the one exception being
				1908	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1909	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1910	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1911	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	1912	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1913	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1914	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1915
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1916	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1917
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1918	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1919	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1920	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1921	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1922	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1923	<pre>
				1924	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]	1925	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1926	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1927
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1928	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1929
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1930	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				1931	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	1932	<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]	1933	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]	1934	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1935
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1936	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1937
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1938	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				1939	the return value. The type of the return value must be a
				1940	'<a href="#t_firstclass">first class</a>' type.</p>
				1941
				1942	<p>A function is not <a href="#wellformed">well formed</a> if
				1943	it it has a non-void return type and contains a '<tt>ret</tt>'
				1944	instruction with no return value or a return value with a type that
				1945	does not match its type, or if it has a void return type and contains
				1946	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1947
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1948	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1949
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1950	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1951	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]	1952	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1953	the instruction after the call. If the caller was an "<a
				1954	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1955	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1956	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]	1957	return value.
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1958
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1959	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1960
				1961	<pre>
				1962	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1963	ret void <i>; Return from a void function</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1964	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]	1965	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1966	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1967	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1968	<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]	1969	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1970	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1971	<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]	1972	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1973	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1974	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1975	transfer to a different basic block in the current function. There are
				1976	two forms of this instruction, corresponding to a conditional branch
				1977	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1978	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1979	<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]	1980	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1981	unconditional form of the '<tt>br</tt>' instruction takes a single
				1982	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1983	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1984	<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]	1985	argument is evaluated. If the value is <tt>true</tt>, control flows
				1986	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1987	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1988	<h5>Example:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1989	<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]	1990	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]	1991	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1992	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1993	<div class="doc_subsubsection">
				1994	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1995	</div>
				1996
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1997	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1998	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1999
				2000	<pre>
				2001	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2002	</pre>
				2003
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2004	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2005
				2006	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2007	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2008	instruction, allowing a branch to occur to one of many possible
				2009	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2010
				2011
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2012	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2013
				2014	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2015	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2016	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2017	table is not allowed to contain duplicate constant entries.</p>
				2018
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2019	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2020
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2021	<p>The <tt>switch</tt> instruction specifies a table of values and
				2022	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2023	table is searched for the given value. If the value is found, control flow is
				2024	transfered to the corresponding destination; otherwise, control flow is
				2025	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2026
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2027	<h5>Implementation:</h5>
				2028
				2029	<p>Depending on properties of the target machine and the particular
				2030	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2031	ways. For example, it could be generated as a series of chained conditional
				2032	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2033
				2034	<h5>Example:</h5>
				2035
				2036	<pre>
				2037	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2038	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2039	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2040
				2041	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2042	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2043
				2044	<i>; Implement a jump table:</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2045	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2046	i32 1, label %onone
				2047	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2048	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2049	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2050
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2051	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2052	<div class="doc_subsubsection">
				2053	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2054	</div>
				2055
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2056	<div class="doc_text">
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	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2059
				2060	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2061	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	6b7a008	2006-05-14 18:23:06 +0000	[diff] [blame]	2062	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2063	</pre>
				2064
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2065	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2066
				2067	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2068	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2069	'<tt>normal</tt>' label or the
				2070	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2071	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2072	"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]	2073	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2074	continued at the dynamically nearest "exception" label.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2075
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2076	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2077
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2078	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2079
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2080	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2081	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2082	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2083	convention</a> the call should use. If none is specified, the call defaults
				2084	to using C calling conventions.
				2085	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2086
				2087	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2088	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2089	and '<tt>inreg</tt>' attributes are valid here.</li>
				2090
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2091	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2092	function value being invoked. In most cases, this is a direct function
				2093	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2094	an arbitrary pointer to function value.
				2095	</li>
				2096
				2097	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2098	function to be invoked. </li>
				2099
				2100	<li>'<tt>function args</tt>': argument list whose types match the function
				2101	signature argument types. If the function signature indicates the function
				2102	accepts a variable number of arguments, the extra arguments can be
				2103	specified. </li>
				2104
				2105	<li>'<tt>normal label</tt>': the label reached when the called function
				2106	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2107
				2108	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2109	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2110
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2111	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2112	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2113	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2114	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2115
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2116	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2117
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2118	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2119	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2120	difference is that it establishes an association with a label, which is used by
				2121	the runtime library to unwind the stack.</p>
				2122
				2123	<p>This instruction is used in languages with destructors to ensure that proper
				2124	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2125	exception. Additionally, this is important for implementation of
				2126	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2127
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2128	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2129	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2130	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2131	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2132	%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]	2133	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2134	</pre>
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
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2138	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2139
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2140	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2141	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2142
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2143	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2144
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2145	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2146	<pre>
				2147	unwind
				2148	</pre>
				2149
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2150	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2151
				2152	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2153	at the first callee in the dynamic call stack which used an <a
				2154	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2155	primarily used to implement exception handling.</p>
				2156
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2157	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2158
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2159	<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]	2160	immediately halt. The dynamic call stack is then searched for the first <a
				2161	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2162	execution continues at the "exceptional" destination block specified by the
				2163	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2164	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2165	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2166
				2167	<!-- _______________________________________________________________________ -->
				2168
				2169	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2170	Instruction</a> </div>
				2171
				2172	<div class="doc_text">
				2173
				2174	<h5>Syntax:</h5>
				2175	<pre>
				2176	unreachable
				2177	</pre>
				2178
				2179	<h5>Overview:</h5>
				2180
				2181	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2182	instruction is used to inform the optimizer that a particular portion of the
				2183	code is not reachable. This can be used to indicate that the code after a
				2184	no-return function cannot be reached, and other facts.</p>
				2185
				2186	<h5>Semantics:</h5>
				2187
				2188	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2189	</div>
				2190
				2191
				2192
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2193	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2194	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2195	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2196	<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]	2197	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]	2198	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2199	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]	2200	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2201	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2202	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2204	<div class="doc_subsubsection">
				2205	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2206	</div>
				2207
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2208	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2209
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2210	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2211
				2212	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2213	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2214	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2215
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2216	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2217
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2218	<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]	2219
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2220	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2221
				2222	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2223	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2224	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2225	types.</p>
				2226
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2227	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2228
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2229	<p>The value produced is the integer or floating point sum of the two
				2230	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2231
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2232	<p>If an integer sum has unsigned overflow, the result returned is the
				2233	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2234	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2235
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2236	<p>Because LLVM integers use a two's complement representation, this
				2237	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2238
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2239	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2240
				2241	<pre>
				2242	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2243	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2244	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2245	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2246	<div class="doc_subsubsection">
				2247	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2248	</div>
				2249
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2250	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2251
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2252	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2253
				2254	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2255	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2256	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2257
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2258	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2259
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2260	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2261	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2262
				2263	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2264	'<tt>neg</tt>' instruction present in most other intermediate
				2265	representations.</p>
				2266
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2267	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2268
				2269	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2270	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2271	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2272	types.</p>
				2273
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2274	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2275
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2276	<p>The value produced is the integer or floating point difference of
				2277	the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2278
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2279	<p>If an integer difference has unsigned overflow, the result returned is the
				2280	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2281	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2282
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2283	<p>Because LLVM integers use a two's complement representation, this
				2284	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2285
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2286	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2287	<pre>
				2288	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2289	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2290	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2291	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2292
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2293	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2294	<div class="doc_subsubsection">
				2295	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2296	</div>
				2297
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2298	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2299
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2300	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2301	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2302	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2303	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2304	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2305	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2306
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2307	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2308
				2309	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2310	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2311	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2312	types.</p>
				2313
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2314	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2315
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2316	<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]	2317	two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2318
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2319	<p>If the result of an integer multiplication has unsigned overflow,
				2320	the result returned is the mathematical result modulo
				2321	2<sup>n</sup>, where n is the bit width of the result.</p>
				2322	<p>Because LLVM integers use a two's complement representation, and the
				2323	result is the same width as the operands, this instruction returns the
				2324	correct result for both signed and unsigned integers. If a full product
				2325	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2326	should be sign-extended or zero-extended as appropriate to the
				2327	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2328	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2329	<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]	2330	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2331	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2332
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2333	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2334	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2335	</a></div>
				2336	<div class="doc_text">
				2337	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2338	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2339	</pre>
				2340	<h5>Overview:</h5>
				2341	<p>The '<tt>udiv</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
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2346	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	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	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2351
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2352	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2353	<p>Note that unsigned integer division and signed integer division are distinct
				2354	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2355	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2356	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2357	<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]	2358	</pre>
				2359	</div>
				2360	<!-- _______________________________________________________________________ -->
				2361	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2362	</a> </div>
				2363	<div class="doc_text">
				2364	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2365	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2366	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2367	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2368
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	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>sdiv</tt>' instruction returns the quotient of its two
				2372	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2373
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2374	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2375
				2376	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2377	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2378	values. Both arguments must have identical types.</p>
				2379
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2380	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2381	<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]	2382	<p>Note that signed integer division and unsigned integer division are distinct
				2383	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2384	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2385	undefined behavior; this is a rare case, but can occur, for example,
				2386	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2387	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2388	<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]	2389	</pre>
				2390	</div>
				2391	<!-- _______________________________________________________________________ -->
				2392	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2393	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2394	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2395	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2396	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2397	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2398	</pre>
				2399	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2400
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2401	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2402	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2403
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2404	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2405
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2406	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2407	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2408	of floating point values. Both arguments must have identical types.</p>
				2409
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2410	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2411
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2412	<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]	2413
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2414	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2415
				2416	<pre>
				2417	<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]	2418	</pre>
				2419	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2420
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2421	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2422	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2423	</div>
				2424	<div class="doc_text">
				2425	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2426	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2427	</pre>
				2428	<h5>Overview:</h5>
				2429	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2430	unsigned division of its two arguments.</p>
				2431	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2432	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2433	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2434	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2435	<h5>Semantics:</h5>
				2436	<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]	2437	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2438	<p>Note that unsigned integer remainder and signed integer remainder are
				2439	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2440	<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]	2441	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2442	<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]	2443	</pre>
				2444
				2445	</div>
				2446	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2447	<div class="doc_subsubsection">
				2448	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2449	</div>
				2450
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2451	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2452
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2453	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2454
				2455	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2456	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2457	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2458
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2459	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2460
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2461	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2462	signed division of its two operands. This instruction can also take
				2463	<a href="#t_vector">vector</a> versions of the values in which case
				2464	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2465
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2466	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2467
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2468	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2469	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2470	values. Both arguments must have identical types.</p>
				2471
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2472	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2473
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2474	<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]	2475	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2476	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]	2477	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2478	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]	2479	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]	2480	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2481	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2482	<p>Note that signed integer remainder and unsigned integer remainder are
				2483	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2484	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2485	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2486	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2487	(The remainder doesn't actually overflow, but this rule lets srem be
				2488	implemented using instructions that return both the result of the division
				2489	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2490	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2491	<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]	2492	</pre>
				2493
				2494	</div>
				2495	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2496	<div class="doc_subsubsection">
				2497	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2498
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2499	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2500
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2501	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2502	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2503	</pre>
				2504	<h5>Overview:</h5>
				2505	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2506	division of its two operands.</p>
				2507	<h5>Arguments:</h5>
				2508	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2509	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2510	of floating point values. Both arguments must have identical types.</p>
				2511
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2512	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2513
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2514	<p>This instruction returns the <i>remainder</i> of a division.
