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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>
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	92	<li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	93	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	94	<li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	95	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	96	<li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	97	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				98	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				99	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	100	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				101	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				102	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	103	</ol>
				104	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	105	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				106	<ol>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	107	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				108	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				109	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	110	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	111	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	112	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	113	</ol>
				114	</li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	115	<li><a href="#vectorops">Vector Operations</a>
				116	<ol>
				117	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				118	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				119	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	120	</ol>
				121	</li>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	122	<li><a href="#aggregateops">Aggregate Operations</a>
				123	<ol>
				124	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				125	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				126	</ol>
				127	</li>
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	128	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	129	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	130	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				131	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				132	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	133	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				134	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				135	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	136	</ol>
				137	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	138	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	139	<ol>
				140	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	145	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				146	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				147	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				148	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	149	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				150	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	151	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	152	</ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	153	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	154	<li><a href="#otherops">Other Operations</a>
				155	<ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	156	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				157	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	158	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				159	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	160	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	161	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	163	<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]	164	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	165	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	166	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	167	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	168	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	169	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	170	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				171	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	172	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				173	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				174	<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]	175	</ol>
				176	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	177	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				178	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	179	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				180	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				181	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	182	</ol>
				183	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	184	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				185	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	186	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				187	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				188	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				189	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				190	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				191	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				192	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	193	</ol>
				194	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	195	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				196	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	197	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				200	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				201	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	202	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				203	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				204	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	205	</ol>
				206	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	207	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	208	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	209	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	210	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				211	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				212	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	213	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				214	<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]	215	</ol>
				216	</li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	217	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				218	<ol>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	219	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				220	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				221	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				222	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				223	<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]	224	<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]	225	</ol>
				226	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	227	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	228	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	229	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	230	<ol>
				231	<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]	232	</ol>
				233	</li>
Bill Wendling	f85850f	2008-11-18 22:10:53 +0000	[diff] [blame]	234	<li><a href="#int_atomics">Atomic intrinsics</a>
				235	<ol>
				236	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				237	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				238	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				239	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				240	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				241	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				242	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				243	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				244	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				245	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				246	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				247	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				248	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				249	</ol>
				250	</li>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	251	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	252	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	253	<li><a href="#int_var_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	255	<li><a href="#int_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	256	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	257	<li><a href="#int_trap">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	258	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				259	<li><a href="#int_stackprotector">
				260	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	261	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	262	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	263	</ol>
				264	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	265	</ol>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	266
				267	<div class="doc_author">
				268	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				269	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	270	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	272	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				274	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	275
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	276	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	277	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	278	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	279	type safety, low-level operations, flexibility, and the capability of
				280	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	281	representation used throughout all phases of the LLVM compilation
				282	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	283	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	285	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				287	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	288
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	289	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	290
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	291	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	292	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]	293	representation (suitable for fast loading by a Just-In-Time compiler),
				294	and as a human readable assembly language representation. This allows
				295	LLVM to provide a powerful intermediate representation for efficient
				296	compiler transformations and analysis, while providing a natural means
				297	to debug and visualize the transformations. The three different forms
				298	of LLVM are all equivalent. This document describes the human readable
				299	representation and notation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	300
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	301	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	302	while being expressive, typed, and extensible at the same time. It
				303	aims to be a "universal IR" of sorts, by being at a low enough level
				304	that high-level ideas may be cleanly mapped to it (similar to how
				305	microprocessors are "universal IR's", allowing many source languages to
				306	be mapped to them). By providing type information, LLVM can be used as
				307	the target of optimizations: for example, through pointer analysis, it
				308	can be proven that a C automatic variable is never accessed outside of
				309	the current function... allowing it to be promoted to a simple SSA
				310	value instead of a memory location.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	312	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	313
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	314	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	315	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	316
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	317	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	319	<p>It is important to note that this document describes 'well formed'
				320	LLVM assembly language. There is a difference between what the parser
				321	accepts and what is considered 'well formed'. For example, the
				322	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	323
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	324	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	325	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	326	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	327	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	328	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	329
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	330	<p>...because the definition of <tt>%x</tt> does not dominate all of
				331	its uses. The LLVM infrastructure provides a verification pass that may
				332	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]	333	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	334	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	335	by the verifier pass indicate bugs in transformation passes or input to
				336	the parser.</p>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	337	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	338
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	339	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	341	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	342	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	343	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	344
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	345	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	346
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	347	<p>LLVM identifiers come in two basic types: global and local. Global
				348	identifiers (functions, global variables) begin with the @ character. Local
				349	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	350	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	351
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	352	<ol>
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	353	<li>Named values are represented as a string of characters with their prefix.
				354	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				355	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]	356	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	0f8155a	2008-10-14 23:51:43 +0000	[diff] [blame]	357	with quotes. Special characters may be escaped using "\xx" where xx is the
				358	ASCII code for the character in hexadecimal. In this way, any character can
				359	be used in a name value, even quotes themselves.
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	360
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	361	<li>Unnamed values are represented as an unsigned numeric value with their
				362	prefix. For example, %12, @2, %44.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	364	<li>Constants, which are described in a <a href="#constants">section about
				365	constants</a>, below.</li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	366	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	367
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	368	<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]	369	don't need to worry about name clashes with reserved words, and the set of
				370	reserved words may be expanded in the future without penalty. Additionally,
				371	unnamed identifiers allow a compiler to quickly come up with a temporary
				372	variable without having to avoid symbol table conflicts.</p>
				373
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	374	<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]	375	languages. There are keywords for different opcodes
				376	('<tt><a href="#i_add">add</a></tt>',
				377	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				378	'<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]	379	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]	380	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	381	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	382
				383	<p>Here is an example of LLVM code to multiply the integer variable
				384	'<tt>%X</tt>' by 8:</p>
				385
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	386	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	387
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	388	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	389	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	390	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	391	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	392	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	394	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	395
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	396	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	397	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	398	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	399	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	400	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	401
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	402	<p>And the hard way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	403
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	404	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	405	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	406	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				407	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				408	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	409	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	410	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	411
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	412	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				413	important lexical features of LLVM:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	414
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	415	<ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	416
				417	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				418	line.</li>
				419
				420	<li>Unnamed temporaries are created when the result of a computation is not
				421	assigned to a named value.</li>
				422
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	423	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	424
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	425	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	426
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	427	<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]	428	demonstrating instructions, we will follow an instruction with a comment that
				429	defines the type and name of value produced. Comments are shown in italic
				430	text.</p>
				431
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	432	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	433
				434	<!-- *********************************************************************** -->
				435	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				436	<!-- *********************************************************************** -->
				437
				438	<!-- ======================================================================= -->
				439	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				440	</div>
				441
				442	<div class="doc_text">
				443
				444	<p>LLVM programs are composed of "Module"s, each of which is a
				445	translation unit of the input programs. Each module consists of
				446	functions, global variables, and symbol table entries. Modules may be
				447	combined together with the LLVM linker, which merges function (and
				448	global variable) definitions, resolves forward declarations, and merges
				449	symbol table entries. Here is an example of the "hello world" module:</p>
				450
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	451	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	452	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	453	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				454	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]	455
				456	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	457	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	458
				459	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	460	define i32 @main() { <i>; i32()* </i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	461	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	462	%cast210 = <a
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	463	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]	464
				465	<i>; Call puts function to write out the string to stdout...</i>
				466	<a
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	467	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	468	<a
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	469	href="#i_ret">ret</a> i32 0<br>}<br>
				470	</pre>
				471	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	472
				473	<p>This example is made up of a <a href="#globalvars">global variable</a>
				474	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				475	function, and a <a href="#functionstructure">function definition</a>
				476	for "<tt>main</tt>".</p>
				477
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	478	<p>In general, a module is made up of a list of global values,
				479	where both functions and global variables are global values. Global values are
				480	represented by a pointer to a memory location (in this case, a pointer to an
				481	array of char, and a pointer to a function), and have one of the following <a
				482	href="#linkage">linkage types</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	483
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	484	</div>
				485
				486	<!-- ======================================================================= -->
				487	<div class="doc_subsection">
				488	<a name="linkage">Linkage Types</a>
				489	</div>
				490
				491	<div class="doc_text">
				492
				493	<p>
				494	All Global Variables and Functions have one of the following types of linkage:
				495	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	496
				497	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	498
Rafael Espindola	6de96a1	2009-01-15 20:18:42 +0000	[diff] [blame]	499	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				500
				501	<dd>Global values with private linkage are only directly accessible by
				502	objects in the current module. In particular, linking code into a module with
				503	an private global value may cause the private to be renamed as necessary to
				504	avoid collisions. Because the symbol is private to the module, all
				505	references can be updated. This doesn't show up in any symbol table in the
				506	object file.
				507	</dd>
				508
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	509	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	510
Duncan Sands	35e43c1	2009-01-16 09:29:46 +0000	[diff] [blame]	511	<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]	512	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]	513	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	514	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	515
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	516	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				517	</dt>
				518
				519	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				520	into the object file corresponding to the LLVM module. They exist to
				521	allow inlining and other optimizations to take place given knowledge of the
				522	definition of the global, which is known to be somewhere outside the module.
				523	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				524	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				525	type is only allowed on definitions, not declarations.</dd>
				526
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	527	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	528
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	529	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				530	the same name when linkage occurs. This is typically used to implement
				531	inline functions, templates, or other code which must be generated in each
				532	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				533	allowed to be discarded.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	534	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	535
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	536	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				537
				538	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				539	linkage, except that unreferenced <tt>common</tt> globals may not be
				540	discarded. This is used for globals that may be emitted in multiple
				541	translation units, but that are not guaranteed to be emitted into every
				542	translation unit that uses them. One example of this is tentative
				543	definitions in C, such as "<tt>int X;</tt>" at global scope.
				544	</dd>
				545
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	546	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	547
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	548	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				549	that some targets may choose to emit different assembly sequences for them
				550	for target-dependent reasons. This is used for globals that are declared
				551	"weak" in C source code.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	552	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	553
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	554	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	555
				556	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				557	pointer to array type. When two global variables with appending linkage are
				558	linked together, the two global arrays are appended together. This is the
				559	LLVM, typesafe, equivalent of having the system linker append together
				560	"sections" with identical names when .o files are linked.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	561	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	562
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	563	<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]	564
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	565	<dd>The semantics of this linkage follow the ELF object file model: the
				566	symbol is weak until linked, if not linked, the symbol becomes null instead
				567	of being an undefined reference.
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	568	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	569
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	570	<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]	571	<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]	572	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	573	functions with different semantics. Other languages, such as <tt>C++</tt>,
				574	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	575	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4581beb	2009-03-11 20:14:15 +0000	[diff] [blame]	576	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				577	be merged with equivalent globals. These linkage types are otherwise the
				578	same as their non-<tt>odr</tt> versions.
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	579	</dd>
				580
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	581	<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]	582
				583	<dd>If none of the above identifiers are used, the global is externally
				584	visible, meaning that it participates in linkage and can be used to resolve
				585	external symbol references.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	586	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	587	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	588
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	589	<p>
				590	The next two types of linkage are targeted for Microsoft Windows platform
				591	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	592	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	593	</p>
				594
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	595	<dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	596	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				597
				598	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				599	or variable via a global pointer to a pointer that is set up by the DLL
				600	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	601	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	602	</dd>
				603
				604	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				605
				606	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				607	pointer to a pointer in a DLL, so that it can be referenced with the
				608	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	609	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]	610	name.
				611	</dd>
				612
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	613	</dl>
				614
Dan Gohman	8ef4498	2008-11-24 17:18:39 +0000	[diff] [blame]	615	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	616	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				617	variable and was linked with this one, one of the two would be renamed,
				618	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				619	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	92c671e	2007-01-05 00:59:10 +0000	[diff] [blame]	620	outside of the current module.</p>
				621	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	e288105	2009-03-11 08:08:06 +0000	[diff] [blame]	622	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				623	or <tt>extern_weak</tt>.</p>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	624	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				625	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	626	</div>
				627
				628	<!-- ======================================================================= -->
				629	<div class="doc_subsection">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	630	<a name="callingconv">Calling Conventions</a>
				631	</div>
				632
				633	<div class="doc_text">
				634
				635	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				636	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				637	specified for the call. The calling convention of any pair of dynamic
				638	caller/callee must match, or the behavior of the program is undefined. The
				639	following calling conventions are supported by LLVM, and more may be added in
				640	the future:</p>
				641
				642	<dl>
				643	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				644
				645	<dd>This calling convention (the default if no other calling convention is
				646	specified) matches the target C calling conventions. This calling convention
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	647	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	648	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	649	</dd>
				650
				651	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				652
				653	<dd>This calling convention attempts to make calls as fast as possible
				654	(e.g. by passing things in registers). This calling convention allows the
				655	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]	656	without having to conform to an externally specified ABI (Application Binary
				657	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	2c6b888	2008-05-14 09:17:12 +0000	[diff] [blame]	658	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				659	supported. This calling convention does not support varargs and requires the
				660	prototype of all callees to exactly match the prototype of the function
				661	definition.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	662	</dd>
				663
				664	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				665
				666	<dd>This calling convention attempts to make code in the caller as efficient
				667	as possible under the assumption that the call is not commonly executed. As
				668	such, these calls often preserve all registers so that the call does not break
				669	any live ranges in the caller side. This calling convention does not support
				670	varargs and requires the prototype of all callees to exactly match the
				671	prototype of the function definition.
				672	</dd>
				673
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	674	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	675
				676	<dd>Any calling convention may be specified by number, allowing
				677	target-specific calling conventions to be used. Target specific calling
				678	conventions start at 64.
				679	</dd>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	680	</dl>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	681
				682	<p>More calling conventions can be added/defined on an as-needed basis, to
				683	support pascal conventions or any other well-known target-independent
				684	convention.</p>
				685
				686	</div>
				687
				688	<!-- ======================================================================= -->
				689	<div class="doc_subsection">
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	690	<a name="visibility">Visibility Styles</a>
				691	</div>
				692
				693	<div class="doc_text">
				694
				695	<p>
				696	All Global Variables and Functions have one of the following visibility styles:
				697	</p>
				698
				699	<dl>
				700	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				701
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	702	<dd>On targets that use the ELF object file format, default visibility means
				703	that the declaration is visible to other
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	704	modules and, in shared libraries, means that the declared entity may be
				705	overridden. On Darwin, default visibility means that the declaration is
				706	visible to other modules. Default visibility corresponds to "external
				707	linkage" in the language.
				708	</dd>
				709
				710	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				711
				712	<dd>Two declarations of an object with hidden visibility refer to the same
				713	object if they are in the same shared object. Usually, hidden visibility
				714	indicates that the symbol will not be placed into the dynamic symbol table,
				715	so no other module (executable or shared library) can reference it
				716	directly.
				717	</dd>
				718
Anton Korobeynikov	39f3cff	2007-04-29 18:35:00 +0000	[diff] [blame]	719	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				720
				721	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				722	the dynamic symbol table, but that references within the defining module will
				723	bind to the local symbol. That is, the symbol cannot be overridden by another
				724	module.
				725	</dd>
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	726	</dl>
				727
				728	</div>
				729
				730	<!-- ======================================================================= -->
				731	<div class="doc_subsection">
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	732	<a name="namedtypes">Named Types</a>
				733	</div>
				734
				735	<div class="doc_text">
				736
				737	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				738	it easier to read the IR and make the IR more condensed (particularly when
				739	recursive types are involved). An example of a name specification is:
				740	</p>
				741
				742	<div class="doc_code">
				743	<pre>
				744	%mytype = type { %mytype*, i32 }
				745	</pre>
				746	</div>
				747
				748	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				749	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				750	expected with the syntax "%mytype".</p>
				751
				752	<p>Note that type names are aliases for the structural type that they indicate,
				753	and that you can therefore specify multiple names for the same type. This often
				754	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				755	structural typing, the name is not part of the type. When printing out LLVM IR,
				756	the printer will pick <em>one name</em> to render all types of a particular
				757	shape. This means that if you have code where two different source types end up
				758	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				759	unexpected type. This is an important design point and isn't going to
				760	change.</p>
				761
				762	</div>
				763
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	764	<!-- ======================================================================= -->
				765	<div class="doc_subsection">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	766	<a name="globalvars">Global Variables</a>
				767	</div>
				768
				769	<div class="doc_text">
				770
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	771	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	772	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	773	an explicit section to be placed in, and may have an optional explicit alignment
				774	specified. A variable may be defined as "thread_local", which means that it
				775	will not be shared by threads (each thread will have a separated copy of the
				776	variable). A variable may be defined as a global "constant," which indicates
				777	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]	778	optimization, allowing the global data to be placed in the read-only section of
				779	an executable, etc). Note that variables that need runtime initialization
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	780	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]	781
				782	<p>
				783	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				784	constant, even if the final definition of the global is not. This capability
				785	can be used to enable slightly better optimization of the program, but requires
				786	the language definition to guarantee that optimizations based on the
				787	'constantness' are valid for the translation units that do not include the
				788	definition.
