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Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				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	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	44	<li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	45	</ol>
				46	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	47	<li><a href="#t_derived">Derived Types</a>
				48	<ol>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	49	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	50	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	51	<li><a href="#t_function">Function Type</a></li>
				52	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	53	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	54	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	55	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	56	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	57	</ol>
				58	</li>
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	59	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	60	</ol>
				61	</li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	62	<li><a href="#constants">Constants</a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	63	<ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	64	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	65	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	66	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				67	<li><a href="#undefvalues">Undefined Values</a></li>
				68	<li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	69	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	70	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	71	</li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	72	<li><a href="#othervalues">Other Values</a>
				73	<ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	74	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	75	</ol>
				76	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	77	<li><a href="#instref">Instruction Reference</a>
				78	<ol>
				79	<li><a href="#terminators">Terminator Instructions</a>
				80	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				82	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	83	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				84	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	85	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	86	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	87	</ol>
				88	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	89	<li><a href="#binaryops">Binary Operations</a>
				90	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	91	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				92	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				93	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	94	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				95	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				96	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	97	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				98	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				99	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	100	</ol>
				101	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	102	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				103	<ol>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	104	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				105	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				106	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	107	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	108	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	109	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	110	</ol>
				111	</li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	112	<li><a href="#vectorops">Vector Operations</a>
				113	<ol>
				114	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				115	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				116	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	117	</ol>
				118	</li>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	119	<li><a href="#aggregateops">Aggregate Operations</a>
				120	<ol>
				121	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				122	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				123	</ol>
				124	</li>
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	125	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	126	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	127	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				128	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				129	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	130	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				131	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				132	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	133	</ol>
				134	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	135	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	136	<ol>
				137	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	142	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				145	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	146	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				147	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	148	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	149	</ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	150	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	151	<li><a href="#otherops">Other Operations</a>
				152	<ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	153	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				154	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	155	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				156	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	157	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	158	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	159	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	160	<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]	161	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	162	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	163	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	164	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	165	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	166	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	167	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				168	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	169	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				170	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				171	<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]	172	</ol>
				173	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	174	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				175	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	176	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				177	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				178	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	179	</ol>
				180	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	181	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				182	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	183	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				184	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				185	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				186	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				187	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				188	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				189	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	190	</ol>
				191	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	192	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				193	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	194	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	199	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				200	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				201	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	202	</ol>
				203	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	204	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	205	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	206	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	207	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				208	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				209	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	210	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				211	<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]	212	</ol>
				213	</li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	214	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				215	<ol>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	216	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				217	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				219	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				220	<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	221	<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	222	</ol>
				223	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	224	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	225	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	226	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	227	<ol>
				228	<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]	229	</ol>
				230	</li>
Bill Wendling	f85850f	2008-11-18 22:10:53 +0000	[diff] [blame]	231	<li><a href="#int_atomics">Atomic intrinsics</a>
				232	<ol>
				233	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				234	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				235	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				236	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				237	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				238	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				239	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				240	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				241	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				242	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				243	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				244	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				245	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				246	</ol>
				247	</li>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	248	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	249	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	250	<li><a href="#int_var_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	251	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	252	<li><a href="#int_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	253	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	254	<li><a href="#int_trap">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	255	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				256	<li><a href="#int_stackprotector">
				257	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	258	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	259	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	260	</ol>
				261	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	262	</ol>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	263
				264	<div class="doc_author">
				265	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				266	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	267	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	268
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	269	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	270	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				271	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	272
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	273	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	274	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	275	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	276	type safety, low-level operations, flexibility, and the capability of
				277	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	278	representation used throughout all phases of the LLVM compilation
				279	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	280	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	281
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	282	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	283	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				284	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	285
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	286	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	287
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	288	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	289	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]	290	representation (suitable for fast loading by a Just-In-Time compiler),
				291	and as a human readable assembly language representation. This allows
				292	LLVM to provide a powerful intermediate representation for efficient
				293	compiler transformations and analysis, while providing a natural means
				294	to debug and visualize the transformations. The three different forms
				295	of LLVM are all equivalent. This document describes the human readable
				296	representation and notation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	297
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	298	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	299	while being expressive, typed, and extensible at the same time. It
				300	aims to be a "universal IR" of sorts, by being at a low enough level
				301	that high-level ideas may be cleanly mapped to it (similar to how
				302	microprocessors are "universal IR's", allowing many source languages to
				303	be mapped to them). By providing type information, LLVM can be used as
				304	the target of optimizations: for example, through pointer analysis, it
				305	can be proven that a C automatic variable is never accessed outside of
				306	the current function... allowing it to be promoted to a simple SSA
				307	value instead of a memory location.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	308
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	309	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	310
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	311	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	312	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	313
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	314	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	315
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	316	<p>It is important to note that this document describes 'well formed'
				317	LLVM assembly language. There is a difference between what the parser
				318	accepts and what is considered 'well formed'. For example, the
				319	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	320
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	321	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	322	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	323	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	324	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	325	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	326
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	327	<p>...because the definition of <tt>%x</tt> does not dominate all of
				328	its uses. The LLVM infrastructure provides a verification pass that may
				329	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]	330	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	331	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	332	by the verifier pass indicate bugs in transformation passes or input to
				333	the parser.</p>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	334	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	335
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	336	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	337
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	338	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	339	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	340	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	341
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	342	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	343
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	344	<p>LLVM identifiers come in two basic types: global and local. Global
				345	identifiers (functions, global variables) begin with the @ character. Local
				346	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	347	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	348
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	349	<ol>
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	350	<li>Named values are represented as a string of characters with their prefix.
				351	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				352	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]	353	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	0f8155a	2008-10-14 23:51:43 +0000	[diff] [blame]	354	with quotes. Special characters may be escaped using "\xx" where xx is the
				355	ASCII code for the character in hexadecimal. In this way, any character can
				356	be used in a name value, even quotes themselves.
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	357
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	358	<li>Unnamed values are represented as an unsigned numeric value with their
				359	prefix. For example, %12, @2, %44.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	360
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	361	<li>Constants, which are described in a <a href="#constants">section about
				362	constants</a>, below.</li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	363	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	364
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	365	<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]	366	don't need to worry about name clashes with reserved words, and the set of
				367	reserved words may be expanded in the future without penalty. Additionally,
				368	unnamed identifiers allow a compiler to quickly come up with a temporary
				369	variable without having to avoid symbol table conflicts.</p>
				370
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	371	<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]	372	languages. There are keywords for different opcodes
				373	('<tt><a href="#i_add">add</a></tt>',
				374	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				375	'<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]	376	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]	377	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	378	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	379
				380	<p>Here is an example of LLVM code to multiply the integer variable
				381	'<tt>%X</tt>' by 8:</p>
				382
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	383	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	384
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	385	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	386	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	387	%result = <a href="#i_mul">mul</a> i32 %X, 8
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
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	391	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	392
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	393	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	394	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	395	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	396	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	397	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	398
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	399	<p>And the hard way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	400
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	401	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	402	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	403	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				404	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				405	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	406	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	407	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	408
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	409	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				410	important lexical features of LLVM:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	411
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	412	<ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	413
				414	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				415	line.</li>
				416
				417	<li>Unnamed temporaries are created when the result of a computation is not
				418	assigned to a named value.</li>
				419
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	420	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	421
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	422	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	423
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	424	<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]	425	demonstrating instructions, we will follow an instruction with a comment that
				426	defines the type and name of value produced. Comments are shown in italic
				427	text.</p>
				428
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	429	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	430
				431	<!-- *********************************************************************** -->
				432	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				433	<!-- *********************************************************************** -->
				434
				435	<!-- ======================================================================= -->
				436	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				437	</div>
				438
				439	<div class="doc_text">
				440
				441	<p>LLVM programs are composed of "Module"s, each of which is a
				442	translation unit of the input programs. Each module consists of
				443	functions, global variables, and symbol table entries. Modules may be
				444	combined together with the LLVM linker, which merges function (and
				445	global variable) definitions, resolves forward declarations, and merges
				446	symbol table entries. Here is an example of the "hello world" module:</p>
				447
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	448	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	449	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	450	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				451	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]	452
				453	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	454	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	455
				456	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	457	define i32 @main() { <i>; i32()* </i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	458	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	459	%cast210 = <a
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	460	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]	461
				462	<i>; Call puts function to write out the string to stdout...</i>
				463	<a
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	464	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	465	<a
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	466	href="#i_ret">ret</a> i32 0<br>}<br>
				467	</pre>
				468	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	469
				470	<p>This example is made up of a <a href="#globalvars">global variable</a>
				471	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				472	function, and a <a href="#functionstructure">function definition</a>
				473	for "<tt>main</tt>".</p>
				474
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	475	<p>In general, a module is made up of a list of global values,
				476	where both functions and global variables are global values. Global values are
				477	represented by a pointer to a memory location (in this case, a pointer to an
				478	array of char, and a pointer to a function), and have one of the following <a
				479	href="#linkage">linkage types</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	480
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	481	</div>
				482
				483	<!-- ======================================================================= -->
				484	<div class="doc_subsection">
				485	<a name="linkage">Linkage Types</a>
				486	</div>
				487
				488	<div class="doc_text">
				489
				490	<p>
				491	All Global Variables and Functions have one of the following types of linkage:
				492	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	493
				494	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	495
Rafael Espindola	6de96a1	2009-01-15 20:18:42 +0000	[diff] [blame]	496	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				497
				498	<dd>Global values with private linkage are only directly accessible by
				499	objects in the current module. In particular, linking code into a module with
				500	an private global value may cause the private to be renamed as necessary to
				501	avoid collisions. Because the symbol is private to the module, all
				502	references can be updated. This doesn't show up in any symbol table in the
				503	object file.
				504	</dd>
				505
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	506	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	507
Duncan Sands	35e43c1	2009-01-16 09:29:46 +0000	[diff] [blame]	508	<dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola	6de96a1	2009-01-15 20:18:42 +0000	[diff] [blame]	509	the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	510	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	511	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	512
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	513	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				514	</dt>
				515
				516	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				517	into the object file corresponding to the LLVM module. They exist to
				518	allow inlining and other optimizations to take place given knowledge of the
				519	definition of the global, which is known to be somewhere outside the module.
				520	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				521	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				522	type is only allowed on definitions, not declarations.</dd>
				523
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	524	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	525
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	526	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				527	the same name when linkage occurs. This is typically used to implement
				528	inline functions, templates, or other code which must be generated in each
				529	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				530	allowed to be discarded.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	531	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	532
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	533	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				534
				535	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				536	linkage, except that unreferenced <tt>common</tt> globals may not be
				537	discarded. This is used for globals that may be emitted in multiple
				538	translation units, but that are not guaranteed to be emitted into every
				539	translation unit that uses them. One example of this is tentative
				540	definitions in C, such as "<tt>int X;</tt>" at global scope.
				541	</dd>
				542
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	543	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	544
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	545	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				546	that some targets may choose to emit different assembly sequences for them
				547	for target-dependent reasons. This is used for globals that are declared
				548	"weak" in C source code.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	549	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	550
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	551	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	552
				553	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				554	pointer to array type. When two global variables with appending linkage are
				555	linked together, the two global arrays are appended together. This is the
				556	LLVM, typesafe, equivalent of having the system linker append together
				557	"sections" with identical names when .o files are linked.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	558	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	559
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	560	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	561
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	562	<dd>The semantics of this linkage follow the ELF object file model: the
				563	symbol is weak until linked, if not linked, the symbol becomes null instead
				564	of being an undefined reference.
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	565	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	566
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	567	<dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	568	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	569	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	570	functions with different semantics. Other languages, such as <tt>C++</tt>,
				571	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	572	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4581beb	2009-03-11 20:14:15 +0000	[diff] [blame]	573	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				574	be merged with equivalent globals. These linkage types are otherwise the
				575	same as their non-<tt>odr</tt> versions.
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	576	</dd>
				577
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	578	<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]	579
				580	<dd>If none of the above identifiers are used, the global is externally
				581	visible, meaning that it participates in linkage and can be used to resolve
				582	external symbol references.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	583	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	584	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	585
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	586	<p>
				587	The next two types of linkage are targeted for Microsoft Windows platform
				588	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	589	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	590	</p>
				591
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	592	<dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	593	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				594
				595	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				596	or variable via a global pointer to a pointer that is set up by the DLL
				597	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	598	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	599	</dd>
				600
				601	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				602
				603	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				604	pointer to a pointer in a DLL, so that it can be referenced with the
				605	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	606	name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	607	name.
				608	</dd>
				609
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	610	</dl>
				611
Dan Gohman	8ef4498	2008-11-24 17:18:39 +0000	[diff] [blame]	612	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	613	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				614	variable and was linked with this one, one of the two would be renamed,
				615	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				616	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	92c671e	2007-01-05 00:59:10 +0000	[diff] [blame]	617	outside of the current module.</p>
				618	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	e288105	2009-03-11 08:08:06 +0000	[diff] [blame]	619	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				620	or <tt>extern_weak</tt>.</p>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	621	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				622	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	623	</div>
				624
				625	<!-- ======================================================================= -->
				626	<div class="doc_subsection">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	627	<a name="callingconv">Calling Conventions</a>
				628	</div>
				629
				630	<div class="doc_text">
				631
				632	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				633	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				634	specified for the call. The calling convention of any pair of dynamic
				635	caller/callee must match, or the behavior of the program is undefined. The
				636	following calling conventions are supported by LLVM, and more may be added in
				637	the future:</p>
				638
				639	<dl>
				640	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				641
				642	<dd>This calling convention (the default if no other calling convention is
				643	specified) matches the target C calling conventions. This calling convention
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	644	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	645	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	646	</dd>
				647
				648	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				649
				650	<dd>This calling convention attempts to make calls as fast as possible
				651	(e.g. by passing things in registers). This calling convention allows the
				652	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]	653	without having to conform to an externally specified ABI (Application Binary
				654	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	2c6b888	2008-05-14 09:17:12 +0000	[diff] [blame]	655	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				656	supported. This calling convention does not support varargs and requires the
				657	prototype of all callees to exactly match the prototype of the function
				658	definition.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	659	</dd>
				660
				661	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				662
				663	<dd>This calling convention attempts to make code in the caller as efficient
				664	as possible under the assumption that the call is not commonly executed. As
				665	such, these calls often preserve all registers so that the call does not break
				666	any live ranges in the caller side. This calling convention does not support
				667	varargs and requires the prototype of all callees to exactly match the
				668	prototype of the function definition.
				669	</dd>
				670
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	671	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	672
				673	<dd>Any calling convention may be specified by number, allowing
				674	target-specific calling conventions to be used. Target specific calling
				675	conventions start at 64.
				676	</dd>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	677	</dl>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	678
				679	<p>More calling conventions can be added/defined on an as-needed basis, to
				680	support pascal conventions or any other well-known target-independent
				681	convention.</p>
				682
				683	</div>
				684
				685	<!-- ======================================================================= -->
				686	<div class="doc_subsection">
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	687	<a name="visibility">Visibility Styles</a>
				688	</div>
				689
				690	<div class="doc_text">
				691
				692	<p>
				693	All Global Variables and Functions have one of the following visibility styles:
				694	</p>
				695
				696	<dl>
				697	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				698
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	699	<dd>On targets that use the ELF object file format, default visibility means
				700	that the declaration is visible to other
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	701	modules and, in shared libraries, means that the declared entity may be
				702	overridden. On Darwin, default visibility means that the declaration is
				703	visible to other modules. Default visibility corresponds to "external
				704	linkage" in the language.
				705	</dd>
				706
				707	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				708
				709	<dd>Two declarations of an object with hidden visibility refer to the same
				710	object if they are in the same shared object. Usually, hidden visibility
				711	indicates that the symbol will not be placed into the dynamic symbol table,
				712	so no other module (executable or shared library) can reference it
				713	directly.
				714	</dd>
				715
Anton Korobeynikov	39f3cff	2007-04-29 18:35:00 +0000	[diff] [blame]	716	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				717
				718	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				719	the dynamic symbol table, but that references within the defining module will
				720	bind to the local symbol. That is, the symbol cannot be overridden by another
				721	module.
				722	</dd>
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	723	</dl>
				724
				725	</div>
				726
				727	<!-- ======================================================================= -->
				728	<div class="doc_subsection">
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	729	<a name="namedtypes">Named Types</a>
				730	</div>
				731
				732	<div class="doc_text">
				733
				734	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				735	it easier to read the IR and make the IR more condensed (particularly when
				736	recursive types are involved). An example of a name specification is:
				737	</p>
				738
				739	<div class="doc_code">
				740	<pre>
				741	%mytype = type { %mytype*, i32 }
				742	</pre>
				743	</div>
				744
				745	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				746	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				747	expected with the syntax "%mytype".</p>
				748
				749	<p>Note that type names are aliases for the structural type that they indicate,
				750	and that you can therefore specify multiple names for the same type. This often
				751	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				752	structural typing, the name is not part of the type. When printing out LLVM IR,
				753	the printer will pick <em>one name</em> to render all types of a particular
				754	shape. This means that if you have code where two different source types end up
				755	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				756	unexpected type. This is an important design point and isn't going to
				757	change.</p>
				758
				759	</div>
				760
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	761	<!-- ======================================================================= -->
				762	<div class="doc_subsection">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	763	<a name="globalvars">Global Variables</a>
				764	</div>
				765
				766	<div class="doc_text">
				767
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	768	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	769	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	770	an explicit section to be placed in, and may have an optional explicit alignment
				771	specified. A variable may be defined as "thread_local", which means that it
				772	will not be shared by threads (each thread will have a separated copy of the
				773	variable). A variable may be defined as a global "constant," which indicates
				774	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]	775	optimization, allowing the global data to be placed in the read-only section of
				776	an executable, etc). Note that variables that need runtime initialization
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	777	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]	778
				779	<p>
				780	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				781	constant, even if the final definition of the global is not. This capability
				782	can be used to enable slightly better optimization of the program, but requires
				783	the language definition to guarantee that optimizations based on the
				784	'constantness' are valid for the translation units that do not include the
				785	definition.