				2515	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2516
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2517	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2518
				2519	<pre>
				2520	<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]	2521	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2522	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2523
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2524	<!-- ======================================================================= -->
				2525	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2526	Operations</a> </div>
				2527	<div class="doc_text">
				2528	<p>Bitwise binary operators are used to do various forms of
				2529	bit-twiddling in a program. They are generally very efficient
				2530	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2531	instructions. They require two operands of the same type, execute an operation on them,
				2532	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]	2533	</div>
				2534
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2535	<!-- _______________________________________________________________________ -->
				2536	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2537	Instruction</a> </div>
				2538	<div class="doc_text">
				2539	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2540	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2541	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2542
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2543	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2544
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2545	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2546	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2547
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2548	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2549
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2550	<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]	2551	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>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2553
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2554	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2555
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2556	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2557	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2558	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]	2559
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2560	<h5>Example:</h5><pre>
				2561	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2562	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2563	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2564	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2565	</pre>
				2566	</div>
				2567	<!-- _______________________________________________________________________ -->
				2568	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2569	Instruction</a> </div>
				2570	<div class="doc_text">
				2571	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2572	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2573	</pre>
				2574
				2575	<h5>Overview:</h5>
				2576	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2577	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]	2578
				2579	<h5>Arguments:</h5>
				2580	<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]	2581	<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]	2582	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2583
				2584	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2585
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2586	<p>This instruction always performs a logical shift right operation. The most
				2587	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]	2588	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2589	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]	2590
				2591	<h5>Example:</h5>
				2592	<pre>
				2593	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2594	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2595	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2596	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2597	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2598	</pre>
				2599	</div>
				2600
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2601	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2602	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2603	Instruction</a> </div>
				2604	<div class="doc_text">
				2605
				2606	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2607	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2608	</pre>
				2609
				2610	<h5>Overview:</h5>
				2611	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2612	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]	2613
				2614	<h5>Arguments:</h5>
				2615	<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]	2616	<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]	2617	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2618
				2619	<h5>Semantics:</h5>
				2620	<p>This instruction always performs an arithmetic shift right operation,
				2621	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]	2622	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2623	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]	2624	</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2625
				2626	<h5>Example:</h5>
				2627	<pre>
				2628	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2629	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2630	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2631	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2632	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2633	</pre>
				2634	</div>
				2635
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2636	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2637	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2638	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2639
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2640	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2641
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2642	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2643
				2644	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2645	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2646	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2647
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2648	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2649
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2650	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2651	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2652
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2653	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2654
				2655	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2656	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2657	values. Both arguments must have identical types.</p>
				2658
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2659	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2660	<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]	2661	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2662	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2663	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2664	<tbody>
				2665	<tr>
				2666	<td>In0</td>
				2667	<td>In1</td>
				2668	<td>Out</td>
				2669	</tr>
				2670	<tr>
				2671	<td>0</td>
				2672	<td>0</td>
				2673	<td>0</td>
				2674	</tr>
				2675	<tr>
				2676	<td>0</td>
				2677	<td>1</td>
				2678	<td>0</td>
				2679	</tr>
				2680	<tr>
				2681	<td>1</td>
				2682	<td>0</td>
				2683	<td>0</td>
				2684	</tr>
				2685	<tr>
				2686	<td>1</td>
				2687	<td>1</td>
				2688	<td>1</td>
				2689	</tr>
				2690	</tbody>
				2691	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2692	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2693	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2694	<pre>
				2695	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2696	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2697	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2698	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2699	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2700	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2701	<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]	2702	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2703	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2704	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2705	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2706	<h5>Overview:</h5>
				2707	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2708	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2709	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2710
				2711	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2712	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2713	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2714	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2715	<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]	2716	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2717	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2718	<table border="1" cellspacing="0" cellpadding="4">
				2719	<tbody>
				2720	<tr>
				2721	<td>In0</td>
				2722	<td>In1</td>
				2723	<td>Out</td>
				2724	</tr>
				2725	<tr>
				2726	<td>0</td>
				2727	<td>0</td>
				2728	<td>0</td>
				2729	</tr>
				2730	<tr>
				2731	<td>0</td>
				2732	<td>1</td>
				2733	<td>1</td>
				2734	</tr>
				2735	<tr>
				2736	<td>1</td>
				2737	<td>0</td>
				2738	<td>1</td>
				2739	</tr>
				2740	<tr>
				2741	<td>1</td>
				2742	<td>1</td>
				2743	<td>1</td>
				2744	</tr>
				2745	</tbody>
				2746	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2747	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2748	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2749	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2750	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2751	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2752	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2753	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2754	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2755	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2756	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2757	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2758	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2759	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2760	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2761	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2762	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2763	or of its two operands. The <tt>xor</tt> is used to implement the
				2764	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2765	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2766	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2767	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2768	values. Both arguments must have identical types.</p>
				2769
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2770	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2771
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2772	<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]	2773	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2774	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2775	<table border="1" cellspacing="0" cellpadding="4">
				2776	<tbody>
				2777	<tr>
				2778	<td>In0</td>
				2779	<td>In1</td>
				2780	<td>Out</td>
				2781	</tr>
				2782	<tr>
				2783	<td>0</td>
				2784	<td>0</td>
				2785	<td>0</td>
				2786	</tr>
				2787	<tr>
				2788	<td>0</td>
				2789	<td>1</td>
				2790	<td>1</td>
				2791	</tr>
				2792	<tr>
				2793	<td>1</td>
				2794	<td>0</td>
				2795	<td>1</td>
				2796	</tr>
				2797	<tr>
				2798	<td>1</td>
				2799	<td>1</td>
				2800	<td>0</td>
				2801	</tr>
				2802	</tbody>
				2803	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2804	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2805	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2806	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2807	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2808	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2809	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2810	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2811	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2812	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	2813
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2814	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	2815	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2816	<a name="vectorops">Vector Operations</a>
				2817	</div>
				2818
				2819	<div class="doc_text">
				2820
				2821	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2822	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2823	vector-specific operations needed to process vectors effectively. While LLVM
				2824	does directly support these vector operations, many sophisticated algorithms
				2825	will want to use target-specific intrinsics to take full advantage of a specific
				2826	target.</p>
				2827
				2828	</div>
				2829
				2830	<!-- _______________________________________________________________________ -->
				2831	<div class="doc_subsubsection">
				2832	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2833	</div>
				2834
				2835	<div class="doc_text">
				2836
				2837	<h5>Syntax:</h5>
				2838
				2839	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2840	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2841	</pre>
				2842
				2843	<h5>Overview:</h5>
				2844
				2845	<p>
				2846	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2847	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2848	</p>
				2849
				2850
				2851	<h5>Arguments:</h5>
				2852
				2853	<p>
				2854	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2855	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]	2856	an index indicating the position from which to extract the element.
				2857	The index may be a variable.</p>
				2858
				2859	<h5>Semantics:</h5>
				2860
				2861	<p>
				2862	The result is a scalar of the same type as the element type of
				2863	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2864	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2865	results are undefined.
				2866	</p>
				2867
				2868	<h5>Example:</h5>
				2869
				2870	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2871	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2872	</pre>
				2873	</div>
				2874
				2875
				2876	<!-- _______________________________________________________________________ -->
				2877	<div class="doc_subsubsection">
				2878	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2879	</div>
				2880
				2881	<div class="doc_text">
				2882
				2883	<h5>Syntax:</h5>
				2884
				2885	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	2886	<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]	2887	</pre>
				2888
				2889	<h5>Overview:</h5>
				2890
				2891	<p>
				2892	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2893	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2894	</p>
				2895
				2896
				2897	<h5>Arguments:</h5>
				2898
				2899	<p>
				2900	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2901	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]	2902	scalar value whose type must equal the element type of the first
				2903	operand. The third operand is an index indicating the position at
				2904	which to insert the value. The index may be a variable.</p>
				2905
				2906	<h5>Semantics:</h5>
				2907
				2908	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2909	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]	2910	element values are those of <tt>val</tt> except at position
				2911	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2912	exceeds the length of <tt>val</tt>, the results are undefined.
				2913	</p>
				2914
				2915	<h5>Example:</h5>
				2916
				2917	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2918	%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]	2919	</pre>
				2920	</div>
				2921
				2922	<!-- _______________________________________________________________________ -->
				2923	<div class="doc_subsubsection">
				2924	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2925	</div>
				2926
				2927	<div class="doc_text">
				2928
				2929	<h5>Syntax:</h5>
				2930
				2931	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2932	<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]	2933	</pre>
				2934
				2935	<h5>Overview:</h5>
				2936
				2937	<p>
				2938	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2939	from two input vectors, returning a vector of the same type.
				2940	</p>
				2941
				2942	<h5>Arguments:</h5>
				2943
				2944	<p>
				2945	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2946	with types that match each other and types that match the result of the
				2947	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]	2948	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]	2949	</p>
				2950
				2951	<p>
				2952	The shuffle mask operand is required to be a constant vector with either
				2953	constant integer or undef values.
				2954	</p>
				2955
				2956	<h5>Semantics:</h5>
				2957
				2958	<p>
				2959	The elements of the two input vectors are numbered from left to right across
				2960	both of the vectors. The shuffle mask operand specifies, for each element of
				2961	the result vector, which element of the two input registers the result element
				2962	gets. The element selector may be undef (meaning "don't care") and the second
				2963	operand may be undef if performing a shuffle from only one vector.
				2964	</p>
				2965
				2966	<h5>Example:</h5>
				2967
				2968	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2969	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2970	<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]	2971	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2972	<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]	2973	</pre>
				2974	</div>
				2975
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	2976
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2977	<!-- ======================================================================= -->
				2978	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2979	<a name="aggregateops">Aggregate Operations</a>
				2980	</div>
				2981
				2982	<div class="doc_text">
				2983
				2984	<p>LLVM supports several instructions for working with aggregate values.
				2985	</p>
				2986
				2987	</div>
				2988
				2989	<!-- _______________________________________________________________________ -->
				2990	<div class="doc_subsubsection">
				2991	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2992	</div>
				2993
				2994	<div class="doc_text">
				2995
				2996	<h5>Syntax:</h5>
				2997
				2998	<pre>
				2999	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3000	</pre>
				3001
				3002	<h5>Overview:</h5>
				3003
				3004	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3005	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3006	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3007	</p>
				3008
				3009
				3010	<h5>Arguments:</h5>
				3011
				3012	<p>
				3013	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3014	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]	3015	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3016	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3017	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3018	</p>
				3019
				3020	<h5>Semantics:</h5>
				3021
				3022	<p>
				3023	The result is the value at the position in the aggregate specified by
				3024	the index operands.
				3025	</p>
				3026
				3027	<h5>Example:</h5>
				3028
				3029	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3030	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3031	</pre>
				3032	</div>
				3033
				3034
				3035	<!-- _______________________________________________________________________ -->
				3036	<div class="doc_subsubsection">
				3037	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3038	</div>
				3039
				3040	<div class="doc_text">
				3041
				3042	<h5>Syntax:</h5>
				3043
				3044	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3045	<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]	3046	</pre>
				3047
				3048	<h5>Overview:</h5>
				3049
				3050	<p>
				3051	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3052	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3053	</p>
				3054
				3055
				3056	<h5>Arguments:</h5>
				3057
				3058	<p>
				3059	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3060	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3061	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3062	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3063	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]	3064	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3065	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3066	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]	3067	by the indices.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3068
				3069	<h5>Semantics:</h5>
				3070
				3071	<p>
				3072	The result is an aggregate of the same type as <tt>val</tt>. Its
				3073	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]	3074	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3075	</p>
				3076
				3077	<h5>Example:</h5>
				3078
				3079	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3080	%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]	3081	</pre>
				3082	</div>
				3083
				3084
				3085	<!-- ======================================================================= -->
				3086	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3087	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3088	</div>
				3089
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3090	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3091
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3092	<p>A key design point of an SSA-based representation is how it
				3093	represents memory. In LLVM, no memory locations are in SSA form, which
				3094	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3095	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3096
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3097	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3098
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3099	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3100	<div class="doc_subsubsection">
				3101	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3102	</div>
				3103
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3104	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3105
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3106	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3107
				3108	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3109	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3110	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3111
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3112	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3113
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3114	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3115	heap and returns a pointer to it. The object is always allocated in the generic
				3116	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3117
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3118	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3119
				3120	<p>The '<tt>malloc</tt>' instruction allocates
				3121	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3122	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]	3123	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3124	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3125	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]	3126	be aligned to at least that boundary. If not specified, or if zero, the target can
				3127	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3128
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3129	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3130
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3131	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3132
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3133	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3134	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3135	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3136
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3137	<h5>Example:</h5>
				3138
				3139	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3140	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3141
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3142	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3143	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3144	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3145	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3146	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3147	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3148	</div>
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	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3151	<div class="doc_subsubsection">
				3152	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3153	</div>
				3154
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3155	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3156
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3157	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3158
				3159	<pre>
				3160	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3161	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3162
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3163	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3164
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3165	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3166	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3167
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3168	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3169
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3170	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3171	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3172	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3173
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3174	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3175
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3176	<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]	3177	after this instruction executes. If the pointer is null, the operation
				3178	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3179
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3180	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3181
				3182	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3183	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3184	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3185	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3186	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3187
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3188	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3189	<div class="doc_subsubsection">
				3190	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3191	</div>
				3192
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3193	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3194
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3195	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3196
				3197	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3198	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3199	</pre>
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>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3202
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3203	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3204	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3205	returns to its caller. The object is always allocated in the generic address
				3206	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3207
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3208	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3209
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3210	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3211	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3212	appropriate type to the program. If "NumElements" is specified, it is the
				3213	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3214	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]	3215	to be aligned to at least that boundary. If not specified, or if zero, the target
				3216	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3217
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3218	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3219
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3220	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3221
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3222	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3223	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3224	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3225	instruction is commonly used to represent automatic variables that must
				3226	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]	3227	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]	3228	instructions), the memory is reclaimed. Allocating zero bytes
				3229	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3230
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3231	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3232
				3233	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3234	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3235	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3236	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3237	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3238	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3239	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3240
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3241	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3242	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3243	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3244	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3245	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3246	<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]	3247	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3248	<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]	3249	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3250	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3251	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3252	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]	3253	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]	3254	the number or order of execution of this <tt>load</tt> with other
				3255	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3256	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3257	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3258	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3259	(that is, the alignment of the memory address). A value of 0 or an
				3260	omitted "align" argument means that the operation has the preferential
				3261	alignment for the target. It is the responsibility of the code emitter
				3262	to ensure that the alignment information is correct. Overestimating
				3263	the alignment results in an undefined behavior. Underestimating the
				3264	alignment may produce less efficient code. An alignment of 1 is always
				3265	safe.