				789	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	790
				791	<p>As SSA values, global variables define pointer values that are in
				792	scope (i.e. they dominate) all basic blocks in the program. Global
				793	variables always define a pointer to their "content" type because they
				794	describe a region of memory, and all memory objects in LLVM are
				795	accessed through pointers.</p>
				796
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	797	<p>A global variable may be declared to reside in a target-specifc numbered
				798	address space. For targets that support them, address spaces may affect how
				799	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	25f5076	2007-12-12 08:44:39 +0000	[diff] [blame]	800	the variable. The default address space is zero. The address space qualifier
				801	must precede any other attributes.</p>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	802
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	803	<p>LLVM allows an explicit section to be specified for globals. If the target
				804	supports it, it will emit globals to the section specified.</p>
				805
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	806	<p>An explicit alignment may be specified for a global. If not present, or if
				807	the alignment is set to zero, the alignment of the global is set by the target
				808	to whatever it feels convenient. If an explicit alignment is specified, the
				809	global is forced to have at least that much alignment. All alignments must be
				810	a power of 2.</p>
				811
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	812	<p>For example, the following defines a global in a numbered address space with
				813	an initializer, section, and alignment:</p>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	814
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	815	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	816	<pre>
Dan Gohman	aaa679b	2009-01-11 00:40:00 +0000	[diff] [blame]	817	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	818	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	819	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	820
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	821	</div>
				822
				823
				824	<!-- ======================================================================= -->
				825	<div class="doc_subsection">
				826	<a name="functionstructure">Functions</a>
				827	</div>
				828
				829	<div class="doc_text">
				830
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	831	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				832	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	833	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	834	<a href="#callingconv">calling convention</a>, a return type, an optional
				835	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				836	name, a (possibly empty) argument list (each with optional
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	837	<a href="#paramattrs">parameter attributes</a>), optional
				838	<a href="#fnattrs">function attributes</a>, an optional section,
				839	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	840	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]	841
				842	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				843	optional <a href="#linkage">linkage type</a>, an optional
				844	<a href="#visibility">visibility style</a>, an optional
				845	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	846	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	847	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]	848	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	849
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	850	<p>A function definition contains a list of basic blocks, forming the CFG
				851	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	852	the function. Each basic block may optionally start with a label (giving the
				853	basic block a symbol table entry), contains a list of instructions, and ends
				854	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				855	function return).</p>
				856
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	857	<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]	858	executed on entrance to the function, and it is not allowed to have predecessor
				859	basic blocks (i.e. there can not be any branches to the entry block of a
				860	function). Because the block can have no predecessors, it also cannot have any
				861	<a href="#i_phi">PHI nodes</a>.</p>
				862
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	863	<p>LLVM allows an explicit section to be specified for functions. If the target
				864	supports it, it will emit functions to the section specified.</p>
				865
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	866	<p>An explicit alignment may be specified for a function. If not present, or if
				867	the alignment is set to zero, the alignment of the function is set by the target
				868	to whatever it feels convenient. If an explicit alignment is specified, the
				869	function is forced to have at least that much alignment. All alignments must be
				870	a power of 2.</p>
				871
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	872	<h5>Syntax:</h5>
				873
				874	<div class="doc_code">
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	875	<tt>
				876	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				877	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				878	<ResultType> @<FunctionName> ([argument list])
				879	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				880	[<a href="#gc">gc</a>] { ... }
				881	</tt>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	882	</div>
				883
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	884	</div>
				885
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	886
				887	<!-- ======================================================================= -->
				888	<div class="doc_subsection">
				889	<a name="aliasstructure">Aliases</a>
				890	</div>
				891	<div class="doc_text">
				892	<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]	893	function, global variable, another alias or bitcast of global value). Aliases
				894	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	895	optional <a href="#visibility">visibility style</a>.</p>
				896
				897	<h5>Syntax:</h5>
				898
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	899	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	900	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	901	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	902	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	903	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	904
				905	</div>
				906
				907
				908
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	909	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	910	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				911	<div class="doc_text">
				912	<p>The return type and each parameter of a function type may have a set of
				913	<i>parameter attributes</i> associated with them. Parameter attributes are
				914	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	915	a function. Parameter attributes are considered to be part of the function,
				916	not of the function type, so functions with different parameter attributes
				917	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	918
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	919	<p>Parameter attributes are simple keywords that follow the type specified. If
				920	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	921	example:</p>
				922
				923	<div class="doc_code">
				924	<pre>
Nick Lewycky	dac78d8	2009-02-15 23:06:14 +0000	[diff] [blame]	925	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	926	declare i32 @atoi(i8 zeroext)
				927	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	928	</pre>
				929	</div>
				930
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	931	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				932	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	933
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	934	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	935	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	936	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	937	<dd>This indicates to the code generator that the parameter or return value
				938	should be zero-extended to a 32-bit value by the caller (for a parameter)
				939	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	940
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	941	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	942	<dd>This indicates to the code generator that the parameter or return value
				943	should be sign-extended to a 32-bit value by the caller (for a parameter)
				944	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	945
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	946	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	947	<dd>This indicates that this parameter or return value should be treated
				948	in a special target-dependent fashion during while emitting code for a
				949	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]	950	to memory, though some targets use it to distinguish between two different
				951	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	952
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	953	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	954	<dd>This indicates that the pointer parameter should really be passed by
				955	value to the function. The attribute implies that a hidden copy of the
				956	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]	957	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]	958	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	959	value, but is also valid on pointers to scalars. The copy is considered to
				960	belong to the caller not the callee (for example,
				961	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	962	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	08aa906	2009-02-05 05:42:28 +0000	[diff] [blame]	963	values. The byval attribute also supports specifying an alignment with the
				964	align attribute. This has a target-specific effect on the code generator
				965	that usually indicates a desired alignment for the synthesized stack
				966	slot.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	967
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	968	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	969	<dd>This indicates that the pointer parameter specifies the address of a
				970	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]	971	This pointer must be guaranteed by the caller to be valid: loads and stores
				972	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]	973	be applied to the first parameter. This is not a valid attribute for
				974	return values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	975
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	976	<dt><tt>noalias</tt></dt>
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	977	<dd>This indicates that the pointer does not alias any global or any other
				978	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	d59572c	2008-11-24 05:00:44 +0000	[diff] [blame]	979	case. On a function return value, <tt>noalias</tt> additionally indicates
				980	that the pointer does not alias any other pointers visible to the
Nick Lewycky	2abb108	2008-12-19 06:39:12 +0000	[diff] [blame]	981	caller. For further details, please see the discussion of the NoAlias
				982	response in
				983	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				984	analysis</a>.</dd>
				985
				986	<dt><tt>nocapture</tt></dt>
				987	<dd>This indicates that the callee does not make any copies of the pointer
				988	that outlive the callee itself. This is not a valid attribute for return
				989	values.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	990
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	991	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	992	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	993	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				994	attribute for return values.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	995	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	996
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	997	</div>
				998
				999	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1000	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	1001	<a name="gc">Garbage Collector Names</a>
				1002	</div>
				1003
				1004	<div class="doc_text">
				1005	<p>Each function may specify a garbage collector name, which is simply a
				1006	string.</p>
				1007
				1008	<div class="doc_code"><pre
				1009	>define void @f() gc "name" { ...</pre></div>
				1010
				1011	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1012	collector which will cause the compiler to alter its output in order to support
				1013	the named garbage collection algorithm.</p>
				1014	</div>
				1015
				1016	<!-- ======================================================================= -->
				1017	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1018	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1019	</div>
				1020
				1021	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1022
				1023	<p>Function attributes are set to communicate additional information about
				1024	a function. Function attributes are considered to be part of the function,
				1025	not of the function type, so functions with different parameter attributes
				1026	can have the same function type.</p>
				1027
				1028	<p>Function attributes are simple keywords that follow the type specified. If
				1029	multiple attributes are needed, they are space separated. For
				1030	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1031
				1032	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1033	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1034	define void @f() noinline { ... }
				1035	define void @f() alwaysinline { ... }
				1036	define void @f() alwaysinline optsize { ... }
				1037	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1038	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1039	</div>
				1040
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1041	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1042	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1043	<dd>This attribute indicates that the inliner should attempt to inline this
				1044	function into callers whenever possible, ignoring any active inlining size
				1045	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1046
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1047	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1048	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame]	1049	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1050	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1051
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1052	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	1053	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1054	make choices that keep the code size of this function low, and otherwise do
				1055	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1056
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1057	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1058	<dd>This function attribute indicates that the function never returns normally.
				1059	This produces undefined behavior at runtime if the function ever does
				1060	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1061
				1062	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1063	<dd>This function attribute indicates that the function never returns with an
				1064	unwind or exceptional control flow. If the function does unwind, its runtime
				1065	behavior is undefined.</dd>
				1066
				1067	<dt><tt>readnone</tt></dt>
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1068	<dd>This attribute indicates that the function computes its result (or decides to
				1069	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1070	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1071	registers, etc) visible to caller functions. It does not write through any
				1072	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1073	never changes any state visible to callers. This means that it cannot unwind
				1074	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1075	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1076
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1077	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1078	<dd>This attribute indicates that the function does not write through any
				1079	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1080	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1081	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1082	be set in the caller. A readonly function always returns the same value (or
				1083	unwinds an exception identically) when called with the same set of arguments
				1084	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1085	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1086
				1087	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1088	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1089	protector. It is in the form of a "canary"—a random value placed on the
				1090	stack before the local variables that's checked upon return from the function to
				1091	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]	1092	needs stack protectors or not.
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1093
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1094	<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
				1095	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
				1096	have an <tt>ssp</tt> attribute.</p></dd>
				1097
				1098	<dt><tt>sspreq</tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1099	<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]	1100	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]	1101	function attribute.
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1102
				1103	<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
				1104	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1105	an <tt>ssp</tt> attribute, then the resulting function will have
				1106	an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1107	</dl>
				1108
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1109	</div>
				1110
				1111	<!-- ======================================================================= -->
				1112	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	1113	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1114	</div>
				1115
				1116	<div class="doc_text">
				1117	<p>
				1118	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1119	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1120	LLVM and treated as a single unit, but may be separated in the .ll file if
				1121	desired. The syntax is very simple:
				1122	</p>
				1123
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1124	<div class="doc_code">
				1125	<pre>
				1126	module asm "inline asm code goes here"
				1127	module asm "more can go here"
				1128	</pre>
				1129	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1130
				1131	<p>The strings can contain any character by escaping non-printable characters.
				1132	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1133	for the number.
				1134	</p>
				1135
				1136	<p>
				1137	The inline asm code is simply printed to the machine code .s file when
				1138	assembly code is generated.
				1139	</p>
				1140	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1141
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1142	<!-- ======================================================================= -->
				1143	<div class="doc_subsection">
				1144	<a name="datalayout">Data Layout</a>
				1145	</div>
				1146
				1147	<div class="doc_text">
				1148	<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]	1149	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1150	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1151	<p>The <i>layout specification</i> consists of a list of specifications
				1152	separated by the minus sign character ('-'). Each specification starts with a
				1153	letter and may include other information after the letter to define some
				1154	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1155	<dl>
				1156	<dt><tt>E</tt></dt>
				1157	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1158	bits with the most significance have the lowest address location.</dd>
				1159	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1160	<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]	1161	the bits with the least significance have the lowest address location.</dd>
				1162	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1163	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1164	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1165	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1166	too.</dd>
				1167	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1168	<dd>This specifies the alignment for an integer type of a given bit
				1169	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1170	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1171	<dd>This specifies the alignment for a vector type of a given bit
				1172	<i>size</i>.</dd>
				1173	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1174	<dd>This specifies the alignment for a floating point type of a given bit
				1175	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1176	(double).</dd>
				1177	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1178	<dd>This specifies the alignment for an aggregate type of a given bit
				1179	<i>size</i>.</dd>
				1180	</dl>
				1181	<p>When constructing the data layout for a given target, LLVM starts with a
				1182	default set of specifications which are then (possibly) overriden by the
				1183	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1184	are given in this list:</p>
				1185	<ul>
				1186	<li><tt>E</tt> - big endian</li>
				1187	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1188	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1189	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1190	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1191	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1192	<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]	1193	alignment of 64-bits</li>
				1194	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1195	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1196	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1197	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1198	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1199	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1200	<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]	1201	following rules:</p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1202	<ol>
				1203	<li>If the type sought is an exact match for one of the specifications, that
				1204	specification is used.</li>
				1205	<li>If no match is found, and the type sought is an integer type, then the
				1206	smallest integer type that is larger than the bitwidth of the sought type is
				1207	used. If none of the specifications are larger than the bitwidth then the the
				1208	largest integer type is used. For example, given the default specifications
				1209	above, the i7 type will use the alignment of i8 (next largest) while both
				1210	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1211	<li>If no match is found, and the type sought is a vector type, then the
				1212	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]	1213	as a fall back. This happens because <128 x double> can be implemented
				1214	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1215	</ol>
				1216	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1217
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1218	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1219	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1220	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1221
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1222	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1223
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1224	<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]	1225	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1226	optimizations to be performed on the intermediate representation directly,
				1227	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1228	extra analyses on the side before the transformation. A strong type
				1229	system makes it easier to read the generated code and enables novel
				1230	analyses and transformations that are not feasible to perform on normal
				1231	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1232
				1233	</div>
				1234
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1235	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1236	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1237	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1238	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1239	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1240	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1241
				1242	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1243	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1244	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1245	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1246	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1247	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1248	</tr>
				1249	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1250	<td><a href="#t_floating">floating point</a></td>
				1251	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1252	</tr>
				1253	<tr>
				1254	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1255	<td><a href="#t_integer">integer</a>,
				1256	<a href="#t_floating">floating point</a>,
				1257	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1258	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1259	<a href="#t_struct">structure</a>,
				1260	<a href="#t_array">array</a>,
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1261	<a href="#t_label">label</a>,
				1262	<a href="#t_metadata">metadata</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1263	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1264	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1265	<tr>
				1266	<td><a href="#t_primitive">primitive</a></td>
				1267	<td><a href="#t_label">label</a>,
				1268	<a href="#t_void">void</a>,
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1269	<a href="#t_floating">floating point</a>,
				1270	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1271	</tr>
				1272	<tr>
				1273	<td><a href="#t_derived">derived</a></td>
				1274	<td><a href="#t_integer">integer</a>,
				1275	<a href="#t_array">array</a>,
				1276	<a href="#t_function">function</a>,
				1277	<a href="#t_pointer">pointer</a>,
				1278	<a href="#t_struct">structure</a>,
				1279	<a href="#t_pstruct">packed structure</a>,
				1280	<a href="#t_vector">vector</a>,
				1281	<a href="#t_opaque">opaque</a>.
Dan Gohman	93bf60d	2008-10-14 16:32:04 +0000	[diff] [blame]	1282	</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1283	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1284	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1285	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1286
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1287	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1288	most important. Values of these types are the only ones which can be
				1289	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1290	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1291	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1292
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1293	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1294	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1295
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1296	<div class="doc_text">
				1297	<p>The primitive types are the fundamental building blocks of the LLVM
				1298	system.</p>
				1299
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1300	</div>
				1301
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1302	<!-- _______________________________________________________________________ -->
				1303	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1304
				1305	<div class="doc_text">
				1306	<table>
				1307	<tbody>
				1308	<tr><th>Type</th><th>Description</th></tr>
				1309	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1310	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1311	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1312	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1313	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1314	</tbody>
				1315	</table>
				1316	</div>
				1317
				1318	<!-- _______________________________________________________________________ -->
				1319	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1320
				1321	<div class="doc_text">
				1322	<h5>Overview:</h5>
				1323	<p>The void type does not represent any value and has no size.</p>
				1324
				1325	<h5>Syntax:</h5>
				1326
				1327	<pre>
				1328	void
				1329	</pre>
				1330	</div>
				1331
				1332	<!-- _______________________________________________________________________ -->
				1333	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1334
				1335	<div class="doc_text">
				1336	<h5>Overview:</h5>
				1337	<p>The label type represents code labels.</p>
				1338
				1339	<h5>Syntax:</h5>
				1340
				1341	<pre>
				1342	label
				1343	</pre>
				1344	</div>
				1345
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1346	<!-- _______________________________________________________________________ -->
				1347	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1348
				1349	<div class="doc_text">
				1350	<h5>Overview:</h5>
				1351	<p>The metadata type represents embedded metadata. The only derived type that
				1352	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1353	takes metadata typed parameters, but not pointer to metadata types.</p>
				1354
				1355	<h5>Syntax:</h5>
				1356
				1357	<pre>
				1358	metadata
				1359	</pre>
				1360	</div>
				1361
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1362
				1363	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1364	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1365
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1366	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1367
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1368	<p>The real power in LLVM comes from the derived types in the system.
				1369	This is what allows a programmer to represent arrays, functions,
				1370	pointers, and other useful types. Note that these derived types may be
				1371	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]	1372
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1373	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1374
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1375	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1376	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1377
				1378	<div class="doc_text">
				1379
				1380	<h5>Overview:</h5>
				1381	<p>The integer type is a very simple derived type that simply specifies an
				1382	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1383	2^23-1 (about 8 million) can be specified.</p>
				1384
				1385	<h5>Syntax:</h5>
				1386
				1387	<pre>
				1388	iN
				1389	</pre>
				1390
				1391	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1392	value.</p>
				1393
				1394	<h5>Examples:</h5>
				1395	<table class="layout">
Nick Lewycky	aab930a	2009-05-24 02:46:06 +0000	[diff] [blame]	1396	<tr class="layout">
				1397	<td class="left"><tt>i1</tt></td>
				1398	<td class="left">a single-bit integer.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1399	</tr>
Nick Lewycky	aab930a	2009-05-24 02:46:06 +0000	[diff] [blame]	1400	<tr class="layout">
				1401	<td class="left"><tt>i32</tt></td>
				1402	<td class="left">a 32-bit integer.</td>
				1403	</tr>
				1404	<tr class="layout">
				1405	<td class="left"><tt>i1942652</tt></td>
				1406	<td class="left">a really big integer of over 1 million bits.</td>
				1407	</tr>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1408	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1409
				1410	<p>Note that the code generator does not yet support large integer types
				1411	to be used as function return types. The specific limit on how large a
				1412	return type the code generator can currently handle is target-dependent;
				1413	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1414	targets.</p>
				1415
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1416	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1417
				1418	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1419	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1420
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1421	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1422
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1423	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1424
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1425	<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]	1426	sequentially in memory. The array type requires a size (number of
				1427	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1428
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1429	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1430
				1431	<pre>
				1432	[<# elements> x <elementtype>]
				1433	</pre>
				1434
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1435	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1436	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1437
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1438	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1439	<table class="layout">
				1440	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1441	<td class="left"><tt>[40 x i32]</tt></td>
				1442	<td class="left">Array of 40 32-bit integer values.</td>
				1443	</tr>
				1444	<tr class="layout">
				1445	<td class="left"><tt>[41 x i32]</tt></td>
				1446	<td class="left">Array of 41 32-bit integer values.</td>
				1447	</tr>
				1448	<tr class="layout">
				1449	<td class="left"><tt>[4 x i8]</tt></td>
				1450	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1451	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1452	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1453	<p>Here are some examples of multidimensional arrays:</p>
				1454	<table class="layout">
				1455	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1456	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1457	<td class="left">3x4 array of 32-bit integer values.</td>
				1458	</tr>
				1459	<tr class="layout">
				1460	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1461	<td class="left">12x10 array of single precision floating point values.</td>
				1462	</tr>
				1463	<tr class="layout">
				1464	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1465	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1466	</tr>
				1467	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1468
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1469	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1470	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]	1471	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1472	As a special case, however, zero length arrays are recognized to be variable
				1473	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1474	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1475
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1476	<p>Note that the code generator does not yet support large aggregate types
				1477	to be used as function return types. The specific limit on how large an
				1478	aggregate return type the code generator can currently handle is
				1479	target-dependent, and also dependent on the aggregate element types.</p>
				1480
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1481	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1482
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1483	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1484	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1485	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1486
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1487	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1488
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1489	<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]	1490	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]	1491	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]	1492	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]	1493	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1494
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1495	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1496
				1497	<pre>
				1498	<returntype list> (<parameter list>)
				1499	</pre>
				1500
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1501	<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]	1502	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1503	which indicates that the function takes a variable number of arguments.
				1504	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1505	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1506	'<tt><returntype list></tt>' is a comma-separated list of
				1507	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1508
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1509	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1510	<table class="layout">
				1511	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1512	<td class="left"><tt>i32 (i32)</tt></td>
				1513	<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]	1514	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1515	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1516	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1517	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1518	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1519	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1520	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1521	<tt>float</tt>.