				786	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	787
				788	<p>As SSA values, global variables define pointer values that are in
				789	scope (i.e. they dominate) all basic blocks in the program. Global
				790	variables always define a pointer to their "content" type because they
				791	describe a region of memory, and all memory objects in LLVM are
				792	accessed through pointers.</p>
				793
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	794	<p>A global variable may be declared to reside in a target-specifc numbered
				795	address space. For targets that support them, address spaces may affect how
				796	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	25f5076	2007-12-12 08:44:39 +0000	[diff] [blame]	797	the variable. The default address space is zero. The address space qualifier
				798	must precede any other attributes.</p>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	799
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	800	<p>LLVM allows an explicit section to be specified for globals. If the target
				801	supports it, it will emit globals to the section specified.</p>
				802
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	803	<p>An explicit alignment may be specified for a global. If not present, or if
				804	the alignment is set to zero, the alignment of the global is set by the target
				805	to whatever it feels convenient. If an explicit alignment is specified, the
				806	global is forced to have at least that much alignment. All alignments must be
				807	a power of 2.</p>
				808
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	809	<p>For example, the following defines a global in a numbered address space with
				810	an initializer, section, and alignment:</p>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	811
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	812	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	813	<pre>
Dan Gohman	aaa679b	2009-01-11 00:40:00 +0000	[diff] [blame]	814	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	815	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	816	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	817
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	818	</div>
				819
				820
				821	<!-- ======================================================================= -->
				822	<div class="doc_subsection">
				823	<a name="functionstructure">Functions</a>
				824	</div>
				825
				826	<div class="doc_text">
				827
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	828	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				829	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	830	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	831	<a href="#callingconv">calling convention</a>, a return type, an optional
				832	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				833	name, a (possibly empty) argument list (each with optional
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	834	<a href="#paramattrs">parameter attributes</a>), optional
				835	<a href="#fnattrs">function attributes</a>, an optional section,
				836	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	837	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]	838
				839	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				840	optional <a href="#linkage">linkage type</a>, an optional
				841	<a href="#visibility">visibility style</a>, an optional
				842	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	843	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	844	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]	845	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	846
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	847	<p>A function definition contains a list of basic blocks, forming the CFG
				848	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	849	the function. Each basic block may optionally start with a label (giving the
				850	basic block a symbol table entry), contains a list of instructions, and ends
				851	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				852	function return).</p>
				853
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	854	<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]	855	executed on entrance to the function, and it is not allowed to have predecessor
				856	basic blocks (i.e. there can not be any branches to the entry block of a
				857	function). Because the block can have no predecessors, it also cannot have any
				858	<a href="#i_phi">PHI nodes</a>.</p>
				859
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	860	<p>LLVM allows an explicit section to be specified for functions. If the target
				861	supports it, it will emit functions to the section specified.</p>
				862
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	863	<p>An explicit alignment may be specified for a function. If not present, or if
				864	the alignment is set to zero, the alignment of the function is set by the target
				865	to whatever it feels convenient. If an explicit alignment is specified, the
				866	function is forced to have at least that much alignment. All alignments must be
				867	a power of 2.</p>
				868
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	869	<h5>Syntax:</h5>
				870
				871	<div class="doc_code">
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	872	<tt>
				873	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				874	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				875	<ResultType> @<FunctionName> ([argument list])
				876	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				877	[<a href="#gc">gc</a>] { ... }
				878	</tt>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	879	</div>
				880
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	881	</div>
				882
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	883
				884	<!-- ======================================================================= -->
				885	<div class="doc_subsection">
				886	<a name="aliasstructure">Aliases</a>
				887	</div>
				888	<div class="doc_text">
				889	<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]	890	function, global variable, another alias or bitcast of global value). Aliases
				891	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	892	optional <a href="#visibility">visibility style</a>.</p>
				893
				894	<h5>Syntax:</h5>
				895
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	896	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	897	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	898	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	899	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	900	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	901
				902	</div>
				903
				904
				905
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	906	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	907	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				908	<div class="doc_text">
				909	<p>The return type and each parameter of a function type may have a set of
				910	<i>parameter attributes</i> associated with them. Parameter attributes are
				911	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	912	a function. Parameter attributes are considered to be part of the function,
				913	not of the function type, so functions with different parameter attributes
				914	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	915
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	916	<p>Parameter attributes are simple keywords that follow the type specified. If
				917	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	918	example:</p>
				919
				920	<div class="doc_code">
				921	<pre>
Nick Lewycky	dac78d8	2009-02-15 23:06:14 +0000	[diff] [blame]	922	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	923	declare i32 @atoi(i8 zeroext)
				924	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	925	</pre>
				926	</div>
				927
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	928	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				929	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	930
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	931	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	932	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	933	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	934	<dd>This indicates to the code generator that the parameter or return value
				935	should be zero-extended to a 32-bit value by the caller (for a parameter)
				936	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	937
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	938	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	939	<dd>This indicates to the code generator that the parameter or return value
				940	should be sign-extended to a 32-bit value by the caller (for a parameter)
				941	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	942
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	943	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	944	<dd>This indicates that this parameter or return value should be treated
				945	in a special target-dependent fashion during while emitting code for a
				946	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]	947	to memory, though some targets use it to distinguish between two different
				948	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	949
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	950	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	951	<dd>This indicates that the pointer parameter should really be passed by
				952	value to the function. The attribute implies that a hidden copy of the
				953	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]	954	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]	955	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	956	value, but is also valid on pointers to scalars. The copy is considered to
				957	belong to the caller not the callee (for example,
				958	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	959	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	08aa906	2009-02-05 05:42:28 +0000	[diff] [blame]	960	values. The byval attribute also supports specifying an alignment with the
				961	align attribute. This has a target-specific effect on the code generator
				962	that usually indicates a desired alignment for the synthesized stack
				963	slot.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	964
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	965	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	966	<dd>This indicates that the pointer parameter specifies the address of a
				967	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]	968	This pointer must be guaranteed by the caller to be valid: loads and stores
				969	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]	970	be applied to the first parameter. This is not a valid attribute for
				971	return values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	972
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	973	<dt><tt>noalias</tt></dt>
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	974	<dd>This indicates that the pointer does not alias any global or any other
				975	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	d59572c	2008-11-24 05:00:44 +0000	[diff] [blame]	976	case. On a function return value, <tt>noalias</tt> additionally indicates
				977	that the pointer does not alias any other pointers visible to the
Nick Lewycky	2abb108	2008-12-19 06:39:12 +0000	[diff] [blame]	978	caller. For further details, please see the discussion of the NoAlias
				979	response in
				980	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				981	analysis</a>.</dd>
				982
				983	<dt><tt>nocapture</tt></dt>
				984	<dd>This indicates that the callee does not make any copies of the pointer
				985	that outlive the callee itself. This is not a valid attribute for return
				986	values.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	987
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	988	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	989	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	990	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				991	attribute for return values.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	992	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	993
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	994	</div>
				995
				996	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	997	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	998	<a name="gc">Garbage Collector Names</a>
				999	</div>
				1000
				1001	<div class="doc_text">
				1002	<p>Each function may specify a garbage collector name, which is simply a
				1003	string.</p>
				1004
				1005	<div class="doc_code"><pre
				1006	>define void @f() gc "name" { ...</pre></div>
				1007
				1008	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1009	collector which will cause the compiler to alter its output in order to support
				1010	the named garbage collection algorithm.</p>
				1011	</div>
				1012
				1013	<!-- ======================================================================= -->
				1014	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1015	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1016	</div>
				1017
				1018	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1019
				1020	<p>Function attributes are set to communicate additional information about
				1021	a function. Function attributes are considered to be part of the function,
				1022	not of the function type, so functions with different parameter attributes
				1023	can have the same function type.</p>
				1024
				1025	<p>Function attributes are simple keywords that follow the type specified. If
				1026	multiple attributes are needed, they are space separated. For
				1027	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1028
				1029	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1030	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1031	define void @f() noinline { ... }
				1032	define void @f() alwaysinline { ... }
				1033	define void @f() alwaysinline optsize { ... }
				1034	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1035	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1036	</div>
				1037
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1038	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1039	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1040	<dd>This attribute indicates that the inliner should attempt to inline this
				1041	function into callers whenever possible, ignoring any active inlining size
				1042	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1043
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1044	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1045	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame]	1046	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1047	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1048
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1049	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	1050	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1051	make choices that keep the code size of this function low, and otherwise do
				1052	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1053
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1054	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1055	<dd>This function attribute indicates that the function never returns normally.
				1056	This produces undefined behavior at runtime if the function ever does
				1057	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1058
				1059	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1060	<dd>This function attribute indicates that the function never returns with an
				1061	unwind or exceptional control flow. If the function does unwind, its runtime
				1062	behavior is undefined.</dd>
				1063
				1064	<dt><tt>readnone</tt></dt>
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1065	<dd>This attribute indicates that the function computes its result (or decides to
				1066	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1067	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1068	registers, etc) visible to caller functions. It does not write through any
				1069	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1070	never changes any state visible to callers. This means that it cannot unwind
				1071	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1072	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1073
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1074	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1075	<dd>This attribute indicates that the function does not write through any
				1076	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1077	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1078	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1079	be set in the caller. A readonly function always returns the same value (or
				1080	unwinds an exception identically) when called with the same set of arguments
				1081	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1082	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1083
				1084	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1085	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1086	protector. It is in the form of a "canary"—a random value placed on the
				1087	stack before the local variables that's checked upon return from the function to
				1088	see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1089	needs stack protectors or not.
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1090
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1091	<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
				1092	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
				1093	have an <tt>ssp</tt> attribute.</p></dd>
				1094
				1095	<dt><tt>sspreq</tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1096	<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1097	stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1098	function attribute.
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1099
				1100	<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
				1101	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1102	an <tt>ssp</tt> attribute, then the resulting function will have
				1103	an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1104	</dl>
				1105
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1106	</div>
				1107
				1108	<!-- ======================================================================= -->
				1109	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	1110	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1111	</div>
				1112
				1113	<div class="doc_text">
				1114	<p>
				1115	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1116	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1117	LLVM and treated as a single unit, but may be separated in the .ll file if
				1118	desired. The syntax is very simple:
				1119	</p>
				1120
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1121	<div class="doc_code">
				1122	<pre>
				1123	module asm "inline asm code goes here"
				1124	module asm "more can go here"
				1125	</pre>
				1126	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1127
				1128	<p>The strings can contain any character by escaping non-printable characters.
				1129	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1130	for the number.
				1131	</p>
				1132
				1133	<p>
				1134	The inline asm code is simply printed to the machine code .s file when
				1135	assembly code is generated.
				1136	</p>
				1137	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1138
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1139	<!-- ======================================================================= -->
				1140	<div class="doc_subsection">
				1141	<a name="datalayout">Data Layout</a>
				1142	</div>
				1143
				1144	<div class="doc_text">
				1145	<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]	1146	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1147	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1148	<p>The <i>layout specification</i> consists of a list of specifications
				1149	separated by the minus sign character ('-'). Each specification starts with a
				1150	letter and may include other information after the letter to define some
				1151	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1152	<dl>
				1153	<dt><tt>E</tt></dt>
				1154	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1155	bits with the most significance have the lowest address location.</dd>
				1156	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1157	<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]	1158	the bits with the least significance have the lowest address location.</dd>
				1159	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1160	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1161	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1162	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1163	too.</dd>
				1164	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1165	<dd>This specifies the alignment for an integer type of a given bit
				1166	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1167	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1168	<dd>This specifies the alignment for a vector type of a given bit
				1169	<i>size</i>.</dd>
				1170	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1171	<dd>This specifies the alignment for a floating point type of a given bit
				1172	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1173	(double).</dd>
				1174	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1175	<dd>This specifies the alignment for an aggregate type of a given bit
				1176	<i>size</i>.</dd>
				1177	</dl>
				1178	<p>When constructing the data layout for a given target, LLVM starts with a
				1179	default set of specifications which are then (possibly) overriden by the
				1180	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1181	are given in this list:</p>
				1182	<ul>
				1183	<li><tt>E</tt> - big endian</li>
				1184	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1185	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1186	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1187	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1188	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1189	<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]	1190	alignment of 64-bits</li>
				1191	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1192	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1193	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1194	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1195	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1196	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1197	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1198	following rules:</p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1199	<ol>
				1200	<li>If the type sought is an exact match for one of the specifications, that
				1201	specification is used.</li>
				1202	<li>If no match is found, and the type sought is an integer type, then the
				1203	smallest integer type that is larger than the bitwidth of the sought type is
				1204	used. If none of the specifications are larger than the bitwidth then the the
				1205	largest integer type is used. For example, given the default specifications
				1206	above, the i7 type will use the alignment of i8 (next largest) while both
				1207	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1208	<li>If no match is found, and the type sought is a vector type, then the
				1209	largest vector type that is smaller than the sought vector type will be used
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1210	as a fall back. This happens because <128 x double> can be implemented
				1211	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1212	</ol>
				1213	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1214
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1215	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1216	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1217	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1218
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1219	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1220
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1221	<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]	1222	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1223	optimizations to be performed on the intermediate representation directly,
				1224	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1225	extra analyses on the side before the transformation. A strong type
				1226	system makes it easier to read the generated code and enables novel
				1227	analyses and transformations that are not feasible to perform on normal
				1228	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1229
				1230	</div>
				1231
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1232	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1233	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1234	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1235	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1236	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1237	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1238
				1239	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1240	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1241	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1242	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1243	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1244	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1245	</tr>
				1246	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1247	<td><a href="#t_floating">floating point</a></td>
				1248	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1249	</tr>
				1250	<tr>
				1251	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1252	<td><a href="#t_integer">integer</a>,
				1253	<a href="#t_floating">floating point</a>,
				1254	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1255	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1256	<a href="#t_struct">structure</a>,
				1257	<a href="#t_array">array</a>,
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1258	<a href="#t_label">label</a>,
				1259	<a href="#t_metadata">metadata</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1260	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1261	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1262	<tr>
				1263	<td><a href="#t_primitive">primitive</a></td>
				1264	<td><a href="#t_label">label</a>,
				1265	<a href="#t_void">void</a>,
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1266	<a href="#t_floating">floating point</a>,
				1267	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1268	</tr>
				1269	<tr>
				1270	<td><a href="#t_derived">derived</a></td>
				1271	<td><a href="#t_integer">integer</a>,
				1272	<a href="#t_array">array</a>,
				1273	<a href="#t_function">function</a>,
				1274	<a href="#t_pointer">pointer</a>,
				1275	<a href="#t_struct">structure</a>,
				1276	<a href="#t_pstruct">packed structure</a>,
				1277	<a href="#t_vector">vector</a>,
				1278	<a href="#t_opaque">opaque</a>.
Dan Gohman	93bf60d	2008-10-14 16:32:04 +0000	[diff] [blame]	1279	</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1280	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1281	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1282	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1283
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1284	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1285	most important. Values of these types are the only ones which can be
				1286	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1287	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1288	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1289
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1290	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1291	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1292
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1293	<div class="doc_text">
				1294	<p>The primitive types are the fundamental building blocks of the LLVM
				1295	system.</p>
				1296
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1297	</div>
				1298
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1299	<!-- _______________________________________________________________________ -->
				1300	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1301
				1302	<div class="doc_text">
				1303	<table>
				1304	<tbody>
				1305	<tr><th>Type</th><th>Description</th></tr>
				1306	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1307	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1308	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1309	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1310	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1311	</tbody>
				1312	</table>
				1313	</div>
				1314
				1315	<!-- _______________________________________________________________________ -->
				1316	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1317
				1318	<div class="doc_text">
				1319	<h5>Overview:</h5>
				1320	<p>The void type does not represent any value and has no size.</p>
				1321
				1322	<h5>Syntax:</h5>
				1323
				1324	<pre>
				1325	void
				1326	</pre>
				1327	</div>
				1328
				1329	<!-- _______________________________________________________________________ -->
				1330	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1331
				1332	<div class="doc_text">
				1333	<h5>Overview:</h5>
				1334	<p>The label type represents code labels.</p>
				1335
				1336	<h5>Syntax:</h5>
				1337
				1338	<pre>
				1339	label
				1340	</pre>
				1341	</div>
				1342
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1343	<!-- _______________________________________________________________________ -->
				1344	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1345
				1346	<div class="doc_text">
				1347	<h5>Overview:</h5>
				1348	<p>The metadata type represents embedded metadata. The only derived type that
				1349	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1350	takes metadata typed parameters, but not pointer to metadata types.</p>
				1351
				1352	<h5>Syntax:</h5>
				1353
				1354	<pre>
				1355	metadata
				1356	</pre>
				1357	</div>
				1358
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1359
				1360	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1361	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1362
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1363	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1364
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1365	<p>The real power in LLVM comes from the derived types in the system.
				1366	This is what allows a programmer to represent arrays, functions,
				1367	pointers, and other useful types. Note that these derived types may be
				1368	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]	1369
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1370	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1371
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1372	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1373	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1374
				1375	<div class="doc_text">
				1376
				1377	<h5>Overview:</h5>
				1378	<p>The integer type is a very simple derived type that simply specifies an
				1379	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1380	2^23-1 (about 8 million) can be specified.</p>
				1381
				1382	<h5>Syntax:</h5>
				1383
				1384	<pre>
				1385	iN
				1386	</pre>
				1387
				1388	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1389	value.</p>
				1390
				1391	<h5>Examples:</h5>
				1392	<table class="layout">
Nick Lewycky	aab930a	2009-05-24 02:46:06 +0000	[diff] [blame]	1393	<tr class="layout">
				1394	<td class="left"><tt>i1</tt></td>
				1395	<td class="left">a single-bit integer.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1396	</tr>
Nick Lewycky	aab930a	2009-05-24 02:46:06 +0000	[diff] [blame]	1397	<tr class="layout">
				1398	<td class="left"><tt>i32</tt></td>
				1399	<td class="left">a 32-bit integer.</td>
				1400	</tr>
				1401	<tr class="layout">
				1402	<td class="left"><tt>i1942652</tt></td>
				1403	<td class="left">a really big integer of over 1 million bits.</td>
				1404	</tr>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1405	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1406
				1407	<p>Note that the code generator does not yet support large integer types
				1408	to be used as function return types. The specific limit on how large a
				1409	return type the code generator can currently handle is target-dependent;
				1410	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1411	targets.</p>
				1412
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1413	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1414
				1415	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1416	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1417
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1418	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1419
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1420	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1421
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1422	<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]	1423	sequentially in memory. The array type requires a size (number of
				1424	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1425
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1426	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1427
				1428	<pre>
				1429	[<# elements> x <elementtype>]
				1430	</pre>
				1431
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1432	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1433	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1434
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1435	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1436	<table class="layout">
				1437	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1438	<td class="left"><tt>[40 x i32]</tt></td>
				1439	<td class="left">Array of 40 32-bit integer values.</td>
				1440	</tr>
				1441	<tr class="layout">
				1442	<td class="left"><tt>[41 x i32]</tt></td>
				1443	<td class="left">Array of 41 32-bit integer values.</td>
				1444	</tr>
				1445	<tr class="layout">
				1446	<td class="left"><tt>[4 x i8]</tt></td>
				1447	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1448	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1449	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1450	<p>Here are some examples of multidimensional arrays:</p>
				1451	<table class="layout">
				1452	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1453	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1454	<td class="left">3x4 array of 32-bit integer values.</td>
				1455	</tr>
				1456	<tr class="layout">
				1457	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1458	<td class="left">12x10 array of single precision floating point values.</td>
				1459	</tr>
				1460	<tr class="layout">
				1461	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1462	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1463	</tr>
				1464	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1465
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1466	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1467	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]	1468	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1469	As a special case, however, zero length arrays are recognized to be variable
				1470	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1471	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1472
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1473	<p>Note that the code generator does not yet support large aggregate types
				1474	to be used as function return types. The specific limit on how large an
				1475	aggregate return type the code generator can currently handle is
				1476	target-dependent, and also dependent on the aggregate element types.</p>
				1477
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1478	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1479
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1480	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1481	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1482	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1483
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1484	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1485
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1486	<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]	1487	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]	1488	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]	1489	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]	1490	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1491
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1492	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1493
				1494	<pre>
				1495	<returntype list> (<parameter list>)
				1496	</pre>
				1497
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1498	<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]	1499	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1500	which indicates that the function takes a variable number of arguments.
				1501	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1502	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1503	'<tt><returntype list></tt>' is a comma-separated list of
				1504	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1505
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1506	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1507	<table class="layout">
				1508	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1509	<td class="left"><tt>i32 (i32)</tt></td>
				1510	<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]	1511	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1512	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1513	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1514	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1515	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1516	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1517	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1518	<tt>float</tt>.
				1519	</td>
				1520	</tr><tr class="layout">
				1521	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1522	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1523	<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]	1524	which returns an integer. This is the signature for <tt>printf</tt> in
				1525	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1526	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1527	</tr><tr class="layout">
				1528	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	c9813bd	2008-11-27 06:41:20 +0000	[diff] [blame]	1529	<td class="left">A function taking an <tt>i32</tt>, returning two
				1530	<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]	1531	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1532	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1533	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1534
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1535	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1536	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1537	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1538	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1539	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1540	<p>The structure type is used to represent a collection of data members
				1541	together in memory. The packing of the field types is defined to match
				1542	the ABI of the underlying processor. The elements of a structure may
				1543	be any type that has a size.</p>
				1544	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1545	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1546	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1547	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1548	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1549	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1550	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1551	<table class="layout">
				1552	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1553	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1554	<td class="left">A triple of three <tt>i32</tt> values</td>
				1555	</tr><tr class="layout">
				1556	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1557	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1558	second element is a <a href="#t_pointer">pointer</a> to a
				1559	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1560	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1561	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1562	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1563
				1564	<p>Note that the code generator does not yet support large aggregate types
				1565	to be used as function return types. The specific limit on how large an
				1566	aggregate return type the code generator can currently handle is
				1567	target-dependent, and also dependent on the aggregate element types.</p>
				1568
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1569	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1570
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1571	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1572	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1573	</div>
				1574	<div class="doc_text">
				1575	<h5>Overview:</h5>
				1576	<p>The packed structure type is used to represent a collection of data members
				1577	together in memory. There is no padding between fields. Further, the alignment
				1578	of a packed structure is 1 byte. The elements of a packed structure may
				1579	be any type that has a size.</p>
				1580	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1581	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1582	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1583	instruction.</p>
				1584	<h5>Syntax:</h5>
				1585	<pre> < { <type list> } > <br></pre>
				1586	<h5>Examples:</h5>
				1587	<table class="layout">
				1588	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1589	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1590	<td class="left">A triple of three <tt>i32</tt> values</td>
				1591	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1592	<td class="left">
				1593	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1594	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1595	second element is a <a href="#t_pointer">pointer</a> to a
				1596	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1597	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1598	</tr>
				1599	</table>
				1600	</div>
				1601
				1602	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1603	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1604	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1605	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1606	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1607	reference to another object, which must live in memory. Pointer types may have
				1608	an optional address space attribute defining the target-specific numbered
				1609	address space where the pointed-to object resides. The default address space is
				1610	zero.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1611
				1612	<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattner	d1d4cff	2009-02-08 22:21:28 +0000	[diff] [blame]	1613	it permit pointers to labels (<tt>label</tt>). Use <tt>i8</tt> instead.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1614
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1615	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1616	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1617	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1618	<table class="layout">
				1619	<tr class="layout">
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	1620	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1621	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1622	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1623	</tr>
				1624	<tr class="layout">
				1625	<td class="left"><tt>i32 (i32 ) </tt></td>
				1626	<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]	1627	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]	1628	<tt>i32</tt>.</td>
				1629	</tr>
				1630	<tr class="layout">
				1631	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1632	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1633	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1634	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1635	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1636	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1637
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1638	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1639	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1640	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1641
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1642	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1643
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1644	<p>A vector type is a simple derived type that represents a vector
				1645	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1646	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1647	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1648	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1649	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1650	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1651
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1652	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1653
				1654	<pre>
				1655	< <# elements> x <elementtype> >
				1656	</pre>
				1657
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1658	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1659	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1660
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1661	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1662
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1663	<table class="layout">
				1664	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1665	<td class="left"><tt><4 x i32></tt></td>
				1666	<td class="left">Vector of 4 32-bit integer values.</td>
				1667	</tr>
				1668	<tr class="layout">
				1669	<td class="left"><tt><8 x float></tt></td>
				1670	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1671	</tr>
				1672	<tr class="layout">
				1673	<td class="left"><tt><2 x i64></tt></td>
				1674	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1675	</tr>
				1676	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1677
				1678	<p>Note that the code generator does not yet support large vector types
				1679	to be used as function return types. The specific limit on how large a
				1680	vector return type codegen can currently handle is target-dependent;
				1681	currently it's often a few times longer than a hardware vector register.</p>
				1682
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1683	</div>
				1684
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1685	<!-- _______________________________________________________________________ -->
				1686	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1687	<div class="doc_text">
				1688
				1689	<h5>Overview:</h5>
				1690
				1691	<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]	1692	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]	1693	In LLVM, opaque types can eventually be resolved to any type (not just a
				1694	structure type).</p>
				1695
				1696	<h5>Syntax:</h5>
				1697
				1698	<pre>
				1699	opaque
				1700	</pre>
				1701
				1702	<h5>Examples:</h5>
				1703
				1704	<table class="layout">
				1705	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1706	<td class="left"><tt>opaque</tt></td>
				1707	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1708	</tr>
				1709	</table>
				1710	</div>
				1711
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1712	<!-- ======================================================================= -->
				1713	<div class="doc_subsection">
				1714	<a name="t_uprefs">Type Up-references</a>
				1715	</div>
				1716
				1717	<div class="doc_text">
				1718	<h5>Overview:</h5>
				1719	<p>
				1720	An "up reference" allows you to refer to a lexically enclosing type without
				1721	requiring it to have a name. For instance, a structure declaration may contain a
				1722	pointer to any of the types it is lexically a member of. Example of up
				1723	references (with their equivalent as named type declarations) include:</p>
				1724
				1725	<pre>
Chris Lattner	bf1d545	2009-02-09 10:00:56 +0000	[diff] [blame]	1726	{ \2 * } %x = type { %x* }
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1727	{ \2 }* %y = type { %y }*
				1728	\1* %z = type %z*
				1729	</pre>
				1730
				1731	<p>
				1732	An up reference is needed by the asmprinter for printing out cyclic types when
				1733	there is no declared name for a type in the cycle. Because the asmprinter does
				1734	not want to print out an infinite type string, it needs a syntax to handle
				1735	recursive types that have no names (all names are optional in llvm IR).