				3266	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3267	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3268	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3269	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3270	<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]	3271	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3272	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3273	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3274	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3275	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3276	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3277	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3278	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3279	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3280	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3281	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3282	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3283	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3284	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3285	<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]	3286	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3287	<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]	3288	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]	3289	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3290	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3291	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]	3292	optimizer is not allowed to modify the number or order of execution of
				3293	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3294	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3295	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3296	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3297	(that is, the alignment of the memory address). A value of 0 or an
				3298	omitted "align" argument means that the operation has the preferential
				3299	alignment for the target. It is the responsibility of the code emitter
				3300	to ensure that the alignment information is correct. Overestimating
				3301	the alignment results in an undefined behavior. Underestimating the
				3302	alignment may produce less efficient code. An alignment of 1 is always
				3303	safe.
				3304	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3305	<h5>Semantics:</h5>
				3306	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3307	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3308	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3309	<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]	3310	store i32 3, i32* %ptr <i>; yields {void}</i>
				3311	%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]	3312	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3313	</div>
				3314
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3315	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3316	<div class="doc_subsubsection">
				3317	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3318	</div>
				3319
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3320	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3321	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3322	<pre>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3323	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3324	</pre>
				3325
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3326	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3327
				3328	<p>
				3329	The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3330	subelement of an aggregate data structure. It performs address calculation only
				3331	and does not access memory.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3332
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3333	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3334
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3335	<p>The first argument is always a pointer, and forms the basis of the
				3336	calculation. The remaining arguments are indices, that indicate which of the
				3337	elements of the aggregate object are indexed. The interpretation of each index
				3338	is dependent on the type being indexed into. The first index always indexes the
				3339	pointer value given as the first argument, the second index indexes a value of
				3340	the type pointed to (not necessarily the value directly pointed to, since the
				3341	first index can be non-zero), etc. The first type indexed into must be a pointer
				3342	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3343	types being indexed into can never be pointers, since that would require loading
				3344	the pointer before continuing calculation.</p>
				3345
				3346	<p>The type of each index argument depends on the type it is indexing into.
				3347	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3348	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
				3349	only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
				3350	will be sign extended to 64-bits if required.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3351
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3352	<p>For example, let's consider a C code fragment and how it gets
				3353	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3354
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3355	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3356	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3357	struct RT {
				3358	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3359	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3360	char C;
				3361	};
				3362	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3363	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3364	double Y;
				3365	struct RT Z;
				3366	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3367
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3368	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3369	return &s[1].Z.B[5][13];
				3370	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3371	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3372	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3373
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3374	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3375
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3376	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3377	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3378	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3379	%ST = type { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3380
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3381	define i32* %foo(%ST* %s) {
				3382	entry:
				3383	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3384	ret i32* %reg
				3385	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3386	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3387	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3388
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3389	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3390
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3391	<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]	3392	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]	3393	}</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]	3394	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3395	i8 }</tt>' type, another structure. The third index indexes into the second
				3396	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]	3397	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3398	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3399	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]	3400
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3401	<p>Note that it is perfectly legal to index partially through a
				3402	structure, returning a pointer to an inner element. Because of this,
				3403	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3404
				3405	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3406	define i32* %foo(%ST* %s) {
				3407	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3408	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3409	%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]	3410	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3411	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3412	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3413	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3414	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3415
				3416	<p>Note that it is undefined to access an array out of bounds: array and
				3417	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]	3418	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]	3419	defined to be accessible as variable length arrays, which requires access
				3420	beyond the zero'th element.</p>
				3421
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3422	<p>The getelementptr instruction is often confusing. For some more insight
				3423	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3424	FAQ</a>.</p>
				3425
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3426	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3427
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3428	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3429	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3430	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3431	<i>; yields i8*:vptr</i>
				3432	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
				3433	<i>; yields i8*:eptr</i>
				3434	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3435	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3436	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3437
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3438	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3439	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3440	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3441	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3442	<p>The instructions in this category are the conversion instructions (casting)
				3443	which all take a single operand and a type. They perform various bit conversions
				3444	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3445	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3446
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3447	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3448	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3449	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3450	</div>
				3451	<div class="doc_text">
				3452
				3453	<h5>Syntax:</h5>
				3454	<pre>
				3455	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3456	</pre>
				3457
				3458	<h5>Overview:</h5>
				3459	<p>
				3460	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3461	</p>
				3462
				3463	<h5>Arguments:</h5>
				3464	<p>
				3465	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3466	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]	3467	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]	3468	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3469	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3470
				3471	<h5>Semantics:</h5>
				3472	<p>
				3473	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]	3474	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3475	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3476	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3477
				3478	<h5>Example:</h5>
				3479	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3480	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3481	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3482	%Y = trunc i32 122 to i1 <i>; yields i1:false</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_zext">'<tt>zext .. to</tt>' Instruction</a>
				3489	</div>
				3490	<div class="doc_text">
				3491
				3492	<h5>Syntax:</h5>
				3493	<pre>
				3494	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3495	</pre>
				3496
				3497	<h5>Overview:</h5>
				3498	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3499	<tt>ty2</tt>.</p>
				3500
				3501
				3502	<h5>Arguments:</h5>
				3503	<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]	3504	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3505	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]	3506	<tt>value</tt> must be smaller than the bit size of the destination type,
				3507	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3508
				3509	<h5>Semantics:</h5>
				3510	<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]	3511	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]	3512
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3513	<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]	3514
				3515	<h5>Example:</h5>
				3516	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3517	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3518	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3519	</pre>
				3520	</div>
				3521
				3522	<!-- _______________________________________________________________________ -->
				3523	<div class="doc_subsubsection">
				3524	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3525	</div>
				3526	<div class="doc_text">
				3527
				3528	<h5>Syntax:</h5>
				3529	<pre>
				3530	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3531	</pre>
				3532
				3533	<h5>Overview:</h5>
				3534	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3535
				3536	<h5>Arguments:</h5>
				3537	<p>
				3538	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]	3539	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3540	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]	3541	<tt>value</tt> must be smaller than the bit size of the destination type,
				3542	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3543
				3544	<h5>Semantics:</h5>
				3545	<p>
				3546	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3547	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]	3548	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3549
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3550	<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]	3551
				3552	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3553	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3554	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3555	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3556	</pre>
				3557	</div>
				3558
				3559	<!-- _______________________________________________________________________ -->
				3560	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3561	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3562	</div>
				3563
				3564	<div class="doc_text">
				3565
				3566	<h5>Syntax:</h5>
				3567
				3568	<pre>
				3569	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3570	</pre>
				3571
				3572	<h5>Overview:</h5>
				3573	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3574	<tt>ty2</tt>.</p>
				3575
				3576
				3577	<h5>Arguments:</h5>
				3578	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3579	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3580	cast it to. The size of <tt>value</tt> must be larger than the size of
				3581	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3582	<i>no-op cast</i>.</p>
				3583
				3584	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3585	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3586	<a href="#t_floating">floating point</a> type to a smaller
				3587	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3588	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3589
				3590	<h5>Example:</h5>
				3591	<pre>
				3592	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3593	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3594	</pre>
				3595	</div>
				3596
				3597	<!-- _______________________________________________________________________ -->
				3598	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3599	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3600	</div>
				3601	<div class="doc_text">
				3602
				3603	<h5>Syntax:</h5>
				3604	<pre>
				3605	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3606	</pre>
				3607
				3608	<h5>Overview:</h5>
				3609	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3610	floating point value.</p>
				3611
				3612	<h5>Arguments:</h5>
				3613	<p>The '<tt>fpext</tt>' instruction takes a
				3614	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3615	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3616	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3617
				3618	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3619	<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]	3620	<a href="#t_floating">floating point</a> type to a larger
				3621	<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]	3622	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]	3623	<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]	3624
				3625	<h5>Example:</h5>
				3626	<pre>
				3627	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3628	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3629	</pre>
				3630	</div>
				3631
				3632	<!-- _______________________________________________________________________ -->
				3633	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	3634	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3635	</div>
				3636	<div class="doc_text">
				3637
				3638	<h5>Syntax:</h5>
				3639	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3640	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3641	</pre>
				3642
				3643	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3644	<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]	3645	unsigned integer equivalent of type <tt>ty2</tt>.
				3646	</p>
				3647
				3648	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3649	<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]	3650	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3651	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3652	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3653	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]	3654
				3655	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3656	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3657	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3658	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3659	the results are undefined.</p>
				3660
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3661	<h5>Example:</h5>
				3662	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3663	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3664	%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]	3665	%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]	3666	</pre>
				3667	</div>
				3668
				3669	<!-- _______________________________________________________________________ -->
				3670	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3671	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3672	</div>
				3673	<div class="doc_text">
				3674
				3675	<h5>Syntax:</h5>
				3676	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3677	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3678	</pre>
				3679
				3680	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3681	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3682	<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]	3683	</p>
				3684
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3685	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3686	<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]	3687	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3688	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3689	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3690	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]	3691
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3692	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3693	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3694	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3695	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3696	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3697
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3698	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3699	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3700	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3701	%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]	3702	%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]	3703	</pre>
				3704	</div>
				3705
				3706	<!-- _______________________________________________________________________ -->
				3707	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3708	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3709	</div>
				3710	<div class="doc_text">
				3711
				3712	<h5>Syntax:</h5>
				3713	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3714	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3715	</pre>
				3716
				3717	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3718	<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]	3719	integer and converts that value to the <tt>ty2</tt> type.</p>
				3720
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3721	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3722	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3723	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3724	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3725	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3726	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]	3727
				3728	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3729	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3730	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3731	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]	3732
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3733	<h5>Example:</h5>
				3734	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3735	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3736	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3737	</pre>
				3738	</div>
				3739
				3740	<!-- _______________________________________________________________________ -->
				3741	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3742	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3743	</div>
				3744	<div class="doc_text">
				3745
				3746	<h5>Syntax:</h5>
				3747	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3748	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3749	</pre>
				3750
				3751	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3752	<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]	3753	integer and converts that value to the <tt>ty2</tt> type.</p>
				3754
				3755	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3756	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3757	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3758	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3759	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3760	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]	3761
				3762	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3763	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3764	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3765	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]	3766
				3767	<h5>Example:</h5>
				3768	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3769	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3770	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3771	</pre>
				3772	</div>
				3773
				3774	<!-- _______________________________________________________________________ -->
				3775	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3776	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3777	</div>
				3778	<div class="doc_text">
				3779
				3780	<h5>Syntax:</h5>
				3781	<pre>
				3782	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3783	</pre>
				3784
				3785	<h5>Overview:</h5>
				3786	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3787	the integer type <tt>ty2</tt>.</p>
				3788
				3789	<h5>Arguments:</h5>
				3790	<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]	3791	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]	3792	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3793
				3794	<h5>Semantics:</h5>
				3795	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3796	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3797	truncating or zero extending that value to the size of the integer type. If
				3798	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3799	<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]	3800	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3801	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3802
				3803	<h5>Example:</h5>
				3804	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3805	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3806	%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]	3807	</pre>
				3808	</div>
				3809
				3810	<!-- _______________________________________________________________________ -->
				3811	<div class="doc_subsubsection">
				3812	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3813	</div>
				3814	<div class="doc_text">
				3815
				3816	<h5>Syntax:</h5>
				3817	<pre>
				3818	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3819	</pre>
				3820
				3821	<h5>Overview:</h5>
				3822	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3823	a pointer type, <tt>ty2</tt>.</p>
				3824
				3825	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	3826	<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]	3827	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]	3828	<a href="#t_pointer">pointer</a> type.