				1522	</td>
				1523	</tr><tr class="layout">
				1524	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1525	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1526	<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]	1527	which returns an integer. This is the signature for <tt>printf</tt> in
				1528	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1529	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1530	</tr><tr class="layout">
				1531	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	c9813bd	2008-11-27 06:41:20 +0000	[diff] [blame]	1532	<td class="left">A function taking an <tt>i32</tt>, returning two
				1533	<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]	1534	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1535	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1536	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1537
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1538	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1539	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1540	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1541	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1542	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1543	<p>The structure type is used to represent a collection of data members
				1544	together in memory. The packing of the field types is defined to match
				1545	the ABI of the underlying processor. The elements of a structure may
				1546	be any type that has a size.</p>
				1547	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1548	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1549	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1550	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1551	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1552	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1553	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1554	<table class="layout">
				1555	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1556	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1557	<td class="left">A triple of three <tt>i32</tt> values</td>
				1558	</tr><tr class="layout">
				1559	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1560	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1561	second element is a <a href="#t_pointer">pointer</a> to a
				1562	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1563	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1564	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1565	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1566
				1567	<p>Note that the code generator does not yet support large aggregate types
				1568	to be used as function return types. The specific limit on how large an
				1569	aggregate return type the code generator can currently handle is
				1570	target-dependent, and also dependent on the aggregate element types.</p>
				1571
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1572	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1573
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1574	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1575	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1576	</div>
				1577	<div class="doc_text">
				1578	<h5>Overview:</h5>
				1579	<p>The packed structure type is used to represent a collection of data members
				1580	together in memory. There is no padding between fields. Further, the alignment
				1581	of a packed structure is 1 byte. The elements of a packed structure may
				1582	be any type that has a size.</p>
				1583	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1584	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1585	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1586	instruction.</p>
				1587	<h5>Syntax:</h5>
				1588	<pre> < { <type list> } > <br></pre>
				1589	<h5>Examples:</h5>
				1590	<table class="layout">
				1591	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1592	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1593	<td class="left">A triple of three <tt>i32</tt> values</td>
				1594	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1595	<td class="left">
				1596	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1597	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1598	second element is a <a href="#t_pointer">pointer</a> to a
				1599	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1600	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1601	</tr>
				1602	</table>
				1603	</div>
				1604
				1605	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1606	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1607	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1608	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1609	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1610	reference to another object, which must live in memory. Pointer types may have
				1611	an optional address space attribute defining the target-specific numbered
				1612	address space where the pointed-to object resides. The default address space is
				1613	zero.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1614
				1615	<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]	1616	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]	1617
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1618	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1619	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1620	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1621	<table class="layout">
				1622	<tr class="layout">
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	1623	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1624	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1625	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1626	</tr>
				1627	<tr class="layout">
				1628	<td class="left"><tt>i32 (i32 ) </tt></td>
				1629	<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]	1630	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]	1631	<tt>i32</tt>.</td>
				1632	</tr>
				1633	<tr class="layout">
				1634	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1635	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1636	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1637	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1638	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1639	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1640
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1641	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1642	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1643	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1644
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1645	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1646
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1647	<p>A vector type is a simple derived type that represents a vector
				1648	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1649	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1650	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1651	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1652	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1653	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1654
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1655	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1656
				1657	<pre>
				1658	< <# elements> x <elementtype> >
				1659	</pre>
				1660
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1661	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1662	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1663
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1664	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1665
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1666	<table class="layout">
				1667	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1668	<td class="left"><tt><4 x i32></tt></td>
				1669	<td class="left">Vector of 4 32-bit integer values.</td>
				1670	</tr>
				1671	<tr class="layout">
				1672	<td class="left"><tt><8 x float></tt></td>
				1673	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1674	</tr>
				1675	<tr class="layout">
				1676	<td class="left"><tt><2 x i64></tt></td>
				1677	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1678	</tr>
				1679	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1680
				1681	<p>Note that the code generator does not yet support large vector types
				1682	to be used as function return types. The specific limit on how large a
				1683	vector return type codegen can currently handle is target-dependent;
				1684	currently it's often a few times longer than a hardware vector register.</p>
				1685
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1686	</div>
				1687
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1688	<!-- _______________________________________________________________________ -->
				1689	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1690	<div class="doc_text">
				1691
				1692	<h5>Overview:</h5>
				1693
				1694	<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]	1695	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]	1696	In LLVM, opaque types can eventually be resolved to any type (not just a
				1697	structure type).</p>
				1698
				1699	<h5>Syntax:</h5>
				1700
				1701	<pre>
				1702	opaque
				1703	</pre>
				1704
				1705	<h5>Examples:</h5>
				1706
				1707	<table class="layout">
				1708	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1709	<td class="left"><tt>opaque</tt></td>
				1710	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1711	</tr>
				1712	</table>
				1713	</div>
				1714
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1715	<!-- ======================================================================= -->
				1716	<div class="doc_subsection">
				1717	<a name="t_uprefs">Type Up-references</a>
				1718	</div>
				1719
				1720	<div class="doc_text">
				1721	<h5>Overview:</h5>
				1722	<p>
				1723	An "up reference" allows you to refer to a lexically enclosing type without
				1724	requiring it to have a name. For instance, a structure declaration may contain a
				1725	pointer to any of the types it is lexically a member of. Example of up
				1726	references (with their equivalent as named type declarations) include:</p>
				1727
				1728	<pre>
Chris Lattner	bf1d545	2009-02-09 10:00:56 +0000	[diff] [blame]	1729	{ \2 * } %x = type { %x* }
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1730	{ \2 }* %y = type { %y }*
				1731	\1* %z = type %z*
				1732	</pre>
				1733
				1734	<p>
				1735	An up reference is needed by the asmprinter for printing out cyclic types when
				1736	there is no declared name for a type in the cycle. Because the asmprinter does
				1737	not want to print out an infinite type string, it needs a syntax to handle
				1738	recursive types that have no names (all names are optional in llvm IR).
				1739	</p>
				1740
				1741	<h5>Syntax:</h5>
				1742	<pre>
				1743	\<level>
				1744	</pre>
				1745
				1746	<p>
				1747	The level is the count of the lexical type that is being referred to.
				1748	</p>
				1749
				1750	<h5>Examples:</h5>
				1751
				1752	<table class="layout">
				1753	<tr class="layout">
				1754	<td class="left"><tt>\1*</tt></td>
				1755	<td class="left">Self-referential pointer.</td>
				1756	</tr>
				1757	<tr class="layout">
				1758	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1759	<td class="left">Recursive structure where the upref refers to the out-most
				1760	structure.</td>
				1761	</tr>
				1762	</table>
				1763	</div>
				1764
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1765
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1766	<!-- *********************************************************************** -->
				1767	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1768	<!-- *********************************************************************** -->
				1769
				1770	<div class="doc_text">
				1771
				1772	<p>LLVM has several different basic types of constants. This section describes
				1773	them all and their syntax.</p>
				1774
				1775	</div>
				1776
				1777	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1778	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1779
				1780	<div class="doc_text">
				1781
				1782	<dl>
				1783	<dt><b>Boolean constants</b></dt>
				1784
				1785	<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]	1786	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1787	</dd>
				1788
				1789	<dt><b>Integer constants</b></dt>
				1790
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1791	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1792	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1793	integer types.
				1794	</dd>
				1795
				1796	<dt><b>Floating point constants</b></dt>
				1797
				1798	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1799	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1800	notation (see below). The assembler requires the exact decimal value of
				1801	a floating-point constant. For example, the assembler accepts 1.25 but
				1802	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1803	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]	1804
				1805	<dt><b>Null pointer constants</b></dt>
				1806
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1807	<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]	1808	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1809
				1810	</dl>
				1811
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1812	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1813	of floating point constants. For example, the form '<tt>double
				1814	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1815	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]	1816	(and the only time that they are generated by the disassembler) is when a
				1817	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]	1818	decimal floating point number in a reasonable number of digits. For example,
				1819	NaN's, infinities, and other
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1820	special values are represented in their IEEE hexadecimal format so that
				1821	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]	1822	<p>When using the hexadecimal form, constants of types float and double are
				1823	represented using the 16-digit form shown above (which matches the IEEE754
				1824	representation for double); float values must, however, be exactly representable
				1825	as IEE754 single precision.
				1826	Hexadecimal format is always used for long
				1827	double, and there are three forms of long double. The 80-bit
				1828	format used by x86 is represented as <tt>0xK</tt>
				1829	followed by 20 hexadecimal digits.
				1830	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1831	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1832	format is represented
				1833	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1834	target uses this format. Long doubles will only work if they match
				1835	the long double format on your target. All hexadecimal formats are big-endian
				1836	(sign bit at the left).</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1837	</div>
				1838
				1839	<!-- ======================================================================= -->
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1840	<div class="doc_subsection">
				1841	<a name="aggregateconstants"> <!-- old anchor -->
				1842	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1843	</div>
				1844
				1845	<div class="doc_text">
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1846	<p>Complex constants are a (potentially recursive) combination of simple
				1847	constants and smaller complex constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1848
				1849	<dl>
				1850	<dt><b>Structure constants</b></dt>
				1851
				1852	<dd>Structure constants are represented with notation similar to structure
				1853	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1854	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1855	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]	1856	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]	1857	types of elements must match those specified by the type.
				1858	</dd>
				1859
				1860	<dt><b>Array constants</b></dt>
				1861
				1862	<dd>Array constants are represented with notation similar to array type
				1863	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1864	(<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]	1865	constants must have <a href="#t_array">array type</a>, and the number and
				1866	types of elements must match those specified by the type.
				1867	</dd>
				1868
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1869	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1870
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1871	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1872	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1873	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1874	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1875	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]	1876	match those specified by the type.
				1877	</dd>
				1878
				1879	<dt><b>Zero initialization</b></dt>
				1880
				1881	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1882	value to zero of <em>any</em> type, including scalar and aggregate types.
				1883	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]	1884	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1885	initializers.
				1886	</dd>
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1887
				1888	<dt><b>Metadata node</b></dt>
				1889
Nick Lewycky	8e2c4f4	2009-05-30 16:08:30 +0000	[diff] [blame]	1890	<dd>A metadata node is a structure-like constant with
				1891	<a href="#t_metadata">metadata type</a>. For example:
				1892	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1893	that are meant to be interpreted as part of the instruction stream, metadata
				1894	is a place to attach additional information such as debug info.
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1895	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1896	</dl>
				1897
				1898	</div>
				1899
				1900	<!-- ======================================================================= -->
				1901	<div class="doc_subsection">
				1902	<a name="globalconstants">Global Variable and Function Addresses</a>
				1903	</div>
				1904
				1905	<div class="doc_text">
				1906
				1907	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1908	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1909	constants. These constants are explicitly referenced when the <a
				1910	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]	1911	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1912	file:</p>
				1913
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1914	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1915	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1916	@X = global i32 17
				1917	@Y = global i32 42
				1918	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1919	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1920	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1921
				1922	</div>
				1923
				1924	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1925	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1926	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1927	<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]	1928	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]	1929	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1930
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1931	<p>Undefined values indicate to the compiler that the program is well defined
				1932	no matter what value is used, giving the compiler more freedom to optimize.
				1933	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1934	</div>
				1935
				1936	<!-- ======================================================================= -->
				1937	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1938	</div>
				1939
				1940	<div class="doc_text">
				1941
				1942	<p>Constant expressions are used to allow expressions involving other constants
				1943	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1944	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]	1945	that does not have side effects (e.g. load and call are not supported). The
				1946	following is the syntax for constant expressions:</p>
				1947
				1948	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1949	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1950	<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]	1951	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1952
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1953	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1954	<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]	1955	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]	1956
				1957	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1958	<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]	1959	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]	1960
				1961	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1962	<dd>Truncate a floating point constant to another floating point type. The
				1963	size of CST must be larger than the size of TYPE. Both types must be
				1964	floating point.</dd>
				1965
				1966	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1967	<dd>Floating point extend a constant to another type. The size of CST must be
				1968	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1969
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1970	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1971	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1972	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1973	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1974	of the same number of elements. If the value won't fit in the integer type,
				1975	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1976
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1977	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1978	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1979	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1980	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1981	of the same number of elements. If the value won't fit in the integer type,
				1982	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1983
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1984	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1985	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1986	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1987	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1988	of the same number of elements. If the value won't fit in the floating point
				1989	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1990
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1991	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1992	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1993	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1994	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1995	of the same number of elements. If the value won't fit in the floating point
				1996	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1997
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1998	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1999	<dd>Convert a pointer typed constant to the corresponding integer constant
				2000	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2001	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2002
				2003	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2004	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2005	pointer type. CST must be of integer type. The CST value is zero extended,
				2006	truncated, or unchanged to make it fit in a pointer size. This one is
				2007	<i>really</i> dangerous!</dd>
				2008
				2009	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	789dee3	2009-02-28 18:27:03 +0000	[diff] [blame]	2010	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2011	are the same as those for the <a href="#i_bitcast">bitcast
				2012	instruction</a>.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2013
				2014	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2015
				2016	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2017	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2018	instruction, the index list may have zero or more indexes, which are required
				2019	to make sense for the type of "CSTPTR".</dd>
				2020
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2021	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2022
				2023	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2024	constants.</dd>
				2025
				2026	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2027	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2028
				2029	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2030	<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]	2031
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	2032	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				2033	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				2034
				2035	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2036	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2037
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2038	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2039
				2040	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2041	operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2042
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2043	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2044
				2045	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2046	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2047
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2048
				2049	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2050
				2051	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2052	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2053
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2054	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2055
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	2056	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2057	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]	2058	binary</a> operations. The constraints on operands are the same as those for
				2059	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2060	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2061	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2062	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	2063
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2064	<!-- ======================================================================= -->
				2065	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2066	</div>
				2067
				2068	<div class="doc_text">
				2069
				2070	<p>Embedded metadata provides a way to attach arbitrary data to the
				2071	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	2072	two metadata primitives, strings and nodes. All metadata has the
				2073	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2074	point ('<tt>!</tt>').
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2075	</p>
				2076
				2077	<p>A metadata string is a string surrounded by double quotes. It can contain
				2078	any character by escaping non-printable characters with "\xx" where "xx" is
				2079	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2080	</p>
				2081
				2082	<p>Metadata nodes are represented with notation similar to structure constants
				2083	(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]	2084	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2085	</p>
				2086
Nick Lewycky	b8f9b7a	2009-05-10 20:57:05 +0000	[diff] [blame]	2087	<p>A metadata node will attempt to track changes to the values it holds. In
				2088	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]	2089	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	b8f9b7a	2009-05-10 20:57:05 +0000	[diff] [blame]	2090
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2091	<p>Optimizations may rely on metadata to provide additional information about
				2092	the program that isn't available in the instructions, or that isn't easily
				2093	computable. Similarly, the code generator may expect a certain metadata format
				2094	to be used to express debugging information.</p>
				2095	</div>
				2096
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2097	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2098	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2099	<!-- *********************************************************************** -->
				2100
				2101	<!-- ======================================================================= -->
				2102	<div class="doc_subsection">
				2103	<a name="inlineasm">Inline Assembler Expressions</a>
				2104	</div>
				2105
				2106	<div class="doc_text">
				2107
				2108	<p>
				2109	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2110	Module-Level Inline Assembly</a>) through the use of a special value. This
				2111	value represents the inline assembler as a string (containing the instructions
				2112	to emit), a list of operand constraints (stored as a string), and a flag that
				2113	indicates whether or not the inline asm expression has side effects. An example
				2114	inline assembler expression is:
				2115	</p>
				2116
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2117	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2118	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2119	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2120	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2121	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2122
				2123	<p>
				2124	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2125	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2126	</p>
				2127
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2128	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2129	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2130	%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]	2131	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2132	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2133
				2134	<p>
				2135	Inline asms with side effects not visible in the constraint list must be marked
				2136	as having side effects. This is done through the use of the
				2137	'<tt>sideeffect</tt>' keyword, like so:
				2138	</p>
				2139
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2140	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2141	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2142	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2143	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2144	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2145
				2146	<p>TODO: The format of the asm and constraints string still need to be
				2147	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]	2148	need to be documented). This is probably best done by reference to another
				2149	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2150	</p>
				2151
				2152	</div>
				2153
				2154	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2155	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2156	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2157
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2158	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2159
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2160	<p>The LLVM instruction set consists of several different
				2161	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	2162	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2163	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2164	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2165	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2166
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2167	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2168
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2169	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2170	<div class="doc_subsection"> <a name="terminators">Terminator
				2171	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2172
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2173	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2174
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2175	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2176	basic block in a program ends with a "Terminator" instruction, which
				2177	indicates which block should be executed after the current block is
				2178	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2179	value: they produce control flow, not values (the one exception being
				2180	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2181	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2182	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2183	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2184	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2185	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2186	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2187
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2188	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2189
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2190	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2191	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2192	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2193	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2194	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2195	<pre>
				2196	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]	2197	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2198	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2199
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2200	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2201
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2202	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2203	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	2204	<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]	2205	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]	2206	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2207
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2208	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2209
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2210	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2211	the return value. The type of the return value must be a
				2212	'<a href="#t_firstclass">first class</a>' type.</p>
				2213
				2214	<p>A function is not <a href="#wellformed">well formed</a> if
				2215	it it has a non-void return type and contains a '<tt>ret</tt>'
				2216	instruction with no return value or a return value with a type that
				2217	does not match its type, or if it has a void return type and contains
				2218	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2219
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2220	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2221
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2222	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2223	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]	2224	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2225	the instruction after the call. If the caller was an "<a
				2226	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2227	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2228	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]	2229	return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2230
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2231	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2232
				2233	<pre>
				2234	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	2235	ret void <i>; Return from a void function</i>
Bill Wendling	050ee8f	2009-02-28 22:12:54 +0000	[diff] [blame]	2236	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]	2237	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2238
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	2239	<p>Note that the code generator does not yet fully support large
				2240	return values. The specific sizes that are currently supported are
				2241	dependent on the target. For integers, on 32-bit targets the limit
				2242	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2243	For aggregate types, the current limits are dependent on the element
				2244	types; for example targets are often limited to 2 total integer
				2245	elements and 2 total floating-point elements.</p>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2246
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2247	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2248	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2249	<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]	2250	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2251	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2252	<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]	2253	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2254	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2255	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2256	transfer to a different basic block in the current function. There are
				2257	two forms of this instruction, corresponding to a conditional branch
				2258	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2259	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2260	<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]	2261	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	2262	unconditional form of the '<tt>br</tt>' instruction takes a single
				2263	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2264	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2265	<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]	2266	argument is evaluated. If the value is <tt>true</tt>, control flows
				2267	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2268	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2269	<h5>Example:</h5>
Chris Lattner	e648c28	2009-05-09 18:11:50 +0000	[diff] [blame]	2270	<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]	2271	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]	2272	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2273	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2274	<div class="doc_subsubsection">
				2275	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2276	</div>
				2277
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2278	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2279	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2280
				2281	<pre>
				2282	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2283	</pre>
				2284
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2285	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2286
				2287	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2288	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2289	instruction, allowing a branch to occur to one of many possible
				2290	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2291
				2292
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2293	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2294
				2295	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2296	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2297	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2298	table is not allowed to contain duplicate constant entries.</p>
				2299
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2300	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2301
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2302	<p>The <tt>switch</tt> instruction specifies a table of values and
				2303	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2304	table is searched for the given value. If the value is found, control flow is
				2305	transfered to the corresponding destination; otherwise, control flow is
				2306	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2307
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2308	<h5>Implementation:</h5>
				2309
				2310	<p>Depending on properties of the target machine and the particular
				2311	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2312	ways. For example, it could be generated as a series of chained conditional
				2313	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2314
				2315	<h5>Example:</h5>
				2316
				2317	<pre>
				2318	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2319	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2320	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2321
				2322	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2323	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2324
				2325	<i>; Implement a jump table:</i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2326	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2327	i32 1, label %onone
				2328	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2329	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2330	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2331
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2332	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2333	<div class="doc_subsubsection">
				2334	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2335	</div>
				2336
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2337	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2338
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2339	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2340
				2341	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2342	<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]	2343	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2344	</pre>
				2345
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2346	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2347
				2348	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2349	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2350	'<tt>normal</tt>' label or the
				2351	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2352	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2353	"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]	2354	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2355	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2356
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2357	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2358
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2359	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2360
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2361	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2362	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2363	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2364	convention</a> the call should use. If none is specified, the call defaults
				2365	to using C calling conventions.
				2366	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2367
				2368	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2369	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2370	and '<tt>inreg</tt>' attributes are valid here.</li>
				2371
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2372	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2373	function value being invoked. In most cases, this is a direct function
				2374	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2375	an arbitrary pointer to function value.