				1736	</p>
				1737
				1738	<h5>Syntax:</h5>
				1739	<pre>
				1740	\<level>
				1741	</pre>
				1742
				1743	<p>
				1744	The level is the count of the lexical type that is being referred to.
				1745	</p>
				1746
				1747	<h5>Examples:</h5>
				1748
				1749	<table class="layout">
				1750	<tr class="layout">
				1751	<td class="left"><tt>\1*</tt></td>
				1752	<td class="left">Self-referential pointer.</td>
				1753	</tr>
				1754	<tr class="layout">
				1755	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1756	<td class="left">Recursive structure where the upref refers to the out-most
				1757	structure.</td>
				1758	</tr>
				1759	</table>
				1760	</div>
				1761
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1762
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1763	<!-- *********************************************************************** -->
				1764	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1765	<!-- *********************************************************************** -->
				1766
				1767	<div class="doc_text">
				1768
				1769	<p>LLVM has several different basic types of constants. This section describes
				1770	them all and their syntax.</p>
				1771
				1772	</div>
				1773
				1774	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1775	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1776
				1777	<div class="doc_text">
				1778
				1779	<dl>
				1780	<dt><b>Boolean constants</b></dt>
				1781
				1782	<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]	1783	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1784	</dd>
				1785
				1786	<dt><b>Integer constants</b></dt>
				1787
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1788	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1789	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1790	integer types.
				1791	</dd>
				1792
				1793	<dt><b>Floating point constants</b></dt>
				1794
				1795	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1796	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1797	notation (see below). The assembler requires the exact decimal value of
				1798	a floating-point constant. For example, the assembler accepts 1.25 but
				1799	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1800	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]	1801
				1802	<dt><b>Null pointer constants</b></dt>
				1803
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1804	<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]	1805	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1806
				1807	</dl>
				1808
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1809	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1810	of floating point constants. For example, the form '<tt>double
				1811	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1812	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]	1813	(and the only time that they are generated by the disassembler) is when a
				1814	floating point constant must be emitted but it cannot be represented as a
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1815	decimal floating point number in a reasonable number of digits. For example,
				1816	NaN's, infinities, and other
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1817	special values are represented in their IEEE hexadecimal format so that
				1818	assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1819	<p>When using the hexadecimal form, constants of types float and double are
				1820	represented using the 16-digit form shown above (which matches the IEEE754
				1821	representation for double); float values must, however, be exactly representable
				1822	as IEE754 single precision.
				1823	Hexadecimal format is always used for long
				1824	double, and there are three forms of long double. The 80-bit
				1825	format used by x86 is represented as <tt>0xK</tt>
				1826	followed by 20 hexadecimal digits.
				1827	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1828	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1829	format is represented
				1830	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1831	target uses this format. Long doubles will only work if they match
				1832	the long double format on your target. All hexadecimal formats are big-endian
				1833	(sign bit at the left).</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1834	</div>
				1835
				1836	<!-- ======================================================================= -->
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1837	<div class="doc_subsection">
				1838	<a name="aggregateconstants"> <!-- old anchor -->
				1839	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1840	</div>
				1841
				1842	<div class="doc_text">
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1843	<p>Complex constants are a (potentially recursive) combination of simple
				1844	constants and smaller complex constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1845
				1846	<dl>
				1847	<dt><b>Structure constants</b></dt>
				1848
				1849	<dd>Structure constants are represented with notation similar to structure
				1850	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1851	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1852	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]	1853	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]	1854	types of elements must match those specified by the type.
				1855	</dd>
				1856
				1857	<dt><b>Array constants</b></dt>
				1858
				1859	<dd>Array constants are represented with notation similar to array type
				1860	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1861	(<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]	1862	constants must have <a href="#t_array">array type</a>, and the number and
				1863	types of elements must match those specified by the type.
				1864	</dd>
				1865
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1866	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1867
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1868	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1869	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1870	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1871	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1872	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]	1873	match those specified by the type.
				1874	</dd>
				1875
				1876	<dt><b>Zero initialization</b></dt>
				1877
				1878	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1879	value to zero of <em>any</em> type, including scalar and aggregate types.
				1880	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]	1881	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1882	initializers.
				1883	</dd>
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1884
				1885	<dt><b>Metadata node</b></dt>
				1886
Nick Lewycky	8e2c4f4	2009-05-30 16:08:30 +0000	[diff] [blame]	1887	<dd>A metadata node is a structure-like constant with
				1888	<a href="#t_metadata">metadata type</a>. For example:
				1889	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1890	that are meant to be interpreted as part of the instruction stream, metadata
				1891	is a place to attach additional information such as debug info.
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1892	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1893	</dl>
				1894
				1895	</div>
				1896
				1897	<!-- ======================================================================= -->
				1898	<div class="doc_subsection">
				1899	<a name="globalconstants">Global Variable and Function Addresses</a>
				1900	</div>
				1901
				1902	<div class="doc_text">
				1903
				1904	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1905	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1906	constants. These constants are explicitly referenced when the <a
				1907	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]	1908	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1909	file:</p>
				1910
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1911	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1912	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1913	@X = global i32 17
				1914	@Y = global i32 42
				1915	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1916	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1917	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1918
				1919	</div>
				1920
				1921	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1922	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1923	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1924	<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]	1925	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]	1926	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1927
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1928	<p>Undefined values indicate to the compiler that the program is well defined
				1929	no matter what value is used, giving the compiler more freedom to optimize.
				1930	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1931	</div>
				1932
				1933	<!-- ======================================================================= -->
				1934	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1935	</div>
				1936
				1937	<div class="doc_text">
				1938
				1939	<p>Constant expressions are used to allow expressions involving other constants
				1940	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1941	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]	1942	that does not have side effects (e.g. load and call are not supported). The
				1943	following is the syntax for constant expressions:</p>
				1944
				1945	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1946	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1947	<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]	1948	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1949
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1950	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1951	<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]	1952	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]	1953
				1954	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1955	<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]	1956	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]	1957
				1958	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1959	<dd>Truncate a floating point constant to another floating point type. The
				1960	size of CST must be larger than the size of TYPE. Both types must be
				1961	floating point.</dd>
				1962
				1963	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1964	<dd>Floating point extend a constant to another type. The size of CST must be
				1965	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1966
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1967	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1968	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1969	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1970	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1971	of the same number of elements. If the value won't fit in the integer type,
				1972	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1973
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1974	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1975	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1976	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1977	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1978	of the same number of elements. If the value won't fit in the integer type,
				1979	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1980
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1981	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1982	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1983	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1984	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1985	of the same number of elements. If the value won't fit in the floating point
				1986	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1987
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1988	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1989	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1990	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1991	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1992	of the same number of elements. If the value won't fit in the floating point
				1993	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1994
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1995	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1996	<dd>Convert a pointer typed constant to the corresponding integer constant
				1997	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1998	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1999
				2000	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2001	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2002	pointer type. CST must be of integer type. The CST value is zero extended,
				2003	truncated, or unchanged to make it fit in a pointer size. This one is
				2004	<i>really</i> dangerous!</dd>
				2005
				2006	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	789dee3	2009-02-28 18:27:03 +0000	[diff] [blame]	2007	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2008	are the same as those for the <a href="#i_bitcast">bitcast
				2009	instruction</a>.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2010
				2011	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2012
				2013	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2014	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2015	instruction, the index list may have zero or more indexes, which are required
				2016	to make sense for the type of "CSTPTR".</dd>
				2017
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2018	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2019
				2020	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2021	constants.</dd>
				2022
				2023	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2024	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2025
				2026	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2027	<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]	2028
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	2029	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				2030	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				2031
				2032	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2033	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2034
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2035	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2036
				2037	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2038	operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2039
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2040	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2041
				2042	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2043	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2044
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2045
				2046	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2047
				2048	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2049	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2050
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2051	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2052
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	2053	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2054	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]	2055	binary</a> operations. The constraints on operands are the same as those for
				2056	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2057	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2058	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2059	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	2060
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2061	<!-- ======================================================================= -->
				2062	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2063	</div>
				2064
				2065	<div class="doc_text">
				2066
				2067	<p>Embedded metadata provides a way to attach arbitrary data to the
				2068	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	2069	two metadata primitives, strings and nodes. All metadata has the
				2070	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2071	point ('<tt>!</tt>').
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2072	</p>
				2073
				2074	<p>A metadata string is a string surrounded by double quotes. It can contain
				2075	any character by escaping non-printable characters with "\xx" where "xx" is
				2076	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2077	</p>
				2078
				2079	<p>Metadata nodes are represented with notation similar to structure constants
				2080	(a comma separated list of elements, surrounded by braces and preceeded by an
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	2081	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2082	</p>
				2083
Nick Lewycky	b8f9b7a	2009-05-10 20:57:05 +0000	[diff] [blame]	2084	<p>A metadata node will attempt to track changes to the values it holds. In
				2085	the event that a value is deleted, it will be replaced with a typeless
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	2086	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	b8f9b7a	2009-05-10 20:57:05 +0000	[diff] [blame]	2087
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2088	<p>Optimizations may rely on metadata to provide additional information about
				2089	the program that isn't available in the instructions, or that isn't easily
				2090	computable. Similarly, the code generator may expect a certain metadata format
				2091	to be used to express debugging information.</p>
				2092	</div>
				2093
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2094	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2095	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2096	<!-- *********************************************************************** -->
				2097
				2098	<!-- ======================================================================= -->
				2099	<div class="doc_subsection">
				2100	<a name="inlineasm">Inline Assembler Expressions</a>
				2101	</div>
				2102
				2103	<div class="doc_text">
				2104
				2105	<p>
				2106	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2107	Module-Level Inline Assembly</a>) through the use of a special value. This
				2108	value represents the inline assembler as a string (containing the instructions
				2109	to emit), a list of operand constraints (stored as a string), and a flag that
				2110	indicates whether or not the inline asm expression has side effects. An example
				2111	inline assembler expression is:
				2112	</p>
				2113
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2114	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2115	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2116	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2117	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2118	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2119
				2120	<p>
				2121	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2122	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2123	</p>
				2124
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2125	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2126	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2127	%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]	2128	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2129	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2130
				2131	<p>
				2132	Inline asms with side effects not visible in the constraint list must be marked
				2133	as having side effects. This is done through the use of the
				2134	'<tt>sideeffect</tt>' keyword, like so:
				2135	</p>
				2136
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2137	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2138	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2139	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2140	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2141	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2142
				2143	<p>TODO: The format of the asm and constraints string still need to be
				2144	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]	2145	need to be documented). This is probably best done by reference to another
				2146	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2147	</p>
				2148
				2149	</div>
				2150
				2151	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2152	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2153	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2154
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2155	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2156
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2157	<p>The LLVM instruction set consists of several different
				2158	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	2159	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2160	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2161	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2162	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2163
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2164	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2165
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2166	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2167	<div class="doc_subsection"> <a name="terminators">Terminator
				2168	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2169
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2170	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2171
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2172	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2173	basic block in a program ends with a "Terminator" instruction, which
				2174	indicates which block should be executed after the current block is
				2175	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2176	value: they produce control flow, not values (the one exception being
				2177	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2178	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2179	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2180	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2181	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2182	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2183	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2184
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2185	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2186
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2187	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2188	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2189	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2190	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2191	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2192	<pre>
				2193	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]	2194	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2195	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2196
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2197	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2198
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2199	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2200	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	2201	<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]	2202	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]	2203	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2204
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2205	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2206
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2207	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2208	the return value. The type of the return value must be a
				2209	'<a href="#t_firstclass">first class</a>' type.</p>
				2210
				2211	<p>A function is not <a href="#wellformed">well formed</a> if
				2212	it it has a non-void return type and contains a '<tt>ret</tt>'
				2213	instruction with no return value or a return value with a type that
				2214	does not match its type, or if it has a void return type and contains
				2215	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2216
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2217	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2218
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2219	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2220	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]	2221	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2222	the instruction after the call. If the caller was an "<a
				2223	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2224	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2225	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2226	return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2227
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2228	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2229
				2230	<pre>
				2231	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	2232	ret void <i>; Return from a void function</i>
Bill Wendling	050ee8f	2009-02-28 22:12:54 +0000	[diff] [blame]	2233	ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2234	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2235
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	2236	<p>Note that the code generator does not yet fully support large
				2237	return values. The specific sizes that are currently supported are
				2238	dependent on the target. For integers, on 32-bit targets the limit
				2239	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2240	For aggregate types, the current limits are dependent on the element
				2241	types; for example targets are often limited to 2 total integer
				2242	elements and 2 total floating-point elements.</p>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2243
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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2246	<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]	2247	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2248	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2249	<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]	2250	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2251	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2252	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2253	transfer to a different basic block in the current function. There are
				2254	two forms of this instruction, corresponding to a conditional branch
				2255	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2256	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2257	<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]	2258	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	2259	unconditional form of the '<tt>br</tt>' instruction takes a single
				2260	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2261	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2262	<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]	2263	argument is evaluated. If the value is <tt>true</tt>, control flows
				2264	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2265	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2266	<h5>Example:</h5>
Chris Lattner	e648c28	2009-05-09 18:11:50 +0000	[diff] [blame]	2267	<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]	2268	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]	2269	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2270	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2271	<div class="doc_subsubsection">
				2272	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2273	</div>
				2274
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2275	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2276	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2277
				2278	<pre>
				2279	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2280	</pre>
				2281
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2282	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2283
				2284	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2285	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2286	instruction, allowing a branch to occur to one of many possible
				2287	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2288
				2289
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2290	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2291
				2292	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2293	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2294	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2295	table is not allowed to contain duplicate constant entries.</p>
				2296
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2297	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2298
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2299	<p>The <tt>switch</tt> instruction specifies a table of values and
				2300	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2301	table is searched for the given value. If the value is found, control flow is
				2302	transfered to the corresponding destination; otherwise, control flow is
				2303	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2304
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2305	<h5>Implementation:</h5>
				2306
				2307	<p>Depending on properties of the target machine and the particular
				2308	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2309	ways. For example, it could be generated as a series of chained conditional
				2310	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2311
				2312	<h5>Example:</h5>
				2313
				2314	<pre>
				2315	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2316	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2317	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2318
				2319	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2320	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2321
				2322	<i>; Implement a jump table:</i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2323	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2324	i32 1, label %onone
				2325	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2326	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2327	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2328
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2329	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2330	<div class="doc_subsubsection">
				2331	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2332	</div>
				2333
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2334	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2335
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2336	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2337
				2338	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2339	<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]	2340	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2341	</pre>
				2342
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2343	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2344
				2345	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2346	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2347	'<tt>normal</tt>' label or the
				2348	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2349	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2350	"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]	2351	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2352	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2353
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2354	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2355
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2356	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2357
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2358	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2359	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2360	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2361	convention</a> the call should use. If none is specified, the call defaults
				2362	to using C calling conventions.
				2363	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2364
				2365	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2366	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2367	and '<tt>inreg</tt>' attributes are valid here.</li>
				2368
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2369	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2370	function value being invoked. In most cases, this is a direct function
				2371	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2372	an arbitrary pointer to function value.