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3829
				3830	<h5>Semantics:</h5>
				3831	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3832	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3833	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3834	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3835	the size of a pointer then a zero extension is done. If they are the same size,
				3836	nothing is done (<i>no-op cast</i>).</p>
				3837
				3838	<h5>Example:</h5>
				3839	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3840	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3841	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3842	%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]	3843	</pre>
				3844	</div>
				3845
				3846	<!-- _______________________________________________________________________ -->
				3847	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3848	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3849	</div>
				3850	<div class="doc_text">
				3851
				3852	<h5>Syntax:</h5>
				3853	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3854	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3855	</pre>
				3856
				3857	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3858
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3859	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3860	<tt>ty2</tt> without changing any bits.</p>
				3861
				3862	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3863
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3864	<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]	3865	a non-aggregate first class value, and a type to cast it to, which must also be
				3866	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3867	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	3868	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]	3869	type is a pointer, the destination type must also be a pointer. This
				3870	instruction supports bitwise conversion of vectors to integers and to vectors
				3871	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3872
				3873	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3874	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3875	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3876	this conversion. The conversion is done as if the <tt>value</tt> had been
				3877	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3878	converted to other pointer types with this instruction. To convert pointers to
				3879	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3880	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3881
				3882	<h5>Example:</h5>
				3883	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3884	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3885	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3886	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3887	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3888	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3889
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3890	<!-- ======================================================================= -->
				3891	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3892	<div class="doc_text">
				3893	<p>The instructions in this category are the "miscellaneous"
				3894	instructions, which defy better classification.</p>
				3895	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3896
				3897	<!-- _______________________________________________________________________ -->
				3898	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3899	</div>
				3900	<div class="doc_text">
				3901	<h5>Syntax:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3902	<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]	3903	</pre>
				3904	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3905	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3906	a vector of boolean values based on comparison
				3907	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3908	<h5>Arguments:</h5>
				3909	<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]	3910	the condition code indicating the kind of comparison to perform. It is not
				3911	a value, just a keyword. The possible condition code are:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3912	<ol>
				3913	<li><tt>eq</tt>: equal</li>
				3914	<li><tt>ne</tt>: not equal </li>
				3915	<li><tt>ugt</tt>: unsigned greater than</li>
				3916	<li><tt>uge</tt>: unsigned greater or equal</li>
				3917	<li><tt>ult</tt>: unsigned less than</li>
				3918	<li><tt>ule</tt>: unsigned less or equal</li>
				3919	<li><tt>sgt</tt>: signed greater than</li>
				3920	<li><tt>sge</tt>: signed greater or equal</li>
				3921	<li><tt>slt</tt>: signed less than</li>
				3922	<li><tt>sle</tt>: signed less or equal</li>
				3923	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3924	<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]	3925	<a href="#t_pointer">pointer</a>
				3926	or integer <a href="#t_vector">vector</a> typed.
				3927	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3928	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3929	<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]	3930	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3931	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]	3932	<ol>
				3933	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3934	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3935	</li>
				3936	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3937	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3938	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3939	<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]	3940	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3941	<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]	3942	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3943	<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]	3944	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3945	<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]	3946	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3947	<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]	3948	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3949	<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]	3950	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3951	<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]	3952	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3953	<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]	3954	</ol>
				3955	<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]	3956	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3957	<p>If the operands are integer vectors, then they are compared
				3958	element by element. The result is an <tt>i1</tt> vector with
				3959	the same number of elements as the values being compared.
				3960	Otherwise, the result is an <tt>i1</tt>.
				3961	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3962
				3963	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3964	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3965	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3966	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3967	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3968	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3969	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3970	</pre>
				3971	</div>
				3972
				3973	<!-- _______________________________________________________________________ -->
				3974	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3975	</div>
				3976	<div class="doc_text">
				3977	<h5>Syntax:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3978	<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]	3979	</pre>
				3980	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3981	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3982	or vector of boolean values based on comparison
				3983	of its operands.
				3984	<p>
				3985	If the operands are floating point scalars, then the result
				3986	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3987	</p>
				3988	<p>If the operands are floating point vectors, then the result type
				3989	is a vector of boolean with the same number of elements as the
				3990	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3991	<h5>Arguments:</h5>
				3992	<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]	3993	the condition code indicating the kind of comparison to perform. It is not
				3994	a value, just a keyword. The possible condition code are:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3995	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3996	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3997	<li><tt>oeq</tt>: ordered and equal</li>
				3998	<li><tt>ogt</tt>: ordered and greater than </li>
				3999	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4000	<li><tt>olt</tt>: ordered and less than </li>
				4001	<li><tt>ole</tt>: ordered and less than or equal</li>
				4002	<li><tt>one</tt>: ordered and not equal</li>
				4003	<li><tt>ord</tt>: ordered (no nans)</li>
				4004	<li><tt>ueq</tt>: unordered or equal</li>
				4005	<li><tt>ugt</tt>: unordered or greater than </li>
				4006	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4007	<li><tt>ult</tt>: unordered or less than </li>
				4008	<li><tt>ule</tt>: unordered or less than or equal</li>
				4009	<li><tt>une</tt>: unordered or not equal</li>
				4010	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4011	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4012	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4013	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	4014	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4015	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4016	either a <a href="#t_floating">floating point</a> type
				4017	or a <a href="#t_vector">vector</a> of floating point type.
				4018	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4019	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4020	<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]	4021	according to the condition code given as <tt>cond</tt>.
				4022	If the operands are vectors, then the vectors are compared
				4023	element by element.
				4024	Each comparison performed
				4025	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4026	<ol>
				4027	<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]	4028	<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]	4029	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4030	<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]	4031	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4032	<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]	4033	<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]	4034	<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]	4035	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4036	<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]	4037	<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]	4038	<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]	4039	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4040	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4041	<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]	4042	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4043	<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]	4044	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4045	<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]	4046	<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]	4047	<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]	4048	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4049	<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]	4050	<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]	4051	<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]	4052	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4053	<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]	4054	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4055	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4056
				4057	<h5>Example:</h5>
				4058	<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]	4059	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4060	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4061	<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]	4062	</pre>
				4063	</div>
				4064
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4065	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4066	<div class="doc_subsubsection">
				4067	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4068	</div>
				4069	<div class="doc_text">
				4070	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4071	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4072	</pre>
				4073	<h5>Overview:</h5>
				4074	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4075	element-wise comparison of its two integer vector operands.</p>
				4076	<h5>Arguments:</h5>
				4077	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4078	the condition code indicating the kind of comparison to perform. It is not
				4079	a value, just a keyword. The possible condition code are:
				4080	<ol>
				4081	<li><tt>eq</tt>: equal</li>
				4082	<li><tt>ne</tt>: not equal </li>
				4083	<li><tt>ugt</tt>: unsigned greater than</li>
				4084	<li><tt>uge</tt>: unsigned greater or equal</li>
				4085	<li><tt>ult</tt>: unsigned less than</li>
				4086	<li><tt>ule</tt>: unsigned less or equal</li>
				4087	<li><tt>sgt</tt>: signed greater than</li>
				4088	<li><tt>sge</tt>: signed greater or equal</li>
				4089	<li><tt>slt</tt>: signed less than</li>
				4090	<li><tt>sle</tt>: signed less or equal</li>
				4091	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4092	<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]	4093	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4094	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4095	<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]	4096	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4097	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4098	identical type as the values being compared. The most significant bit in each
				4099	element is 1 if the element-wise comparison evaluates to true, and is 0
				4100	otherwise. All other bits of the result are undefined. The condition codes
				4101	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4102	instruction</a>.
				4103
				4104	<h5>Example:</h5>
				4105	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4106	<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>
				4107	<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]	4108	</pre>
				4109	</div>
				4110
				4111	<!-- _______________________________________________________________________ -->
				4112	<div class="doc_subsubsection">
				4113	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4114	</div>
				4115	<div class="doc_text">
				4116	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4117	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4118	<h5>Overview:</h5>
				4119	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4120	element-wise comparison of its two floating point vector operands. The output
				4121	elements have the same width as the input elements.</p>
				4122	<h5>Arguments:</h5>
				4123	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4124	the condition code indicating the kind of comparison to perform. It is not
				4125	a value, just a keyword. The possible condition code are:
				4126	<ol>
				4127	<li><tt>false</tt>: no comparison, always returns false</li>
				4128	<li><tt>oeq</tt>: ordered and equal</li>
				4129	<li><tt>ogt</tt>: ordered and greater than </li>
				4130	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4131	<li><tt>olt</tt>: ordered and less than </li>
				4132	<li><tt>ole</tt>: ordered and less than or equal</li>
				4133	<li><tt>one</tt>: ordered and not equal</li>
				4134	<li><tt>ord</tt>: ordered (no nans)</li>
				4135	<li><tt>ueq</tt>: unordered or equal</li>
				4136	<li><tt>ugt</tt>: unordered or greater than </li>
				4137	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4138	<li><tt>ult</tt>: unordered or less than </li>
				4139	<li><tt>ule</tt>: unordered or less than or equal</li>
				4140	<li><tt>une</tt>: unordered or not equal</li>
				4141	<li><tt>uno</tt>: unordered (either nans)</li>
				4142	<li><tt>true</tt>: no comparison, always returns true</li>
				4143	</ol>
				4144	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4145	<a href="#t_floating">floating point</a> typed. They must also be identical
				4146	types.</p>
				4147	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4148	<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]	4149	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4150	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4151	an identical number of elements as the values being compared, and each element
				4152	having identical with to the width of the floating point elements. The most
				4153	significant bit in each element is 1 if the element-wise comparison evaluates to
				4154	true, and is 0 otherwise. All other bits of the result are undefined. The
				4155	condition codes are evaluated identically to the
				4156	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4157
				4158	<h5>Example:</h5>
				4159	<pre>
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame^]	4160	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4161	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4162
				4163	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4164	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4165	</pre>
				4166	</div>
				4167
				4168	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4169	<div class="doc_subsubsection">
				4170	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4171	</div>
				4172
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4173	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4174
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4175	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4176
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4177	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4178	<h5>Overview:</h5>
				4179	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4180	the SSA graph representing the function.</p>
				4181	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4182
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4183	<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]	4184	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4185	as arguments, with one pair for each predecessor basic block of the
				4186	current block. Only values of <a href="#t_firstclass">first class</a>
				4187	type may be used as the value arguments to the PHI node. Only labels
				4188	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4189
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4190	<p>There must be no non-phi instructions between the start of a basic
				4191	block and the PHI instructions: i.e. PHI instructions must be first in
				4192	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4193
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4194	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4195
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4196	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4197	specified by the pair corresponding to the predecessor basic block that executed
				4198	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4199
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4200	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4201	<pre>
				4202	Loop: ; Infinite loop that counts from 0 on up...
				4203	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4204	%nextindvar = add i32 %indvar, 1
				4205	br label %Loop
				4206	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4207	</div>
				4208
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4209	<!-- _______________________________________________________________________ -->
				4210	<div class="doc_subsubsection">
				4211	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4212	</div>
				4213
				4214	<div class="doc_text">
				4215
				4216	<h5>Syntax:</h5>
				4217
				4218	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4219	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4220
				4221	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4222	</pre>
				4223
				4224	<h5>Overview:</h5>
				4225
				4226	<p>
				4227	The '<tt>select</tt>' instruction is used to choose one value based on a
				4228	condition, without branching.
				4229	</p>
				4230
				4231
				4232	<h5>Arguments:</h5>
				4233
				4234	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4235	The '<tt>select</tt>' instruction requires an 'i1' value or
				4236	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4237	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]	4238	type. If the val1/val2 are vectors and
				4239	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4240	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4241	</p>
				4242
				4243	<h5>Semantics:</h5>
				4244
				4245	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4246	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]	4247	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4248	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4249	<p>
				4250	If the condition is a vector of i1, then the value arguments must
				4251	be vectors of the same size, and the selection is done element
				4252	by element.