				2376	</li>
				2377
				2378	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2379	function to be invoked. </li>
				2380
				2381	<li>'<tt>function args</tt>': argument list whose types match the function
				2382	signature argument types. If the function signature indicates the function
				2383	accepts a variable number of arguments, the extra arguments can be
				2384	specified. </li>
				2385
				2386	<li>'<tt>normal label</tt>': the label reached when the called function
				2387	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2388
				2389	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2390	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2391
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2392	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2393	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2394	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2395	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2396
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2397	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2398
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2399	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2400	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2401	difference is that it establishes an association with a label, which is used by
				2402	the runtime library to unwind the stack.</p>
				2403
				2404	<p>This instruction is used in languages with destructors to ensure that proper
				2405	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2406	exception. Additionally, this is important for implementation of
				2407	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2408
Jay Foad	1a4eea5	2009-06-03 10:20:10 +0000	[diff] [blame]	2409	<p>For the purposes of the SSA form, the definition of the value
				2410	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2411	the edge from the current block to the "normal" label. If the callee
				2412	unwinds then no return value is available.</p>
Dan Gohman	9069d89	2009-05-22 21:47:08 +0000	[diff] [blame]	2413
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2414	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2415	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2416	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2417	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2418	%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]	2419	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2420	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2421	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2422
				2423
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2424	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2425
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2426	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2427	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2428
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2429	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2430
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2431	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2432	<pre>
				2433	unwind
				2434	</pre>
				2435
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2436	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2437
				2438	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2439	at the first callee in the dynamic call stack which used an <a
				2440	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2441	primarily used to implement exception handling.</p>
				2442
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2443	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2444
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2445	<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]	2446	immediately halt. The dynamic call stack is then searched for the first <a
				2447	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2448	execution continues at the "exceptional" destination block specified by the
				2449	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2450	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2451	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2452
				2453	<!-- _______________________________________________________________________ -->
				2454
				2455	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2456	Instruction</a> </div>
				2457
				2458	<div class="doc_text">
				2459
				2460	<h5>Syntax:</h5>
				2461	<pre>
				2462	unreachable
				2463	</pre>
				2464
				2465	<h5>Overview:</h5>
				2466
				2467	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2468	instruction is used to inform the optimizer that a particular portion of the
				2469	code is not reachable. This can be used to indicate that the code after a
				2470	no-return function cannot be reached, and other facts.</p>
				2471
				2472	<h5>Semantics:</h5>
				2473
				2474	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2475	</div>
				2476
				2477
				2478
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2479	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2480	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2481	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2482	<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]	2483	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]	2484	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2485	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]	2486	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2487	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2488	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2489	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2490	<div class="doc_subsubsection">
				2491	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2492	</div>
				2493
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2494	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2495
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2496	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2497
				2498	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2499	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2500	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2501
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2502	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2503
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2504	<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]	2505
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2506	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2507
				2508	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2509	href="#t_integer">integer</a> or
				2510	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2511	have identical types.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2512
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2513	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2514
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2515	<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2516
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2517	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2518	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2519	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2520
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2521	<p>Because LLVM integers use a two's complement representation, this
				2522	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2523
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2524	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2525
				2526	<pre>
				2527	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2528	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2529	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2530	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2531	<div class="doc_subsubsection">
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2532	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2533	</div>
				2534
				2535	<div class="doc_text">
				2536
				2537	<h5>Syntax:</h5>
				2538
				2539	<pre>
				2540	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2541	</pre>
				2542
				2543	<h5>Overview:</h5>
				2544
				2545	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2546
				2547	<h5>Arguments:</h5>
				2548
				2549	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2550	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2551	floating point values. Both arguments must have identical types.</p>
				2552
				2553	<h5>Semantics:</h5>
				2554
				2555	<p>The value produced is the floating point sum of the two operands.</p>
				2556
				2557	<h5>Example:</h5>
				2558
				2559	<pre>
				2560	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2561	</pre>
				2562	</div>
				2563	<!-- _______________________________________________________________________ -->
				2564	<div class="doc_subsubsection">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2565	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2566	</div>
				2567
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2568	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2569
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2570	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2571
				2572	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2573	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2574	</pre>
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	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2577
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2578	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2579	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2580
				2581	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2582	'<tt>neg</tt>' instruction present in most other intermediate
				2583	representations.</p>
				2584
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2585	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2586
				2587	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2588	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2589	integer values. Both arguments must have identical types.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2590
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2591	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2592
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2593	<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2594
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2595	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2596	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2597	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2598
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2599	<p>Because LLVM integers use a two's complement representation, this
				2600	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2601
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2602	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2603	<pre>
				2604	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2605	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2606	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2607	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2608
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2609	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2610	<div class="doc_subsubsection">
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2611	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2612	</div>
				2613
				2614	<div class="doc_text">
				2615
				2616	<h5>Syntax:</h5>
				2617
				2618	<pre>
				2619	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2620	</pre>
				2621
				2622	<h5>Overview:</h5>
				2623
				2624	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2625	operands.</p>
				2626
				2627	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2628	'<tt>fneg</tt>' instruction present in most other intermediate
				2629	representations.</p>
				2630
				2631	<h5>Arguments:</h5>
				2632
				2633	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2634	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2635	of floating point values. Both arguments must have identical types.</p>
				2636
				2637	<h5>Semantics:</h5>
				2638
				2639	<p>The value produced is the floating point difference of the two operands.</p>
				2640
				2641	<h5>Example:</h5>
				2642	<pre>
				2643	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2644	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2645	</pre>
				2646	</div>
				2647
				2648	<!-- _______________________________________________________________________ -->
				2649	<div class="doc_subsubsection">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2650	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2651	</div>
				2652
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2653	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2654
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2655	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2656	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2657	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2658	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2659	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2660	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2661
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2662	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2663
				2664	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2665	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2666	values. Both arguments must have identical types.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2667
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2668	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2669
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2670	<p>The value produced is the integer product of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2671
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2672	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2673	the result returned is the mathematical result modulo
				2674	2<sup>n</sup>, where n is the bit width of the result.</p>
				2675	<p>Because LLVM integers use a two's complement representation, and the
				2676	result is the same width as the operands, this instruction returns the
				2677	correct result for both signed and unsigned integers. If a full product
				2678	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2679	should be sign-extended or zero-extended as appropriate to the
				2680	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2681	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2682	<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]	2683	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2684	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2685
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2686	<!-- _______________________________________________________________________ -->
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2687	<div class="doc_subsubsection">
				2688	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2689	</div>
				2690
				2691	<div class="doc_text">
				2692
				2693	<h5>Syntax:</h5>
				2694	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2695	</pre>
				2696	<h5>Overview:</h5>
				2697	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2698	operands.</p>
				2699
				2700	<h5>Arguments:</h5>
				2701
				2702	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2703	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2704	of floating point values. Both arguments must have identical types.</p>
				2705
				2706	<h5>Semantics:</h5>
				2707
				2708	<p>The value produced is the floating point product of the two operands.</p>
				2709
				2710	<h5>Example:</h5>
				2711	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2712	</pre>
				2713	</div>
				2714
				2715	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2716	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2717	</a></div>
				2718	<div class="doc_text">
				2719	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2720	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2721	</pre>
				2722	<h5>Overview:</h5>
				2723	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2724	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2725
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2726	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2727
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2728	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2729	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2730	values. Both arguments must have identical types.</p>
				2731
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2732	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2733
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2734	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2735	<p>Note that unsigned integer division and signed integer division are distinct
				2736	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2737	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2738	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2739	<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]	2740	</pre>
				2741	</div>
				2742	<!-- _______________________________________________________________________ -->
				2743	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2744	</a> </div>
				2745	<div class="doc_text">
				2746	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2747	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2748	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2749	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2750
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2751	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2752
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2753	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2754	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2755
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2756	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2757
				2758	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2759	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2760	values. Both arguments must have identical types.</p>
				2761
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2762	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2763	<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]	2764	<p>Note that signed integer division and unsigned integer division are distinct
				2765	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2766	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2767	undefined behavior; this is a rare case, but can occur, for example,
				2768	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2769	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2770	<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]	2771	</pre>
				2772	</div>
				2773	<!-- _______________________________________________________________________ -->
				2774	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2775	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2776	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2777	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2778	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2779	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2780	</pre>
				2781	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2782
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2783	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2784	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2785
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2786	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2787
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2788	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2789	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2790	of floating point values. Both arguments must have identical types.</p>
				2791
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2792	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2793
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2794	<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]	2795
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2796	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2797
				2798	<pre>
				2799	<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]	2800	</pre>
				2801	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2802
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2803	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2804	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2805	</div>
				2806	<div class="doc_text">
				2807	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2808	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2809	</pre>
				2810	<h5>Overview:</h5>
				2811	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2812	unsigned division of its two arguments.</p>
				2813	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2814	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2815	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2816	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2817	<h5>Semantics:</h5>
				2818	<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]	2819	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2820	<p>Note that unsigned integer remainder and signed integer remainder are
				2821	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2822	<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]	2823	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2824	<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]	2825	</pre>
				2826
				2827	</div>
				2828	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2829	<div class="doc_subsubsection">
				2830	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2831	</div>
				2832
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2833	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2834
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2835	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2836
				2837	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2838	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2839	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2840
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2841	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2842
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2843	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2844	signed division of its two operands. This instruction can also take
				2845	<a href="#t_vector">vector</a> versions of the values in which case
				2846	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2847
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2848	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2849
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2850	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2851	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2852	values. Both arguments must have identical types.</p>
				2853
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2854	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2855
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2856	<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]	2857	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2858	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]	2859	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2860	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]	2861	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]	2862	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2863	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2864	<p>Note that signed integer remainder and unsigned integer remainder are
				2865	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2866	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2867	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2868	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2869	(The remainder doesn't actually overflow, but this rule lets srem be
				2870	implemented using instructions that return both the result of the division
				2871	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2872	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2873	<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]	2874	</pre>
				2875
				2876	</div>
				2877	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2878	<div class="doc_subsubsection">
				2879	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2880
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2881	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2882
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2883	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2884	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2885	</pre>
				2886	<h5>Overview:</h5>
				2887	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2888	division of its two operands.</p>
				2889	<h5>Arguments:</h5>
				2890	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2891	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2892	of floating point values. Both arguments must have identical types.</p>
				2893
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2894	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2895
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2896	<p>This instruction returns the <i>remainder</i> of a division.
				2897	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2898
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2899	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2900
				2901	<pre>
				2902	<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]	2903	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2904	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2905
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2906	<!-- ======================================================================= -->
				2907	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2908	Operations</a> </div>
				2909	<div class="doc_text">
				2910	<p>Bitwise binary operators are used to do various forms of
				2911	bit-twiddling in a program. They are generally very efficient
				2912	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2913	instructions. They require two operands of the same type, execute an operation on them,
				2914	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]	2915	</div>
				2916
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2917	<!-- _______________________________________________________________________ -->
				2918	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2919	Instruction</a> </div>
				2920	<div class="doc_text">
				2921	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2922	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2923	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2924
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2925	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2926
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2927	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2928	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2929
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2930	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2931
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2932	<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]	2933	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]	2934	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2935
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2936	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2937
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2938	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2939	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]	2940	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2941	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2942	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2943
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2944	<h5>Example:</h5><pre>
				2945	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2946	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2947	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2948	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2949	<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]	2950	</pre>
				2951	</div>
				2952	<!-- _______________________________________________________________________ -->
				2953	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2954	Instruction</a> </div>
				2955	<div class="doc_text">
				2956	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2957	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2958	</pre>
				2959
				2960	<h5>Overview:</h5>
				2961	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2962	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]	2963
				2964	<h5>Arguments:</h5>
				2965	<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]	2966	<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]	2967	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2968
				2969	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2970
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2971	<p>This instruction always performs a logical shift right operation. The most
				2972	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]	2973	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]	2974	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2975	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2976	amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2977
				2978	<h5>Example:</h5>
				2979	<pre>
				2980	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2981	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2982	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2983	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2984	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2985	<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]	2986	</pre>
				2987	</div>
				2988
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2989	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2990	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2991	Instruction</a> </div>
				2992	<div class="doc_text">
				2993
				2994	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2995	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2996	</pre>
				2997
				2998	<h5>Overview:</h5>
				2999	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3000	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]	3001
				3002	<h5>Arguments:</h5>
				3003	<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]	3004	<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]	3005	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	3006
				3007	<h5>Semantics:</h5>
				3008	<p>This instruction always performs an arithmetic shift right operation,
				3009	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]	3010	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]	3011	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3012	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3013	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	3014
				3015	<h5>Example:</h5>
				3016	<pre>
				3017	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3018	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3019	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3020	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	3021	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	3022	<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]	3023	</pre>
				3024	</div>
				3025
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3026	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3027	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3028	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3029
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3030	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3031
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3032	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3033
				3034	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3035	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3036	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3037
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3038	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3039
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3040	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3041	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3042
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3043	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3044
				3045	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3046	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3047	values. Both arguments must have identical types.</p>
				3048
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3049	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3050	<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]	3051	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3052	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3053	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3054	<tbody>
				3055	<tr>
				3056	<td>In0</td>
				3057	<td>In1</td>
				3058	<td>Out</td>
				3059	</tr>
				3060	<tr>
				3061	<td>0</td>
				3062	<td>0</td>
				3063	<td>0</td>
				3064	</tr>
				3065	<tr>
				3066	<td>0</td>
				3067	<td>1</td>
				3068	<td>0</td>
				3069	</tr>
				3070	<tr>
				3071	<td>1</td>
				3072	<td>0</td>
				3073	<td>0</td>
				3074	</tr>
				3075	<tr>
				3076	<td>1</td>
				3077	<td>1</td>
				3078	<td>1</td>
				3079	</tr>
				3080	</tbody>
				3081	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3082	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3083	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3084	<pre>
				3085	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3086	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3087	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3088	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3089	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3090	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3091	<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]	3092	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3093	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3094	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3095	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3096	<h5>Overview:</h5>
				3097	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3098	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3099	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3100
				3101	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3102	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3103	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3104	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3105	<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]	3106	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3107	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3108	<table border="1" cellspacing="0" cellpadding="4">
				3109	<tbody>
				3110	<tr>
				3111	<td>In0</td>
				3112	<td>In1</td>
				3113	<td>Out</td>
				3114	</tr>
				3115	<tr>
				3116	<td>0</td>
				3117	<td>0</td>
				3118	<td>0</td>
				3119	</tr>
				3120	<tr>
				3121	<td>0</td>
				3122	<td>1</td>
				3123	<td>1</td>
				3124	</tr>
				3125	<tr>
				3126	<td>1</td>
				3127	<td>0</td>
				3128	<td>1</td>
				3129	</tr>
				3130	<tr>
				3131	<td>1</td>
				3132	<td>1</td>
				3133	<td>1</td>
				3134	</tr>
				3135	</tbody>
				3136	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3137	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3138	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3139	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3140	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3141	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3142	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3143	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3144	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3145	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3146	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3147	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3148	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3149	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3150	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3151	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3152	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3153	or of its two operands. The <tt>xor</tt> is used to implement the
				3154	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3155	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3156	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3157	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3158	values. Both arguments must have identical types.</p>
				3159
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3160	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3161
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3162	<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]	3163	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3164	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3165	<table border="1" cellspacing="0" cellpadding="4">
				3166	<tbody>
				3167	<tr>
				3168	<td>In0</td>
				3169	<td>In1</td>
				3170	<td>Out</td>
				3171	</tr>
				3172	<tr>
				3173	<td>0</td>
				3174	<td>0</td>
				3175	<td>0</td>
				3176	</tr>
				3177	<tr>
				3178	<td>0</td>
				3179	<td>1</td>
				3180	<td>1</td>
				3181	</tr>
				3182	<tr>
				3183	<td>1</td>
				3184	<td>0</td>
				3185	<td>1</td>
				3186	</tr>
				3187	<tr>
				3188	<td>1</td>
				3189	<td>1</td>
				3190	<td>0</td>
				3191	</tr>
				3192	</tbody>
				3193	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3194	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3195	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3196	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3197	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3198	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3199	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3200	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3201	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3202	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3203
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3204	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3205	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3206	<a name="vectorops">Vector Operations</a>
				3207	</div>
				3208
				3209	<div class="doc_text">
				3210
				3211	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3212	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3213	vector-specific operations needed to process vectors effectively. While LLVM
				3214	does directly support these vector operations, many sophisticated algorithms
				3215	will want to use target-specific intrinsics to take full advantage of a specific
				3216	target.</p>
				3217
				3218	</div>
				3219
				3220	<!-- _______________________________________________________________________ -->
				3221	<div class="doc_subsubsection">
				3222	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3223	</div>
				3224
				3225	<div class="doc_text">
				3226
				3227	<h5>Syntax:</h5>
				3228
				3229	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3230	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3231	</pre>
				3232
				3233	<h5>Overview:</h5>
				3234
				3235	<p>
				3236	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3237	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3238	</p>
				3239
				3240
				3241	<h5>Arguments:</h5>
				3242
				3243	<p>
				3244	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3245	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]	3246	an index indicating the position from which to extract the element.
				3247	The index may be a variable.</p>
				3248
				3249	<h5>Semantics:</h5>
				3250
				3251	<p>
				3252	The result is a scalar of the same type as the element type of
				3253	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3254	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3255	results are undefined.
				3256	</p>
				3257
				3258	<h5>Example:</h5>
				3259
				3260	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3261	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3262	</pre>
				3263	</div>
				3264
				3265
				3266	<!-- _______________________________________________________________________ -->
				3267	<div class="doc_subsubsection">
				3268	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3269	</div>
				3270
				3271	<div class="doc_text">
				3272
				3273	<h5>Syntax:</h5>
				3274
				3275	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	3276	<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]	3277	</pre>
				3278
				3279	<h5>Overview:</h5>
				3280
				3281	<p>
				3282	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3283	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3284	</p>
				3285
				3286
				3287	<h5>Arguments:</h5>
				3288
				3289	<p>
				3290	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3291	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]	3292	scalar value whose type must equal the element type of the first
				3293	operand. The third operand is an index indicating the position at
				3294	which to insert the value. The index may be a variable.</p>
				3295
				3296	<h5>Semantics:</h5>
				3297
				3298	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3299	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]	3300	element values are those of <tt>val</tt> except at position
				3301	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3302	exceeds the length of <tt>val</tt>, the results are undefined.
				3303	</p>
				3304
				3305	<h5>Example:</h5>
				3306
				3307	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3308	%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]	3309	</pre>
				3310	</div>
				3311
				3312	<!-- _______________________________________________________________________ -->
				3313	<div class="doc_subsubsection">
				3314	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3315	</div>
				3316
				3317	<div class="doc_text">
				3318
				3319	<h5>Syntax:</h5>
				3320
				3321	<pre>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3322	<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]	3323	</pre>
				3324
				3325	<h5>Overview:</h5>
				3326
				3327	<p>
				3328	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3329	from two input vectors, returning a vector with the same element type as
				3330	the input and length that is the same as the shuffle mask.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3331	</p>
				3332
				3333	<h5>Arguments:</h5>
				3334
				3335	<p>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3336	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3337	with types that match each other. The third argument is a shuffle mask whose
				3338	element type is always 'i32'. The result of the instruction is a vector whose
				3339	length is the same as the shuffle mask and whose element type is the same as
				3340	the element type of the first two operands.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3341	</p>
				3342
				3343	<p>
				3344	The shuffle mask operand is required to be a constant vector with either
				3345	constant integer or undef values.
				3346	</p>
				3347
				3348	<h5>Semantics:</h5>
				3349
				3350	<p>
				3351	The elements of the two input vectors are numbered from left to right across
				3352	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]	3353	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]	3354	gets. The element selector may be undef (meaning "don't care") and the second
				3355	operand may be undef if performing a shuffle from only one vector.
				3356	</p>
				3357
				3358	<h5>Example:</h5>
				3359
				3360	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3361	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3362	<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]	3363	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3364	<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]	3365	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3366	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3367	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3368	<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]	3369	</pre>
				3370	</div>
				3371
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	3372
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3373	<!-- ======================================================================= -->
				3374	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3375	<a name="aggregateops">Aggregate Operations</a>
				3376	</div>
				3377
				3378	<div class="doc_text">
				3379
				3380	<p>LLVM supports several instructions for working with aggregate values.
				3381	</p>
				3382
				3383	</div>
				3384
				3385	<!-- _______________________________________________________________________ -->
				3386	<div class="doc_subsubsection">
				3387	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3388	</div>
				3389
				3390	<div class="doc_text">
				3391
				3392	<h5>Syntax:</h5>
				3393
				3394	<pre>
				3395	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3396	</pre>
				3397
				3398	<h5>Overview:</h5>
				3399
				3400	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3401	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3402	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3403	</p>
				3404
				3405
				3406	<h5>Arguments:</h5>
				3407
				3408	<p>
				3409	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3410	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]	3411	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3412	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3413	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3414	</p>
				3415
				3416	<h5>Semantics:</h5>
				3417
				3418	<p>
				3419	The result is the value at the position in the aggregate specified by
				3420	the index operands.