				2373	</li>
				2374
				2375	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2376	function to be invoked. </li>
				2377
				2378	<li>'<tt>function args</tt>': argument list whose types match the function
				2379	signature argument types. If the function signature indicates the function
				2380	accepts a variable number of arguments, the extra arguments can be
				2381	specified. </li>
				2382
				2383	<li>'<tt>normal label</tt>': the label reached when the called function
				2384	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2385
				2386	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2387	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2388
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2389	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2390	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2391	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2392	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2393
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2394	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2395
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2396	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2397	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2398	difference is that it establishes an association with a label, which is used by
				2399	the runtime library to unwind the stack.</p>
				2400
				2401	<p>This instruction is used in languages with destructors to ensure that proper
				2402	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2403	exception. Additionally, this is important for implementation of
				2404	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2405
Jay Foad	1a4eea5	2009-06-03 10:20:10 +0000	[diff] [blame^]	2406	<p>For the purposes of the SSA form, the definition of the value
				2407	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2408	the edge from the current block to the "normal" label. If the callee
				2409	unwinds then no return value is available.</p>
Dan Gohman	9069d89	2009-05-22 21:47:08 +0000	[diff] [blame]	2410
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2411	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2412	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2413	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2414	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2415	%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]	2416	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2417	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2418	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2419
				2420
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2421	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2422
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2423	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2424	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2425
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2426	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2427
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2428	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2429	<pre>
				2430	unwind
				2431	</pre>
				2432
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2433	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2434
				2435	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2436	at the first callee in the dynamic call stack which used an <a
				2437	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2438	primarily used to implement exception handling.</p>
				2439
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2440	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2441
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2442	<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]	2443	immediately halt. The dynamic call stack is then searched for the first <a
				2444	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2445	execution continues at the "exceptional" destination block specified by the
				2446	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2447	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2448	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2449
				2450	<!-- _______________________________________________________________________ -->
				2451
				2452	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2453	Instruction</a> </div>
				2454
				2455	<div class="doc_text">
				2456
				2457	<h5>Syntax:</h5>
				2458	<pre>
				2459	unreachable
				2460	</pre>
				2461
				2462	<h5>Overview:</h5>
				2463
				2464	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2465	instruction is used to inform the optimizer that a particular portion of the
				2466	code is not reachable. This can be used to indicate that the code after a
				2467	no-return function cannot be reached, and other facts.</p>
				2468
				2469	<h5>Semantics:</h5>
				2470
				2471	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2472	</div>
				2473
				2474
				2475
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2476	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2477	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2478	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2479	<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]	2480	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]	2481	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2482	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]	2483	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2484	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2485	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2486	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2487	<div class="doc_subsubsection">
				2488	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2489	</div>
				2490
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2491	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2492
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2493	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2494
				2495	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2496	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2497	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2498
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2499	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2500
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2501	<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]	2502
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2503	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2504
				2505	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2506	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2507	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2508	types.</p>
				2509
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2510	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2511
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2512	<p>The value produced is the integer or floating point sum of the two
				2513	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2514
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2515	<p>If an integer sum has unsigned overflow, the result returned is the
				2516	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2517	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2518
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2519	<p>Because LLVM integers use a two's complement representation, this
				2520	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2521
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2522	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2523
				2524	<pre>
				2525	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2526	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2527	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2528	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2529	<div class="doc_subsubsection">
				2530	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2531	</div>
				2532
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2533	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2534
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2535	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2536
				2537	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2538	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2539	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2540
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2541	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2542
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2543	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2544	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2545
				2546	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2547	'<tt>neg</tt>' instruction present in most other intermediate
				2548	representations.</p>
				2549
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2550	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2551
				2552	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2553	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2554	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2555	types.</p>
				2556
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2557	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2558
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2559	<p>The value produced is the integer or floating point difference of
				2560	the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2561
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2562	<p>If an integer difference has unsigned overflow, the result returned is the
				2563	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2564	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2565
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2566	<p>Because LLVM integers use a two's complement representation, this
				2567	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2568
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2569	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2570	<pre>
				2571	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2572	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2573	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2574	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2575
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2576	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2577	<div class="doc_subsubsection">
				2578	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2579	</div>
				2580
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2581	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2582
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2583	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2584	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2585	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2586	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2587	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2588	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2589
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2590	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2591
				2592	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2593	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2594	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2595	types.</p>
				2596
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2597	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2598
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2599	<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]	2600	two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2601
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2602	<p>If the result of an integer multiplication has unsigned overflow,
				2603	the result returned is the mathematical result modulo
				2604	2<sup>n</sup>, where n is the bit width of the result.</p>
				2605	<p>Because LLVM integers use a two's complement representation, and the
				2606	result is the same width as the operands, this instruction returns the
				2607	correct result for both signed and unsigned integers. If a full product
				2608	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2609	should be sign-extended or zero-extended as appropriate to the
				2610	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2611	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2612	<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]	2613	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2614	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2615
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2616	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2617	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2618	</a></div>
				2619	<div class="doc_text">
				2620	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2621	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2622	</pre>
				2623	<h5>Overview:</h5>
				2624	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2625	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2626
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2627	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2628
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2629	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2630	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2631	values. Both arguments must have identical types.</p>
				2632
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2633	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2634
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2635	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2636	<p>Note that unsigned integer division and signed integer division are distinct
				2637	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2638	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2639	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2640	<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]	2641	</pre>
				2642	</div>
				2643	<!-- _______________________________________________________________________ -->
				2644	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2645	</a> </div>
				2646	<div class="doc_text">
				2647	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2648	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2649	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2650	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2651
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2652	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2653
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2654	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2655	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2656
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2657	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2658
				2659	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2660	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2661	values. Both arguments must have identical types.</p>
				2662
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2663	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2664	<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]	2665	<p>Note that signed integer division and unsigned integer division are distinct
				2666	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2667	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2668	undefined behavior; this is a rare case, but can occur, for example,
				2669	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2670	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2671	<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]	2672	</pre>
				2673	</div>
				2674	<!-- _______________________________________________________________________ -->
				2675	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2676	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2677	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2678	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2679	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2680	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2681	</pre>
				2682	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2683
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2684	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2685	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2686
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2687	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2688
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2689	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2690	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2691	of floating point values. Both arguments must have identical types.</p>
				2692
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2693	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2694
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2695	<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]	2696
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2697	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2698
				2699	<pre>
				2700	<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]	2701	</pre>
				2702	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2703
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2704	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2705	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2706	</div>
				2707	<div class="doc_text">
				2708	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2709	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2710	</pre>
				2711	<h5>Overview:</h5>
				2712	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2713	unsigned division of its two arguments.</p>
				2714	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2715	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2716	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2717	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2718	<h5>Semantics:</h5>
				2719	<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]	2720	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2721	<p>Note that unsigned integer remainder and signed integer remainder are
				2722	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2723	<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]	2724	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2725	<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]	2726	</pre>
				2727
				2728	</div>
				2729	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2730	<div class="doc_subsubsection">
				2731	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2732	</div>
				2733
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2734	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2735
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2736	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2737
				2738	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2739	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2740	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2741
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2742	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2743
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2744	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2745	signed division of its two operands. This instruction can also take
				2746	<a href="#t_vector">vector</a> versions of the values in which case
				2747	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2748
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2749	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2750
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2751	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2752	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2753	values. Both arguments must have identical types.</p>
				2754
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2755	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2756
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2757	<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]	2758	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2759	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]	2760	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2761	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]	2762	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]	2763	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2764	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2765	<p>Note that signed integer remainder and unsigned integer remainder are
				2766	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2767	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2768	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2769	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2770	(The remainder doesn't actually overflow, but this rule lets srem be
				2771	implemented using instructions that return both the result of the division
				2772	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2773	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2774	<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]	2775	</pre>
				2776
				2777	</div>
				2778	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2779	<div class="doc_subsubsection">
				2780	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2781
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2782	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2783
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2784	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2785	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2786	</pre>
				2787	<h5>Overview:</h5>
				2788	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2789	division of its two operands.</p>
				2790	<h5>Arguments:</h5>
				2791	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2792	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2793	of floating point values. Both arguments must have identical types.</p>
				2794
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2795	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2796
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2797	<p>This instruction returns the <i>remainder</i> of a division.
				2798	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2799
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2800	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2801
				2802	<pre>
				2803	<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]	2804	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2805	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2806
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2807	<!-- ======================================================================= -->
				2808	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2809	Operations</a> </div>
				2810	<div class="doc_text">
				2811	<p>Bitwise binary operators are used to do various forms of
				2812	bit-twiddling in a program. They are generally very efficient
				2813	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2814	instructions. They require two operands of the same type, execute an operation on them,
				2815	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]	2816	</div>
				2817
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2818	<!-- _______________________________________________________________________ -->
				2819	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2820	Instruction</a> </div>
				2821	<div class="doc_text">
				2822	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2823	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2824	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2825
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2826	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2827
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2828	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2829	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2830
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2831	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2832
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2833	<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]	2834	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]	2835	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2836
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2837	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2838
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2839	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2840	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2841	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2842	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2843	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2844
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2845	<h5>Example:</h5><pre>
				2846	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2847	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2848	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2849	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2850	<result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 2, i32 4></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2851	</pre>
				2852	</div>
				2853	<!-- _______________________________________________________________________ -->
				2854	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2855	Instruction</a> </div>
				2856	<div class="doc_text">
				2857	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2858	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2859	</pre>
				2860
				2861	<h5>Overview:</h5>
				2862	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2863	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]	2864
				2865	<h5>Arguments:</h5>
				2866	<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]	2867	<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]	2868	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2869
				2870	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2871
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2872	<p>This instruction always performs a logical shift right operation. The most
				2873	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]	2874	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2875	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2876	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2877	amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2878
				2879	<h5>Example:</h5>
				2880	<pre>
				2881	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2882	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2883	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2884	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2885	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2886	<result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2887	</pre>
				2888	</div>
				2889
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2890	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2891	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2892	Instruction</a> </div>
				2893	<div class="doc_text">
				2894
				2895	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2896	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2897	</pre>
				2898
				2899	<h5>Overview:</h5>
				2900	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2901	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]	2902
				2903	<h5>Arguments:</h5>
				2904	<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]	2905	<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]	2906	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2907
				2908	<h5>Semantics:</h5>
				2909	<p>This instruction always performs an arithmetic shift right operation,
				2910	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]	2911	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2912	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				2913	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2914	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2915
				2916	<h5>Example:</h5>
				2917	<pre>
				2918	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2919	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2920	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2921	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2922	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2923	<result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3> <i>; yields: result=<2 x i32> < i32 -1, i32 0></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2924	</pre>
				2925	</div>
				2926
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2927	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2928	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2929	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2930
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2931	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2932
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2933	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2934
				2935	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2936	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2937	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2938
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2939	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2940
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2941	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2942	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2943
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2944	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2945
				2946	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2947	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2948	values. Both arguments must have identical types.</p>
				2949
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2950	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2951	<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]	2952	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2953	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2954	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2955	<tbody>
				2956	<tr>
				2957	<td>In0</td>
				2958	<td>In1</td>
				2959	<td>Out</td>
				2960	</tr>
				2961	<tr>
				2962	<td>0</td>
				2963	<td>0</td>
				2964	<td>0</td>
				2965	</tr>
				2966	<tr>
				2967	<td>0</td>
				2968	<td>1</td>
				2969	<td>0</td>
				2970	</tr>
				2971	<tr>
				2972	<td>1</td>
				2973	<td>0</td>
				2974	<td>0</td>
				2975	</tr>
				2976	<tr>
				2977	<td>1</td>
				2978	<td>1</td>
				2979	<td>1</td>
				2980	</tr>
				2981	</tbody>
				2982	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2983	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2984	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2985	<pre>
				2986	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2987	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2988	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2989	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2990	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2991	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2992	<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]	2993	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2994	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2995	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2996	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2997	<h5>Overview:</h5>
				2998	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2999	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3000	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3001
				3002	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3003	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3004	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3005	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3006	<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]	3007	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3008	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3009	<table border="1" cellspacing="0" cellpadding="4">
				3010	<tbody>
				3011	<tr>
				3012	<td>In0</td>
				3013	<td>In1</td>
				3014	<td>Out</td>
				3015	</tr>
				3016	<tr>
				3017	<td>0</td>
				3018	<td>0</td>
				3019	<td>0</td>
				3020	</tr>
				3021	<tr>
				3022	<td>0</td>
				3023	<td>1</td>
				3024	<td>1</td>
				3025	</tr>
				3026	<tr>
				3027	<td>1</td>
				3028	<td>0</td>
				3029	<td>1</td>
				3030	</tr>
				3031	<tr>
				3032	<td>1</td>
				3033	<td>1</td>
				3034	<td>1</td>
				3035	</tr>
				3036	</tbody>
				3037	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3038	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3039	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3040	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3041	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3042	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3043	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3044	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3045	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3046	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3047	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3048	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3049	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3050	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3051	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3052	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3053	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3054	or of its two operands. The <tt>xor</tt> is used to implement the
				3055	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3056	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3057	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3058	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3059	values. Both arguments must have identical types.</p>
				3060
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3061	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3062
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3063	<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]	3064	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3065	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3066	<table border="1" cellspacing="0" cellpadding="4">
				3067	<tbody>
				3068	<tr>
				3069	<td>In0</td>
				3070	<td>In1</td>
				3071	<td>Out</td>
				3072	</tr>
				3073	<tr>
				3074	<td>0</td>
				3075	<td>0</td>
				3076	<td>0</td>
				3077	</tr>
				3078	<tr>
				3079	<td>0</td>
				3080	<td>1</td>
				3081	<td>1</td>
				3082	</tr>
				3083	<tr>
				3084	<td>1</td>
				3085	<td>0</td>
				3086	<td>1</td>
				3087	</tr>
				3088	<tr>
				3089	<td>1</td>
				3090	<td>1</td>
				3091	<td>0</td>
				3092	</tr>
				3093	</tbody>
				3094	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3095	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3096	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3097	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3098	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3099	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3100	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3101	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3102	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3103	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3104
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3105	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3106	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3107	<a name="vectorops">Vector Operations</a>
				3108	</div>
				3109
				3110	<div class="doc_text">
				3111
				3112	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3113	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3114	vector-specific operations needed to process vectors effectively. While LLVM
				3115	does directly support these vector operations, many sophisticated algorithms
				3116	will want to use target-specific intrinsics to take full advantage of a specific
				3117	target.</p>
				3118
				3119	</div>
				3120
				3121	<!-- _______________________________________________________________________ -->
				3122	<div class="doc_subsubsection">
				3123	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3124	</div>
				3125
				3126	<div class="doc_text">
				3127
				3128	<h5>Syntax:</h5>
				3129
				3130	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3131	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3132	</pre>
				3133
				3134	<h5>Overview:</h5>
				3135
				3136	<p>
				3137	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3138	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3139	</p>
				3140
				3141
				3142	<h5>Arguments:</h5>
				3143
				3144	<p>
				3145	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3146	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]	3147	an index indicating the position from which to extract the element.
				3148	The index may be a variable.</p>
				3149
				3150	<h5>Semantics:</h5>
				3151
				3152	<p>
				3153	The result is a scalar of the same type as the element type of
				3154	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3155	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3156	results are undefined.
				3157	</p>
				3158
				3159	<h5>Example:</h5>
				3160
				3161	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3162	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3163	</pre>
				3164	</div>
				3165
				3166
				3167	<!-- _______________________________________________________________________ -->
				3168	<div class="doc_subsubsection">
				3169	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3170	</div>
				3171
				3172	<div class="doc_text">
				3173
				3174	<h5>Syntax:</h5>
				3175
				3176	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	3177	<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]	3178	</pre>
				3179
				3180	<h5>Overview:</h5>
				3181
				3182	<p>
				3183	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3184	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3185	</p>
				3186
				3187
				3188	<h5>Arguments:</h5>
				3189
				3190	<p>
				3191	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3192	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]	3193	scalar value whose type must equal the element type of the first
				3194	operand. The third operand is an index indicating the position at
				3195	which to insert the value. The index may be a variable.</p>
				3196
				3197	<h5>Semantics:</h5>
				3198
				3199	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3200	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]	3201	element values are those of <tt>val</tt> except at position
				3202	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3203	exceeds the length of <tt>val</tt>, the results are undefined.
				3204	</p>
				3205
				3206	<h5>Example:</h5>
				3207
				3208	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3209	%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]	3210	</pre>
				3211	</div>
				3212
				3213	<!-- _______________________________________________________________________ -->
				3214	<div class="doc_subsubsection">
				3215	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3216	</div>
				3217
				3218	<div class="doc_text">
				3219
				3220	<h5>Syntax:</h5>
				3221
				3222	<pre>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3223	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> <i>; yields <m x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3224	</pre>
				3225
				3226	<h5>Overview:</h5>
				3227
				3228	<p>
				3229	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3230	from two input vectors, returning a vector with the same element type as
				3231	the input and length that is the same as the shuffle mask.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3232	</p>
				3233
				3234	<h5>Arguments:</h5>
				3235
				3236	<p>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3237	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3238	with types that match each other. The third argument is a shuffle mask whose
				3239	element type is always 'i32'. The result of the instruction is a vector whose
				3240	length is the same as the shuffle mask and whose element type is the same as
				3241	the element type of the first two operands.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3242	</p>
				3243
				3244	<p>
				3245	The shuffle mask operand is required to be a constant vector with either
				3246	constant integer or undef values.
				3247	</p>
				3248
				3249	<h5>Semantics:</h5>
				3250
				3251	<p>
				3252	The elements of the two input vectors are numbered from left to right across
				3253	both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3254	the result vector, which element of the two input vectors the result element
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3255	gets. The element selector may be undef (meaning "don't care") and the second
				3256	operand may be undef if performing a shuffle from only one vector.
				3257	</p>
				3258
				3259	<h5>Example:</h5>
				3260
				3261	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3262	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3263	<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]	3264	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3265	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3266	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3267	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3268	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3269	<8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 > <i>; yields <8 x i32></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3270	</pre>
				3271	</div>
				3272
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	3273
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3274	<!-- ======================================================================= -->
				3275	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3276	<a name="aggregateops">Aggregate Operations</a>
				3277	</div>
				3278
				3279	<div class="doc_text">
				3280
				3281	<p>LLVM supports several instructions for working with aggregate values.
				3282	</p>
				3283
				3284	</div>
				3285
				3286	<!-- _______________________________________________________________________ -->
				3287	<div class="doc_subsubsection">
				3288	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3289	</div>
				3290
				3291	<div class="doc_text">
				3292
				3293	<h5>Syntax:</h5>
				3294
				3295	<pre>
				3296	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3297	</pre>
				3298
				3299	<h5>Overview:</h5>
				3300
				3301	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3302	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3303	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3304	</p>
				3305
				3306
				3307	<h5>Arguments:</h5>
				3308
				3309	<p>
				3310	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3311	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]	3312	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3313	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3314	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3315	</p>
				3316
				3317	<h5>Semantics:</h5>
				3318
				3319	<p>
				3320	The result is the value at the position in the aggregate specified by
				3321	the index operands.
				3322	</p>
				3323
				3324	<h5>Example:</h5>
				3325
				3326	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3327	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3328	</pre>
				3329	</div>
				3330
				3331
				3332	<!-- _______________________________________________________________________ -->
				3333	<div class="doc_subsubsection">
				3334	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3335	</div>
				3336
				3337	<div class="doc_text">
				3338
				3339	<h5>Syntax:</h5>
				3340
				3341	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3342	<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]	3343	</pre>
				3344
				3345	<h5>Overview:</h5>
				3346
				3347	<p>
				3348	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3349	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3350	</p>
				3351
				3352
				3353	<h5>Arguments:</h5>
				3354
				3355	<p>
				3356	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3357	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3358	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3359	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3360	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]	3361	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3362	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3363	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]	3364	by the indices.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3365	</p>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3366
				3367	<h5>Semantics:</h5>
				3368
				3369	<p>
				3370	The result is an aggregate of the same type as <tt>val</tt>. Its
				3371	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]	3372	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3373	</p>
				3374
				3375	<h5>Example:</h5>
				3376
				3377	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3378	%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]	3379	</pre>
				3380	</div>
				3381
				3382
				3383	<!-- ======================================================================= -->
				3384	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3385	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3386	</div>
				3387
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3388	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3389
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3390	<p>A key design point of an SSA-based representation is how it
				3391	represents memory. In LLVM, no memory locations are in SSA form, which
				3392	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3393	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3394
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3395	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3396
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3397	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3398	<div class="doc_subsubsection">
				3399	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3400	</div>
				3401
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3402	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3403
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3404	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3405
				3406	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3407	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3408	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3409
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3410	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3411
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3412	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3413	heap and returns a pointer to it. The object is always allocated in the generic
				3414	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3415
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3416	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3417
				3418	<p>The '<tt>malloc</tt>' instruction allocates
				3419	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3420	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]	3421	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3422	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3423	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]	3424	be aligned to at least that boundary. If not specified, or if zero, the target can
				3425	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3426
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3427	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3428
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3429	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3430
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3431	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	3432	a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3433	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3434
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3435	<h5>Example:</h5>
				3436
				3437	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3438	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3439
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3440	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3441	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3442	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3443	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3444	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3445	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	3446
				3447	<p>Note that the code generator does not yet respect the
				3448	alignment value.</p>
				3449
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3450	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3451
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3452	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3453	<div class="doc_subsubsection">
				3454	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3455	</div>
				3456
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3457	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3458
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3459	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3460
				3461	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3462	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3463	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3464
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3465	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3466
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3467	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3468	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3469
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3470	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3471
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3472	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3473	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3474	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3475
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3476	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3477
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3478	<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]	3479	after this instruction executes. If the pointer is null, the operation
				3480	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3481
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3482	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3483
				3484	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3485	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3486	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3487	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3488	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3489
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3490	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3491	<div class="doc_subsubsection">
				3492	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3493	</div>
				3494
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3495	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3496
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3497	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3498
				3499	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3500	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3501	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3502
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3503	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3504
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3505	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3506	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3507	returns to its caller. The object is always allocated in the generic address
				3508	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3509
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3510	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3511
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3512	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3513	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3514	appropriate type to the program. If "NumElements" is specified, it is the
				3515	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3516	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]	3517	to be aligned to at least that boundary. If not specified, or if zero, the target
				3518	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3519
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3520	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3521
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3522	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3523
Bill Wendling	9ee6a31	2009-05-08 20:49:29 +0000	[diff] [blame]	3524	<p>Memory is allocated; a pointer is returned. The operation is undefined if
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3525	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3526	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3527	instruction is commonly used to represent automatic variables that must
				3528	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]	3529	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]	3530	instructions), the memory is reclaimed. Allocating zero bytes
				3531	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3532
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3533	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3534
				3535	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3536	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3537	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3538	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3539	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3540	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3541	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3542
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3543	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3544	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3545	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3546	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3547	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3548	<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]	3549	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3550	<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]	3551	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3552	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3553	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3554	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]	3555	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]	3556	the number or order of execution of this <tt>load</tt> with other
				3557	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3558	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3559	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3560	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3561	(that is, the alignment of the memory address). A value of 0 or an
				3562	omitted "align" argument means that the operation has the preferential
				3563	alignment for the target. It is the responsibility of the code emitter
				3564	to ensure that the alignment information is correct. Overestimating
				3565	the alignment results in an undefined behavior. Underestimating the
				3566	alignment may produce less efficient code. An alignment of 1 is always
				3567	safe.