				4253	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4254
				4255	<h5>Example:</h5>
				4256
				4257	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4258	%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]	4259	</pre>
				4260	</div>
				4261
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4262
				4263	<!-- _______________________________________________________________________ -->
				4264	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4265	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4266	</div>
				4267
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4268	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4269
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4270	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4271	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4272	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4273	</pre>
				4274
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4275	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4276
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4277	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4278
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4279	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4280
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4281	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4282
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4283	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4284	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4285	<p>The optional "tail" marker indicates whether the callee function accesses
				4286	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]	4287	function call is eligible for tail call optimization. Note that calls may
				4288	be marked "tail" even if they do not occur before a <a
				4289	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4290	</li>
				4291	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4292	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4293	convention</a> the call should use. If none is specified, the call defaults
				4294	to using C calling conventions.
				4295	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4296
				4297	<li>
				4298	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4299	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4300	and '<tt>inreg</tt>' attributes are valid here.</p>
				4301	</li>
				4302
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4303	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4304	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4305	the type of the return value. Functions that return no value are marked
				4306	<tt><a href="#t_void">void</a></tt>.</p>
				4307	</li>
				4308	<li>
				4309	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4310	value being invoked. The argument types must match the types implied by
				4311	this signature. This type can be omitted if the function is not varargs
				4312	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]	4313	</li>
				4314	<li>
				4315	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4316	be invoked. In most cases, this is a direct function invocation, but
				4317	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]	4318	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4319	</li>
				4320	<li>
				4321	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4322	function signature argument types. All arguments must be of
				4323	<a href="#t_firstclass">first class</a> type. If the function signature
				4324	indicates the function accepts a variable number of arguments, the extra
				4325	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4326	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4327	<li>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4328	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4329	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4330	'<tt>readnone</tt>' attributes are valid here.</p>
				4331	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4332	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4333
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4334	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4335
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4336	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4337	transfer to a specified function, with its incoming arguments bound to
				4338	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4339	instruction in the called function, control flow continues with the
				4340	instruction after the function call, and the return value of the
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4341	function is bound to the result argument.
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4342
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4343	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4344
				4345	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4346	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4347	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4348	%X = tail call i32 @foo() <i>; yields i32</i>
				4349	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4350	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4351
				4352	%struct.A = type { i32, i8 }
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4353	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4354	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4355	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	6cbe8e9	2008-10-08 06:26:11 +0000	[diff] [blame]	4356	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	eefa7df	2008-10-07 10:03:45 +0000	[diff] [blame]	4357	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4358	</pre>
				4359
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4360	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4361
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4362	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4363	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4364	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4365	</div>
				4366
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4367	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4368
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4369	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4370
				4371	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4372	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4373	</pre>
				4374
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4375	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4376
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4377	<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]	4378	the "variable argument" area of a function call. It is used to implement the
				4379	<tt>va_arg</tt> macro in C.</p>
				4380
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4381	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4382
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4383	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4384	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4385	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]	4386	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4387
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4388	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4389
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4390	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4391	type from the specified <tt>va_list</tt> and causes the
				4392	<tt>va_list</tt> to point to the next argument. For more information,
				4393	see the variable argument handling <a href="#int_varargs">Intrinsic
				4394	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4395
				4396	<p>It is legal for this instruction to be called in a function which does not
				4397	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4398	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4399
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4400	<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]	4401	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4402	argument.</p>
				4403
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4404	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4405
				4406	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4407
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4408	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4409
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4410	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4411	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4412	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4413
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4414	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4415
				4416	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4417	well known names and semantics and are required to follow certain restrictions.
				4418	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4419	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]	4420	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]	4421
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4422	<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]	4423	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4424	begin with this prefix. Intrinsic functions must always be external functions:
				4425	you cannot define the body of intrinsic functions. Intrinsic functions may
				4426	only be used in call or invoke instructions: it is illegal to take the address
				4427	of an intrinsic function. Additionally, because intrinsic functions are part
				4428	of the LLVM language, it is required if any are added that they be documented
				4429	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4430
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4431	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4432	a family of functions that perform the same operation but on different data
				4433	types. Because LLVM can represent over 8 million different integer types,
				4434	overloading is used commonly to allow an intrinsic function to operate on any
				4435	integer type. One or more of the argument types or the result type can be
				4436	overloaded to accept any integer type. Argument types may also be defined as
				4437	exactly matching a previous argument's type or the result type. This allows an
				4438	intrinsic function which accepts multiple arguments, but needs all of them to
				4439	be of the same type, to only be overloaded with respect to a single argument or
				4440	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4441
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4442	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4443	encoded into its function name, each preceded by a period. Only those types
				4444	which are overloaded result in a name suffix. Arguments whose type is matched
				4445	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4446	take an integer of any width and returns an integer of exactly the same integer
				4447	width. This leads to a family of functions such as
				4448	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4449	Only one type, the return type, is overloaded, and only one type suffix is
				4450	required. Because the argument's type is matched against the return type, it
				4451	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4452
				4453	<p>To learn how to add an intrinsic function, please see the
				4454	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4455	</p>
				4456
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4457	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4458
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4459	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4460	<div class="doc_subsection">
				4461	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4462	</div>
				4463
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4464	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4465
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4466	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4467	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]	4468	intrinsic functions. These functions are related to the similarly
				4469	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4470
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4471	<p>All of these functions operate on arguments that use a
				4472	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4473	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4474	transformations should be prepared to handle these functions regardless of
				4475	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4476
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4477	<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]	4478	instruction and the variable argument handling intrinsic functions are
				4479	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4480
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4481	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4482	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4483	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4484	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4485	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4486	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4487	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4488
				4489	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4490	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4491
				4492	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4493	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4494	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4495	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4496	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4497
				4498	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4499	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4500	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4501	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4502
				4503	declare void @llvm.va_start(i8*)
				4504	declare void @llvm.va_copy(i8, i8)
				4505	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4506	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4507	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4508
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4509	</div>
				4510
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4511	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4512	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4513	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4514	</div>
				4515
				4516
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4517	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4518	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4519	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4520	<h5>Overview:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4521	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4522	<tt>*<arglist></tt> for subsequent use by <tt><a
				4523	href="#i_va_arg">va_arg</a></tt>.</p>
				4524
				4525	<h5>Arguments:</h5>
				4526
				4527	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4528
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4529	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4530
				4531	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4532	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4533	<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]	4534	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4535	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]	4536	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]	4537
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4538	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4539
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4540	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4541	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4542	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4543	</div>
				4544
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4545	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4546	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4547	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4548	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4549
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4550	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4551	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]	4552	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]	4553
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4554	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4555
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4556	<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]	4557
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4558	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4559
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4560	<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]	4561	macro available in C. In a target-dependent way, it destroys the
				4562	<tt>va_list</tt> element to which the argument points. Calls to <a
				4563	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4564	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4565	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4566
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4567	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4568
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4569	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4570	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4571	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4572	</div>
				4573
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4574	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4575
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4576	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4577
				4578	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4579	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4580	</pre>
				4581
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4582	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4583
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4584	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4585	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4586
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4587	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4588
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4589	<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]	4590	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]	4591
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4592
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4593	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4594
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4595	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4596	macro available in C. In a target-dependent way, it copies the source
				4597	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4598	intrinsic is necessary because the <tt><a href="#int_va_start">
				4599	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4600	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4601
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4602	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4603
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4604	<!-- ======================================================================= -->
				4605	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4606	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4607	</div>
				4608
				4609	<div class="doc_text">
				4610
				4611	<p>
				4612	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4613	Collection</a> (GC) requires the implementation and generation of these
				4614	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4615	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]	4616	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4617	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]	4618	Front-ends for type-safe garbage collected languages should generate these
				4619	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4620	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4621	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	4622
				4623	<p>The garbage collection intrinsics only operate on objects in the generic
				4624	address space (address space zero).</p>
				4625
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4626	</div>
				4627
				4628	<!-- _______________________________________________________________________ -->
				4629	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4630	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4631	</div>
				4632
				4633	<div class="doc_text">
				4634
				4635	<h5>Syntax:</h5>
				4636
				4637	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4638	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4639	</pre>
				4640
				4641	<h5>Overview:</h5>
				4642
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	4643	<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]	4644	the code generator, and allows some metadata to be associated with it.</p>
				4645
				4646	<h5>Arguments:</h5>
				4647
				4648	<p>The first argument specifies the address of a stack object that contains the
				4649	root pointer. The second pointer (which must be either a constant or a global
				4650	value address) contains the meta-data to be associated with the root.</p>
				4651
				4652	<h5>Semantics:</h5>
				4653
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	4654	<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]	4655	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4656	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4657	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4658	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4659
				4660	</div>
				4661
				4662
				4663	<!-- _______________________________________________________________________ -->
				4664	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4665	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4666	</div>
				4667
				4668	<div class="doc_text">
				4669
				4670	<h5>Syntax:</h5>
				4671
				4672	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4673	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4674	</pre>
				4675
				4676	<h5>Overview:</h5>
				4677
				4678	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4679	locations, allowing garbage collector implementations that require read
				4680	barriers.</p>
				4681
				4682	<h5>Arguments:</h5>
				4683
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4684	<p>The second argument is the address to read from, which should be an address
				4685	allocated from the garbage collector. The first object is a pointer to the
				4686	start of the referenced object, if needed by the language runtime (otherwise
				4687	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4688
				4689	<h5>Semantics:</h5>
				4690
				4691	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4692	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4693	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4694	may only be used in a function which <a href="#gc">specifies a GC
				4695	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4696
				4697	</div>
				4698
				4699
				4700	<!-- _______________________________________________________________________ -->
				4701	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4702	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4703	</div>
				4704
				4705	<div class="doc_text">
				4706
				4707	<h5>Syntax:</h5>
				4708
				4709	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4710	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4711	</pre>
				4712
				4713	<h5>Overview:</h5>
				4714
				4715	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4716	locations, allowing garbage collector implementations that require write
				4717	barriers (such as generational or reference counting collectors).</p>
				4718
				4719	<h5>Arguments:</h5>
				4720
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4721	<p>The first argument is the reference to store, the second is the start of the
				4722	object to store it to, and the third is the address of the field of Obj to
				4723	store to. If the runtime does not require a pointer to the object, Obj may be
				4724	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4725
				4726	<h5>Semantics:</h5>
				4727
				4728	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4729	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4730	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4731	may only be used in a function which <a href="#gc">specifies a GC
				4732	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4733
				4734	</div>
				4735
				4736
				4737
				4738	<!-- ======================================================================= -->
				4739	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4740	<a name="int_codegen">Code Generator Intrinsics</a>
				4741	</div>
				4742
				4743	<div class="doc_text">
				4744	<p>
				4745	These intrinsics are provided by LLVM to expose special features that may only
				4746	be implemented with code generator support.
				4747	</p>
				4748
				4749	</div>
				4750
				4751	<!-- _______________________________________________________________________ -->
				4752	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4753	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4754	</div>
				4755
				4756	<div class="doc_text">
				4757
				4758	<h5>Syntax:</h5>
				4759	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4760	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4761	</pre>
				4762
				4763	<h5>Overview:</h5>
				4764
				4765	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	4766	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4767	target-specific value indicating the return address of the current function
				4768	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4769	</p>
				4770
				4771	<h5>Arguments:</h5>
				4772
				4773	<p>
				4774	The argument to this intrinsic indicates which function to return the address
				4775	for. Zero indicates the calling function, one indicates its caller, etc. The
				4776	argument is <b>required</b> to be a constant integer value.
				4777	</p>
				4778
				4779	<h5>Semantics:</h5>
				4780
				4781	<p>
				4782	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4783	the return address of the specified call frame, or zero if it cannot be
				4784	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4785	for arguments other than zero, so it should only be used for debugging purposes.
				4786	</p>
				4787
				4788	<p>
				4789	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	4790	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]	4791	source-language caller.
				4792	</p>
				4793	</div>
				4794
				4795
				4796	<!-- _______________________________________________________________________ -->
				4797	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4798	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4799	</div>
				4800
				4801	<div class="doc_text">
				4802
				4803	<h5>Syntax:</h5>
				4804	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4805	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4806	</pre>
				4807
				4808	<h5>Overview:</h5>
				4809
				4810	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	4811	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4812	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4813	</p>
				4814
				4815	<h5>Arguments:</h5>
				4816
				4817	<p>
				4818	The argument to this intrinsic indicates which function to return the frame
				4819	pointer for. Zero indicates the calling function, one indicates its caller,
				4820	etc. The argument is <b>required</b> to be a constant integer value.
				4821	</p>
				4822
				4823	<h5>Semantics:</h5>
				4824
				4825	<p>
				4826	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4827	the frame address of the specified call frame, or zero if it cannot be
				4828	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4829	for arguments other than zero, so it should only be used for debugging purposes.