				3421	</p>
				3422
				3423	<h5>Example:</h5>
				3424
				3425	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3426	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3427	</pre>
				3428	</div>
				3429
				3430
				3431	<!-- _______________________________________________________________________ -->
				3432	<div class="doc_subsubsection">
				3433	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3434	</div>
				3435
				3436	<div class="doc_text">
				3437
				3438	<h5>Syntax:</h5>
				3439
				3440	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3441	<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]	3442	</pre>
				3443
				3444	<h5>Overview:</h5>
				3445
				3446	<p>
				3447	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3448	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3449	</p>
				3450
				3451
				3452	<h5>Arguments:</h5>
				3453
				3454	<p>
				3455	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3456	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3457	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3458	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3459	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]	3460	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3461	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3462	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]	3463	by the indices.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3464	</p>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3465
				3466	<h5>Semantics:</h5>
				3467
				3468	<p>
				3469	The result is an aggregate of the same type as <tt>val</tt>. Its
				3470	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]	3471	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3472	</p>
				3473
				3474	<h5>Example:</h5>
				3475
				3476	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3477	%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]	3478	</pre>
				3479	</div>
				3480
				3481
				3482	<!-- ======================================================================= -->
				3483	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3484	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3485	</div>
				3486
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3487	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3488
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3489	<p>A key design point of an SSA-based representation is how it
				3490	represents memory. In LLVM, no memory locations are in SSA form, which
				3491	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3492	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3493
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3494	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3495
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3496	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3497	<div class="doc_subsubsection">
				3498	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3499	</div>
				3500
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3501	<div class="doc_text">
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>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3504
				3505	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3506	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3507	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3508
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3509	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3510
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3511	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3512	heap and returns a pointer to it. The object is always allocated in the generic
				3513	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3514
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3515	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3516
				3517	<p>The '<tt>malloc</tt>' instruction allocates
				3518	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3519	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]	3520	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3521	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3522	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]	3523	be aligned to at least that boundary. If not specified, or if zero, the target can
				3524	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3525
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3526	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3527
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3528	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3529
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3530	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	3531	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]	3532	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3533
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3534	<h5>Example:</h5>
				3535
				3536	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3537	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3538
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3539	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3540	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3541	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3542	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3543	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3544	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	3545
				3546	<p>Note that the code generator does not yet respect the
				3547	alignment value.</p>
				3548
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3549	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3550
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3551	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3552	<div class="doc_subsubsection">
				3553	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3554	</div>
				3555
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3556	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3557
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3558	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3559
				3560	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3561	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3562	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3563
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3564	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3565
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3566	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3567	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3568
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3569	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3570
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3571	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3572	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3573	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3574
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3575	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3576
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3577	<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]	3578	after this instruction executes. If the pointer is null, the operation
				3579	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3580
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3581	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3582
				3583	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3584	%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]	3585	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3586	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3587	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3588
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3589	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3590	<div class="doc_subsubsection">
				3591	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3592	</div>
				3593
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3594	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3595
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3596	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3597
				3598	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3599	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3600	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3601
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3602	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3603
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3604	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3605	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3606	returns to its caller. The object is always allocated in the generic address
				3607	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3608
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3609	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3610
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3611	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3612	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3613	appropriate type to the program. If "NumElements" is specified, it is the
				3614	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3615	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]	3616	to be aligned to at least that boundary. If not specified, or if zero, the target
				3617	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3618
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3619	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3620
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3621	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3622
Bill Wendling	9ee6a31	2009-05-08 20:49:29 +0000	[diff] [blame]	3623	<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]	3624	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3625	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3626	instruction is commonly used to represent automatic variables that must
				3627	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]	3628	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]	3629	instructions), the memory is reclaimed. Allocating zero bytes
				3630	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3631
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3632	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3633
				3634	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3635	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3636	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3637	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3638	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3639	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3640	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3641
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3642	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3643	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3644	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3645	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3646	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3647	<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]	3648	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3649	<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]	3650	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3651	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3652	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3653	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]	3654	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]	3655	the number or order of execution of this <tt>load</tt> with other
				3656	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3657	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3658	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3659	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3660	(that is, the alignment of the memory address). A value of 0 or an
				3661	omitted "align" argument means that the operation has the preferential
				3662	alignment for the target. It is the responsibility of the code emitter
				3663	to ensure that the alignment information is correct. Overestimating
				3664	the alignment results in an undefined behavior. Underestimating the
				3665	alignment may produce less efficient code. An alignment of 1 is always
				3666	safe.
				3667	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3668	<h5>Semantics:</h5>
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3669	<p>The location of memory pointed to is loaded. If the value being loaded
				3670	is of scalar type then the number of bytes read does not exceed the minimum
				3671	number of bytes needed to hold all bits of the type. For example, loading an
				3672	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3673	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3674	is undefined if the value was not originally written using a store of the
				3675	same type.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3676	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3677	<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]	3678	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3679	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3680	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3681	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3682	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3683	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3684	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3685	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3686	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3687	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3688	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3689	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3690	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3691	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3692	<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]	3693	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3694	<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]	3695	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]	3696	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3697	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3698	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]	3699	optimizer is not allowed to modify the number or order of execution of
				3700	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3701	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3702	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3703	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3704	(that is, the alignment of the memory address). A value of 0 or an
				3705	omitted "align" argument means that the operation has the preferential
				3706	alignment for the target. It is the responsibility of the code emitter
				3707	to ensure that the alignment information is correct. Overestimating
				3708	the alignment results in an undefined behavior. Underestimating the
				3709	alignment may produce less efficient code. An alignment of 1 is always
				3710	safe.
				3711	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3712	<h5>Semantics:</h5>
				3713	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3714	at the location specified by the '<tt><pointer></tt>' operand.
				3715	If '<tt><value></tt>' is of scalar type then the number of bytes
				3716	written does not exceed the minimum number of bytes needed to hold all
				3717	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3718	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3719	size that is not an integral number of bytes, it is unspecified what
				3720	happens to the extra bits that do not belong to the type, but they will
				3721	typically be overwritten.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3722	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3723	<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]	3724	store i32 3, i32* %ptr <i>; yields {void}</i>
				3725	%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]	3726	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3727	</div>
				3728
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3729	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3730	<div class="doc_subsubsection">
				3731	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3732	</div>
				3733
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3734	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3735	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3736	<pre>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3737	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3738	</pre>
				3739
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3740	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3741
				3742	<p>
				3743	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]	3744	subelement of an aggregate data structure. It performs address calculation only
				3745	and does not access memory.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3746
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3747	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3748
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3749	<p>The first argument is always a pointer, and forms the basis of the
				3750	calculation. The remaining arguments are indices, that indicate which of the
				3751	elements of the aggregate object are indexed. The interpretation of each index
				3752	is dependent on the type being indexed into. The first index always indexes the
				3753	pointer value given as the first argument, the second index indexes a value of
				3754	the type pointed to (not necessarily the value directly pointed to, since the
				3755	first index can be non-zero), etc. The first type indexed into must be a pointer
				3756	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3757	types being indexed into can never be pointers, since that would require loading
				3758	the pointer before continuing calculation.</p>
				3759
				3760	<p>The type of each index argument depends on the type it is indexing into.
				3761	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3762	<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]	3763	integers of any width are allowed (also non-constants).</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3764
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3765	<p>For example, let's consider a C code fragment and how it gets
				3766	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3767
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3768	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3769	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3770	struct RT {
				3771	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3772	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3773	char C;
				3774	};
				3775	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3776	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3777	double Y;
				3778	struct RT Z;
				3779	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3780
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3781	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3782	return &s[1].Z.B[5][13];
				3783	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3784	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3785	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3786
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3787	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3788
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3789	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3790	<pre>
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	3791	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3792	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3793
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3794	define i32* %foo(%ST* %s) {
				3795	entry:
				3796	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3797	ret i32* %reg
				3798	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3799	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3800	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3801
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3802	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3803
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3804	<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]	3805	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]	3806	}</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]	3807	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3808	i8 }</tt>' type, another structure. The third index indexes into the second
				3809	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]	3810	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3811	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3812	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]	3813
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3814	<p>Note that it is perfectly legal to index partially through a
				3815	structure, returning a pointer to an inner element. Because of this,
				3816	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3817
				3818	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3819	define i32* %foo(%ST* %s) {
				3820	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3821	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3822	%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]	3823	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3824	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3825	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3826	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3827	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3828
Chris Lattner	dd28282	2009-03-09 20:55:18 +0000	[diff] [blame]	3829	<p>Note that it is undefined to access an array out of bounds: array
				3830	and pointer indexes must always be within the defined bounds of the
				3831	array type when accessed with an instruction that dereferences the
				3832	pointer (e.g. a load or store instruction). The one exception for
				3833	this rule is zero length arrays. These arrays are defined to be
				3834	accessible as variable length arrays, which requires access beyond the
				3835	zero'th element.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3836
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3837	<p>The getelementptr instruction is often confusing. For some more insight
				3838	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3839	FAQ</a>.</p>
				3840
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3841	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3842
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3843	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3844	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3845	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3846	<i>; yields i8*:vptr</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3847	%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]	3848	<i>; yields i8*:eptr</i>
				3849	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	0c155e6	2009-04-25 07:27:44 +0000	[diff] [blame]	3850	<i>; yields i32*:iptr</i>
Sanjiv Gupta	77abea0	2009-04-24 16:38:13 +0000	[diff] [blame]	3851	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3852	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3853	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3854
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3855	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3856	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3857	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3858	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3859	<p>The instructions in this category are the conversion instructions (casting)
				3860	which all take a single operand and a type. They perform various bit conversions
				3861	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3862	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3863
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3864	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3865	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3866	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3867	</div>
				3868	<div class="doc_text">
				3869
				3870	<h5>Syntax:</h5>
				3871	<pre>
				3872	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3873	</pre>
				3874
				3875	<h5>Overview:</h5>
				3876	<p>
				3877	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3878	</p>
				3879
				3880	<h5>Arguments:</h5>
				3881	<p>
				3882	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3883	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]	3884	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]	3885	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3886	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3887
				3888	<h5>Semantics:</h5>
				3889	<p>
				3890	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]	3891	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3892	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3893	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3894
				3895	<h5>Example:</h5>
				3896	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3897	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3898	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3899	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3900	</pre>
				3901	</div>
				3902
				3903	<!-- _______________________________________________________________________ -->
				3904	<div class="doc_subsubsection">
				3905	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3906	</div>
				3907	<div class="doc_text">
				3908
				3909	<h5>Syntax:</h5>
				3910	<pre>
				3911	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3912	</pre>
				3913
				3914	<h5>Overview:</h5>
				3915	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3916	<tt>ty2</tt>.</p>
				3917
				3918
				3919	<h5>Arguments:</h5>
				3920	<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]	3921	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3922	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]	3923	<tt>value</tt> must be smaller than the bit size of the destination type,
				3924	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3925
				3926	<h5>Semantics:</h5>
				3927	<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]	3928	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]	3929
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3930	<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]	3931
				3932	<h5>Example:</h5>
				3933	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3934	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3935	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3936	</pre>
				3937	</div>
				3938
				3939	<!-- _______________________________________________________________________ -->
				3940	<div class="doc_subsubsection">
				3941	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3942	</div>
				3943	<div class="doc_text">
				3944
				3945	<h5>Syntax:</h5>
				3946	<pre>
				3947	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3948	</pre>
				3949
				3950	<h5>Overview:</h5>
				3951	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3952
				3953	<h5>Arguments:</h5>
				3954	<p>
				3955	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]	3956	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3957	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]	3958	<tt>value</tt> must be smaller than the bit size of the destination type,
				3959	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3960
				3961	<h5>Semantics:</h5>
				3962	<p>
				3963	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3964	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]	3965	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3966
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3967	<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]	3968
				3969	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3970	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3971	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3972	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3973	</pre>
				3974	</div>
				3975
				3976	<!-- _______________________________________________________________________ -->
				3977	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3978	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3979	</div>
				3980
				3981	<div class="doc_text">
				3982
				3983	<h5>Syntax:</h5>
				3984
				3985	<pre>
				3986	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3987	</pre>
				3988
				3989	<h5>Overview:</h5>
				3990	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3991	<tt>ty2</tt>.</p>
				3992
				3993
				3994	<h5>Arguments:</h5>
				3995	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3996	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3997	cast it to. The size of <tt>value</tt> must be larger than the size of
				3998	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3999	<i>no-op cast</i>.</p>
				4000
				4001	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4002	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4003	<a href="#t_floating">floating point</a> type to a smaller
				4004	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4005	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	4006
				4007	<h5>Example:</h5>
				4008	<pre>
				4009	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4010	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4011	</pre>
				4012	</div>
				4013
				4014	<!-- _______________________________________________________________________ -->
				4015	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4016	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4017	</div>
				4018	<div class="doc_text">
				4019
				4020	<h5>Syntax:</h5>
				4021	<pre>
				4022	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4023	</pre>
				4024
				4025	<h5>Overview:</h5>
				4026	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4027	floating point value.</p>
				4028
				4029	<h5>Arguments:</h5>
				4030	<p>The '<tt>fpext</tt>' instruction takes a
				4031	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4032	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4033	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4034
				4035	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4036	<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]	4037	<a href="#t_floating">floating point</a> type to a larger
				4038	<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]	4039	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]	4040	<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]	4041
				4042	<h5>Example:</h5>
				4043	<pre>
				4044	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4045	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4046	</pre>
				4047	</div>
				4048
				4049	<!-- _______________________________________________________________________ -->
				4050	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	4051	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4052	</div>
				4053	<div class="doc_text">
				4054
				4055	<h5>Syntax:</h5>
				4056	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4057	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4058	</pre>
				4059
				4060	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4061	<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]	4062	unsigned integer equivalent of type <tt>ty2</tt>.
				4063	</p>
				4064
				4065	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4066	<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]	4067	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4068	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4069	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4070	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]	4071
				4072	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4073	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4074	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4075	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4076	the results are undefined.</p>
				4077
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4078	<h5>Example:</h5>
				4079	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4080	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	4081	%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]	4082	%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]	4083	</pre>
				4084	</div>
				4085
				4086	<!-- _______________________________________________________________________ -->
				4087	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4088	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4089	</div>
				4090	<div class="doc_text">
				4091
				4092	<h5>Syntax:</h5>
				4093	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4094	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4095	</pre>
				4096
				4097	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4098	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4099	<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]	4100	</p>
				4101
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4102	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4103	<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]	4104	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4105	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4106	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4107	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]	4108
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4109	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4110	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4111	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4112	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4113	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4114
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	4115	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4116	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4117	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	4118	%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]	4119	%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]	4120	</pre>
				4121	</div>
				4122
				4123	<!-- _______________________________________________________________________ -->
				4124	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4125	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4126	</div>
				4127	<div class="doc_text">
				4128
				4129	<h5>Syntax:</h5>
				4130	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4131	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4132	</pre>
				4133
				4134	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4135	<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]	4136	integer and converts that value to the <tt>ty2</tt> type.</p>
				4137
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4138	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4139	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4140	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4141	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4142	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4143	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]	4144
				4145	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4146	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4147	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4148	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]	4149
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4150	<h5>Example:</h5>
				4151	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4152	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4153	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4154	</pre>
				4155	</div>
				4156
				4157	<!-- _______________________________________________________________________ -->
				4158	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4159	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4160	</div>
				4161	<div class="doc_text">
				4162
				4163	<h5>Syntax:</h5>
				4164	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4165	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4166	</pre>
				4167
				4168	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4169	<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]	4170	integer and converts that value to the <tt>ty2</tt> type.</p>
				4171
				4172	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4173	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4174	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4175	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4176	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4177	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]	4178
				4179	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4180	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4181	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4182	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]	4183
				4184	<h5>Example:</h5>
				4185	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4186	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4187	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4188	</pre>
				4189	</div>
				4190
				4191	<!-- _______________________________________________________________________ -->
				4192	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4193	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4194	</div>
				4195	<div class="doc_text">
				4196
				4197	<h5>Syntax:</h5>
				4198	<pre>
				4199	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4200	</pre>
				4201
				4202	<h5>Overview:</h5>
				4203	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4204	the integer type <tt>ty2</tt>.</p>
				4205
				4206	<h5>Arguments:</h5>
				4207	<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]	4208	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]	4209	<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]	4210
				4211	<h5>Semantics:</h5>
				4212	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4213	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4214	truncating or zero extending that value to the size of the integer type. If
				4215	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4216	<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]	4217	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4218	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4219
				4220	<h5>Example:</h5>
				4221	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4222	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4223	%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]	4224	</pre>
				4225	</div>
				4226
				4227	<!-- _______________________________________________________________________ -->
				4228	<div class="doc_subsubsection">
				4229	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4230	</div>
				4231	<div class="doc_text">
				4232
				4233	<h5>Syntax:</h5>
				4234	<pre>
				4235	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4236	</pre>
				4237
				4238	<h5>Overview:</h5>
				4239	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4240	a pointer type, <tt>ty2</tt>.</p>
				4241
				4242	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4243	<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]	4244	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]	4245	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4246
				4247	<h5>Semantics:</h5>
				4248	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4249	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4250	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4251	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4252	the size of a pointer then a zero extension is done. If they are the same size,
				4253	nothing is done (<i>no-op cast</i>).</p>
				4254
				4255	<h5>Example:</h5>
				4256	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4257	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4258	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4259	%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]	4260	</pre>
				4261	</div>
				4262
				4263	<!-- _______________________________________________________________________ -->
				4264	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4265	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4266	</div>
				4267	<div class="doc_text">
				4268
				4269	<h5>Syntax:</h5>
				4270	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4271	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4272	</pre>
				4273
				4274	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4275
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4276	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4277	<tt>ty2</tt> without changing any bits.</p>
				4278
				4279	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4280
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4281	<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]	4282	a non-aggregate first class value, and a type to cast it to, which must also be
				4283	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4284	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	4285	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]	4286	type is a pointer, the destination type must also be a pointer. This
				4287	instruction supports bitwise conversion of vectors to integers and to vectors
				4288	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4289
				4290	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4291	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4292	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4293	this conversion. The conversion is done as if the <tt>value</tt> had been
				4294	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4295	converted to other pointer types with this instruction. To convert pointers to
				4296	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4297	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4298
				4299	<h5>Example:</h5>
				4300	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4301	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4302	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4303	%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]	4304	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4305	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4306
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4307	<!-- ======================================================================= -->
				4308	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4309	<div class="doc_text">
				4310	<p>The instructions in this category are the "miscellaneous"
				4311	instructions, which defy better classification.</p>
				4312	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4313
				4314	<!-- _______________________________________________________________________ -->
				4315	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4316	</div>
				4317	<div class="doc_text">
				4318	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4319	<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]	4320	</pre>
				4321	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4322	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4323	a vector of boolean values based on comparison
				4324	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4325	<h5>Arguments:</h5>
				4326	<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]	4327	the condition code indicating the kind of comparison to perform. It is not
				4328	a value, just a keyword. The possible condition code are:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4329	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4330	<ol>
				4331	<li><tt>eq</tt>: equal</li>
				4332	<li><tt>ne</tt>: not equal </li>
				4333	<li><tt>ugt</tt>: unsigned greater than</li>
				4334	<li><tt>uge</tt>: unsigned greater or equal</li>
				4335	<li><tt>ult</tt>: unsigned less than</li>
				4336	<li><tt>ule</tt>: unsigned less or equal</li>
				4337	<li><tt>sgt</tt>: signed greater than</li>
				4338	<li><tt>sge</tt>: signed greater or equal</li>
				4339	<li><tt>slt</tt>: signed less than</li>
				4340	<li><tt>sle</tt>: signed less or equal</li>
				4341	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	4342	<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]	4343	<a href="#t_pointer">pointer</a>
				4344	or integer <a href="#t_vector">vector</a> typed.
				4345	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4346	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4347	<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]	4348	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4349	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]	4350	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4351	<ol>
				4352	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4353	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4354	</li>
				4355	<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]	4356	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4357	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4358	<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]	4359	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4360	<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]	4361	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4362	<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]	4363	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4364	<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]	4365	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4366	<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]	4367	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4368	<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]	4369	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4370	<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]	4371	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4372	<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]	4373	</ol>
				4374	<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]	4375	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4376	<p>If the operands are integer vectors, then they are compared
				4377	element by element. The result is an <tt>i1</tt> vector with
				4378	the same number of elements as the values being compared.
				4379	Otherwise, the result is an <tt>i1</tt>.
				4380	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4381
				4382	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4383	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4384	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4385	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4386	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4387	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4388	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4389	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4390
				4391	<p>Note that the code generator does not yet support vector types with
				4392	the <tt>icmp</tt> instruction.</p>
				4393
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4394	</div>
				4395
				4396	<!-- _______________________________________________________________________ -->
				4397	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4398	</div>
				4399	<div class="doc_text">
				4400	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4401	<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]	4402	</pre>
				4403	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4404	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4405	or vector of boolean values based on comparison
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4406	of its operands.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4407	<p>
				4408	If the operands are floating point scalars, then the result
				4409	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4410	</p>
				4411	<p>If the operands are floating point vectors, then the result type
				4412	is a vector of boolean with the same number of elements as the
				4413	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4414	<h5>Arguments:</h5>
				4415	<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]	4416	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]	4417	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4418	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4419	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4420	<li><tt>oeq</tt>: ordered and equal</li>
				4421	<li><tt>ogt</tt>: ordered and greater than </li>
				4422	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4423	<li><tt>olt</tt>: ordered and less than </li>
				4424	<li><tt>ole</tt>: ordered and less than or equal</li>
				4425	<li><tt>one</tt>: ordered and not equal</li>
				4426	<li><tt>ord</tt>: ordered (no nans)</li>
				4427	<li><tt>ueq</tt>: unordered or equal</li>
				4428	<li><tt>ugt</tt>: unordered or greater than </li>
				4429	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4430	<li><tt>ult</tt>: unordered or less than </li>
				4431	<li><tt>ule</tt>: unordered or less than or equal</li>
				4432	<li><tt>une</tt>: unordered or not equal</li>
				4433	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4434	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4435	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4436	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	4437	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4438	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4439	either a <a href="#t_floating">floating point</a> type
				4440	or a <a href="#t_vector">vector</a> of floating point type.