				3568	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3569	<h5>Semantics:</h5>
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3570	<p>The location of memory pointed to is loaded. If the value being loaded
				3571	is of scalar type then the number of bytes read does not exceed the minimum
				3572	number of bytes needed to hold all bits of the type. For example, loading an
				3573	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3574	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3575	is undefined if the value was not originally written using a store of the
				3576	same type.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3577	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3578	<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]	3579	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3580	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3581	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3582	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3583	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3584	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3585	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3586	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3587	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3588	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3589	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3590	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3591	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3592	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3593	<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]	3594	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3595	<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]	3596	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]	3597	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3598	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3599	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]	3600	optimizer is not allowed to modify the number or order of execution of
				3601	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3602	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3603	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3604	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3605	(that is, the alignment of the memory address). A value of 0 or an
				3606	omitted "align" argument means that the operation has the preferential
				3607	alignment for the target. It is the responsibility of the code emitter
				3608	to ensure that the alignment information is correct. Overestimating
				3609	the alignment results in an undefined behavior. Underestimating the
				3610	alignment may produce less efficient code. An alignment of 1 is always
				3611	safe.
				3612	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3613	<h5>Semantics:</h5>
				3614	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3615	at the location specified by the '<tt><pointer></tt>' operand.
				3616	If '<tt><value></tt>' is of scalar type then the number of bytes
				3617	written does not exceed the minimum number of bytes needed to hold all
				3618	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3619	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3620	size that is not an integral number of bytes, it is unspecified what
				3621	happens to the extra bits that do not belong to the type, but they will
				3622	typically be overwritten.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3623	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3624	<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]	3625	store i32 3, i32* %ptr <i>; yields {void}</i>
				3626	%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]	3627	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3628	</div>
				3629
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3630	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3631	<div class="doc_subsubsection">
				3632	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3633	</div>
				3634
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3635	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3636	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3637	<pre>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3638	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3639	</pre>
				3640
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3641	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3642
				3643	<p>
				3644	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]	3645	subelement of an aggregate data structure. It performs address calculation only
				3646	and does not access memory.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3647
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3648	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3649
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3650	<p>The first argument is always a pointer, and forms the basis of the
				3651	calculation. The remaining arguments are indices, that indicate which of the
				3652	elements of the aggregate object are indexed. The interpretation of each index
				3653	is dependent on the type being indexed into. The first index always indexes the
				3654	pointer value given as the first argument, the second index indexes a value of
				3655	the type pointed to (not necessarily the value directly pointed to, since the
				3656	first index can be non-zero), etc. The first type indexed into must be a pointer
				3657	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3658	types being indexed into can never be pointers, since that would require loading
				3659	the pointer before continuing calculation.</p>
				3660
				3661	<p>The type of each index argument depends on the type it is indexing into.
				3662	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3663	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
Sanjiv Gupta	1f8555a	2009-04-27 03:21:00 +0000	[diff] [blame]	3664	integers of any width are allowed (also non-constants).</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3665
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3666	<p>For example, let's consider a C code fragment and how it gets
				3667	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3668
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3669	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3670	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3671	struct RT {
				3672	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3673	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3674	char C;
				3675	};
				3676	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3677	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3678	double Y;
				3679	struct RT Z;
				3680	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3681
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3682	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3683	return &s[1].Z.B[5][13];
				3684	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3685	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3686	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3687
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3688	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3689
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3690	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3691	<pre>
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	3692	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3693	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3694
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3695	define i32* %foo(%ST* %s) {
				3696	entry:
				3697	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3698	ret i32* %reg
				3699	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3700	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3701	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3702
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3703	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3704
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3705	<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]	3706	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]	3707	}</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]	3708	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3709	i8 }</tt>' type, another structure. The third index indexes into the second
				3710	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]	3711	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3712	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3713	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]	3714
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3715	<p>Note that it is perfectly legal to index partially through a
				3716	structure, returning a pointer to an inner element. Because of this,
				3717	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3718
				3719	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3720	define i32* %foo(%ST* %s) {
				3721	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3722	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3723	%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]	3724	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3725	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3726	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3727	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3728	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3729
Chris Lattner	dd28282	2009-03-09 20:55:18 +0000	[diff] [blame]	3730	<p>Note that it is undefined to access an array out of bounds: array
				3731	and pointer indexes must always be within the defined bounds of the
				3732	array type when accessed with an instruction that dereferences the
				3733	pointer (e.g. a load or store instruction). The one exception for
				3734	this rule is zero length arrays. These arrays are defined to be
				3735	accessible as variable length arrays, which requires access beyond the
				3736	zero'th element.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3737
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3738	<p>The getelementptr instruction is often confusing. For some more insight
				3739	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3740	FAQ</a>.</p>
				3741
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3742	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3743
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3744	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3745	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3746	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3747	<i>; yields i8*:vptr</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3748	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3749	<i>; yields i8*:eptr</i>
				3750	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	0c155e6	2009-04-25 07:27:44 +0000	[diff] [blame]	3751	<i>; yields i32*:iptr</i>
Sanjiv Gupta	77abea0	2009-04-24 16:38:13 +0000	[diff] [blame]	3752	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3753	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3754	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3755
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3756	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3757	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3758	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3759	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3760	<p>The instructions in this category are the conversion instructions (casting)
				3761	which all take a single operand and a type. They perform various bit conversions
				3762	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3763	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3764
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3765	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3766	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3767	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3768	</div>
				3769	<div class="doc_text">
				3770
				3771	<h5>Syntax:</h5>
				3772	<pre>
				3773	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3774	</pre>
				3775
				3776	<h5>Overview:</h5>
				3777	<p>
				3778	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3779	</p>
				3780
				3781	<h5>Arguments:</h5>
				3782	<p>
				3783	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3784	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]	3785	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]	3786	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3787	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3788
				3789	<h5>Semantics:</h5>
				3790	<p>
				3791	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]	3792	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3793	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3794	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3795
				3796	<h5>Example:</h5>
				3797	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3798	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3799	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3800	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3801	</pre>
				3802	</div>
				3803
				3804	<!-- _______________________________________________________________________ -->
				3805	<div class="doc_subsubsection">
				3806	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3807	</div>
				3808	<div class="doc_text">
				3809
				3810	<h5>Syntax:</h5>
				3811	<pre>
				3812	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3813	</pre>
				3814
				3815	<h5>Overview:</h5>
				3816	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3817	<tt>ty2</tt>.</p>
				3818
				3819
				3820	<h5>Arguments:</h5>
				3821	<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]	3822	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3823	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]	3824	<tt>value</tt> must be smaller than the bit size of the destination type,
				3825	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3826
				3827	<h5>Semantics:</h5>
				3828	<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]	3829	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]	3830
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3831	<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]	3832
				3833	<h5>Example:</h5>
				3834	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3835	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3836	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3837	</pre>
				3838	</div>
				3839
				3840	<!-- _______________________________________________________________________ -->
				3841	<div class="doc_subsubsection">
				3842	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3843	</div>
				3844	<div class="doc_text">
				3845
				3846	<h5>Syntax:</h5>
				3847	<pre>
				3848	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3849	</pre>
				3850
				3851	<h5>Overview:</h5>
				3852	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3853
				3854	<h5>Arguments:</h5>
				3855	<p>
				3856	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]	3857	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3858	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]	3859	<tt>value</tt> must be smaller than the bit size of the destination type,
				3860	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3861
				3862	<h5>Semantics:</h5>
				3863	<p>
				3864	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3865	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]	3866	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3867
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3868	<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]	3869
				3870	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3871	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3872	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3873	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3874	</pre>
				3875	</div>
				3876
				3877	<!-- _______________________________________________________________________ -->
				3878	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3879	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3880	</div>
				3881
				3882	<div class="doc_text">
				3883
				3884	<h5>Syntax:</h5>
				3885
				3886	<pre>
				3887	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3888	</pre>
				3889
				3890	<h5>Overview:</h5>
				3891	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3892	<tt>ty2</tt>.</p>
				3893
				3894
				3895	<h5>Arguments:</h5>
				3896	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3897	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3898	cast it to. The size of <tt>value</tt> must be larger than the size of
				3899	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3900	<i>no-op cast</i>.</p>
				3901
				3902	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3903	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3904	<a href="#t_floating">floating point</a> type to a smaller
				3905	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3906	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3907
				3908	<h5>Example:</h5>
				3909	<pre>
				3910	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3911	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3912	</pre>
				3913	</div>
				3914
				3915	<!-- _______________________________________________________________________ -->
				3916	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3917	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3918	</div>
				3919	<div class="doc_text">
				3920
				3921	<h5>Syntax:</h5>
				3922	<pre>
				3923	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3924	</pre>
				3925
				3926	<h5>Overview:</h5>
				3927	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3928	floating point value.</p>
				3929
				3930	<h5>Arguments:</h5>
				3931	<p>The '<tt>fpext</tt>' instruction takes a
				3932	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3933	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3934	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3935
				3936	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3937	<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]	3938	<a href="#t_floating">floating point</a> type to a larger
				3939	<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]	3940	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]	3941	<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]	3942
				3943	<h5>Example:</h5>
				3944	<pre>
				3945	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3946	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3947	</pre>
				3948	</div>
				3949
				3950	<!-- _______________________________________________________________________ -->
				3951	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	3952	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3953	</div>
				3954	<div class="doc_text">
				3955
				3956	<h5>Syntax:</h5>
				3957	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3958	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3959	</pre>
				3960
				3961	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3962	<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]	3963	unsigned integer equivalent of type <tt>ty2</tt>.
				3964	</p>
				3965
				3966	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3967	<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]	3968	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3969	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3970	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3971	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]	3972
				3973	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3974	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3975	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3976	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3977	the results are undefined.</p>
				3978
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3979	<h5>Example:</h5>
				3980	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3981	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3982	%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]	3983	%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]	3984	</pre>
				3985	</div>
				3986
				3987	<!-- _______________________________________________________________________ -->
				3988	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3989	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3990	</div>
				3991	<div class="doc_text">
				3992
				3993	<h5>Syntax:</h5>
				3994	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3995	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3996	</pre>
				3997
				3998	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3999	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4000	<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]	4001	</p>
				4002
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4003	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4004	<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]	4005	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4006	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4007	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4008	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]	4009
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4010	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4011	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4012	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4013	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4014	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4015
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	4016	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4017	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4018	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	4019	%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]	4020	%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]	4021	</pre>
				4022	</div>
				4023
				4024	<!-- _______________________________________________________________________ -->
				4025	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4026	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4027	</div>
				4028	<div class="doc_text">
				4029
				4030	<h5>Syntax:</h5>
				4031	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4032	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4033	</pre>
				4034
				4035	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4036	<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]	4037	integer and converts that value to the <tt>ty2</tt> type.</p>
				4038
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4039	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4040	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4041	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4042	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4043	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4044	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]	4045
				4046	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4047	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4048	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4049	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]	4050
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4051	<h5>Example:</h5>
				4052	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4053	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4054	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4055	</pre>
				4056	</div>
				4057
				4058	<!-- _______________________________________________________________________ -->
				4059	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4060	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4061	</div>
				4062	<div class="doc_text">
				4063
				4064	<h5>Syntax:</h5>
				4065	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4066	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4067	</pre>
				4068
				4069	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4070	<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]	4071	integer and converts that value to the <tt>ty2</tt> type.</p>
				4072
				4073	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4074	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4075	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4076	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4077	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4078	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]	4079
				4080	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4081	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4082	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4083	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]	4084
				4085	<h5>Example:</h5>
				4086	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4087	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4088	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4089	</pre>
				4090	</div>
				4091
				4092	<!-- _______________________________________________________________________ -->
				4093	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4094	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4095	</div>
				4096	<div class="doc_text">
				4097
				4098	<h5>Syntax:</h5>
				4099	<pre>
				4100	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4101	</pre>
				4102
				4103	<h5>Overview:</h5>
				4104	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4105	the integer type <tt>ty2</tt>.</p>
				4106
				4107	<h5>Arguments:</h5>
				4108	<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]	4109	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4110	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4111
				4112	<h5>Semantics:</h5>
				4113	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4114	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4115	truncating or zero extending that value to the size of the integer type. If
				4116	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4117	<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]	4118	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4119	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4120
				4121	<h5>Example:</h5>
				4122	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4123	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4124	%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]	4125	</pre>
				4126	</div>
				4127
				4128	<!-- _______________________________________________________________________ -->
				4129	<div class="doc_subsubsection">
				4130	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4131	</div>
				4132	<div class="doc_text">
				4133
				4134	<h5>Syntax:</h5>
				4135	<pre>
				4136	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4137	</pre>
				4138
				4139	<h5>Overview:</h5>
				4140	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4141	a pointer type, <tt>ty2</tt>.</p>
				4142
				4143	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4144	<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]	4145	value to cast, and a type to cast it to, which must be a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4146	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4147
				4148	<h5>Semantics:</h5>
				4149	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4150	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4151	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4152	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4153	the size of a pointer then a zero extension is done. If they are the same size,
				4154	nothing is done (<i>no-op cast</i>).</p>
				4155
				4156	<h5>Example:</h5>
				4157	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4158	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4159	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4160	%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]	4161	</pre>
				4162	</div>
				4163
				4164	<!-- _______________________________________________________________________ -->
				4165	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4166	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4167	</div>
				4168	<div class="doc_text">
				4169
				4170	<h5>Syntax:</h5>
				4171	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4172	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4173	</pre>
				4174
				4175	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4176
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4177	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4178	<tt>ty2</tt> without changing any bits.</p>
				4179
				4180	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4181
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4182	<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]	4183	a non-aggregate first class value, and a type to cast it to, which must also be
				4184	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4185	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	4186	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]	4187	type is a pointer, the destination type must also be a pointer. This
				4188	instruction supports bitwise conversion of vectors to integers and to vectors
				4189	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4190
				4191	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4192	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4193	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4194	this conversion. The conversion is done as if the <tt>value</tt> had been
				4195	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4196	converted to other pointer types with this instruction. To convert pointers to
				4197	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4198	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4199
				4200	<h5>Example:</h5>
				4201	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4202	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4203	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4204	%Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	4205	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4206	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4207
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4208	<!-- ======================================================================= -->
				4209	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4210	<div class="doc_text">
				4211	<p>The instructions in this category are the "miscellaneous"
				4212	instructions, which defy better classification.</p>
				4213	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4214
				4215	<!-- _______________________________________________________________________ -->
				4216	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4217	</div>
				4218	<div class="doc_text">
				4219	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4220	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4221	</pre>
				4222	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4223	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4224	a vector of boolean values based on comparison
				4225	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4226	<h5>Arguments:</h5>
				4227	<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]	4228	the condition code indicating the kind of comparison to perform. It is not
				4229	a value, just a keyword. The possible condition code are:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4230	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4231	<ol>
				4232	<li><tt>eq</tt>: equal</li>
				4233	<li><tt>ne</tt>: not equal </li>
				4234	<li><tt>ugt</tt>: unsigned greater than</li>
				4235	<li><tt>uge</tt>: unsigned greater or equal</li>
				4236	<li><tt>ult</tt>: unsigned less than</li>
				4237	<li><tt>ule</tt>: unsigned less or equal</li>
				4238	<li><tt>sgt</tt>: signed greater than</li>
				4239	<li><tt>sge</tt>: signed greater or equal</li>
				4240	<li><tt>slt</tt>: signed less than</li>
				4241	<li><tt>sle</tt>: signed less or equal</li>
				4242	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	4243	<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]	4244	<a href="#t_pointer">pointer</a>
				4245	or integer <a href="#t_vector">vector</a> typed.
				4246	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4247	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4248	<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]	4249	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4250	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4251	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4252	<ol>
				4253	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4254	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4255	</li>
				4256	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4257	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4258	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4259	<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]	4260	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4261	<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]	4262	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4263	<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]	4264	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4265	<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]	4266	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4267	<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]	4268	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4269	<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]	4270	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4271	<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]	4272	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4273	<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]	4274	</ol>
				4275	<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]	4276	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4277	<p>If the operands are integer vectors, then they are compared
				4278	element by element. The result is an <tt>i1</tt> vector with
				4279	the same number of elements as the values being compared.
				4280	Otherwise, the result is an <tt>i1</tt>.
				4281	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4282
				4283	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4284	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4285	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4286	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4287	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4288	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4289	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4290	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4291
				4292	<p>Note that the code generator does not yet support vector types with
				4293	the <tt>icmp</tt> instruction.</p>
				4294
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4295	</div>
				4296
				4297	<!-- _______________________________________________________________________ -->
				4298	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4299	</div>
				4300	<div class="doc_text">
				4301	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4302	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4303	</pre>
				4304	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4305	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4306	or vector of boolean values based on comparison
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4307	of its operands.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4308	<p>
				4309	If the operands are floating point scalars, then the result
				4310	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4311	</p>
				4312	<p>If the operands are floating point vectors, then the result type
				4313	is a vector of boolean with the same number of elements as the
				4314	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4315	<h5>Arguments:</h5>
				4316	<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]	4317	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4318	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4319	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4320	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4321	<li><tt>oeq</tt>: ordered and equal</li>
				4322	<li><tt>ogt</tt>: ordered and greater than </li>
				4323	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4324	<li><tt>olt</tt>: ordered and less than </li>
				4325	<li><tt>ole</tt>: ordered and less than or equal</li>
				4326	<li><tt>one</tt>: ordered and not equal</li>
				4327	<li><tt>ord</tt>: ordered (no nans)</li>
				4328	<li><tt>ueq</tt>: unordered or equal</li>
				4329	<li><tt>ugt</tt>: unordered or greater than </li>
				4330	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4331	<li><tt>ult</tt>: unordered or less than </li>
				4332	<li><tt>ule</tt>: unordered or less than or equal</li>
				4333	<li><tt>une</tt>: unordered or not equal</li>
				4334	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4335	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4336	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4337	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	4338	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4339	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4340	either a <a href="#t_floating">floating point</a> type
				4341	or a <a href="#t_vector">vector</a> of floating point type.
				4342	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4343	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4344	<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]	4345	according to the condition code given as <tt>cond</tt>.
				4346	If the operands are vectors, then the vectors are compared
				4347	element by element.
				4348	Each comparison performed
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4349	always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4350	<ol>
				4351	<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]	4352	<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]	4353	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4354	<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]	4355	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4356	<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]	4357	<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]	4358	<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]	4359	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4360	<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]	4361	<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]	4362	<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]	4363	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4364	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4365	<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]	4366	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4367	<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]	4368	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4369	<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]	4370	<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]	4371	<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]	4372	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4373	<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]	4374	<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]	4375	<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]	4376	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4377	<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]	4378	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4379	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4380
				4381	<h5>Example:</h5>
				4382	<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]	4383	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4384	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4385	<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]	4386	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4387
				4388	<p>Note that the code generator does not yet support vector types with
				4389	the <tt>fcmp</tt> instruction.</p>
				4390
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4391	</div>
				4392
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4393	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4394	<div class="doc_subsubsection">
				4395	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4396	</div>
				4397	<div class="doc_text">
				4398	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4399	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4400	</pre>
				4401	<h5>Overview:</h5>
				4402	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4403	element-wise comparison of its two integer vector operands.</p>
				4404	<h5>Arguments:</h5>
				4405	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4406	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4407	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4408	<ol>
				4409	<li><tt>eq</tt>: equal</li>
				4410	<li><tt>ne</tt>: not equal </li>
				4411	<li><tt>ugt</tt>: unsigned greater than</li>
				4412	<li><tt>uge</tt>: unsigned greater or equal</li>
				4413	<li><tt>ult</tt>: unsigned less than</li>
				4414	<li><tt>ule</tt>: unsigned less or equal</li>
				4415	<li><tt>sgt</tt>: signed greater than</li>
				4416	<li><tt>sge</tt>: signed greater or equal</li>
				4417	<li><tt>slt</tt>: signed less than</li>
				4418	<li><tt>sle</tt>: signed less or equal</li>
				4419	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4420	<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]	4421	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4422	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4423	<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]	4424	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4425	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4426	identical type as the values being compared. The most significant bit in each
				4427	element is 1 if the element-wise comparison evaluates to true, and is 0
				4428	otherwise. All other bits of the result are undefined. The condition codes
				4429	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4430	instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4431
				4432	<h5>Example:</h5>
				4433	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4434	<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>
				4435	<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]	4436	</pre>
				4437	</div>
				4438
				4439	<!-- _______________________________________________________________________ -->
				4440	<div class="doc_subsubsection">
				4441	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4442	</div>
				4443	<div class="doc_text">
				4444	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4445	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4446	<h5>Overview:</h5>
				4447	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4448	element-wise comparison of its two floating point vector operands. The output
				4449	elements have the same width as the input elements.</p>
				4450	<h5>Arguments:</h5>
				4451	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4452	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4453	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4454	<ol>
				4455	<li><tt>false</tt>: no comparison, always returns false</li>
				4456	<li><tt>oeq</tt>: ordered and equal</li>
				4457	<li><tt>ogt</tt>: ordered and greater than </li>
				4458	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4459	<li><tt>olt</tt>: ordered and less than </li>
				4460	<li><tt>ole</tt>: ordered and less than or equal</li>
				4461	<li><tt>one</tt>: ordered and not equal</li>
				4462	<li><tt>ord</tt>: ordered (no nans)</li>
				4463	<li><tt>ueq</tt>: unordered or equal</li>
				4464	<li><tt>ugt</tt>: unordered or greater than </li>
				4465	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4466	<li><tt>ult</tt>: unordered or less than </li>
				4467	<li><tt>ule</tt>: unordered or less than or equal</li>
				4468	<li><tt>une</tt>: unordered or not equal</li>
				4469	<li><tt>uno</tt>: unordered (either nans)</li>
				4470	<li><tt>true</tt>: no comparison, always returns true</li>
				4471	</ol>
				4472	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4473	<a href="#t_floating">floating point</a> typed. They must also be identical
				4474	types.</p>
				4475	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4476	<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]	4477	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4478	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4479	an identical number of elements as the values being compared, and each element
				4480	having identical with to the width of the floating point elements. The most
				4481	significant bit in each element is 1 if the element-wise comparison evaluates to
				4482	true, and is 0 otherwise. All other bits of the result are undefined. The
				4483	condition codes are evaluated identically to the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4484	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4485
				4486	<h5>Example:</h5>
				4487	<pre>
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	4488	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4489	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4490
				4491	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4492	<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]	4493	</pre>
				4494	</div>
				4495
				4496	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4497	<div class="doc_subsubsection">
				4498	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4499	</div>
				4500
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4501	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4502
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4503	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4504
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4505	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4506	<h5>Overview:</h5>
				4507	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4508	the SSA graph representing the function.</p>
				4509	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4510
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4511	<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]	4512	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4513	as arguments, with one pair for each predecessor basic block of the
				4514	current block. Only values of <a href="#t_firstclass">first class</a>
				4515	type may be used as the value arguments to the PHI node. Only labels
				4516	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4517
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4518	<p>There must be no non-phi instructions between the start of a basic
				4519	block and the PHI instructions: i.e. PHI instructions must be first in
				4520	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4521
Jay Foad	1a4eea5	2009-06-03 10:20:10 +0000	[diff] [blame^]	4522	<p>For the purposes of the SSA form, the use of each incoming value is
				4523	deemed to occur on the edge from the corresponding predecessor block
				4524	to the current block (but after any definition of an '<tt>invoke</tt>'
				4525	instruction's return value on the same edge).</p>
				4526
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4527	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4528
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4529	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4530	specified by the pair corresponding to the predecessor basic block that executed
				4531	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4532
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4533	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4534	<pre>
				4535	Loop: ; Infinite loop that counts from 0 on up...
				4536	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4537	%nextindvar = add i32 %indvar, 1
				4538	br label %Loop
				4539	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4540	</div>
				4541
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4542	<!-- _______________________________________________________________________ -->
				4543	<div class="doc_subsubsection">
				4544	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4545	</div>
				4546
				4547	<div class="doc_text">
				4548
				4549	<h5>Syntax:</h5>
				4550
				4551	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4552	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4553
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4554	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4555	</pre>
				4556
				4557	<h5>Overview:</h5>
				4558
				4559	<p>
				4560	The '<tt>select</tt>' instruction is used to choose one value based on a
				4561	condition, without branching.