				4830	</p>
				4831
				4832	<p>
				4833	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	4834	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]	4835	source-language caller.
				4836	</p>
				4837	</div>
				4838
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4839	<!-- _______________________________________________________________________ -->
				4840	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4841	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4842	</div>
				4843
				4844	<div class="doc_text">
				4845
				4846	<h5>Syntax:</h5>
				4847	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4848	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4849	</pre>
				4850
				4851	<h5>Overview:</h5>
				4852
				4853	<p>
				4854	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]	4855	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4856	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4857	features like scoped automatic variable sized arrays in C99.
				4858	</p>
				4859
				4860	<h5>Semantics:</h5>
				4861
				4862	<p>
				4863	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]	4864	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4865	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4866	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4867	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4868	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4869	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4870	</p>
				4871
				4872	</div>
				4873
				4874	<!-- _______________________________________________________________________ -->
				4875	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4876	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4877	</div>
				4878
				4879	<div class="doc_text">
				4880
				4881	<h5>Syntax:</h5>
				4882	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4883	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4884	</pre>
				4885
				4886	<h5>Overview:</h5>
				4887
				4888	<p>
				4889	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4890	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]	4891	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4892	useful for implementing language features like scoped automatic variable sized
				4893	arrays in C99.
				4894	</p>
				4895
				4896	<h5>Semantics:</h5>
				4897
				4898	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4899	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]	4900	</p>
				4901
				4902	</div>
				4903
				4904
				4905	<!-- _______________________________________________________________________ -->
				4906	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4907	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4908	</div>
				4909
				4910	<div class="doc_text">
				4911
				4912	<h5>Syntax:</h5>
				4913	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4914	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4915	</pre>
				4916
				4917	<h5>Overview:</h5>
				4918
				4919
				4920	<p>
				4921	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]	4922	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4923	no
				4924	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	4925	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4926	</p>
				4927
				4928	<h5>Arguments:</h5>
				4929
				4930	<p>
				4931	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4932	determining if the fetch should be for a read (0) or write (1), and
				4933	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	4934	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]	4935	<tt>locality</tt> arguments must be constant integers.
				4936	</p>
				4937
				4938	<h5>Semantics:</h5>
				4939
				4940	<p>
				4941	This intrinsic does not modify the behavior of the program. In particular,
				4942	prefetches cannot trap and do not produce a value. On targets that support this
				4943	intrinsic, the prefetch can provide hints to the processor cache for better
				4944	performance.
				4945	</p>
				4946
				4947	</div>
				4948
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4949	<!-- _______________________________________________________________________ -->
				4950	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4951	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4952	</div>
				4953
				4954	<div class="doc_text">
				4955
				4956	<h5>Syntax:</h5>
				4957	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4958	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4959	</pre>
				4960
				4961	<h5>Overview:</h5>
				4962
				4963
				4964	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4965	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]	4966	(PC) in a region of
				4967	code to simulators and other tools. The method is target specific, but it is
				4968	expected that the marker will use exported symbols to transmit the PC of the
				4969	marker.
				4970	The marker makes no guarantees that it will remain with any specific instruction
				4971	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]	4972	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4973	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4974	</p>
				4975
				4976	<h5>Arguments:</h5>
				4977
				4978	<p>
				4979	<tt>id</tt> is a numerical id identifying the marker.
				4980	</p>
				4981
				4982	<h5>Semantics:</h5>
				4983
				4984	<p>
				4985	This intrinsic does not modify the behavior of the program. Backends that do not
				4986	support this intrinisic may ignore it.
				4987	</p>
				4988
				4989	</div>
				4990
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4991	<!-- _______________________________________________________________________ -->
				4992	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4993	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4994	</div>
				4995
				4996	<div class="doc_text">
				4997
				4998	<h5>Syntax:</h5>
				4999	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5000	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5001	</pre>
				5002
				5003	<h5>Overview:</h5>
				5004
				5005
				5006	<p>
				5007	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5008	counter register (or similar low latency, high accuracy clocks) on those targets
				5009	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5010	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5011	should only be used for small timings.
				5012	</p>
				5013
				5014	<h5>Semantics:</h5>
				5015
				5016	<p>
				5017	When directly supported, reading the cycle counter should not modify any memory.
				5018	Implementations are allowed to either return a application specific value or a
				5019	system wide value. On backends without support, this is lowered to a constant 0.
				5020	</p>
				5021
				5022	</div>
				5023
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5024	<!-- ======================================================================= -->
				5025	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5026	<a name="int_libc">Standard C Library Intrinsics</a>
				5027	</div>
				5028
				5029	<div class="doc_text">
				5030	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5031	LLVM provides intrinsics for a few important standard C library functions.
				5032	These intrinsics allow source-language front-ends to pass information about the
				5033	alignment of the pointer arguments to the code generator, providing opportunity
				5034	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5035	</p>
				5036
				5037	</div>
				5038
				5039	<!-- _______________________________________________________________________ -->
				5040	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5041	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5042	</div>
				5043
				5044	<div class="doc_text">
				5045
				5046	<h5>Syntax:</h5>
				5047	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5048	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5049	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5050	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5051	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5052	</pre>
				5053
				5054	<h5>Overview:</h5>
				5055
				5056	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5057	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]	5058	location to the destination location.
				5059	</p>
				5060
				5061	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5062	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5063	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5064	</p>
				5065
				5066	<h5>Arguments:</h5>
				5067
				5068	<p>
				5069	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]	5070	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5071	specifying the number of bytes to copy, and the fourth argument is the alignment
				5072	of the source and destination locations.
				5073	</p>
				5074
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5075	<p>
				5076	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]	5077	the caller guarantees that both the source and destination pointers are aligned
				5078	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5079	</p>
				5080
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5081	<h5>Semantics:</h5>
				5082
				5083	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5084	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]	5085	location to the destination location, which are not allowed to overlap. It
				5086	copies "len" bytes of memory over. If the argument is known to be aligned to
				5087	some boundary, this can be specified as the fourth argument, otherwise it should
				5088	be set to 0 or 1.
				5089	</p>
				5090	</div>
				5091
				5092
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5093	<!-- _______________________________________________________________________ -->
				5094	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5095	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5096	</div>
				5097
				5098	<div class="doc_text">
				5099
				5100	<h5>Syntax:</h5>
				5101	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5102	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5103	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5104	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5105	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5106	</pre>
				5107
				5108	<h5>Overview:</h5>
				5109
				5110	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5111	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5112	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5113	'<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]	5114	</p>
				5115
				5116	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5117	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5118	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5119	</p>
				5120
				5121	<h5>Arguments:</h5>
				5122
				5123	<p>
				5124	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]	5125	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5126	specifying the number of bytes to copy, and the fourth argument is the alignment
				5127	of the source and destination locations.
				5128	</p>
				5129
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5130	<p>
				5131	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]	5132	the caller guarantees that the source and destination pointers are aligned to
				5133	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5134	</p>
				5135
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5136	<h5>Semantics:</h5>
				5137
				5138	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5139	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]	5140	location to the destination location, which may overlap. It
				5141	copies "len" bytes of memory over. If the argument is known to be aligned to
				5142	some boundary, this can be specified as the fourth argument, otherwise it should
				5143	be set to 0 or 1.
				5144	</p>
				5145	</div>
				5146
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5147
Chris Lattner	3649c3a	2004-02-14 04:08:35 +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_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5151	</div>
				5152
				5153	<div class="doc_text">
				5154
				5155	<h5>Syntax:</h5>
				5156	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5157	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5158	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5159	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5160	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5161	</pre>
				5162
				5163	<h5>Overview:</h5>
				5164
				5165	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5166	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]	5167	byte value.
				5168	</p>
				5169
				5170	<p>
				5171	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5172	does not return a value, and takes an extra alignment argument.
				5173	</p>
				5174
				5175	<h5>Arguments:</h5>
				5176
				5177	<p>
				5178	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]	5179	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5180	argument specifying the number of bytes to fill, and the fourth argument is the
				5181	known alignment of destination location.
				5182	</p>
				5183
				5184	<p>
				5185	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]	5186	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5187	</p>
				5188
				5189	<h5>Semantics:</h5>
				5190
				5191	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5192	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5193	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5194	destination location. If the argument is known to be aligned to some boundary,
				5195	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5196	1.
				5197	</p>
				5198	</div>
				5199
				5200
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5201	<!-- _______________________________________________________________________ -->
				5202	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5203	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5204	</div>
				5205
				5206	<div class="doc_text">
				5207
				5208	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5209	<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]	5210	floating point or vector of floating point type. Not all targets support all
				5211	types however.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5212	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5213	declare float @llvm.sqrt.f32(float %Val)
				5214	declare double @llvm.sqrt.f64(double %Val)
				5215	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5216	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5217	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5218	</pre>
				5219
				5220	<h5>Overview:</h5>
				5221
				5222	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5223	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]	5224	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]	5225	<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]	5226	negative numbers other than -0.0 (which allows for better optimization, because
				5227	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5228	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5229	</p>
				5230
				5231	<h5>Arguments:</h5>
				5232
				5233	<p>
				5234	The argument and return value are floating point numbers of the same type.
				5235	</p>
				5236
				5237	<h5>Semantics:</h5>
				5238
				5239	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5240	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]	5241	floating point number.
				5242	</p>
				5243	</div>
				5244
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5245	<!-- _______________________________________________________________________ -->
				5246	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5247	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5248	</div>
				5249
				5250	<div class="doc_text">
				5251
				5252	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5253	<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]	5254	floating point or vector of floating point type. Not all targets support all
				5255	types however.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5256	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5257	declare float @llvm.powi.f32(float %Val, i32 %power)
				5258	declare double @llvm.powi.f64(double %Val, i32 %power)
				5259	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5260	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5261	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5262	</pre>
				5263
				5264	<h5>Overview:</h5>
				5265
				5266	<p>
				5267	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5268	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5269	multiplications is not defined. When a vector of floating point type is
				5270	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5271	</p>
				5272
				5273	<h5>Arguments:</h5>
				5274
				5275	<p>
				5276	The second argument is an integer power, and the first is a value to raise to
				5277	that power.
				5278	</p>
				5279
				5280	<h5>Semantics:</h5>
				5281
				5282	<p>
				5283	This function returns the first value raised to the second power with an
				5284	unspecified sequence of rounding operations.</p>
				5285	</div>
				5286
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5287	<!-- _______________________________________________________________________ -->
				5288	<div class="doc_subsubsection">
				5289	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5290	</div>
				5291
				5292	<div class="doc_text">
				5293
				5294	<h5>Syntax:</h5>
				5295	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5296	floating point or vector of floating point type. Not all targets support all
				5297	types however.
				5298	<pre>
				5299	declare float @llvm.sin.f32(float %Val)
				5300	declare double @llvm.sin.f64(double %Val)
				5301	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5302	declare fp128 @llvm.sin.f128(fp128 %Val)
				5303	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5304	</pre>
				5305
				5306	<h5>Overview:</h5>
				5307
				5308	<p>
				5309	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5310	</p>
				5311
				5312	<h5>Arguments:</h5>
				5313
				5314	<p>
				5315	The argument and return value are floating point numbers of the same type.
				5316	</p>
				5317
				5318	<h5>Semantics:</h5>
				5319
				5320	<p>
				5321	This function returns the sine of the specified operand, returning the
				5322	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]	5323	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5324	</div>
				5325
				5326	<!-- _______________________________________________________________________ -->
				5327	<div class="doc_subsubsection">
				5328	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5329	</div>
				5330
				5331	<div class="doc_text">
				5332
				5333	<h5>Syntax:</h5>
				5334	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5335	floating point or vector of floating point type. Not all targets support all
				5336	types however.
				5337	<pre>
				5338	declare float @llvm.cos.f32(float %Val)
				5339	declare double @llvm.cos.f64(double %Val)
				5340	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5341	declare fp128 @llvm.cos.f128(fp128 %Val)
				5342	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5343	</pre>
				5344
				5345	<h5>Overview:</h5>
				5346
				5347	<p>
				5348	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5349	</p>
				5350
				5351	<h5>Arguments:</h5>
				5352
				5353	<p>
				5354	The argument and return value are floating point numbers of the same type.
				5355	</p>
				5356
				5357	<h5>Semantics:</h5>
				5358
				5359	<p>
				5360	This function returns the cosine of the specified operand, returning the
				5361	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]	5362	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5363	</div>
				5364
				5365	<!-- _______________________________________________________________________ -->
				5366	<div class="doc_subsubsection">
				5367	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5368	</div>
				5369
				5370	<div class="doc_text">
				5371
				5372	<h5>Syntax:</h5>
				5373	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5374	floating point or vector of floating point type. Not all targets support all
				5375	types however.