				4441	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4442	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4443	<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]	4444	according to the condition code given as <tt>cond</tt>.
				4445	If the operands are vectors, then the vectors are compared
				4446	element by element.
				4447	Each comparison performed
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4448	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]	4449	<ol>
				4450	<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]	4451	<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]	4452	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4453	<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]	4454	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4455	<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]	4456	<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]	4457	<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]	4458	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4459	<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]	4460	<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]	4461	<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]	4462	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4463	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4464	<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]	4465	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4466	<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]	4467	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4468	<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]	4469	<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]	4470	<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]	4471	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4472	<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]	4473	<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]	4474	<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]	4475	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4476	<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]	4477	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4478	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4479
				4480	<h5>Example:</h5>
				4481	<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]	4482	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4483	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4484	<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]	4485	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4486
				4487	<p>Note that the code generator does not yet support vector types with
				4488	the <tt>fcmp</tt> instruction.</p>
				4489
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4490	</div>
				4491
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4492	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4493	<div class="doc_subsubsection">
				4494	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4495	</div>
				4496	<div class="doc_text">
				4497	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4498	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4499	</pre>
				4500	<h5>Overview:</h5>
				4501	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4502	element-wise comparison of its two integer vector operands.</p>
				4503	<h5>Arguments:</h5>
				4504	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4505	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]	4506	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4507	<ol>
				4508	<li><tt>eq</tt>: equal</li>
				4509	<li><tt>ne</tt>: not equal </li>
				4510	<li><tt>ugt</tt>: unsigned greater than</li>
				4511	<li><tt>uge</tt>: unsigned greater or equal</li>
				4512	<li><tt>ult</tt>: unsigned less than</li>
				4513	<li><tt>ule</tt>: unsigned less or equal</li>
				4514	<li><tt>sgt</tt>: signed greater than</li>
				4515	<li><tt>sge</tt>: signed greater or equal</li>
				4516	<li><tt>slt</tt>: signed less than</li>
				4517	<li><tt>sle</tt>: signed less or equal</li>
				4518	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4519	<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]	4520	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4521	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4522	<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]	4523	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4524	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4525	identical type as the values being compared. The most significant bit in each
				4526	element is 1 if the element-wise comparison evaluates to true, and is 0
				4527	otherwise. All other bits of the result are undefined. The condition codes
				4528	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4529	instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4530
				4531	<h5>Example:</h5>
				4532	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4533	<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>
				4534	<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]	4535	</pre>
				4536	</div>
				4537
				4538	<!-- _______________________________________________________________________ -->
				4539	<div class="doc_subsubsection">
				4540	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4541	</div>
				4542	<div class="doc_text">
				4543	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4544	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4545	<h5>Overview:</h5>
				4546	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4547	element-wise comparison of its two floating point vector operands. The output
				4548	elements have the same width as the input elements.</p>
				4549	<h5>Arguments:</h5>
				4550	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4551	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]	4552	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4553	<ol>
				4554	<li><tt>false</tt>: no comparison, always returns false</li>
				4555	<li><tt>oeq</tt>: ordered and equal</li>
				4556	<li><tt>ogt</tt>: ordered and greater than </li>
				4557	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4558	<li><tt>olt</tt>: ordered and less than </li>
				4559	<li><tt>ole</tt>: ordered and less than or equal</li>
				4560	<li><tt>one</tt>: ordered and not equal</li>
				4561	<li><tt>ord</tt>: ordered (no nans)</li>
				4562	<li><tt>ueq</tt>: unordered or equal</li>
				4563	<li><tt>ugt</tt>: unordered or greater than </li>
				4564	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4565	<li><tt>ult</tt>: unordered or less than </li>
				4566	<li><tt>ule</tt>: unordered or less than or equal</li>
				4567	<li><tt>une</tt>: unordered or not equal</li>
				4568	<li><tt>uno</tt>: unordered (either nans)</li>
				4569	<li><tt>true</tt>: no comparison, always returns true</li>
				4570	</ol>
				4571	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4572	<a href="#t_floating">floating point</a> typed. They must also be identical
				4573	types.</p>
				4574	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4575	<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]	4576	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4577	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4578	an identical number of elements as the values being compared, and each element
				4579	having identical with to the width of the floating point elements. The most
				4580	significant bit in each element is 1 if the element-wise comparison evaluates to
				4581	true, and is 0 otherwise. All other bits of the result are undefined. The
				4582	condition codes are evaluated identically to the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4583	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4584
				4585	<h5>Example:</h5>
				4586	<pre>
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	4587	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4588	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4589
				4590	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4591	<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]	4592	</pre>
				4593	</div>
				4594
				4595	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4596	<div class="doc_subsubsection">
				4597	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4598	</div>
				4599
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4600	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4601
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4602	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4603
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4604	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4605	<h5>Overview:</h5>
				4606	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4607	the SSA graph representing the function.</p>
				4608	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4609
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4610	<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]	4611	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4612	as arguments, with one pair for each predecessor basic block of the
				4613	current block. Only values of <a href="#t_firstclass">first class</a>
				4614	type may be used as the value arguments to the PHI node. Only labels
				4615	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4616
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4617	<p>There must be no non-phi instructions between the start of a basic
				4618	block and the PHI instructions: i.e. PHI instructions must be first in
				4619	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4620
Jay Foad	1a4eea5	2009-06-03 10:20:10 +0000	[diff] [blame]	4621	<p>For the purposes of the SSA form, the use of each incoming value is
				4622	deemed to occur on the edge from the corresponding predecessor block
				4623	to the current block (but after any definition of an '<tt>invoke</tt>'
				4624	instruction's return value on the same edge).</p>
				4625
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4626	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4627
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4628	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4629	specified by the pair corresponding to the predecessor basic block that executed
				4630	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4631
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4632	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4633	<pre>
				4634	Loop: ; Infinite loop that counts from 0 on up...
				4635	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4636	%nextindvar = add i32 %indvar, 1
				4637	br label %Loop
				4638	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4639	</div>
				4640
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4641	<!-- _______________________________________________________________________ -->
				4642	<div class="doc_subsubsection">
				4643	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4644	</div>
				4645
				4646	<div class="doc_text">
				4647
				4648	<h5>Syntax:</h5>
				4649
				4650	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4651	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4652
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4653	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4654	</pre>
				4655
				4656	<h5>Overview:</h5>
				4657
				4658	<p>
				4659	The '<tt>select</tt>' instruction is used to choose one value based on a
				4660	condition, without branching.
				4661	</p>
				4662
				4663
				4664	<h5>Arguments:</h5>
				4665
				4666	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4667	The '<tt>select</tt>' instruction requires an 'i1' value or
				4668	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4669	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]	4670	type. If the val1/val2 are vectors and
				4671	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4672	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4673	</p>
				4674
				4675	<h5>Semantics:</h5>
				4676
				4677	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4678	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]	4679	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4680	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4681	<p>
				4682	If the condition is a vector of i1, then the value arguments must
				4683	be vectors of the same size, and the selection is done element
				4684	by element.
				4685	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4686
				4687	<h5>Example:</h5>
				4688
				4689	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4690	%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]	4691	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4692
				4693	<p>Note that the code generator does not yet support conditions
				4694	with vector type.</p>
				4695
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4696	</div>
				4697
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4698
				4699	<!-- _______________________________________________________________________ -->
				4700	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4701	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4702	</div>
				4703
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4704	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4705
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4706	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4707	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4708	<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]	4709	</pre>
				4710
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4711	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4712
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4713	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4714
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4715	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4716
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4717	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4718
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4719	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4720	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4721	<p>The optional "tail" marker indicates whether the callee function accesses
				4722	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]	4723	function call is eligible for tail call optimization. Note that calls may
				4724	be marked "tail" even if they do not occur before a <a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4725	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4726	</li>
				4727	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4728	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4729	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]	4730	to using C calling conventions.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4731	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4732
				4733	<li>
				4734	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4735	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4736	and '<tt>inreg</tt>' attributes are valid here.</p>
				4737	</li>
				4738
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4739	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4740	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4741	the type of the return value. Functions that return no value are marked
				4742	<tt><a href="#t_void">void</a></tt>.</p>
				4743	</li>
				4744	<li>
				4745	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4746	value being invoked. The argument types must match the types implied by
				4747	this signature. This type can be omitted if the function is not varargs
				4748	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]	4749	</li>
				4750	<li>
				4751	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4752	be invoked. In most cases, this is a direct function invocation, but
				4753	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]	4754	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4755	</li>
				4756	<li>
				4757	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4758	function signature argument types. All arguments must be of
				4759	<a href="#t_firstclass">first class</a> type. If the function signature
				4760	indicates the function accepts a variable number of arguments, the extra
				4761	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4762	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4763	<li>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4764	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4765	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4766	'<tt>readnone</tt>' attributes are valid here.</p>
				4767	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4768	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4769
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4770	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4771
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4772	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4773	transfer to a specified function, with its incoming arguments bound to
				4774	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4775	instruction in the called function, control flow continues with the
				4776	instruction after the function call, and the return value of the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4777	function is bound to the result argument.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4778
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4779	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4780
				4781	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4782	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4783	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4784	%X = tail call i32 @foo() <i>; yields i32</i>
				4785	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4786	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4787
				4788	%struct.A = type { i32, i8 }
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4789	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4790	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4791	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	6cbe8e9	2008-10-08 06:26:11 +0000	[diff] [blame]	4792	%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]	4793	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4794	</pre>
				4795
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4796	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4797
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4798	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4799	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4800	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4801	</div>
				4802
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4803	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4804
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4805	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4806
				4807	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4808	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4809	</pre>
				4810
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4811	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4812
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4813	<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]	4814	the "variable argument" area of a function call. It is used to implement the
				4815	<tt>va_arg</tt> macro in C.</p>
				4816
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4817	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4818
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4819	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4820	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4821	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]	4822	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4823
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4824	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4825
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4826	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4827	type from the specified <tt>va_list</tt> and causes the
				4828	<tt>va_list</tt> to point to the next argument. For more information,
				4829	see the variable argument handling <a href="#int_varargs">Intrinsic
				4830	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4831
				4832	<p>It is legal for this instruction to be called in a function which does not
				4833	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4834	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4835
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4836	<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]	4837	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4838	argument.</p>
				4839
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4840	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4841
				4842	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4843
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	4844	<p>Note that the code generator does not yet fully support va_arg
				4845	on many targets. Also, it does not currently support va_arg with
				4846	aggregate types on any target.</p>
				4847
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
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4850	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4851	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4852	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4853
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4854	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4855
				4856	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4857	well known names and semantics and are required to follow certain restrictions.
				4858	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4859	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]	4860	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]	4861
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4862	<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]	4863	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4864	begin with this prefix. Intrinsic functions must always be external functions:
				4865	you cannot define the body of intrinsic functions. Intrinsic functions may
				4866	only be used in call or invoke instructions: it is illegal to take the address
				4867	of an intrinsic function. Additionally, because intrinsic functions are part
				4868	of the LLVM language, it is required if any are added that they be documented
				4869	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4870
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4871	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4872	a family of functions that perform the same operation but on different data
				4873	types. Because LLVM can represent over 8 million different integer types,
				4874	overloading is used commonly to allow an intrinsic function to operate on any
				4875	integer type. One or more of the argument types or the result type can be
				4876	overloaded to accept any integer type. Argument types may also be defined as
				4877	exactly matching a previous argument's type or the result type. This allows an
				4878	intrinsic function which accepts multiple arguments, but needs all of them to
				4879	be of the same type, to only be overloaded with respect to a single argument or
				4880	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4881
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4882	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4883	encoded into its function name, each preceded by a period. Only those types
				4884	which are overloaded result in a name suffix. Arguments whose type is matched
				4885	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4886	take an integer of any width and returns an integer of exactly the same integer
				4887	width. This leads to a family of functions such as
				4888	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4889	Only one type, the return type, is overloaded, and only one type suffix is
				4890	required. Because the argument's type is matched against the return type, it
				4891	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4892
				4893	<p>To learn how to add an intrinsic function, please see the
				4894	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4895	</p>
				4896
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4897	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4898
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4899	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4900	<div class="doc_subsection">
				4901	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4902	</div>
				4903
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4904	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4905
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4906	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4907	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]	4908	intrinsic functions. These functions are related to the similarly
				4909	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4910
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4911	<p>All of these functions operate on arguments that use a
				4912	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4913	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4914	transformations should be prepared to handle these functions regardless of
				4915	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4916
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4917	<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]	4918	instruction and the variable argument handling intrinsic functions are
				4919	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4920
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4921	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4922	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4923	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4924	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4925	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4926	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4927	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4928
				4929	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4930	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4931
				4932	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4933	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4934	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4935	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4936	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4937
				4938	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4939	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4940	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4941	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4942
				4943	declare void @llvm.va_start(i8*)
				4944	declare void @llvm.va_copy(i8, i8)
				4945	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4946	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4947	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4948
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4949	</div>
				4950
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4951	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4952	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4953	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4954	</div>
				4955
				4956
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4957	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4958	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4959	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4960	<h5>Overview:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4961	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4962	<tt>*<arglist></tt> for subsequent use by <tt><a
				4963	href="#i_va_arg">va_arg</a></tt>.</p>
				4964
				4965	<h5>Arguments:</h5>
				4966
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4967	<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]	4968
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4969	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4970
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4971	<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]	4972	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4973	<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]	4974	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4975	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]	4976	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]	4977
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4978	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4979
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4980	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4981	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4982	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4983	</div>
				4984
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4985	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4986	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4987	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4988	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4989
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4990	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4991	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]	4992	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]	4993
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4994	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4995
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4996	<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]	4997
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4998	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4999
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5000	<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]	5001	macro available in C. In a target-dependent way, it destroys the
				5002	<tt>va_list</tt> element to which the argument points. Calls to <a
				5003	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				5004	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				5005	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	5006
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5007	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5008
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5009	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5010	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5011	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5012	</div>
				5013
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5014	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5015
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5016	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5017
				5018	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5019	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5020	</pre>
				5021
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5022	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5023
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	5024	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				5025	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5026
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5027	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5028
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	5029	<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]	5030	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]	5031
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5032
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5033	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5034
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	5035	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				5036	macro available in C. In a target-dependent way, it copies the source
				5037	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				5038	intrinsic is necessary because the <tt><a href="#int_va_start">
				5039	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				5040	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5041
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5042	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5043
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5044	<!-- ======================================================================= -->
				5045	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5046	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				5047	</div>
				5048
				5049	<div class="doc_text">
				5050
				5051	<p>
				5052	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	5053	Collection</a> (GC) requires the implementation and generation of these
				5054	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5055	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]	5056	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5057	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]	5058	Front-ends for type-safe garbage collected languages should generate these
				5059	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				5060	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				5061	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	5062
				5063	<p>The garbage collection intrinsics only operate on objects in the generic
				5064	address space (address space zero).</p>
				5065
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5066	</div>
				5067
				5068	<!-- _______________________________________________________________________ -->
				5069	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5070	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5071	</div>
				5072
				5073	<div class="doc_text">
				5074
				5075	<h5>Syntax:</h5>
				5076
				5077	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5078	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5079	</pre>
				5080
				5081	<h5>Overview:</h5>
				5082
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	5083	<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]	5084	the code generator, and allows some metadata to be associated with it.</p>
				5085
				5086	<h5>Arguments:</h5>
				5087
				5088	<p>The first argument specifies the address of a stack object that contains the
				5089	root pointer. The second pointer (which must be either a constant or a global
				5090	value address) contains the meta-data to be associated with the root.</p>
				5091
				5092	<h5>Semantics:</h5>
				5093
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	5094	<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]	5095	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5096	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5097	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5098	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5099
				5100	</div>
				5101
				5102
				5103	<!-- _______________________________________________________________________ -->
				5104	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5105	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5106	</div>
				5107
				5108	<div class="doc_text">
				5109
				5110	<h5>Syntax:</h5>
				5111
				5112	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5113	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5114	</pre>
				5115
				5116	<h5>Overview:</h5>
				5117
				5118	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5119	locations, allowing garbage collector implementations that require read
				5120	barriers.</p>
				5121
				5122	<h5>Arguments:</h5>
				5123
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5124	<p>The second argument is the address to read from, which should be an address
				5125	allocated from the garbage collector. The first object is a pointer to the
				5126	start of the referenced object, if needed by the language runtime (otherwise
				5127	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5128
				5129	<h5>Semantics:</h5>
				5130
				5131	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5132	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5133	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5134	may only be used in a function which <a href="#gc">specifies a GC
				5135	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5136
				5137	</div>
				5138
				5139
				5140	<!-- _______________________________________________________________________ -->
				5141	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5142	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5143	</div>
				5144
				5145	<div class="doc_text">
				5146
				5147	<h5>Syntax:</h5>
				5148
				5149	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5150	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5151	</pre>
				5152
				5153	<h5>Overview:</h5>
				5154
				5155	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5156	locations, allowing garbage collector implementations that require write
				5157	barriers (such as generational or reference counting collectors).</p>
				5158
				5159	<h5>Arguments:</h5>
				5160
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5161	<p>The first argument is the reference to store, the second is the start of the
				5162	object to store it to, and the third is the address of the field of Obj to
				5163	store to. If the runtime does not require a pointer to the object, Obj may be
				5164	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5165
				5166	<h5>Semantics:</h5>
				5167
				5168	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5169	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5170	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5171	may only be used in a function which <a href="#gc">specifies a GC
				5172	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5173
				5174	</div>
				5175
				5176
				5177
				5178	<!-- ======================================================================= -->
				5179	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5180	<a name="int_codegen">Code Generator Intrinsics</a>
				5181	</div>
				5182
				5183	<div class="doc_text">
				5184	<p>
				5185	These intrinsics are provided by LLVM to expose special features that may only
				5186	be implemented with code generator support.
				5187	</p>
				5188
				5189	</div>
				5190
				5191	<!-- _______________________________________________________________________ -->
				5192	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5193	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5194	</div>
				5195
				5196	<div class="doc_text">
				5197
				5198	<h5>Syntax:</h5>
				5199	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5200	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5201	</pre>
				5202
				5203	<h5>Overview:</h5>
				5204
				5205	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5206	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5207	target-specific value indicating the return address of the current function
				5208	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5209	</p>
				5210
				5211	<h5>Arguments:</h5>
				5212
				5213	<p>
				5214	The argument to this intrinsic indicates which function to return the address
				5215	for. Zero indicates the calling function, one indicates its caller, etc. The
				5216	argument is <b>required</b> to be a constant integer value.
				5217	</p>
				5218
				5219	<h5>Semantics:</h5>
				5220
				5221	<p>
				5222	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5223	the return address of the specified call frame, or zero if it cannot be
				5224	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5225	for arguments other than zero, so it should only be used for debugging purposes.
				5226	</p>
				5227
				5228	<p>
				5229	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5230	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]	5231	source-language caller.
				5232	</p>
				5233	</div>
				5234
				5235
				5236	<!-- _______________________________________________________________________ -->
				5237	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5238	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5239	</div>
				5240
				5241	<div class="doc_text">
				5242
				5243	<h5>Syntax:</h5>
				5244	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5245	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5246	</pre>
				5247
				5248	<h5>Overview:</h5>
				5249
				5250	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5251	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5252	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5253	</p>
				5254
				5255	<h5>Arguments:</h5>
				5256
				5257	<p>
				5258	The argument to this intrinsic indicates which function to return the frame
				5259	pointer for. Zero indicates the calling function, one indicates its caller,
				5260	etc. The argument is <b>required</b> to be a constant integer value.
				5261	</p>
				5262
				5263	<h5>Semantics:</h5>
				5264
				5265	<p>
				5266	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5267	the frame address of the specified call frame, or zero if it cannot be
				5268	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5269	for arguments other than zero, so it should only be used for debugging purposes.