				4562	</p>
				4563
				4564
				4565	<h5>Arguments:</h5>
				4566
				4567	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4568	The '<tt>select</tt>' instruction requires an 'i1' value or
				4569	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4570	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]	4571	type. If the val1/val2 are vectors and
				4572	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4573	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4574	</p>
				4575
				4576	<h5>Semantics:</h5>
				4577
				4578	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4579	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]	4580	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4581	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4582	<p>
				4583	If the condition is a vector of i1, then the value arguments must
				4584	be vectors of the same size, and the selection is done element
				4585	by element.
				4586	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4587
				4588	<h5>Example:</h5>
				4589
				4590	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4591	%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]	4592	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4593
				4594	<p>Note that the code generator does not yet support conditions
				4595	with vector type.</p>
				4596
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4597	</div>
				4598
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4599
				4600	<!-- _______________________________________________________________________ -->
				4601	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4602	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4603	</div>
				4604
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4605	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4606
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4607	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4608	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4609	<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]	4610	</pre>
				4611
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4612	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4613
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4614	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4615
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4616	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4617
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4618	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4619
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4620	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4621	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4622	<p>The optional "tail" marker indicates whether the callee function accesses
				4623	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]	4624	function call is eligible for tail call optimization. Note that calls may
				4625	be marked "tail" even if they do not occur before a <a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4626	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4627	</li>
				4628	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4629	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4630	convention</a> the call should use. If none is specified, the call defaults
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4631	to using C calling conventions.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4632	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4633
				4634	<li>
				4635	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4636	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4637	and '<tt>inreg</tt>' attributes are valid here.</p>
				4638	</li>
				4639
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4640	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4641	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4642	the type of the return value. Functions that return no value are marked
				4643	<tt><a href="#t_void">void</a></tt>.</p>
				4644	</li>
				4645	<li>
				4646	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4647	value being invoked. The argument types must match the types implied by
				4648	this signature. This type can be omitted if the function is not varargs
				4649	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]	4650	</li>
				4651	<li>
				4652	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4653	be invoked. In most cases, this is a direct function invocation, but
				4654	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]	4655	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4656	</li>
				4657	<li>
				4658	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4659	function signature argument types. All arguments must be of
				4660	<a href="#t_firstclass">first class</a> type. If the function signature
				4661	indicates the function accepts a variable number of arguments, the extra
				4662	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4663	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4664	<li>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4665	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4666	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4667	'<tt>readnone</tt>' attributes are valid here.</p>
				4668	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4669	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4670
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4671	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4672
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4673	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4674	transfer to a specified function, with its incoming arguments bound to
				4675	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4676	instruction in the called function, control flow continues with the
				4677	instruction after the function call, and the return value of the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4678	function is bound to the result argument.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4679
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4680	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4681
				4682	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4683	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4684	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4685	%X = tail call i32 @foo() <i>; yields i32</i>
				4686	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4687	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4688
				4689	%struct.A = type { i32, i8 }
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4690	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4691	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4692	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	6cbe8e9	2008-10-08 06:26:11 +0000	[diff] [blame]	4693	%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]	4694	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4695	</pre>
				4696
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4697	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4698
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4699	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4700	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4701	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4702	</div>
				4703
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4704	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4705
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4706	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4707
				4708	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4709	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4710	</pre>
				4711
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4712	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4713
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4714	<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]	4715	the "variable argument" area of a function call. It is used to implement the
				4716	<tt>va_arg</tt> macro in C.</p>
				4717
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4718	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4719
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4720	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4721	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4722	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]	4723	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4724
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4725	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4726
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4727	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4728	type from the specified <tt>va_list</tt> and causes the
				4729	<tt>va_list</tt> to point to the next argument. For more information,
				4730	see the variable argument handling <a href="#int_varargs">Intrinsic
				4731	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4732
				4733	<p>It is legal for this instruction to be called in a function which does not
				4734	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4735	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4736
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4737	<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]	4738	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4739	argument.</p>
				4740
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4741	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4742
				4743	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4744
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	4745	<p>Note that the code generator does not yet fully support va_arg
				4746	on many targets. Also, it does not currently support va_arg with
				4747	aggregate types on any target.</p>
				4748
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4749	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4750
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4751	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4752	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4753	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4754
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4755	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4756
				4757	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4758	well known names and semantics and are required to follow certain restrictions.
				4759	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4760	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]	4761	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]	4762
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4763	<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]	4764	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4765	begin with this prefix. Intrinsic functions must always be external functions:
				4766	you cannot define the body of intrinsic functions. Intrinsic functions may
				4767	only be used in call or invoke instructions: it is illegal to take the address
				4768	of an intrinsic function. Additionally, because intrinsic functions are part
				4769	of the LLVM language, it is required if any are added that they be documented
				4770	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4771
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4772	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4773	a family of functions that perform the same operation but on different data
				4774	types. Because LLVM can represent over 8 million different integer types,
				4775	overloading is used commonly to allow an intrinsic function to operate on any
				4776	integer type. One or more of the argument types or the result type can be
				4777	overloaded to accept any integer type. Argument types may also be defined as
				4778	exactly matching a previous argument's type or the result type. This allows an
				4779	intrinsic function which accepts multiple arguments, but needs all of them to
				4780	be of the same type, to only be overloaded with respect to a single argument or
				4781	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4782
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4783	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4784	encoded into its function name, each preceded by a period. Only those types
				4785	which are overloaded result in a name suffix. Arguments whose type is matched
				4786	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4787	take an integer of any width and returns an integer of exactly the same integer
				4788	width. This leads to a family of functions such as
				4789	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4790	Only one type, the return type, is overloaded, and only one type suffix is
				4791	required. Because the argument's type is matched against the return type, it
				4792	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4793
				4794	<p>To learn how to add an intrinsic function, please see the
				4795	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4796	</p>
				4797
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4798	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4799
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4800	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4801	<div class="doc_subsection">
				4802	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4803	</div>
				4804
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4805	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4806
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4807	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4808	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]	4809	intrinsic functions. These functions are related to the similarly
				4810	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4811
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4812	<p>All of these functions operate on arguments that use a
				4813	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4814	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4815	transformations should be prepared to handle these functions regardless of
				4816	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4817
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4818	<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]	4819	instruction and the variable argument handling intrinsic functions are
				4820	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4821
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4822	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4823	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4824	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4825	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4826	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4827	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4828	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4829
				4830	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4831	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4832
				4833	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4834	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4835	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4836	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4837	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4838
				4839	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4840	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4841	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4842	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4843
				4844	declare void @llvm.va_start(i8*)
				4845	declare void @llvm.va_copy(i8, i8)
				4846	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4847	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4848	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4849
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4850	</div>
				4851
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4852	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4853	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4854	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4855	</div>
				4856
				4857
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4858	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4859	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4860	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4861	<h5>Overview:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4862	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4863	<tt>*<arglist></tt> for subsequent use by <tt><a
				4864	href="#i_va_arg">va_arg</a></tt>.</p>
				4865
				4866	<h5>Arguments:</h5>
				4867
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4868	<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4869
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4870	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4871
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4872	<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4873	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4874	<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]	4875	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4876	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]	4877	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]	4878
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4879	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4880
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4881	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4882	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4883	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4884	</div>
				4885
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4886	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4887	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4888	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4889	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4890
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4891	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4892	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]	4893	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]	4894
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4895	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4896
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4897	<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]	4898
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4899	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4900
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4901	<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]	4902	macro available in C. In a target-dependent way, it destroys the
				4903	<tt>va_list</tt> element to which the argument points. Calls to <a
				4904	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4905	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4906	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4907
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4908	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4909
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4910	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4911	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4912	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4913	</div>
				4914
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4915	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4916
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4917	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4918
				4919	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4920	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4921	</pre>
				4922
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4923	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4924
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4925	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4926	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4927
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4928	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4929
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4930	<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]	4931	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]	4932
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4933
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4934	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4935
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4936	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4937	macro available in C. In a target-dependent way, it copies the source
				4938	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4939	intrinsic is necessary because the <tt><a href="#int_va_start">
				4940	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4941	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4942
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4943	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4944
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4945	<!-- ======================================================================= -->
				4946	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4947	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4948	</div>
				4949
				4950	<div class="doc_text">
				4951
				4952	<p>
				4953	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4954	Collection</a> (GC) requires the implementation and generation of these
				4955	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4956	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]	4957	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4958	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]	4959	Front-ends for type-safe garbage collected languages should generate these
				4960	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4961	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4962	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	4963
				4964	<p>The garbage collection intrinsics only operate on objects in the generic
				4965	address space (address space zero).</p>
				4966
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4967	</div>
				4968
				4969	<!-- _______________________________________________________________________ -->
				4970	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4971	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4972	</div>
				4973
				4974	<div class="doc_text">
				4975
				4976	<h5>Syntax:</h5>
				4977
				4978	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4979	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4980	</pre>
				4981
				4982	<h5>Overview:</h5>
				4983
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	4984	<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]	4985	the code generator, and allows some metadata to be associated with it.</p>
				4986
				4987	<h5>Arguments:</h5>
				4988
				4989	<p>The first argument specifies the address of a stack object that contains the
				4990	root pointer. The second pointer (which must be either a constant or a global
				4991	value address) contains the meta-data to be associated with the root.</p>
				4992
				4993	<h5>Semantics:</h5>
				4994
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	4995	<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]	4996	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4997	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4998	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4999	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5000
				5001	</div>
				5002
				5003
				5004	<!-- _______________________________________________________________________ -->
				5005	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5006	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5007	</div>
				5008
				5009	<div class="doc_text">
				5010
				5011	<h5>Syntax:</h5>
				5012
				5013	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5014	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5015	</pre>
				5016
				5017	<h5>Overview:</h5>
				5018
				5019	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5020	locations, allowing garbage collector implementations that require read
				5021	barriers.</p>
				5022
				5023	<h5>Arguments:</h5>
				5024
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5025	<p>The second argument is the address to read from, which should be an address
				5026	allocated from the garbage collector. The first object is a pointer to the
				5027	start of the referenced object, if needed by the language runtime (otherwise
				5028	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5029
				5030	<h5>Semantics:</h5>
				5031
				5032	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5033	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5034	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5035	may only be used in a function which <a href="#gc">specifies a GC
				5036	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5037
				5038	</div>
				5039
				5040
				5041	<!-- _______________________________________________________________________ -->
				5042	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5043	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5044	</div>
				5045
				5046	<div class="doc_text">
				5047
				5048	<h5>Syntax:</h5>
				5049
				5050	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5051	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5052	</pre>
				5053
				5054	<h5>Overview:</h5>
				5055
				5056	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5057	locations, allowing garbage collector implementations that require write
				5058	barriers (such as generational or reference counting collectors).</p>
				5059
				5060	<h5>Arguments:</h5>
				5061
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5062	<p>The first argument is the reference to store, the second is the start of the
				5063	object to store it to, and the third is the address of the field of Obj to
				5064	store to. If the runtime does not require a pointer to the object, Obj may be
				5065	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5066
				5067	<h5>Semantics:</h5>
				5068
				5069	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5070	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5071	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5072	may only be used in a function which <a href="#gc">specifies a GC
				5073	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5074
				5075	</div>
				5076
				5077
				5078
				5079	<!-- ======================================================================= -->
				5080	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5081	<a name="int_codegen">Code Generator Intrinsics</a>
				5082	</div>
				5083
				5084	<div class="doc_text">
				5085	<p>
				5086	These intrinsics are provided by LLVM to expose special features that may only
				5087	be implemented with code generator support.
				5088	</p>
				5089
				5090	</div>
				5091
				5092	<!-- _______________________________________________________________________ -->
				5093	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5094	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5095	</div>
				5096
				5097	<div class="doc_text">
				5098
				5099	<h5>Syntax:</h5>
				5100	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5101	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5102	</pre>
				5103
				5104	<h5>Overview:</h5>
				5105
				5106	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5107	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5108	target-specific value indicating the return address of the current function
				5109	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5110	</p>
				5111
				5112	<h5>Arguments:</h5>
				5113
				5114	<p>
				5115	The argument to this intrinsic indicates which function to return the address
				5116	for. Zero indicates the calling function, one indicates its caller, etc. The
				5117	argument is <b>required</b> to be a constant integer value.
				5118	</p>
				5119
				5120	<h5>Semantics:</h5>
				5121
				5122	<p>
				5123	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5124	the return address of the specified call frame, or zero if it cannot be
				5125	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5126	for arguments other than zero, so it should only be used for debugging purposes.
				5127	</p>
				5128
				5129	<p>
				5130	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5131	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]	5132	source-language caller.
				5133	</p>
				5134	</div>
				5135
				5136
				5137	<!-- _______________________________________________________________________ -->
				5138	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5139	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5140	</div>
				5141
				5142	<div class="doc_text">
				5143
				5144	<h5>Syntax:</h5>
				5145	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5146	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5147	</pre>
				5148
				5149	<h5>Overview:</h5>
				5150
				5151	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5152	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5153	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5154	</p>
				5155
				5156	<h5>Arguments:</h5>
				5157
				5158	<p>
				5159	The argument to this intrinsic indicates which function to return the frame
				5160	pointer for. Zero indicates the calling function, one indicates its caller,
				5161	etc. The argument is <b>required</b> to be a constant integer value.
				5162	</p>
				5163
				5164	<h5>Semantics:</h5>
				5165
				5166	<p>
				5167	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5168	the frame address of the specified call frame, or zero if it cannot be
				5169	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5170	for arguments other than zero, so it should only be used for debugging purposes.
				5171	</p>
				5172
				5173	<p>
				5174	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5175	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]	5176	source-language caller.
				5177	</p>
				5178	</div>
				5179
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5180	<!-- _______________________________________________________________________ -->
				5181	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5182	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5183	</div>
				5184
				5185	<div class="doc_text">
				5186
				5187	<h5>Syntax:</h5>
				5188	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5189	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5190	</pre>
				5191
				5192	<h5>Overview:</h5>
				5193
				5194	<p>
				5195	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]	5196	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5197	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5198	features like scoped automatic variable sized arrays in C99.
				5199	</p>
				5200
				5201	<h5>Semantics:</h5>
				5202
				5203	<p>
				5204	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]	5205	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5206	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5207	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5208	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5209	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5210	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5211	</p>
				5212
				5213	</div>
				5214
				5215	<!-- _______________________________________________________________________ -->
				5216	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5217	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5218	</div>
				5219
				5220	<div class="doc_text">
				5221
				5222	<h5>Syntax:</h5>
				5223	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5224	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5225	</pre>
				5226
				5227	<h5>Overview:</h5>
				5228
				5229	<p>
				5230	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5231	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]	5232	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5233	useful for implementing language features like scoped automatic variable sized
				5234	arrays in C99.
				5235	</p>
				5236
				5237	<h5>Semantics:</h5>
				5238
				5239	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5240	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]	5241	</p>
				5242
				5243	</div>
				5244
				5245
				5246	<!-- _______________________________________________________________________ -->
				5247	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5248	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5249	</div>
				5250
				5251	<div class="doc_text">
				5252
				5253	<h5>Syntax:</h5>
				5254	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5255	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5256	</pre>
				5257
				5258	<h5>Overview:</h5>
				5259
				5260
				5261	<p>
				5262	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]	5263	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5264	no
				5265	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	5266	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5267	</p>
				5268
				5269	<h5>Arguments:</h5>
				5270
				5271	<p>
				5272	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5273	determining if the fetch should be for a read (0) or write (1), and
				5274	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	5275	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]	5276	<tt>locality</tt> arguments must be constant integers.
				5277	</p>
				5278
				5279	<h5>Semantics:</h5>
				5280
				5281	<p>
				5282	This intrinsic does not modify the behavior of the program. In particular,
				5283	prefetches cannot trap and do not produce a value. On targets that support this
				5284	intrinsic, the prefetch can provide hints to the processor cache for better
				5285	performance.
				5286	</p>
				5287
				5288	</div>
				5289
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5290	<!-- _______________________________________________________________________ -->
				5291	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5292	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5293	</div>
				5294
				5295	<div class="doc_text">
				5296
				5297	<h5>Syntax:</h5>
				5298	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5299	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5300	</pre>
				5301
				5302	<h5>Overview:</h5>
				5303
				5304
				5305	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5306	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]	5307	(PC) in a region of
				5308	code to simulators and other tools. The method is target specific, but it is
				5309	expected that the marker will use exported symbols to transmit the PC of the
				5310	marker.
				5311	The marker makes no guarantees that it will remain with any specific instruction
				5312	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]	5313	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5314	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5315	</p>
				5316
				5317	<h5>Arguments:</h5>
				5318
				5319	<p>
				5320	<tt>id</tt> is a numerical id identifying the marker.
				5321	</p>
				5322
				5323	<h5>Semantics:</h5>
				5324
				5325	<p>
				5326	This intrinsic does not modify the behavior of the program. Backends that do not
				5327	support this intrinisic may ignore it.
				5328	</p>
				5329
				5330	</div>
				5331
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5332	<!-- _______________________________________________________________________ -->
				5333	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5334	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5335	</div>
				5336
				5337	<div class="doc_text">
				5338
				5339	<h5>Syntax:</h5>
				5340	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5341	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5342	</pre>
				5343
				5344	<h5>Overview:</h5>
				5345
				5346
				5347	<p>
				5348	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5349	counter register (or similar low latency, high accuracy clocks) on those targets
				5350	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5351	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5352	should only be used for small timings.
				5353	</p>
				5354
				5355	<h5>Semantics:</h5>
				5356
				5357	<p>
				5358	When directly supported, reading the cycle counter should not modify any memory.
				5359	Implementations are allowed to either return a application specific value or a
				5360	system wide value. On backends without support, this is lowered to a constant 0.
				5361	</p>
				5362
				5363	</div>
				5364
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5365	<!-- ======================================================================= -->
				5366	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5367	<a name="int_libc">Standard C Library Intrinsics</a>
				5368	</div>
				5369
				5370	<div class="doc_text">
				5371	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5372	LLVM provides intrinsics for a few important standard C library functions.