				5376	<pre>
				5377	declare float @llvm.pow.f32(float %Val, float %Power)
				5378	declare double @llvm.pow.f64(double %Val, double %Power)
				5379	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5380	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5381	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5382	</pre>
				5383
				5384	<h5>Overview:</h5>
				5385
				5386	<p>
				5387	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5388	specified (positive or negative) power.
				5389	</p>
				5390
				5391	<h5>Arguments:</h5>
				5392
				5393	<p>
				5394	The second argument is a floating point power, and the first is a value to
				5395	raise to that power.
				5396	</p>
				5397
				5398	<h5>Semantics:</h5>
				5399
				5400	<p>
				5401	This function returns the first value raised to the second power,
				5402	returning the
				5403	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]	5404	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5405	</div>
				5406
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5407
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5408	<!-- ======================================================================= -->
				5409	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5410	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5411	</div>
				5412
				5413	<div class="doc_text">
				5414	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5415	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5416	These allow efficient code generation for some algorithms.
				5417	</p>
				5418
				5419	</div>
				5420
				5421	<!-- _______________________________________________________________________ -->
				5422	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5423	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5424	</div>
				5425
				5426	<div class="doc_text">
				5427
				5428	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5429	<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]	5430	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]	5431	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5432	declare i16 @llvm.bswap.i16(i16 <id>)
				5433	declare i32 @llvm.bswap.i32(i32 <id>)
				5434	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5435	</pre>
				5436
				5437	<h5>Overview:</h5>
				5438
				5439	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5440	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]	5441	values with an even number of bytes (positive multiple of 16 bits). These are
				5442	useful for performing operations on data that is not in the target's native
				5443	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5444	</p>
				5445
				5446	<h5>Semantics:</h5>
				5447
				5448	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5449	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]	5450	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5451	intrinsic returns an i32 value that has the four bytes of the input i32
				5452	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]	5453	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5454	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5455	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5456	</p>
				5457
				5458	</div>
				5459
				5460	<!-- _______________________________________________________________________ -->
				5461	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5462	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5463	</div>
				5464
				5465	<div class="doc_text">
				5466
				5467	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5468	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5469	width. Not all targets support all bit widths however.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5470	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5471	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5472	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5473	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5474	declare i64 @llvm.ctpop.i64(i64 <src>)
				5475	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5476	</pre>
				5477
				5478	<h5>Overview:</h5>
				5479
				5480	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5481	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5482	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5483	</p>
				5484
				5485	<h5>Arguments:</h5>
				5486
				5487	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5488	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]	5489	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5490	</p>
				5491
				5492	<h5>Semantics:</h5>
				5493
				5494	<p>
				5495	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5496	</p>
				5497	</div>
				5498
				5499	<!-- _______________________________________________________________________ -->
				5500	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5501	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5502	</div>
				5503
				5504	<div class="doc_text">
				5505
				5506	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5507	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5508	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5509	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5510	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5511	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5512	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5513	declare i64 @llvm.ctlz.i64(i64 <src>)
				5514	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5515	</pre>
				5516
				5517	<h5>Overview:</h5>
				5518
				5519	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5520	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5521	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5522	</p>
				5523
				5524	<h5>Arguments:</h5>
				5525
				5526	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5527	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]	5528	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5529	</p>
				5530
				5531	<h5>Semantics:</h5>
				5532
				5533	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5534	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5535	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]	5536	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5537	</p>
				5538	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5539
				5540
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5541
				5542	<!-- _______________________________________________________________________ -->
				5543	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5544	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5545	</div>
				5546
				5547	<div class="doc_text">
				5548
				5549	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5550	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5551	integer bit width. Not all targets support all bit widths however.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5552	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5553	declare i8 @llvm.cttz.i8 (i8 <src>)
				5554	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5555	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5556	declare i64 @llvm.cttz.i64(i64 <src>)
				5557	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5558	</pre>
				5559
				5560	<h5>Overview:</h5>
				5561
				5562	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5563	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5564	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5565	</p>
				5566
				5567	<h5>Arguments:</h5>
				5568
				5569	<p>
				5570	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]	5571	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5572	</p>
				5573
				5574	<h5>Semantics:</h5>
				5575
				5576	<p>
				5577	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5578	in a variable. If the src == 0 then the result is the size in bits of the type
				5579	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5580	</p>
				5581	</div>
				5582
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	5583	<!-- _______________________________________________________________________ -->
				5584	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5585	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5586	</div>
				5587
				5588	<div class="doc_text">
				5589
				5590	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5591	<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]	5592	on any integer bit width.
				5593	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5594	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5595	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5596	</pre>
				5597
				5598	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5599	<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]	5600	range of bits from an integer value and returns them in the same bit width as
				5601	the original value.</p>
				5602
				5603	<h5>Arguments:</h5>
				5604	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5605	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]	5606	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]	5607
				5608	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5609	<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]	5610	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5611	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5612	operates in forward mode.</p>
				5613	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5614	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]	5615	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5616	<ol>
				5617	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5618	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5619	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5620	to determine the number of bits to retain.</li>
				5621	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5622	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5623	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	5624	<p>In reverse mode, a similar computation is made except that the bits are
				5625	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5626	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5627	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5628	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5629	</div>
				5630
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5631	<div class="doc_subsubsection">
				5632	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5633	</div>
				5634
				5635	<div class="doc_text">
				5636
				5637	<h5>Syntax:</h5>
				5638	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5639	on any integer bit width.
				5640	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5641	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5642	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]	5643	</pre>
				5644
				5645	<h5>Overview:</h5>
				5646	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5647	of bits in an integer value with another integer value. It returns the integer
				5648	with the replaced bits.</p>
				5649
				5650	<h5>Arguments:</h5>
				5651	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5652	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5653	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5654	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5655	type since they specify only a bit index.</p>
				5656
				5657	<h5>Semantics:</h5>
				5658	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5659	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5660	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5661	operates in forward mode.</p>
				5662	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5663	truncating it down to the size of the replacement area or zero extending it
				5664	up to that size.</p>
				5665	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5666	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5667	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5668	to the <tt>%hi</tt>th bit.
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5669	<p>In reverse mode, a similar computation is made except that the bits are
				5670	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5671	<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]	5672	<h5>Examples:</h5>
				5673	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5674	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5675	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5676	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5677	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5678	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	5679	</pre>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5680	</div>
				5681
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5682	<!-- ======================================================================= -->
				5683	<div class="doc_subsection">
				5684	<a name="int_debugger">Debugger Intrinsics</a>
				5685	</div>
				5686
				5687	<div class="doc_text">
				5688	<p>
				5689	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5690	are described in the <a
				5691	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5692	Debugging</a> document.
				5693	</p>
				5694	</div>
				5695
				5696
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	5697	<!-- ======================================================================= -->
				5698	<div class="doc_subsection">
				5699	<a name="int_eh">Exception Handling Intrinsics</a>
				5700	</div>
				5701
				5702	<div class="doc_text">
				5703	<p> The LLVM exception handling intrinsics (which all start with
				5704	<tt>llvm.eh.</tt> prefix), are described in the <a
				5705	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5706	Handling</a> document. </p>
				5707	</div>
				5708
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	5709	<!-- ======================================================================= -->
				5710	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5711	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5712	</div>
				5713
				5714	<div class="doc_text">
				5715	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5716	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5717	the <tt>nest</tt> attribute, from a function. The result is a callable
				5718	function pointer lacking the nest parameter - the caller does not need
				5719	to provide a value for it. Instead, the value to use is stored in
				5720	advance in a "trampoline", a block of memory usually allocated
				5721	on the stack, which also contains code to splice the nest value into the
				5722	argument list. This is used to implement the GCC nested function address
				5723	extension.
				5724	</p>
				5725	<p>
				5726	For example, if the function is
				5727	<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]	5728	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]	5729	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5730	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5731	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5732	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5733	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5734	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	5735	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5736	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]	5737	</div>
				5738
				5739	<!-- _______________________________________________________________________ -->
				5740	<div class="doc_subsubsection">
				5741	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5742	</div>
				5743	<div class="doc_text">
				5744	<h5>Syntax:</h5>
				5745	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5746	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5747	</pre>
				5748	<h5>Overview:</h5>
				5749	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5750	This fills the memory pointed to by <tt>tramp</tt> with code
				5751	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5752	</p>
				5753	<h5>Arguments:</h5>
				5754	<p>
				5755	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5756	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5757	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]	5758	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5759	currently provides no portable way of determining them, so a front-end that
				5760	generates this intrinsic needs to have some target-specific knowledge.
				5761	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]	5762	</p>
				5763	<h5>Semantics:</h5>
				5764	<p>
				5765	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]	5766	dependent code, turning it into a function. A pointer to this function is
				5767	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5768	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5769	before being called. The new function's signature is the same as that of
				5770	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5771	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5772	of pointer type. Calling the new function is equivalent to calling
				5773	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5774	missing <tt>nest</tt> argument. If, after calling
				5775	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5776	modified, then the effect of any later call to the returned function pointer is
				5777	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5778	</p>
				5779	</div>
				5780
				5781	<!-- ======================================================================= -->
				5782	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	5783	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5784	</div>
				5785
				5786	<div class="doc_text">
				5787	<p>
				5788	These intrinsic functions expand the "universal IR" of LLVM to represent
				5789	hardware constructs for atomic operations and memory synchronization. This
				5790	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]	5791	is aimed at a low enough level to allow any programming models or APIs
				5792	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	5793	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5794	hardware behavior. Just as hardware provides a "universal IR" for source
				5795	languages, it also provides a starting point for developing a "universal"
				5796	atomic operation and synchronization IR.
				5797	</p>
				5798	<p>
				5799	These do <em>not</em> form an API such as high-level threading libraries,
				5800	software transaction memory systems, atomic primitives, and intrinsic
				5801	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5802	application libraries. The hardware interface provided by LLVM should allow
				5803	a clean implementation of all of these APIs and parallel programming models.
				5804	No one model or paradigm should be selected above others unless the hardware
				5805	itself ubiquitously does so.
				5806
				5807	</p>
				5808	</div>
				5809
				5810	<!-- _______________________________________________________________________ -->
				5811	<div class="doc_subsubsection">
				5812	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5813	</div>
				5814	<div class="doc_text">
				5815	<h5>Syntax:</h5>
				5816	<pre>
				5817	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5818	i1 <device> )
				5819
				5820	</pre>
				5821	<h5>Overview:</h5>
				5822	<p>
				5823	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5824	specific pairs of memory access types.
				5825	</p>
				5826	<h5>Arguments:</h5>
				5827	<p>
				5828	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5829	The first four arguments enables a specific barrier as listed below. The fith
				5830	argument specifies that the barrier applies to io or device or uncached memory.
				5831
				5832	</p>
				5833	<ul>
				5834	<li><tt>ll</tt>: load-load barrier</li>
				5835	<li><tt>ls</tt>: load-store barrier</li>
				5836	<li><tt>sl</tt>: store-load barrier</li>
				5837	<li><tt>ss</tt>: store-store barrier</li>
				5838	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5839	</ul>
				5840	<h5>Semantics:</h5>
				5841	<p>
				5842	This intrinsic causes the system to enforce some ordering constraints upon
				5843	the loads and stores of the program. This barrier does not indicate
				5844	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5845	which they occur. For any of the specified pairs of load and store operations
				5846	(f.ex. load-load, or store-load), all of the first operations preceding the
				5847	barrier will complete before any of the second operations succeeding the
				5848	barrier begin. Specifically the semantics for each pairing is as follows:
				5849	</p>
				5850	<ul>
				5851	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5852	after the barrier begins.</li>
				5853
				5854	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5855	store after the barrier begins.</li>
				5856	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5857	store after the barrier begins.</li>
				5858	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5859	load after the barrier begins.</li>
				5860	</ul>
				5861	<p>
				5862	These semantics are applied with a logical "and" behavior when more than one
				5863	is enabled in a single memory barrier intrinsic.
				5864	</p>
				5865	<p>
				5866	Backends may implement stronger barriers than those requested when they do not
				5867	support as fine grained a barrier as requested. Some architectures do not
				5868	need all types of barriers and on such architectures, these become noops.