				5270	</p>
				5271
				5272	<p>
				5273	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5274	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]	5275	source-language caller.
				5276	</p>
				5277	</div>
				5278
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5279	<!-- _______________________________________________________________________ -->
				5280	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5281	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5282	</div>
				5283
				5284	<div class="doc_text">
				5285
				5286	<h5>Syntax:</h5>
				5287	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5288	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5289	</pre>
				5290
				5291	<h5>Overview:</h5>
				5292
				5293	<p>
				5294	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]	5295	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5296	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5297	features like scoped automatic variable sized arrays in C99.
				5298	</p>
				5299
				5300	<h5>Semantics:</h5>
				5301
				5302	<p>
				5303	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]	5304	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5305	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5306	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5307	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5308	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5309	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5310	</p>
				5311
				5312	</div>
				5313
				5314	<!-- _______________________________________________________________________ -->
				5315	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5316	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5317	</div>
				5318
				5319	<div class="doc_text">
				5320
				5321	<h5>Syntax:</h5>
				5322	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5323	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5324	</pre>
				5325
				5326	<h5>Overview:</h5>
				5327
				5328	<p>
				5329	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5330	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]	5331	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5332	useful for implementing language features like scoped automatic variable sized
				5333	arrays in C99.
				5334	</p>
				5335
				5336	<h5>Semantics:</h5>
				5337
				5338	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5339	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]	5340	</p>
				5341
				5342	</div>
				5343
				5344
				5345	<!-- _______________________________________________________________________ -->
				5346	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5347	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5348	</div>
				5349
				5350	<div class="doc_text">
				5351
				5352	<h5>Syntax:</h5>
				5353	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5354	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5355	</pre>
				5356
				5357	<h5>Overview:</h5>
				5358
				5359
				5360	<p>
				5361	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]	5362	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5363	no
				5364	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	5365	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5366	</p>
				5367
				5368	<h5>Arguments:</h5>
				5369
				5370	<p>
				5371	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5372	determining if the fetch should be for a read (0) or write (1), and
				5373	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	5374	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]	5375	<tt>locality</tt> arguments must be constant integers.
				5376	</p>
				5377
				5378	<h5>Semantics:</h5>
				5379
				5380	<p>
				5381	This intrinsic does not modify the behavior of the program. In particular,
				5382	prefetches cannot trap and do not produce a value. On targets that support this
				5383	intrinsic, the prefetch can provide hints to the processor cache for better
				5384	performance.
				5385	</p>
				5386
				5387	</div>
				5388
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5389	<!-- _______________________________________________________________________ -->
				5390	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5391	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5392	</div>
				5393
				5394	<div class="doc_text">
				5395
				5396	<h5>Syntax:</h5>
				5397	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5398	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5399	</pre>
				5400
				5401	<h5>Overview:</h5>
				5402
				5403
				5404	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5405	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]	5406	(PC) in a region of
				5407	code to simulators and other tools. The method is target specific, but it is
				5408	expected that the marker will use exported symbols to transmit the PC of the
				5409	marker.
				5410	The marker makes no guarantees that it will remain with any specific instruction
				5411	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]	5412	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5413	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5414	</p>
				5415
				5416	<h5>Arguments:</h5>
				5417
				5418	<p>
				5419	<tt>id</tt> is a numerical id identifying the marker.
				5420	</p>
				5421
				5422	<h5>Semantics:</h5>
				5423
				5424	<p>
				5425	This intrinsic does not modify the behavior of the program. Backends that do not
				5426	support this intrinisic may ignore it.
				5427	</p>
				5428
				5429	</div>
				5430
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5431	<!-- _______________________________________________________________________ -->
				5432	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5433	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5434	</div>
				5435
				5436	<div class="doc_text">
				5437
				5438	<h5>Syntax:</h5>
				5439	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5440	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5441	</pre>
				5442
				5443	<h5>Overview:</h5>
				5444
				5445
				5446	<p>
				5447	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5448	counter register (or similar low latency, high accuracy clocks) on those targets
				5449	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5450	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5451	should only be used for small timings.
				5452	</p>
				5453
				5454	<h5>Semantics:</h5>
				5455
				5456	<p>
				5457	When directly supported, reading the cycle counter should not modify any memory.
				5458	Implementations are allowed to either return a application specific value or a
				5459	system wide value. On backends without support, this is lowered to a constant 0.
				5460	</p>
				5461
				5462	</div>
				5463
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5464	<!-- ======================================================================= -->
				5465	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5466	<a name="int_libc">Standard C Library Intrinsics</a>
				5467	</div>
				5468
				5469	<div class="doc_text">
				5470	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5471	LLVM provides intrinsics for a few important standard C library functions.
				5472	These intrinsics allow source-language front-ends to pass information about the
				5473	alignment of the pointer arguments to the code generator, providing opportunity
				5474	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5475	</p>
				5476
				5477	</div>
				5478
				5479	<!-- _______________________________________________________________________ -->
				5480	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5481	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5482	</div>
				5483
				5484	<div class="doc_text">
				5485
				5486	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5487	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5488	width. Not all targets support all bit widths however.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5489	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5490	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5491	i8 <len>, i32 <align>)
				5492	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5493	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5494	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5495	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5496	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5497	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5498	</pre>
				5499
				5500	<h5>Overview:</h5>
				5501
				5502	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5503	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]	5504	location to the destination location.
				5505	</p>
				5506
				5507	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5508	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5509	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5510	</p>
				5511
				5512	<h5>Arguments:</h5>
				5513
				5514	<p>
				5515	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]	5516	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5517	specifying the number of bytes to copy, and the fourth argument is the alignment
				5518	of the source and destination locations.
				5519	</p>
				5520
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5521	<p>
				5522	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]	5523	the caller guarantees that both the source and destination pointers are aligned
				5524	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5525	</p>
				5526
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5527	<h5>Semantics:</h5>
				5528
				5529	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5530	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]	5531	location to the destination location, which are not allowed to overlap. It
				5532	copies "len" bytes of memory over. If the argument is known to be aligned to
				5533	some boundary, this can be specified as the fourth argument, otherwise it should
				5534	be set to 0 or 1.
				5535	</p>
				5536	</div>
				5537
				5538
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5539	<!-- _______________________________________________________________________ -->
				5540	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5541	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5542	</div>
				5543
				5544	<div class="doc_text">
				5545
				5546	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5547	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5548	width. Not all targets support all bit widths however.</p>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5549	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5550	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5551	i8 <len>, i32 <align>)
				5552	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5553	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5554	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5555	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5556	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5557	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5558	</pre>
				5559
				5560	<h5>Overview:</h5>
				5561
				5562	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5563	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5564	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5565	'<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]	5566	</p>
				5567
				5568	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5569	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5570	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5571	</p>
				5572
				5573	<h5>Arguments:</h5>
				5574
				5575	<p>
				5576	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]	5577	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5578	specifying the number of bytes to copy, and the fourth argument is the alignment
				5579	of the source and destination locations.
				5580	</p>
				5581
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5582	<p>
				5583	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]	5584	the caller guarantees that the source and destination pointers are aligned to
				5585	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5586	</p>
				5587
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5588	<h5>Semantics:</h5>
				5589
				5590	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5591	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]	5592	location to the destination location, which may overlap. It
				5593	copies "len" bytes of memory over. If the argument is known to be aligned to
				5594	some boundary, this can be specified as the fourth argument, otherwise it should
				5595	be set to 0 or 1.
				5596	</p>
				5597	</div>
				5598
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5599
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5600	<!-- _______________________________________________________________________ -->
				5601	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5602	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5603	</div>
				5604
				5605	<div class="doc_text">
				5606
				5607	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5608	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5609	width. Not all targets support all bit widths however.</p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5610	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5611	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5612	i8 <len>, i32 <align>)
				5613	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5614	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5615	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5616	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5617	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5618	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5619	</pre>
				5620
				5621	<h5>Overview:</h5>
				5622
				5623	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5624	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]	5625	byte value.
				5626	</p>
				5627
				5628	<p>
				5629	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5630	does not return a value, and takes an extra alignment argument.
				5631	</p>
				5632
				5633	<h5>Arguments:</h5>
				5634
				5635	<p>
				5636	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]	5637	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5638	argument specifying the number of bytes to fill, and the fourth argument is the
				5639	known alignment of destination location.
				5640	</p>
				5641
				5642	<p>
				5643	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]	5644	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5645	</p>
				5646
				5647	<h5>Semantics:</h5>
				5648
				5649	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5650	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5651	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5652	destination location. If the argument is known to be aligned to some boundary,
				5653	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5654	1.
				5655	</p>
				5656	</div>
				5657
				5658
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5659	<!-- _______________________________________________________________________ -->
				5660	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5661	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5662	</div>
				5663
				5664	<div class="doc_text">
				5665
				5666	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5667	<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]	5668	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]	5669	types however.</p>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5670	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5671	declare float @llvm.sqrt.f32(float %Val)
				5672	declare double @llvm.sqrt.f64(double %Val)
				5673	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5674	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5675	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5676	</pre>
				5677
				5678	<h5>Overview:</h5>
				5679
				5680	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5681	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]	5682	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]	5683	<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]	5684	negative numbers other than -0.0 (which allows for better optimization, because
				5685	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5686	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5687	</p>
				5688
				5689	<h5>Arguments:</h5>
				5690
				5691	<p>
				5692	The argument and return value are floating point numbers of the same type.
				5693	</p>
				5694
				5695	<h5>Semantics:</h5>
				5696
				5697	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5698	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]	5699	floating point number.
				5700	</p>
				5701	</div>
				5702
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5703	<!-- _______________________________________________________________________ -->
				5704	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5705	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5706	</div>
				5707
				5708	<div class="doc_text">
				5709
				5710	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5711	<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]	5712	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]	5713	types however.</p>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5714	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5715	declare float @llvm.powi.f32(float %Val, i32 %power)
				5716	declare double @llvm.powi.f64(double %Val, i32 %power)
				5717	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5718	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5719	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5720	</pre>
				5721
				5722	<h5>Overview:</h5>
				5723
				5724	<p>
				5725	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5726	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5727	multiplications is not defined. When a vector of floating point type is
				5728	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5729	</p>
				5730
				5731	<h5>Arguments:</h5>
				5732
				5733	<p>
				5734	The second argument is an integer power, and the first is a value to raise to
				5735	that power.
				5736	</p>
				5737
				5738	<h5>Semantics:</h5>
				5739
				5740	<p>
				5741	This function returns the first value raised to the second power with an
				5742	unspecified sequence of rounding operations.</p>
				5743	</div>
				5744
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5745	<!-- _______________________________________________________________________ -->
				5746	<div class="doc_subsubsection">
				5747	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5748	</div>
				5749
				5750	<div class="doc_text">
				5751
				5752	<h5>Syntax:</h5>
				5753	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5754	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]	5755	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5756	<pre>
				5757	declare float @llvm.sin.f32(float %Val)
				5758	declare double @llvm.sin.f64(double %Val)
				5759	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5760	declare fp128 @llvm.sin.f128(fp128 %Val)
				5761	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5762	</pre>
				5763
				5764	<h5>Overview:</h5>
				5765
				5766	<p>
				5767	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5768	</p>
				5769
				5770	<h5>Arguments:</h5>
				5771
				5772	<p>
				5773	The argument and return value are floating point numbers of the same type.
				5774	</p>
				5775
				5776	<h5>Semantics:</h5>
				5777
				5778	<p>
				5779	This function returns the sine of the specified operand, returning the
				5780	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]	5781	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5782	</div>
				5783
				5784	<!-- _______________________________________________________________________ -->
				5785	<div class="doc_subsubsection">
				5786	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5787	</div>
				5788
				5789	<div class="doc_text">
				5790
				5791	<h5>Syntax:</h5>
				5792	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5793	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]	5794	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5795	<pre>
				5796	declare float @llvm.cos.f32(float %Val)
				5797	declare double @llvm.cos.f64(double %Val)
				5798	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5799	declare fp128 @llvm.cos.f128(fp128 %Val)
				5800	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5801	</pre>
				5802
				5803	<h5>Overview:</h5>
				5804
				5805	<p>
				5806	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5807	</p>
				5808
				5809	<h5>Arguments:</h5>
				5810
				5811	<p>
				5812	The argument and return value are floating point numbers of the same type.
				5813	</p>
				5814
				5815	<h5>Semantics:</h5>
				5816
				5817	<p>
				5818	This function returns the cosine of the specified operand, returning the
				5819	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]	5820	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5821	</div>
				5822
				5823	<!-- _______________________________________________________________________ -->
				5824	<div class="doc_subsubsection">
				5825	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5826	</div>
				5827
				5828	<div class="doc_text">
				5829
				5830	<h5>Syntax:</h5>
				5831	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5832	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]	5833	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5834	<pre>
				5835	declare float @llvm.pow.f32(float %Val, float %Power)
				5836	declare double @llvm.pow.f64(double %Val, double %Power)
				5837	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5838	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5839	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5840	</pre>
				5841
				5842	<h5>Overview:</h5>
				5843
				5844	<p>
				5845	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5846	specified (positive or negative) power.
				5847	</p>
				5848
				5849	<h5>Arguments:</h5>
				5850
				5851	<p>
				5852	The second argument is a floating point power, and the first is a value to
				5853	raise to that power.
				5854	</p>
				5855
				5856	<h5>Semantics:</h5>
				5857
				5858	<p>
				5859	This function returns the first value raised to the second power,
				5860	returning the
				5861	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]	5862	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5863	</div>
				5864
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5865
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5866	<!-- ======================================================================= -->
				5867	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5868	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5869	</div>
				5870
				5871	<div class="doc_text">
				5872	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5873	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5874	These allow efficient code generation for some algorithms.
				5875	</p>
				5876
				5877	</div>
				5878
				5879	<!-- _______________________________________________________________________ -->
				5880	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5881	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5882	</div>
				5883
				5884	<div class="doc_text">
				5885
				5886	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5887	<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]	5888	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]	5889	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5890	declare i16 @llvm.bswap.i16(i16 <id>)
				5891	declare i32 @llvm.bswap.i32(i32 <id>)
				5892	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5893	</pre>
				5894
				5895	<h5>Overview:</h5>
				5896
				5897	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5898	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]	5899	values with an even number of bytes (positive multiple of 16 bits). These are
				5900	useful for performing operations on data that is not in the target's native
				5901	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5902	</p>
				5903
				5904	<h5>Semantics:</h5>
				5905
				5906	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5907	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]	5908	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5909	intrinsic returns an i32 value that has the four bytes of the input i32
				5910	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]	5911	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5912	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5913	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5914	</p>
				5915
				5916	</div>
				5917
				5918	<!-- _______________________________________________________________________ -->
				5919	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5920	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5921	</div>
				5922
				5923	<div class="doc_text">
				5924
				5925	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5926	<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]	5927	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5928	<pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5929	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5930	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5931	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5932	declare i64 @llvm.ctpop.i64(i64 <src>)
				5933	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5934	</pre>
				5935
				5936	<h5>Overview:</h5>
				5937
				5938	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5939	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5940	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5941	</p>
				5942
				5943	<h5>Arguments:</h5>
				5944
				5945	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5946	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]	5947	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5948	</p>
				5949
				5950	<h5>Semantics:</h5>
				5951
				5952	<p>
				5953	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5954	</p>
				5955	</div>
				5956
				5957	<!-- _______________________________________________________________________ -->
				5958	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5959	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5960	</div>
				5961
				5962	<div class="doc_text">
				5963
				5964	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5965	<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]	5966	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5967	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5968	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5969	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5970	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5971	declare i64 @llvm.ctlz.i64(i64 <src>)
				5972	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5973	</pre>
				5974
				5975	<h5>Overview:</h5>
				5976
				5977	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5978	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5979	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5980	</p>
				5981
				5982	<h5>Arguments:</h5>
				5983
				5984	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5985	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]	5986	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5987	</p>
				5988
				5989	<h5>Semantics:</h5>
				5990
				5991	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5992	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5993	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]	5994	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5995	</p>
				5996	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5997
				5998
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5999
				6000	<!-- _______________________________________________________________________ -->
				6001	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	6002	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6003	</div>
				6004
				6005	<div class="doc_text">
				6006
				6007	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	6008	<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]	6009	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6010	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6011	declare i8 @llvm.cttz.i8 (i8 <src>)
				6012	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	6013	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6014	declare i64 @llvm.cttz.i64(i64 <src>)
				6015	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6016	</pre>
				6017
				6018	<h5>Overview:</h5>
				6019
				6020	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	6021	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				6022	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6023	</p>
				6024
				6025	<h5>Arguments:</h5>
				6026
				6027	<p>
				6028	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]	6029	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6030	</p>
				6031
				6032	<h5>Semantics:</h5>
				6033
				6034	<p>
				6035	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				6036	in a variable. If the src == 0 then the result is the size in bits of the type
				6037	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				6038	</p>
				6039	</div>
				6040
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	6041	<!-- _______________________________________________________________________ -->
				6042	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	6043	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6044	</div>
				6045
				6046	<div class="doc_text">
				6047
				6048	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	6049	<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]	6050	on any integer bit width.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6051	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6052	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				6053	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6054	</pre>
				6055
				6056	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	6057	<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]	6058	range of bits from an integer value and returns them in the same bit width as
				6059	the original value.</p>
				6060
				6061	<h5>Arguments:</h5>
				6062	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				6063	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]	6064	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]	6065
				6066	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	6067	<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]	6068	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				6069	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				6070	operates in forward mode.</p>
				6071	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				6072	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]	6073	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				6074	<ol>
				6075	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				6076	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				6077	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				6078	to determine the number of bits to retain.</li>
				6079	<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]	6080	<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]	6081	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	6082	<p>In reverse mode, a similar computation is made except that the bits are
				6083	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				6084	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				6085	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				6086	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6087	</div>
				6088
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6089	<div class="doc_subsubsection">
				6090	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				6091	</div>
				6092
				6093	<div class="doc_text">
				6094
				6095	<h5>Syntax:</h5>
				6096	<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]	6097	on any integer bit width.</p>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6098	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6099	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				6100	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]	6101	</pre>
				6102
				6103	<h5>Overview:</h5>
				6104	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				6105	of bits in an integer value with another integer value. It returns the integer
				6106	with the replaced bits.</p>
				6107
				6108	<h5>Arguments:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6109	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				6110	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]	6111	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				6112	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				6113	type since they specify only a bit index.</p>
				6114
				6115	<h5>Semantics:</h5>
				6116	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				6117	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				6118	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				6119	operates in forward mode.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6120
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6121	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				6122	truncating it down to the size of the replacement area or zero extending it
				6123	up to that size.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6124
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6125	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				6126	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				6127	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]	6128	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6129
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6130	<p>In reverse mode, a similar computation is made except that the bits are
				6131	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]	6132	<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]	6133
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6134	<h5>Examples:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6135
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6136	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6137	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6138	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6139	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6140	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6141	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	6142	</pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6143
				6144	</div>
				6145
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6146	<!-- ======================================================================= -->