				5373	These intrinsics allow source-language front-ends to pass information about the
				5374	alignment of the pointer arguments to the code generator, providing opportunity
				5375	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5376	</p>
				5377
				5378	</div>
				5379
				5380	<!-- _______________________________________________________________________ -->
				5381	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5382	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5383	</div>
				5384
				5385	<div class="doc_text">
				5386
				5387	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5388	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5389	width. Not all targets support all bit widths however.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5390	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5391	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5392	i8 <len>, i32 <align>)
				5393	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5394	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5395	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5396	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5397	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5398	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5399	</pre>
				5400
				5401	<h5>Overview:</h5>
				5402
				5403	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5404	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]	5405	location to the destination location.
				5406	</p>
				5407
				5408	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5409	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5410	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5411	</p>
				5412
				5413	<h5>Arguments:</h5>
				5414
				5415	<p>
				5416	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]	5417	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5418	specifying the number of bytes to copy, and the fourth argument is the alignment
				5419	of the source and destination locations.
				5420	</p>
				5421
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5422	<p>
				5423	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]	5424	the caller guarantees that both the source and destination pointers are aligned
				5425	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5426	</p>
				5427
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5428	<h5>Semantics:</h5>
				5429
				5430	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5431	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]	5432	location to the destination location, which are not allowed to overlap. It
				5433	copies "len" bytes of memory over. If the argument is known to be aligned to
				5434	some boundary, this can be specified as the fourth argument, otherwise it should
				5435	be set to 0 or 1.
				5436	</p>
				5437	</div>
				5438
				5439
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5440	<!-- _______________________________________________________________________ -->
				5441	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5442	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5443	</div>
				5444
				5445	<div class="doc_text">
				5446
				5447	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5448	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5449	width. Not all targets support all bit widths however.</p>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5450	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5451	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5452	i8 <len>, i32 <align>)
				5453	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5454	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5455	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5456	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5457	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5458	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5459	</pre>
				5460
				5461	<h5>Overview:</h5>
				5462
				5463	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5464	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5465	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5466	'<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]	5467	</p>
				5468
				5469	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5470	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5471	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5472	</p>
				5473
				5474	<h5>Arguments:</h5>
				5475
				5476	<p>
				5477	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]	5478	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5479	specifying the number of bytes to copy, and the fourth argument is the alignment
				5480	of the source and destination locations.
				5481	</p>
				5482
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5483	<p>
				5484	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]	5485	the caller guarantees that the source and destination pointers are aligned to
				5486	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5487	</p>
				5488
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5489	<h5>Semantics:</h5>
				5490
				5491	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5492	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]	5493	location to the destination location, which may overlap. It
				5494	copies "len" bytes of memory over. If the argument is known to be aligned to
				5495	some boundary, this can be specified as the fourth argument, otherwise it should
				5496	be set to 0 or 1.
				5497	</p>
				5498	</div>
				5499
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5500
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5501	<!-- _______________________________________________________________________ -->
				5502	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5503	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5504	</div>
				5505
				5506	<div class="doc_text">
				5507
				5508	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5509	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5510	width. Not all targets support all bit widths however.</p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5511	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5512	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5513	i8 <len>, i32 <align>)
				5514	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5515	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5516	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5517	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5518	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5519	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5520	</pre>
				5521
				5522	<h5>Overview:</h5>
				5523
				5524	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5525	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]	5526	byte value.
				5527	</p>
				5528
				5529	<p>
				5530	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5531	does not return a value, and takes an extra alignment argument.
				5532	</p>
				5533
				5534	<h5>Arguments:</h5>
				5535
				5536	<p>
				5537	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]	5538	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5539	argument specifying the number of bytes to fill, and the fourth argument is the
				5540	known alignment of destination location.
				5541	</p>
				5542
				5543	<p>
				5544	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]	5545	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5546	</p>
				5547
				5548	<h5>Semantics:</h5>
				5549
				5550	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5551	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5552	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5553	destination location. If the argument is known to be aligned to some boundary,
				5554	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5555	1.
				5556	</p>
				5557	</div>
				5558
				5559
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5560	<!-- _______________________________________________________________________ -->
				5561	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5562	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5563	</div>
				5564
				5565	<div class="doc_text">
				5566
				5567	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5568	<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]	5569	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5570	types however.</p>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5571	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5572	declare float @llvm.sqrt.f32(float %Val)
				5573	declare double @llvm.sqrt.f64(double %Val)
				5574	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5575	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5576	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5577	</pre>
				5578
				5579	<h5>Overview:</h5>
				5580
				5581	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5582	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]	5583	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]	5584	<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]	5585	negative numbers other than -0.0 (which allows for better optimization, because
				5586	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5587	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5588	</p>
				5589
				5590	<h5>Arguments:</h5>
				5591
				5592	<p>
				5593	The argument and return value are floating point numbers of the same type.
				5594	</p>
				5595
				5596	<h5>Semantics:</h5>
				5597
				5598	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5599	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]	5600	floating point number.
				5601	</p>
				5602	</div>
				5603
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5604	<!-- _______________________________________________________________________ -->
				5605	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5606	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5607	</div>
				5608
				5609	<div class="doc_text">
				5610
				5611	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5612	<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]	5613	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5614	types however.</p>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5615	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5616	declare float @llvm.powi.f32(float %Val, i32 %power)
				5617	declare double @llvm.powi.f64(double %Val, i32 %power)
				5618	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5619	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5620	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5621	</pre>
				5622
				5623	<h5>Overview:</h5>
				5624
				5625	<p>
				5626	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5627	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5628	multiplications is not defined. When a vector of floating point type is
				5629	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5630	</p>
				5631
				5632	<h5>Arguments:</h5>
				5633
				5634	<p>
				5635	The second argument is an integer power, and the first is a value to raise to
				5636	that power.
				5637	</p>
				5638
				5639	<h5>Semantics:</h5>
				5640
				5641	<p>
				5642	This function returns the first value raised to the second power with an
				5643	unspecified sequence of rounding operations.</p>
				5644	</div>
				5645
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5646	<!-- _______________________________________________________________________ -->
				5647	<div class="doc_subsubsection">
				5648	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5649	</div>
				5650
				5651	<div class="doc_text">
				5652
				5653	<h5>Syntax:</h5>
				5654	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5655	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5656	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5657	<pre>
				5658	declare float @llvm.sin.f32(float %Val)
				5659	declare double @llvm.sin.f64(double %Val)
				5660	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5661	declare fp128 @llvm.sin.f128(fp128 %Val)
				5662	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5663	</pre>
				5664
				5665	<h5>Overview:</h5>
				5666
				5667	<p>
				5668	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5669	</p>
				5670
				5671	<h5>Arguments:</h5>
				5672
				5673	<p>
				5674	The argument and return value are floating point numbers of the same type.
				5675	</p>
				5676
				5677	<h5>Semantics:</h5>
				5678
				5679	<p>
				5680	This function returns the sine of the specified operand, returning the
				5681	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]	5682	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5683	</div>
				5684
				5685	<!-- _______________________________________________________________________ -->
				5686	<div class="doc_subsubsection">
				5687	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5688	</div>
				5689
				5690	<div class="doc_text">
				5691
				5692	<h5>Syntax:</h5>
				5693	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5694	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5695	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5696	<pre>
				5697	declare float @llvm.cos.f32(float %Val)
				5698	declare double @llvm.cos.f64(double %Val)
				5699	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5700	declare fp128 @llvm.cos.f128(fp128 %Val)
				5701	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5702	</pre>
				5703
				5704	<h5>Overview:</h5>
				5705
				5706	<p>
				5707	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5708	</p>
				5709
				5710	<h5>Arguments:</h5>
				5711
				5712	<p>
				5713	The argument and return value are floating point numbers of the same type.
				5714	</p>
				5715
				5716	<h5>Semantics:</h5>
				5717
				5718	<p>
				5719	This function returns the cosine of the specified operand, returning the
				5720	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]	5721	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5722	</div>
				5723
				5724	<!-- _______________________________________________________________________ -->
				5725	<div class="doc_subsubsection">
				5726	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5727	</div>
				5728
				5729	<div class="doc_text">
				5730
				5731	<h5>Syntax:</h5>
				5732	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5733	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5734	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5735	<pre>
				5736	declare float @llvm.pow.f32(float %Val, float %Power)
				5737	declare double @llvm.pow.f64(double %Val, double %Power)
				5738	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5739	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5740	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5741	</pre>
				5742
				5743	<h5>Overview:</h5>
				5744
				5745	<p>
				5746	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5747	specified (positive or negative) power.
				5748	</p>
				5749
				5750	<h5>Arguments:</h5>
				5751
				5752	<p>
				5753	The second argument is a floating point power, and the first is a value to
				5754	raise to that power.
				5755	</p>
				5756
				5757	<h5>Semantics:</h5>
				5758
				5759	<p>
				5760	This function returns the first value raised to the second power,
				5761	returning the
				5762	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]	5763	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5764	</div>
				5765
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5766
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5767	<!-- ======================================================================= -->
				5768	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5769	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5770	</div>
				5771
				5772	<div class="doc_text">
				5773	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5774	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5775	These allow efficient code generation for some algorithms.
				5776	</p>
				5777
				5778	</div>
				5779
				5780	<!-- _______________________________________________________________________ -->
				5781	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5782	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5783	</div>
				5784
				5785	<div class="doc_text">
				5786
				5787	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5788	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5789	type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5790	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5791	declare i16 @llvm.bswap.i16(i16 <id>)
				5792	declare i32 @llvm.bswap.i32(i32 <id>)
				5793	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5794	</pre>
				5795
				5796	<h5>Overview:</h5>
				5797
				5798	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5799	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]	5800	values with an even number of bytes (positive multiple of 16 bits). These are
				5801	useful for performing operations on data that is not in the target's native
				5802	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5803	</p>
				5804
				5805	<h5>Semantics:</h5>
				5806
				5807	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5808	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]	5809	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5810	intrinsic returns an i32 value that has the four bytes of the input i32
				5811	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]	5812	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5813	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5814	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5815	</p>
				5816
				5817	</div>
				5818
				5819	<!-- _______________________________________________________________________ -->
				5820	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5821	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5822	</div>
				5823
				5824	<div class="doc_text">
				5825
				5826	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5827	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5828	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5829	<pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5830	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5831	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5832	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5833	declare i64 @llvm.ctpop.i64(i64 <src>)
				5834	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5835	</pre>
				5836
				5837	<h5>Overview:</h5>
				5838
				5839	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5840	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5841	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5842	</p>
				5843
				5844	<h5>Arguments:</h5>
				5845
				5846	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5847	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]	5848	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5849	</p>
				5850
				5851	<h5>Semantics:</h5>
				5852
				5853	<p>
				5854	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5855	</p>
				5856	</div>
				5857
				5858	<!-- _______________________________________________________________________ -->
				5859	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5860	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5861	</div>
				5862
				5863	<div class="doc_text">
				5864
				5865	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5866	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5867	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5868	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5869	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5870	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5871	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5872	declare i64 @llvm.ctlz.i64(i64 <src>)
				5873	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5874	</pre>
				5875
				5876	<h5>Overview:</h5>
				5877
				5878	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5879	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5880	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5881	</p>
				5882
				5883	<h5>Arguments:</h5>
				5884
				5885	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5886	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]	5887	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5888	</p>
				5889
				5890	<h5>Semantics:</h5>
				5891
				5892	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5893	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5894	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]	5895	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5896	</p>
				5897	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5898
				5899
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5900
				5901	<!-- _______________________________________________________________________ -->
				5902	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5903	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5904	</div>
				5905
				5906	<div class="doc_text">
				5907
				5908	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5909	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5910	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5911	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5912	declare i8 @llvm.cttz.i8 (i8 <src>)
				5913	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5914	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5915	declare i64 @llvm.cttz.i64(i64 <src>)
				5916	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5917	</pre>
				5918
				5919	<h5>Overview:</h5>
				5920
				5921	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5922	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5923	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5924	</p>
				5925
				5926	<h5>Arguments:</h5>
				5927
				5928	<p>
				5929	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]	5930	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5931	</p>
				5932
				5933	<h5>Semantics:</h5>
				5934
				5935	<p>
				5936	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5937	in a variable. If the src == 0 then the result is the size in bits of the type
				5938	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5939	</p>
				5940	</div>
				5941
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	5942	<!-- _______________________________________________________________________ -->
				5943	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5944	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5945	</div>
				5946
				5947	<div class="doc_text">
				5948
				5949	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5950	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5951	on any integer bit width.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5952	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5953	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5954	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5955	</pre>
				5956
				5957	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5958	<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]	5959	range of bits from an integer value and returns them in the same bit width as
				5960	the original value.</p>
				5961
				5962	<h5>Arguments:</h5>
				5963	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5964	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]	5965	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]	5966
				5967	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5968	<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]	5969	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5970	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5971	operates in forward mode.</p>
				5972	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5973	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]	5974	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5975	<ol>
				5976	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5977	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5978	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5979	to determine the number of bits to retain.</li>
				5980	<li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5981	<li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5982	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	5983	<p>In reverse mode, a similar computation is made except that the bits are
				5984	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5985	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5986	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5987	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5988	</div>
				5989
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5990	<div class="doc_subsubsection">
				5991	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5992	</div>
				5993
				5994	<div class="doc_text">
				5995
				5996	<h5>Syntax:</h5>
				5997	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5998	on any integer bit width.</p>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5999	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6000	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				6001	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]	6002	</pre>
				6003
				6004	<h5>Overview:</h5>
				6005	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				6006	of bits in an integer value with another integer value. It returns the integer
				6007	with the replaced bits.</p>
				6008
				6009	<h5>Arguments:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6010	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				6011	any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6012	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				6013	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				6014	type since they specify only a bit index.</p>
				6015
				6016	<h5>Semantics:</h5>
				6017	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				6018	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				6019	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				6020	operates in forward mode.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6021
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6022	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				6023	truncating it down to the size of the replacement area or zero extending it
				6024	up to that size.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6025
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6026	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				6027	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				6028	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6029	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6030
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6031	<p>In reverse mode, a similar computation is made except that the bits are
				6032	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6033	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6034
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6035	<h5>Examples:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6036
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6037	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6038	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6039	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6040	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6041	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6042	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	6043	</pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6044
				6045	</div>
				6046
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6047	<!-- ======================================================================= -->
				6048	<div class="doc_subsection">
				6049	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6050	</div>
				6051
				6052	<div class="doc_text">
				6053	<p>
				6054	LLVM provides intrinsics for some arithmetic with overflow operations.
				6055	</p>
				6056
				6057	</div>
				6058
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6059	<!-- _______________________________________________________________________ -->
				6060	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6061	<a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6062	</div>
				6063
				6064	<div class="doc_text">
				6065
				6066	<h5>Syntax:</h5>
				6067
				6068	<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6069	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6070
				6071	<pre>
				6072	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6073	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6074	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6075	</pre>
				6076
				6077	<h5>Overview:</h5>
				6078
				6079	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6080	a signed addition of the two arguments, and indicate whether an overflow
				6081	occurred during the signed summation.</p>
				6082
				6083	<h5>Arguments:</h5>
				6084
				6085	<p>The arguments (%a and %b) and the first element of the result structure may
				6086	be of integer types of any bit width, but they must have the same bit width. The
				6087	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6088	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6089
				6090	<h5>Semantics:</h5>
				6091
				6092	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6093	a signed addition of the two variables. They return a structure — the
				6094	first element of which is the signed summation, and the second element of which
				6095	is a bit specifying if the signed summation resulted in an overflow.</p>
				6096
				6097	<h5>Examples:</h5>
				6098	<pre>
				6099	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6100	%sum = extractvalue {i32, i1} %res, 0
				6101	%obit = extractvalue {i32, i1} %res, 1
				6102	br i1 %obit, label %overflow, label %normal
				6103	</pre>
				6104
				6105	</div>
				6106
				6107	<!-- _______________________________________________________________________ -->
				6108	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6109	<a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6110	</div>
				6111
				6112	<div class="doc_text">
				6113
				6114	<h5>Syntax:</h5>
				6115
				6116	<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6117	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6118
				6119	<pre>
				6120	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6121	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6122	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6123	</pre>
				6124
				6125	<h5>Overview:</h5>
				6126
				6127	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6128	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6129	during the unsigned summation.</p>
				6130
				6131	<h5>Arguments:</h5>
				6132
				6133	<p>The arguments (%a and %b) and the first element of the result structure may
				6134	be of integer types of any bit width, but they must have the same bit width. The
				6135	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6136	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6137
				6138	<h5>Semantics:</h5>
				6139
				6140	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6141	an unsigned addition of the two arguments. They return a structure — the
				6142	first element of which is the sum, and the second element of which is a bit
				6143	specifying if the unsigned summation resulted in a carry.</p>
				6144
				6145	<h5>Examples:</h5>
				6146	<pre>
				6147	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6148	%sum = extractvalue {i32, i1} %res, 0
				6149	%obit = extractvalue {i32, i1} %res, 1
				6150	br i1 %obit, label %carry, label %normal
				6151	</pre>
				6152
				6153	</div>
				6154
				6155	<!-- _______________________________________________________________________ -->
				6156	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6157	<a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6158	</div>
				6159
				6160	<div class="doc_text">
				6161
				6162	<h5>Syntax:</h5>
				6163
				6164	<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6165	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6166
				6167	<pre>
				6168	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6169	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6170	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6171	</pre>
				6172
				6173	<h5>Overview:</h5>
				6174
				6175	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6176	a signed subtraction of the two arguments, and indicate whether an overflow
				6177	occurred during the signed subtraction.</p>
				6178
				6179	<h5>Arguments:</h5>
				6180
				6181	<p>The arguments (%a and %b) and the first element of the result structure may
				6182	be of integer types of any bit width, but they must have the same bit width. The
				6183	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6184	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6185
				6186	<h5>Semantics:</h5>
				6187
				6188	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6189	a signed subtraction of the two arguments. They return a structure — the
				6190	first element of which is the subtraction, and the second element of which is a bit
				6191	specifying if the signed subtraction resulted in an overflow.</p>
				6192
				6193	<h5>Examples:</h5>
				6194	<pre>
				6195	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6196	%sum = extractvalue {i32, i1} %res, 0
				6197	%obit = extractvalue {i32, i1} %res, 1
				6198	br i1 %obit, label %overflow, label %normal
				6199	</pre>
				6200
				6201	</div>
				6202
				6203	<!-- _______________________________________________________________________ -->
				6204	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6205	<a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6206	</div>
				6207
				6208	<div class="doc_text">
				6209
				6210	<h5>Syntax:</h5>
				6211
				6212	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6213	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6214
				6215	<pre>
				6216	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6217	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6218	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6219	</pre>
				6220
				6221	<h5>Overview:</h5>
				6222
				6223	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6224	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6225	occurred during the unsigned subtraction.</p>
				6226
				6227	<h5>Arguments:</h5>
				6228
				6229	<p>The arguments (%a and %b) and the first element of the result structure may
				6230	be of integer types of any bit width, but they must have the same bit width. The
				6231	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6232	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6233
				6234	<h5>Semantics:</h5>
				6235
				6236	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6237	an unsigned subtraction of the two arguments. They return a structure — the
				6238	first element of which is the subtraction, and the second element of which is a bit
				6239	specifying if the unsigned subtraction resulted in an overflow.</p>
				6240
				6241	<h5>Examples:</h5>
				6242	<pre>
				6243	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6244	%sum = extractvalue {i32, i1} %res, 0
				6245	%obit = extractvalue {i32, i1} %res, 1
				6246	br i1 %obit, label %overflow, label %normal
				6247	</pre>
				6248
				6249	</div>
				6250
				6251	<!-- _______________________________________________________________________ -->
				6252	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6253	<a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6254	</div>
				6255
				6256	<div class="doc_text">
				6257
				6258	<h5>Syntax:</h5>
				6259
				6260	<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6261	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6262
				6263	<pre>
				6264	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6265	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6266	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6267	</pre>
				6268
				6269	<h5>Overview:</h5>
				6270
				6271	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6272	a signed multiplication of the two arguments, and indicate whether an overflow
				6273	occurred during the signed multiplication.</p>
				6274
				6275	<h5>Arguments:</h5>
				6276
				6277	<p>The arguments (%a and %b) and the first element of the result structure may
				6278	be of integer types of any bit width, but they must have the same bit width. The
				6279	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6280	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6281
				6282	<h5>Semantics:</h5>
				6283
				6284	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6285	a signed multiplication of the two arguments. They return a structure —
				6286	the first element of which is the multiplication, and the second element of
				6287	which is a bit specifying if the signed multiplication resulted in an
				6288	overflow.</p>
				6289
				6290	<h5>Examples:</h5>
				6291	<pre>
				6292	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6293	%sum = extractvalue {i32, i1} %res, 0
				6294	%obit = extractvalue {i32, i1} %res, 1
				6295	br i1 %obit, label %overflow, label %normal
				6296	</pre>
				6297
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6298	</div>
				6299
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	6300	<!-- _______________________________________________________________________ -->
				6301	<div class="doc_subsubsection">
				6302	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6303	</div>
				6304
				6305	<div class="doc_text">
				6306
				6307	<h5>Syntax:</h5>
				6308
				6309	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6310	on any integer bit width.</p>
				6311
				6312	<pre>
				6313	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6314	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6315	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6316	</pre>
				6317
				6318	<h5>Overview:</h5>
				6319
				6320	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6321	actively being fixed, but it should not currently be used!</i></p>
				6322
				6323	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6324	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6325	occurred during the unsigned multiplication.</p>
				6326
				6327	<h5>Arguments:</h5>
				6328
				6329	<p>The arguments (%a and %b) and the first element of the result structure may
				6330	be of integer types of any bit width, but they must have the same bit width. The
				6331	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6332	and <tt>%b</tt> are the two values that will undergo unsigned
				6333	multiplication.</p>
				6334
				6335	<h5>Semantics:</h5>
				6336
				6337	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6338	an unsigned multiplication of the two arguments. They return a structure —
				6339	the first element of which is the multiplication, and the second element of
				6340	which is a bit specifying if the unsigned multiplication resulted in an
				6341	overflow.</p>
				6342
				6343	<h5>Examples:</h5>
				6344	<pre>
				6345	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6346	%sum = extractvalue {i32, i1} %res, 0
				6347	%obit = extractvalue {i32, i1} %res, 1
				6348	br i1 %obit, label %overflow, label %normal
				6349	</pre>
				6350
				6351	</div>
				6352
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	6353	<!-- ======================================================================= -->
				6354	<div class="doc_subsection">
				6355	<a name="int_debugger">Debugger Intrinsics</a>
				6356	</div>
				6357
				6358	<div class="doc_text">
				6359	<p>
				6360	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6361	are described in the <a
				6362	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6363	Debugging</a> document.