				5869	</p>
				5870	<h5>Example:</h5>
				5871	<pre>
				5872	%ptr = malloc i32
				5873	store i32 4, %ptr
				5874
				5875	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5876	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5877	<i>; guarantee the above finishes</i>
				5878	store i32 8, %ptr <i>; before this begins</i>
				5879	</pre>
				5880	</div>
				5881
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5882	<!-- _______________________________________________________________________ -->
				5883	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5884	<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]	5885	</div>
				5886	<div class="doc_text">
				5887	<h5>Syntax:</h5>
				5888	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5889	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5890	any integer bit width and for different address spaces. Not all targets
				5891	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5892
				5893	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5894	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5895	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5896	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5897	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]	5898
				5899	</pre>
				5900	<h5>Overview:</h5>
				5901	<p>
				5902	This loads a value in memory and compares it to a given value. If they are
				5903	equal, it stores a new value into the memory.
				5904	</p>
				5905	<h5>Arguments:</h5>
				5906	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5907	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]	5908	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5909	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5910	this integer type. While any bit width integer may be used, targets may only
				5911	lower representations they support in hardware.
				5912
				5913	</p>
				5914	<h5>Semantics:</h5>
				5915	<p>
				5916	This entire intrinsic must be executed atomically. It first loads the value
				5917	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5918	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5919	loaded value is yielded in all cases. This provides the equivalent of an
				5920	atomic compare-and-swap operation within the SSA framework.
				5921	</p>
				5922	<h5>Examples:</h5>
				5923
				5924	<pre>
				5925	%ptr = malloc i32
				5926	store i32 4, %ptr
				5927
				5928	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5929	%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]	5930	<i>; yields {i32}:result1 = 4</i>
				5931	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5932	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5933
				5934	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5935	%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]	5936	<i>; yields {i32}:result2 = 8</i>
				5937	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5938
				5939	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5940	</pre>
				5941	</div>
				5942
				5943	<!-- _______________________________________________________________________ -->
				5944	<div class="doc_subsubsection">
				5945	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5946	</div>
				5947	<div class="doc_text">
				5948	<h5>Syntax:</h5>
				5949
				5950	<p>
				5951	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5952	integer bit width. Not all targets support all bit widths however.</p>
				5953	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5954	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5955	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5956	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5957	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5958
				5959	</pre>
				5960	<h5>Overview:</h5>
				5961	<p>
				5962	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5963	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5964	at <tt>ptr</tt>.
				5965	</p>
				5966	<h5>Arguments:</h5>
				5967
				5968	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5969	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5970	<tt>val</tt> argument and the result must be integers of the same bit width.
				5971	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5972	integer type. The targets may only lower integer representations they
				5973	support.
				5974	</p>
				5975	<h5>Semantics:</h5>
				5976	<p>
				5977	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5978	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5979	equivalent of an atomic swap operation within the SSA framework.
				5980
				5981	</p>
				5982	<h5>Examples:</h5>
				5983	<pre>
				5984	%ptr = malloc i32
				5985	store i32 4, %ptr
				5986
				5987	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5988	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5989	<i>; yields {i32}:result1 = 4</i>
				5990	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5991	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5992
				5993	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5994	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5995	<i>; yields {i32}:result2 = 8</i>
				5996
				5997	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5998	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5999	</pre>
				6000	</div>
				6001
				6002	<!-- _______________________________________________________________________ -->
				6003	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6004	<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]	6005
				6006	</div>
				6007	<div class="doc_text">
				6008	<h5>Syntax:</h5>
				6009	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6010	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]	6011	integer bit width. Not all targets support all bit widths however.</p>
				6012	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6013	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6014	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6015	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6016	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6017
				6018	</pre>
				6019	<h5>Overview:</h5>
				6020	<p>
				6021	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6022	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6023	</p>
				6024	<h5>Arguments:</h5>
				6025	<p>
				6026
				6027	The intrinsic takes two arguments, the first a pointer to an integer value
				6028	and the second an integer value. The result is also an integer value. These
				6029	integer types can have any bit width, but they must all have the same bit
				6030	width. The targets may only lower integer representations they support.
				6031	</p>
				6032	<h5>Semantics:</h5>
				6033	<p>
				6034	This intrinsic does a series of operations atomically. It first loads the
				6035	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6036	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6037	</p>
				6038
				6039	<h5>Examples:</h5>
				6040	<pre>
				6041	%ptr = malloc i32
				6042	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6043	%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]	6044	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6045	%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]	6046	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6047	%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]	6048	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6049	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6050	</pre>
				6051	</div>
				6052
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6053	<!-- _______________________________________________________________________ -->
				6054	<div class="doc_subsubsection">
				6055	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6056
				6057	</div>
				6058	<div class="doc_text">
				6059	<h5>Syntax:</h5>
				6060	<p>
				6061	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]	6062	any integer bit width and for different address spaces. Not all targets
				6063	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6064	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6065	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6066	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6067	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6068	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]	6069
				6070	</pre>
				6071	<h5>Overview:</h5>
				6072	<p>
				6073	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6074	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6075	</p>
				6076	<h5>Arguments:</h5>
				6077	<p>
				6078
				6079	The intrinsic takes two arguments, the first a pointer to an integer value
				6080	and the second an integer value. The result is also an integer value. These
				6081	integer types can have any bit width, but they must all have the same bit
				6082	width. The targets may only lower integer representations they support.
				6083	</p>
				6084	<h5>Semantics:</h5>
				6085	<p>
				6086	This intrinsic does a series of operations atomically. It first loads the
				6087	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6088	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6089	</p>
				6090
				6091	<h5>Examples:</h5>
				6092	<pre>
				6093	%ptr = malloc i32
				6094	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6095	%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]	6096	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6097	%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]	6098	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6099	%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]	6100	<i>; yields {i32}:result3 = 2</i>
				6101	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6102	</pre>
				6103	</div>
				6104
				6105	<!-- _______________________________________________________________________ -->
				6106	<div class="doc_subsubsection">
				6107	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6108	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6109	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6110	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6111
				6112	</div>
				6113	<div class="doc_text">
				6114	<h5>Syntax:</h5>
				6115	<p>
				6116	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6117	<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]	6118	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6119	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6120	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6121	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6122	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6123	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6124	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]	6125
				6126	</pre>
				6127
				6128	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6129	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6130	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6131	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6132	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]	6133
				6134	</pre>
				6135
				6136	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6137	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6138	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6139	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6140	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]	6141
				6142	</pre>
				6143
				6144	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6145	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6146	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6147	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6148	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]	6149
				6150	</pre>
				6151	<h5>Overview:</h5>
				6152	<p>
				6153	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6154	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6155	at <tt>ptr</tt>.
				6156	</p>
				6157	<h5>Arguments:</h5>
				6158	<p>
				6159
				6160	These intrinsics take two arguments, the first a pointer to an integer value
				6161	and the second an integer value. The result is also an integer value. These
				6162	integer types can have any bit width, but they must all have the same bit
				6163	width. The targets may only lower integer representations they support.
				6164	</p>
				6165	<h5>Semantics:</h5>
				6166	<p>
				6167	These intrinsics does a series of operations atomically. They first load the
				6168	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6169	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6170	value stored at <tt>ptr</tt>.
				6171	</p>
				6172
				6173	<h5>Examples:</h5>
				6174	<pre>
				6175	%ptr = malloc i32
				6176	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6177	%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]	6178	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6179	%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]	6180	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6181	%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]	6182	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6183	%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]	6184	<i>; yields {i32}:result3 = FF</i>
				6185	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6186	</pre>
				6187	</div>
				6188
				6189
				6190	<!-- _______________________________________________________________________ -->
				6191	<div class="doc_subsubsection">
				6192	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6193	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6194	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6195	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6196
				6197	</div>
				6198	<div class="doc_text">
				6199	<h5>Syntax:</h5>
				6200	<p>
				6201	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6202	<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]	6203	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6204	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6205	support all bit widths however.</p>
				6206	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6207	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6208	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6209	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6210	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]	6211
				6212	</pre>
				6213
				6214	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6215	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6216	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6217	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6218	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]	6219
				6220	</pre>
				6221
				6222	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6223	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6224	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6225	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6226	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]	6227
				6228	</pre>
				6229
				6230	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6231	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6232	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6233	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6234	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]	6235
				6236	</pre>
				6237	<h5>Overview:</h5>
				6238	<p>
				6239	These intrinsics takes the signed or unsigned minimum or maximum of
				6240	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6241	original value at <tt>ptr</tt>.
				6242	</p>
				6243	<h5>Arguments:</h5>
				6244	<p>
				6245
				6246	These intrinsics take two arguments, the first a pointer to an integer value
				6247	and the second an integer value. The result is also an integer value. These
				6248	integer types can have any bit width, but they must all have the same bit
				6249	width. The targets may only lower integer representations they support.
				6250	</p>
				6251	<h5>Semantics:</h5>
				6252	<p>
				6253	These intrinsics does a series of operations atomically. They first load the
				6254	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6255	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6256	the original value stored at <tt>ptr</tt>.
				6257	</p>
				6258
				6259	<h5>Examples:</h5>
				6260	<pre>
				6261	%ptr = malloc i32
				6262	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6263	%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]	6264	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6265	%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]	6266	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6267	%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]	6268	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6269	%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]	6270	<i>; yields {i32}:result3 = 8</i>
				6271	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6272	</pre>
				6273	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6274
				6275	<!-- ======================================================================= -->
				6276	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6277	<a name="int_general">General Intrinsics</a>
				6278	</div>
				6279
				6280	<div class="doc_text">
				6281	<p> This class of intrinsics is designed to be generic and has
				6282	no specific purpose. </p>
				6283	</div>
				6284
				6285	<!-- _______________________________________________________________________ -->
				6286	<div class="doc_subsubsection">
				6287	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6288	</div>
				6289
				6290	<div class="doc_text">
				6291
				6292	<h5>Syntax:</h5>
				6293	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6294	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]	6295	</pre>
				6296
				6297	<h5>Overview:</h5>
				6298
				6299	<p>
				6300	The '<tt>llvm.var.annotation</tt>' intrinsic
				6301	</p>
				6302
				6303	<h5>Arguments:</h5>
				6304
				6305	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6306	The first argument is a pointer to a value, the second is a pointer to a
				6307	global string, the third is a pointer to a global string which is the source
				6308	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6309	</p>
				6310
				6311	<h5>Semantics:</h5>
				6312
				6313	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6314	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6315	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]	6316	annotations. These have no other defined use, they are ignored by code
				6317	generation and optimization.
				6318	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6319	</div>
				6320
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6321	<!-- _______________________________________________________________________ -->
				6322	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	6323	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6324	</div>
				6325
				6326	<div class="doc_text">
				6327
				6328	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6329	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6330	any integer bit width.
				6331	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6332	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	6333	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6334	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6335	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6336	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6337	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]	6338	</pre>
				6339
				6340	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6341
				6342	<p>
				6343	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6344	</p>
				6345
				6346	<h5>Arguments:</h5>
				6347
				6348	<p>
				6349	The first argument is an integer value (result of some expression),
				6350	the second is a pointer to a global string, the third is a pointer to a global
				6351	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]	6352	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6353	</p>
				6354
				6355	<h5>Semantics:</h5>
				6356
				6357	<p>
				6358	This intrinsic allows annotations to be put on arbitrary expressions
				6359	with arbitrary strings. This can be useful for special purpose optimizations
				6360	that want to look for these annotations. These have no other defined use, they
				6361	are ignored by code generation and optimization.
				6362	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6363
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6364	<!-- _______________________________________________________________________ -->
				6365	<div class="doc_subsubsection">
				6366	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6367	</div>
				6368
				6369	<div class="doc_text">
				6370
				6371	<h5>Syntax:</h5>
				6372	<pre>
				6373	declare void @llvm.trap()
				6374	</pre>
				6375
				6376	<h5>Overview:</h5>
				6377
				6378	<p>
				6379	The '<tt>llvm.trap</tt>' intrinsic
				6380	</p>
				6381
				6382	<h5>Arguments:</h5>
				6383
				6384	<p>
				6385	None
				6386	</p>
				6387
				6388	<h5>Semantics:</h5>
				6389
				6390	<p>
				6391	This intrinsics is lowered to the target dependent trap instruction. If the
				6392	target does not have a trap instruction, this intrinsic will be lowered to the
				6393	call of the abort() function.
				6394	</p>
				6395	</div>
				6396
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	6397	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	6398	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6399	<address>
				6400	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6401	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6402	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	6403	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]	6404
				6405	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	6406	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6407	Last modified: $Date$
				6408	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	6409
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	6410	</body>
				6411	</html>