				6364	</p>
				6365	</div>
				6366
				6367
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6368	<!-- ======================================================================= -->
				6369	<div class="doc_subsection">
				6370	<a name="int_eh">Exception Handling Intrinsics</a>
				6371	</div>
				6372
				6373	<div class="doc_text">
				6374	<p> The LLVM exception handling intrinsics (which all start with
				6375	<tt>llvm.eh.</tt> prefix), are described in the <a
				6376	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6377	Handling</a> document. </p>
				6378	</div>
				6379
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6380	<!-- ======================================================================= -->
				6381	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6382	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6383	</div>
				6384
				6385	<div class="doc_text">
				6386	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6387	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6388	the <tt>nest</tt> attribute, from a function. The result is a callable
				6389	function pointer lacking the nest parameter - the caller does not need
				6390	to provide a value for it. Instead, the value to use is stored in
				6391	advance in a "trampoline", a block of memory usually allocated
				6392	on the stack, which also contains code to splice the nest value into the
				6393	argument list. This is used to implement the GCC nested function address
				6394	extension.
				6395	</p>
				6396	<p>
				6397	For example, if the function is
				6398	<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]	6399	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]	6400	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6401	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6402	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6403	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6404	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6405	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	6406	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6407	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]	6408	</div>
				6409
				6410	<!-- _______________________________________________________________________ -->
				6411	<div class="doc_subsubsection">
				6412	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6413	</div>
				6414	<div class="doc_text">
				6415	<h5>Syntax:</h5>
				6416	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6417	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6418	</pre>
				6419	<h5>Overview:</h5>
				6420	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6421	This fills the memory pointed to by <tt>tramp</tt> with code
				6422	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6423	</p>
				6424	<h5>Arguments:</h5>
				6425	<p>
				6426	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6427	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6428	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]	6429	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6430	currently provides no portable way of determining them, so a front-end that
				6431	generates this intrinsic needs to have some target-specific knowledge.
				6432	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]	6433	</p>
				6434	<h5>Semantics:</h5>
				6435	<p>
				6436	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]	6437	dependent code, turning it into a function. A pointer to this function is
				6438	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6439	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6440	before being called. The new function's signature is the same as that of
				6441	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6442	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6443	of pointer type. Calling the new function is equivalent to calling
				6444	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6445	missing <tt>nest</tt> argument. If, after calling
				6446	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6447	modified, then the effect of any later call to the returned function pointer is
				6448	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6449	</p>
				6450	</div>
				6451
				6452	<!-- ======================================================================= -->
				6453	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6454	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6455	</div>
				6456
				6457	<div class="doc_text">
				6458	<p>
				6459	These intrinsic functions expand the "universal IR" of LLVM to represent
				6460	hardware constructs for atomic operations and memory synchronization. This
				6461	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]	6462	is aimed at a low enough level to allow any programming models or APIs
				6463	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6464	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6465	hardware behavior. Just as hardware provides a "universal IR" for source
				6466	languages, it also provides a starting point for developing a "universal"
				6467	atomic operation and synchronization IR.
				6468	</p>
				6469	<p>
				6470	These do <em>not</em> form an API such as high-level threading libraries,
				6471	software transaction memory systems, atomic primitives, and intrinsic
				6472	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6473	application libraries. The hardware interface provided by LLVM should allow
				6474	a clean implementation of all of these APIs and parallel programming models.
				6475	No one model or paradigm should be selected above others unless the hardware
				6476	itself ubiquitously does so.
				6477
				6478	</p>
				6479	</div>
				6480
				6481	<!-- _______________________________________________________________________ -->
				6482	<div class="doc_subsubsection">
				6483	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6484	</div>
				6485	<div class="doc_text">
				6486	<h5>Syntax:</h5>
				6487	<pre>
				6488	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6489	i1 <device> )
				6490
				6491	</pre>
				6492	<h5>Overview:</h5>
				6493	<p>
				6494	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6495	specific pairs of memory access types.
				6496	</p>
				6497	<h5>Arguments:</h5>
				6498	<p>
				6499	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6500	The first four arguments enables a specific barrier as listed below. The fith
				6501	argument specifies that the barrier applies to io or device or uncached memory.
				6502
				6503	</p>
				6504	<ul>
				6505	<li><tt>ll</tt>: load-load barrier</li>
				6506	<li><tt>ls</tt>: load-store barrier</li>
				6507	<li><tt>sl</tt>: store-load barrier</li>
				6508	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6509	<li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6510	</ul>
				6511	<h5>Semantics:</h5>
				6512	<p>
				6513	This intrinsic causes the system to enforce some ordering constraints upon
				6514	the loads and stores of the program. This barrier does not indicate
				6515	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6516	which they occur. For any of the specified pairs of load and store operations
				6517	(f.ex. load-load, or store-load), all of the first operations preceding the
				6518	barrier will complete before any of the second operations succeeding the
				6519	barrier begin. Specifically the semantics for each pairing is as follows:
				6520	</p>
				6521	<ul>
				6522	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6523	after the barrier begins.</li>
				6524
				6525	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6526	store after the barrier begins.</li>
				6527	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6528	store after the barrier begins.</li>
				6529	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6530	load after the barrier begins.</li>
				6531	</ul>
				6532	<p>
				6533	These semantics are applied with a logical "and" behavior when more than one
				6534	is enabled in a single memory barrier intrinsic.
				6535	</p>
				6536	<p>
				6537	Backends may implement stronger barriers than those requested when they do not
				6538	support as fine grained a barrier as requested. Some architectures do not
				6539	need all types of barriers and on such architectures, these become noops.
				6540	</p>
				6541	<h5>Example:</h5>
				6542	<pre>
				6543	%ptr = malloc i32
				6544	store i32 4, %ptr
				6545
				6546	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6547	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6548	<i>; guarantee the above finishes</i>
				6549	store i32 8, %ptr <i>; before this begins</i>
				6550	</pre>
				6551	</div>
				6552
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6553	<!-- _______________________________________________________________________ -->
				6554	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6555	<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]	6556	</div>
				6557	<div class="doc_text">
				6558	<h5>Syntax:</h5>
				6559	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6560	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6561	any integer bit width and for different address spaces. Not all targets
				6562	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6563
				6564	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6565	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6566	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6567	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6568	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]	6569
				6570	</pre>
				6571	<h5>Overview:</h5>
				6572	<p>
				6573	This loads a value in memory and compares it to a given value. If they are
				6574	equal, it stores a new value into the memory.
				6575	</p>
				6576	<h5>Arguments:</h5>
				6577	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6578	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]	6579	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6580	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6581	this integer type. While any bit width integer may be used, targets may only
				6582	lower representations they support in hardware.
				6583
				6584	</p>
				6585	<h5>Semantics:</h5>
				6586	<p>
				6587	This entire intrinsic must be executed atomically. It first loads the value
				6588	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6589	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6590	loaded value is yielded in all cases. This provides the equivalent of an
				6591	atomic compare-and-swap operation within the SSA framework.
				6592	</p>
				6593	<h5>Examples:</h5>
				6594
				6595	<pre>
				6596	%ptr = malloc i32
				6597	store i32 4, %ptr
				6598
				6599	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6600	%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]	6601	<i>; yields {i32}:result1 = 4</i>
				6602	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6603	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6604
				6605	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6606	%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]	6607	<i>; yields {i32}:result2 = 8</i>
				6608	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6609
				6610	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6611	</pre>
				6612	</div>
				6613
				6614	<!-- _______________________________________________________________________ -->
				6615	<div class="doc_subsubsection">
				6616	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6617	</div>
				6618	<div class="doc_text">
				6619	<h5>Syntax:</h5>
				6620
				6621	<p>
				6622	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6623	integer bit width. Not all targets support all bit widths however.</p>
				6624	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6625	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6626	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6627	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6628	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6629
				6630	</pre>
				6631	<h5>Overview:</h5>
				6632	<p>
				6633	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6634	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6635	at <tt>ptr</tt>.
				6636	</p>
				6637	<h5>Arguments:</h5>
				6638
				6639	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6640	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6641	<tt>val</tt> argument and the result must be integers of the same bit width.
				6642	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6643	integer type. The targets may only lower integer representations they
				6644	support.
				6645	</p>
				6646	<h5>Semantics:</h5>
				6647	<p>
				6648	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6649	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6650	equivalent of an atomic swap operation within the SSA framework.
				6651
				6652	</p>
				6653	<h5>Examples:</h5>
				6654	<pre>
				6655	%ptr = malloc i32
				6656	store i32 4, %ptr
				6657
				6658	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6659	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6660	<i>; yields {i32}:result1 = 4</i>
				6661	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6662	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6663
				6664	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6665	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6666	<i>; yields {i32}:result2 = 8</i>
				6667
				6668	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6669	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6670	</pre>
				6671	</div>
				6672
				6673	<!-- _______________________________________________________________________ -->
				6674	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6675	<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]	6676
				6677	</div>
				6678	<div class="doc_text">
				6679	<h5>Syntax:</h5>
				6680	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6681	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]	6682	integer bit width. Not all targets support all bit widths however.</p>
				6683	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6684	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6685	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6686	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6687	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6688
				6689	</pre>
				6690	<h5>Overview:</h5>
				6691	<p>
				6692	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6693	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6694	</p>
				6695	<h5>Arguments:</h5>
				6696	<p>
				6697
				6698	The intrinsic takes two arguments, the first a pointer to an integer value
				6699	and the second an integer value. The result is also an integer value. These
				6700	integer types can have any bit width, but they must all have the same bit
				6701	width. The targets may only lower integer representations they support.
				6702	</p>
				6703	<h5>Semantics:</h5>
				6704	<p>
				6705	This intrinsic does a series of operations atomically. It first loads the
				6706	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6707	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6708	</p>
				6709
				6710	<h5>Examples:</h5>
				6711	<pre>
				6712	%ptr = malloc i32
				6713	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6714	%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]	6715	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6716	%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]	6717	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6718	%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]	6719	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6720	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6721	</pre>
				6722	</div>
				6723
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6724	<!-- _______________________________________________________________________ -->
				6725	<div class="doc_subsubsection">
				6726	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6727
				6728	</div>
				6729	<div class="doc_text">
				6730	<h5>Syntax:</h5>
				6731	<p>
				6732	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]	6733	any integer bit width and for different address spaces. Not all targets
				6734	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6735	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6736	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6737	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6738	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6739	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]	6740
				6741	</pre>
				6742	<h5>Overview:</h5>
				6743	<p>
				6744	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6745	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6746	</p>
				6747	<h5>Arguments:</h5>
				6748	<p>
				6749
				6750	The intrinsic takes two arguments, the first a pointer to an integer value
				6751	and the second an integer value. The result is also an integer value. These
				6752	integer types can have any bit width, but they must all have the same bit
				6753	width. The targets may only lower integer representations they support.
				6754	</p>
				6755	<h5>Semantics:</h5>
				6756	<p>
				6757	This intrinsic does a series of operations atomically. It first loads the
				6758	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6759	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6760	</p>
				6761
				6762	<h5>Examples:</h5>
				6763	<pre>
				6764	%ptr = malloc i32
				6765	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6766	%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]	6767	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6768	%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]	6769	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6770	%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]	6771	<i>; yields {i32}:result3 = 2</i>
				6772	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6773	</pre>
				6774	</div>
				6775
				6776	<!-- _______________________________________________________________________ -->
				6777	<div class="doc_subsubsection">
				6778	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6779	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6780	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6781	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6782
				6783	</div>
				6784	<div class="doc_text">
				6785	<h5>Syntax:</h5>
				6786	<p>
				6787	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6788	<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]	6789	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6790	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6791	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6792	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6793	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6794	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6795	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]	6796
				6797	</pre>
				6798
				6799	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6800	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6801	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6802	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6803	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]	6804
				6805	</pre>
				6806
				6807	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6808	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6809	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6810	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6811	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]	6812
				6813	</pre>
				6814
				6815	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6816	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6817	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6818	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6819	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]	6820
				6821	</pre>
				6822	<h5>Overview:</h5>
				6823	<p>
				6824	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6825	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6826	at <tt>ptr</tt>.
				6827	</p>
				6828	<h5>Arguments:</h5>
				6829	<p>
				6830
				6831	These intrinsics take two arguments, the first a pointer to an integer value
				6832	and the second an integer value. The result is also an integer value. These
				6833	integer types can have any bit width, but they must all have the same bit
				6834	width. The targets may only lower integer representations they support.
				6835	</p>
				6836	<h5>Semantics:</h5>
				6837	<p>
				6838	These intrinsics does a series of operations atomically. They first load the
				6839	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6840	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6841	value stored at <tt>ptr</tt>.
				6842	</p>
				6843
				6844	<h5>Examples:</h5>
				6845	<pre>
				6846	%ptr = malloc i32
				6847	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6848	%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]	6849	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6850	%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]	6851	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6852	%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]	6853	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6854	%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]	6855	<i>; yields {i32}:result3 = FF</i>
				6856	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6857	</pre>
				6858	</div>
				6859
				6860
				6861	<!-- _______________________________________________________________________ -->
				6862	<div class="doc_subsubsection">
				6863	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6864	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6865	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6866	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6867
				6868	</div>
				6869	<div class="doc_text">
				6870	<h5>Syntax:</h5>
				6871	<p>
				6872	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6873	<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]	6874	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6875	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6876	support all bit widths however.</p>
				6877	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6878	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6879	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6880	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6881	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]	6882
				6883	</pre>
				6884
				6885	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6886	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6887	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6888	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6889	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]	6890
				6891	</pre>
				6892
				6893	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6894	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6895	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6896	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6897	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]	6898
				6899	</pre>
				6900
				6901	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6902	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6903	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6904	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6905	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]	6906
				6907	</pre>
				6908	<h5>Overview:</h5>
				6909	<p>
				6910	These intrinsics takes the signed or unsigned minimum or maximum of
				6911	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6912	original value at <tt>ptr</tt>.
				6913	</p>
				6914	<h5>Arguments:</h5>
				6915	<p>
				6916
				6917	These intrinsics take two arguments, the first a pointer to an integer value
				6918	and the second an integer value. The result is also an integer value. These
				6919	integer types can have any bit width, but they must all have the same bit
				6920	width. The targets may only lower integer representations they support.
				6921	</p>
				6922	<h5>Semantics:</h5>
				6923	<p>
				6924	These intrinsics does a series of operations atomically. They first load the
				6925	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6926	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6927	the original value stored at <tt>ptr</tt>.
				6928	</p>
				6929
				6930	<h5>Examples:</h5>
				6931	<pre>
				6932	%ptr = malloc i32
				6933	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6934	%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]	6935	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6936	%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]	6937	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6938	%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]	6939	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6940	%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]	6941	<i>; yields {i32}:result3 = 8</i>
				6942	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6943	</pre>
				6944	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6945
				6946	<!-- ======================================================================= -->
				6947	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6948	<a name="int_general">General Intrinsics</a>
				6949	</div>
				6950
				6951	<div class="doc_text">
				6952	<p> This class of intrinsics is designed to be generic and has
				6953	no specific purpose. </p>
				6954	</div>
				6955
				6956	<!-- _______________________________________________________________________ -->
				6957	<div class="doc_subsubsection">
				6958	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6959	</div>
				6960
				6961	<div class="doc_text">
				6962
				6963	<h5>Syntax:</h5>
				6964	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6965	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]	6966	</pre>
				6967
				6968	<h5>Overview:</h5>
				6969
				6970	<p>
				6971	The '<tt>llvm.var.annotation</tt>' intrinsic
				6972	</p>
				6973
				6974	<h5>Arguments:</h5>
				6975
				6976	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6977	The first argument is a pointer to a value, the second is a pointer to a
				6978	global string, the third is a pointer to a global string which is the source
				6979	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6980	</p>
				6981
				6982	<h5>Semantics:</h5>
				6983
				6984	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6985	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6986	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]	6987	annotations. These have no other defined use, they are ignored by code
				6988	generation and optimization.
				6989	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6990	</div>
				6991
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6992	<!-- _______________________________________________________________________ -->
				6993	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	6994	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6995	</div>
				6996
				6997	<div class="doc_text">
				6998
				6999	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	7000	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				7001	any integer bit width.
				7002	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7003	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	7004	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				7005	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				7006	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				7007	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				7008	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]	7009	</pre>
				7010
				7011	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	7012
				7013	<p>
				7014	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7015	</p>
				7016
				7017	<h5>Arguments:</h5>
				7018
				7019	<p>
				7020	The first argument is an integer value (result of some expression),
				7021	the second is a pointer to a global string, the third is a pointer to a global
				7022	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]	7023	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7024	</p>
				7025
				7026	<h5>Semantics:</h5>
				7027
				7028	<p>
				7029	This intrinsic allows annotations to be put on arbitrary expressions
				7030	with arbitrary strings. This can be useful for special purpose optimizations
				7031	that want to look for these annotations. These have no other defined use, they
				7032	are ignored by code generation and optimization.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	7033	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7034	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	7035
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	7036	<!-- _______________________________________________________________________ -->
				7037	<div class="doc_subsubsection">
				7038	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7039	</div>
				7040
				7041	<div class="doc_text">
				7042
				7043	<h5>Syntax:</h5>
				7044	<pre>
				7045	declare void @llvm.trap()
				7046	</pre>
				7047
				7048	<h5>Overview:</h5>
				7049
				7050	<p>
				7051	The '<tt>llvm.trap</tt>' intrinsic
				7052	</p>
				7053
				7054	<h5>Arguments:</h5>
				7055
				7056	<p>
				7057	None
				7058	</p>
				7059
				7060	<h5>Semantics:</h5>
				7061
				7062	<p>
				7063	This intrinsics is lowered to the target dependent trap instruction. If the
				7064	target does not have a trap instruction, this intrinsic will be lowered to the
				7065	call of the abort() function.
				7066	</p>
				7067	</div>
				7068
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7069	<!-- _______________________________________________________________________ -->
				7070	<div class="doc_subsubsection">
Misha Brukman	50de2b2	2008-11-22 23:55:29 +0000	[diff] [blame]	7071	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7072	</div>
				7073	<div class="doc_text">
				7074	<h5>Syntax:</h5>
				7075	<pre>
				7076	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7077
				7078	</pre>
				7079	<h5>Overview:</h5>
				7080	<p>
				7081	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7082	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7083	it is placed on the stack before local variables.
				7084	</p>
				7085	<h5>Arguments:</h5>
				7086	<p>
				7087	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7088	first argument is the value loaded from the stack guard
				7089	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7090	has enough space to hold the value of the guard.
				7091	</p>
				7092	<h5>Semantics:</h5>
				7093	<p>
				7094	This intrinsic causes the prologue/epilogue inserter to force the position of
				7095	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7096	stack. This is to ensure that if a local variable on the stack is overwritten,
				7097	it will destroy the value of the guard. When the function exits, the guard on
				7098	the stack is checked against the original guard. If they're different, then
				7099	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7100	</p>
				7101	</div>
				7102
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7103	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7104	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7105	<address>
				7106	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7107	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7108	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7109	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7110
				7111	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	7112	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7113	Last modified: $Date$
				7114	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	7115
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	7116	</body>
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