				6147	<div class="doc_subsection">
				6148	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6149	</div>
				6150
				6151	<div class="doc_text">
				6152	<p>
				6153	LLVM provides intrinsics for some arithmetic with overflow operations.
				6154	</p>
				6155
				6156	</div>
				6157
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6158	<!-- _______________________________________________________________________ -->
				6159	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6160	<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]	6161	</div>
				6162
				6163	<div class="doc_text">
				6164
				6165	<h5>Syntax:</h5>
				6166
				6167	<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]	6168	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6169
				6170	<pre>
				6171	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6172	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6173	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6174	</pre>
				6175
				6176	<h5>Overview:</h5>
				6177
				6178	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6179	a signed addition of the two arguments, and indicate whether an overflow
				6180	occurred during the signed summation.</p>
				6181
				6182	<h5>Arguments:</h5>
				6183
				6184	<p>The arguments (%a and %b) and the first element of the result structure may
				6185	be of integer types of any bit width, but they must have the same bit width. The
				6186	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6187	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6188
				6189	<h5>Semantics:</h5>
				6190
				6191	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6192	a signed addition of the two variables. They return a structure — the
				6193	first element of which is the signed summation, and the second element of which
				6194	is a bit specifying if the signed summation resulted in an overflow.</p>
				6195
				6196	<h5>Examples:</h5>
				6197	<pre>
				6198	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6199	%sum = extractvalue {i32, i1} %res, 0
				6200	%obit = extractvalue {i32, i1} %res, 1
				6201	br i1 %obit, label %overflow, label %normal
				6202	</pre>
				6203
				6204	</div>
				6205
				6206	<!-- _______________________________________________________________________ -->
				6207	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6208	<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]	6209	</div>
				6210
				6211	<div class="doc_text">
				6212
				6213	<h5>Syntax:</h5>
				6214
				6215	<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]	6216	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6217
				6218	<pre>
				6219	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6220	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6221	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6222	</pre>
				6223
				6224	<h5>Overview:</h5>
				6225
				6226	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6227	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6228	during the unsigned summation.</p>
				6229
				6230	<h5>Arguments:</h5>
				6231
				6232	<p>The arguments (%a and %b) and the first element of the result structure may
				6233	be of integer types of any bit width, but they must have the same bit width. The
				6234	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6235	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6236
				6237	<h5>Semantics:</h5>
				6238
				6239	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6240	an unsigned addition of the two arguments. They return a structure — the
				6241	first element of which is the sum, and the second element of which is a bit
				6242	specifying if the unsigned summation resulted in a carry.</p>
				6243
				6244	<h5>Examples:</h5>
				6245	<pre>
				6246	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6247	%sum = extractvalue {i32, i1} %res, 0
				6248	%obit = extractvalue {i32, i1} %res, 1
				6249	br i1 %obit, label %carry, label %normal
				6250	</pre>
				6251
				6252	</div>
				6253
				6254	<!-- _______________________________________________________________________ -->
				6255	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6256	<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]	6257	</div>
				6258
				6259	<div class="doc_text">
				6260
				6261	<h5>Syntax:</h5>
				6262
				6263	<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]	6264	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6265
				6266	<pre>
				6267	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6268	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6269	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6270	</pre>
				6271
				6272	<h5>Overview:</h5>
				6273
				6274	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6275	a signed subtraction of the two arguments, and indicate whether an overflow
				6276	occurred during the signed subtraction.</p>
				6277
				6278	<h5>Arguments:</h5>
				6279
				6280	<p>The arguments (%a and %b) and the first element of the result structure may
				6281	be of integer types of any bit width, but they must have the same bit width. The
				6282	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6283	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6284
				6285	<h5>Semantics:</h5>
				6286
				6287	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6288	a signed subtraction of the two arguments. They return a structure — the
				6289	first element of which is the subtraction, and the second element of which is a bit
				6290	specifying if the signed subtraction resulted in an overflow.</p>
				6291
				6292	<h5>Examples:</h5>
				6293	<pre>
				6294	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6295	%sum = extractvalue {i32, i1} %res, 0
				6296	%obit = extractvalue {i32, i1} %res, 1
				6297	br i1 %obit, label %overflow, label %normal
				6298	</pre>
				6299
				6300	</div>
				6301
				6302	<!-- _______________________________________________________________________ -->
				6303	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6304	<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]	6305	</div>
				6306
				6307	<div class="doc_text">
				6308
				6309	<h5>Syntax:</h5>
				6310
				6311	<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]	6312	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6313
				6314	<pre>
				6315	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6316	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6317	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6318	</pre>
				6319
				6320	<h5>Overview:</h5>
				6321
				6322	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6323	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6324	occurred during the unsigned subtraction.</p>
				6325
				6326	<h5>Arguments:</h5>
				6327
				6328	<p>The arguments (%a and %b) and the first element of the result structure may
				6329	be of integer types of any bit width, but they must have the same bit width. The
				6330	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6331	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6332
				6333	<h5>Semantics:</h5>
				6334
				6335	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6336	an unsigned subtraction of the two arguments. They return a structure — the
				6337	first element of which is the subtraction, and the second element of which is a bit
				6338	specifying if the unsigned subtraction resulted in an overflow.</p>
				6339
				6340	<h5>Examples:</h5>
				6341	<pre>
				6342	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6343	%sum = extractvalue {i32, i1} %res, 0
				6344	%obit = extractvalue {i32, i1} %res, 1
				6345	br i1 %obit, label %overflow, label %normal
				6346	</pre>
				6347
				6348	</div>
				6349
				6350	<!-- _______________________________________________________________________ -->
				6351	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6352	<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]	6353	</div>
				6354
				6355	<div class="doc_text">
				6356
				6357	<h5>Syntax:</h5>
				6358
				6359	<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]	6360	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6361
				6362	<pre>
				6363	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6364	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6365	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6366	</pre>
				6367
				6368	<h5>Overview:</h5>
				6369
				6370	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6371	a signed multiplication of the two arguments, and indicate whether an overflow
				6372	occurred during the signed multiplication.</p>
				6373
				6374	<h5>Arguments:</h5>
				6375
				6376	<p>The arguments (%a and %b) and the first element of the result structure may
				6377	be of integer types of any bit width, but they must have the same bit width. The
				6378	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6379	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6380
				6381	<h5>Semantics:</h5>
				6382
				6383	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6384	a signed multiplication of the two arguments. They return a structure —
				6385	the first element of which is the multiplication, and the second element of
				6386	which is a bit specifying if the signed multiplication resulted in an
				6387	overflow.</p>
				6388
				6389	<h5>Examples:</h5>
				6390	<pre>
				6391	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6392	%sum = extractvalue {i32, i1} %res, 0
				6393	%obit = extractvalue {i32, i1} %res, 1
				6394	br i1 %obit, label %overflow, label %normal
				6395	</pre>
				6396
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6397	</div>
				6398
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	6399	<!-- _______________________________________________________________________ -->
				6400	<div class="doc_subsubsection">
				6401	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6402	</div>
				6403
				6404	<div class="doc_text">
				6405
				6406	<h5>Syntax:</h5>
				6407
				6408	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6409	on any integer bit width.</p>
				6410
				6411	<pre>
				6412	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6413	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6414	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6415	</pre>
				6416
				6417	<h5>Overview:</h5>
				6418
				6419	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6420	actively being fixed, but it should not currently be used!</i></p>
				6421
				6422	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6423	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6424	occurred during the unsigned multiplication.</p>
				6425
				6426	<h5>Arguments:</h5>
				6427
				6428	<p>The arguments (%a and %b) and the first element of the result structure may
				6429	be of integer types of any bit width, but they must have the same bit width. The
				6430	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6431	and <tt>%b</tt> are the two values that will undergo unsigned
				6432	multiplication.</p>
				6433
				6434	<h5>Semantics:</h5>
				6435
				6436	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6437	an unsigned multiplication of the two arguments. They return a structure —
				6438	the first element of which is the multiplication, and the second element of
				6439	which is a bit specifying if the unsigned multiplication resulted in an
				6440	overflow.</p>
				6441
				6442	<h5>Examples:</h5>
				6443	<pre>
				6444	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6445	%sum = extractvalue {i32, i1} %res, 0
				6446	%obit = extractvalue {i32, i1} %res, 1
				6447	br i1 %obit, label %overflow, label %normal
				6448	</pre>
				6449
				6450	</div>
				6451
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	6452	<!-- ======================================================================= -->
				6453	<div class="doc_subsection">
				6454	<a name="int_debugger">Debugger Intrinsics</a>
				6455	</div>
				6456
				6457	<div class="doc_text">
				6458	<p>
				6459	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6460	are described in the <a
				6461	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6462	Debugging</a> document.
				6463	</p>
				6464	</div>
				6465
				6466
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6467	<!-- ======================================================================= -->
				6468	<div class="doc_subsection">
				6469	<a name="int_eh">Exception Handling Intrinsics</a>
				6470	</div>
				6471
				6472	<div class="doc_text">
				6473	<p> The LLVM exception handling intrinsics (which all start with
				6474	<tt>llvm.eh.</tt> prefix), are described in the <a
				6475	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6476	Handling</a> document. </p>
				6477	</div>
				6478
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6479	<!-- ======================================================================= -->
				6480	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6481	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6482	</div>
				6483
				6484	<div class="doc_text">
				6485	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6486	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6487	the <tt>nest</tt> attribute, from a function. The result is a callable
				6488	function pointer lacking the nest parameter - the caller does not need
				6489	to provide a value for it. Instead, the value to use is stored in
				6490	advance in a "trampoline", a block of memory usually allocated
				6491	on the stack, which also contains code to splice the nest value into the
				6492	argument list. This is used to implement the GCC nested function address
				6493	extension.
				6494	</p>
				6495	<p>
				6496	For example, if the function is
				6497	<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]	6498	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]	6499	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6500	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6501	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6502	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6503	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6504	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	6505	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6506	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]	6507	</div>
				6508
				6509	<!-- _______________________________________________________________________ -->
				6510	<div class="doc_subsubsection">
				6511	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6512	</div>
				6513	<div class="doc_text">
				6514	<h5>Syntax:</h5>
				6515	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6516	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6517	</pre>
				6518	<h5>Overview:</h5>
				6519	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6520	This fills the memory pointed to by <tt>tramp</tt> with code
				6521	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6522	</p>
				6523	<h5>Arguments:</h5>
				6524	<p>
				6525	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6526	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6527	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]	6528	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6529	currently provides no portable way of determining them, so a front-end that
				6530	generates this intrinsic needs to have some target-specific knowledge.
				6531	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]	6532	</p>
				6533	<h5>Semantics:</h5>
				6534	<p>
				6535	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]	6536	dependent code, turning it into a function. A pointer to this function is
				6537	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6538	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6539	before being called. The new function's signature is the same as that of
				6540	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6541	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6542	of pointer type. Calling the new function is equivalent to calling
				6543	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6544	missing <tt>nest</tt> argument. If, after calling
				6545	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6546	modified, then the effect of any later call to the returned function pointer is
				6547	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6548	</p>
				6549	</div>
				6550
				6551	<!-- ======================================================================= -->
				6552	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6553	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6554	</div>
				6555
				6556	<div class="doc_text">
				6557	<p>
				6558	These intrinsic functions expand the "universal IR" of LLVM to represent
				6559	hardware constructs for atomic operations and memory synchronization. This
				6560	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]	6561	is aimed at a low enough level to allow any programming models or APIs
				6562	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6563	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6564	hardware behavior. Just as hardware provides a "universal IR" for source
				6565	languages, it also provides a starting point for developing a "universal"
				6566	atomic operation and synchronization IR.
				6567	</p>
				6568	<p>
				6569	These do <em>not</em> form an API such as high-level threading libraries,
				6570	software transaction memory systems, atomic primitives, and intrinsic
				6571	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6572	application libraries. The hardware interface provided by LLVM should allow
				6573	a clean implementation of all of these APIs and parallel programming models.
				6574	No one model or paradigm should be selected above others unless the hardware
				6575	itself ubiquitously does so.
				6576
				6577	</p>
				6578	</div>
				6579
				6580	<!-- _______________________________________________________________________ -->
				6581	<div class="doc_subsubsection">
				6582	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6583	</div>
				6584	<div class="doc_text">
				6585	<h5>Syntax:</h5>
				6586	<pre>
				6587	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6588	i1 <device> )
				6589
				6590	</pre>
				6591	<h5>Overview:</h5>
				6592	<p>
				6593	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6594	specific pairs of memory access types.
				6595	</p>
				6596	<h5>Arguments:</h5>
				6597	<p>
				6598	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6599	The first four arguments enables a specific barrier as listed below. The fith
				6600	argument specifies that the barrier applies to io or device or uncached memory.
				6601
				6602	</p>
				6603	<ul>
				6604	<li><tt>ll</tt>: load-load barrier</li>
				6605	<li><tt>ls</tt>: load-store barrier</li>
				6606	<li><tt>sl</tt>: store-load barrier</li>
				6607	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6608	<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]	6609	</ul>
				6610	<h5>Semantics:</h5>
				6611	<p>
				6612	This intrinsic causes the system to enforce some ordering constraints upon
				6613	the loads and stores of the program. This barrier does not indicate
				6614	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6615	which they occur. For any of the specified pairs of load and store operations
				6616	(f.ex. load-load, or store-load), all of the first operations preceding the
				6617	barrier will complete before any of the second operations succeeding the
				6618	barrier begin. Specifically the semantics for each pairing is as follows:
				6619	</p>
				6620	<ul>
				6621	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6622	after the barrier begins.</li>
				6623
				6624	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6625	store after the barrier begins.</li>
				6626	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6627	store after the barrier begins.</li>
				6628	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6629	load after the barrier begins.</li>
				6630	</ul>
				6631	<p>
				6632	These semantics are applied with a logical "and" behavior when more than one
				6633	is enabled in a single memory barrier intrinsic.
				6634	</p>
				6635	<p>
				6636	Backends may implement stronger barriers than those requested when they do not
				6637	support as fine grained a barrier as requested. Some architectures do not
				6638	need all types of barriers and on such architectures, these become noops.
				6639	</p>
				6640	<h5>Example:</h5>
				6641	<pre>
				6642	%ptr = malloc i32
				6643	store i32 4, %ptr
				6644
				6645	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6646	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6647	<i>; guarantee the above finishes</i>
				6648	store i32 8, %ptr <i>; before this begins</i>
				6649	</pre>
				6650	</div>
				6651
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6652	<!-- _______________________________________________________________________ -->
				6653	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6654	<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]	6655	</div>
				6656	<div class="doc_text">
				6657	<h5>Syntax:</h5>
				6658	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6659	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6660	any integer bit width and for different address spaces. Not all targets
				6661	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6662
				6663	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6664	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6665	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6666	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6667	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]	6668
				6669	</pre>
				6670	<h5>Overview:</h5>
				6671	<p>
				6672	This loads a value in memory and compares it to a given value. If they are
				6673	equal, it stores a new value into the memory.
				6674	</p>
				6675	<h5>Arguments:</h5>
				6676	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6677	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]	6678	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6679	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6680	this integer type. While any bit width integer may be used, targets may only
				6681	lower representations they support in hardware.
				6682
				6683	</p>
				6684	<h5>Semantics:</h5>
				6685	<p>
				6686	This entire intrinsic must be executed atomically. It first loads the value
				6687	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6688	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6689	loaded value is yielded in all cases. This provides the equivalent of an
				6690	atomic compare-and-swap operation within the SSA framework.
				6691	</p>
				6692	<h5>Examples:</h5>
				6693
				6694	<pre>
				6695	%ptr = malloc i32
				6696	store i32 4, %ptr
				6697
				6698	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6699	%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]	6700	<i>; yields {i32}:result1 = 4</i>
				6701	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6702	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6703
				6704	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6705	%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]	6706	<i>; yields {i32}:result2 = 8</i>
				6707	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6708
				6709	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6710	</pre>
				6711	</div>
				6712
				6713	<!-- _______________________________________________________________________ -->
				6714	<div class="doc_subsubsection">
				6715	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6716	</div>
				6717	<div class="doc_text">
				6718	<h5>Syntax:</h5>
				6719
				6720	<p>
				6721	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6722	integer bit width. Not all targets support all bit widths however.</p>
				6723	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6724	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6725	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6726	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6727	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6728
				6729	</pre>
				6730	<h5>Overview:</h5>
				6731	<p>
				6732	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6733	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6734	at <tt>ptr</tt>.
				6735	</p>
				6736	<h5>Arguments:</h5>
				6737
				6738	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6739	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6740	<tt>val</tt> argument and the result must be integers of the same bit width.
				6741	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6742	integer type. The targets may only lower integer representations they
				6743	support.
				6744	</p>
				6745	<h5>Semantics:</h5>
				6746	<p>
				6747	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6748	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6749	equivalent of an atomic swap operation within the SSA framework.
				6750
				6751	</p>
				6752	<h5>Examples:</h5>
				6753	<pre>
				6754	%ptr = malloc i32
				6755	store i32 4, %ptr
				6756
				6757	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6758	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6759	<i>; yields {i32}:result1 = 4</i>
				6760	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6761	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6762
				6763	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6764	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6765	<i>; yields {i32}:result2 = 8</i>
				6766
				6767	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6768	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6769	</pre>
				6770	</div>
				6771
				6772	<!-- _______________________________________________________________________ -->
				6773	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6774	<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]	6775
				6776	</div>
				6777	<div class="doc_text">
				6778	<h5>Syntax:</h5>
				6779	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6780	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]	6781	integer bit width. Not all targets support all bit widths however.</p>
				6782	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6783	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6784	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6785	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6786	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6787
				6788	</pre>
				6789	<h5>Overview:</h5>
				6790	<p>
				6791	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6792	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6793	</p>
				6794	<h5>Arguments:</h5>
				6795	<p>
				6796
				6797	The intrinsic takes two arguments, the first a pointer to an integer value
				6798	and the second an integer value. The result is also an integer value. These
				6799	integer types can have any bit width, but they must all have the same bit
				6800	width. The targets may only lower integer representations they support.
				6801	</p>
				6802	<h5>Semantics:</h5>
				6803	<p>
				6804	This intrinsic does a series of operations atomically. It first loads the
				6805	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6806	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6807	</p>
				6808
				6809	<h5>Examples:</h5>
				6810	<pre>
				6811	%ptr = malloc i32
				6812	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6813	%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]	6814	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6815	%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]	6816	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6817	%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]	6818	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6819	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6820	</pre>
				6821	</div>
				6822
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6823	<!-- _______________________________________________________________________ -->
				6824	<div class="doc_subsubsection">
				6825	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6826
				6827	</div>
				6828	<div class="doc_text">
				6829	<h5>Syntax:</h5>
				6830	<p>
				6831	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]	6832	any integer bit width and for different address spaces. Not all targets
				6833	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6834	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6835	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6836	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6837	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6838	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]	6839
				6840	</pre>
				6841	<h5>Overview:</h5>
				6842	<p>
				6843	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6844	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6845	</p>
				6846	<h5>Arguments:</h5>
				6847	<p>
				6848
				6849	The intrinsic takes two arguments, the first a pointer to an integer value
				6850	and the second an integer value. The result is also an integer value. These
				6851	integer types can have any bit width, but they must all have the same bit
				6852	width. The targets may only lower integer representations they support.
				6853	</p>
				6854	<h5>Semantics:</h5>
				6855	<p>
				6856	This intrinsic does a series of operations atomically. It first loads the
				6857	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6858	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6859	</p>
				6860
				6861	<h5>Examples:</h5>
				6862	<pre>
				6863	%ptr = malloc i32
				6864	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6865	%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]	6866	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6867	%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]	6868	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6869	%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]	6870	<i>; yields {i32}:result3 = 2</i>
				6871	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6872	</pre>
				6873	</div>
				6874
				6875	<!-- _______________________________________________________________________ -->
				6876	<div class="doc_subsubsection">
				6877	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6878	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6879	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6880	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6881
				6882	</div>
				6883	<div class="doc_text">
				6884	<h5>Syntax:</h5>
				6885	<p>
				6886	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6887	<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]	6888	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6889	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6890	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6891	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6892	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6893	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6894	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]	6895
				6896	</pre>
				6897
				6898	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6899	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6900	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6901	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6902	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]	6903
				6904	</pre>
				6905
				6906	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6907	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6908	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6909	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6910	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]	6911
				6912	</pre>
				6913
				6914	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6915	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6916	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6917	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6918	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]	6919
				6920	</pre>
				6921	<h5>Overview:</h5>
				6922	<p>
				6923	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6924	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6925	at <tt>ptr</tt>.
				6926	</p>
				6927	<h5>Arguments:</h5>
				6928	<p>
				6929
				6930	These intrinsics take two arguments, the first a pointer to an integer value
				6931	and the second an integer value. The result is also an integer value. These
				6932	integer types can have any bit width, but they must all have the same bit
				6933	width. The targets may only lower integer representations they support.
				6934	</p>
				6935	<h5>Semantics:</h5>
				6936	<p>
				6937	These intrinsics does a series of operations atomically. They first load the
				6938	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6939	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6940	value stored at <tt>ptr</tt>.
				6941	</p>
				6942
				6943	<h5>Examples:</h5>
				6944	<pre>
				6945	%ptr = malloc i32
				6946	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6947	%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]	6948	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6949	%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]	6950	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6951	%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]	6952	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6953	%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]	6954	<i>; yields {i32}:result3 = FF</i>
				6955	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6956	</pre>
				6957	</div>
				6958
				6959
				6960	<!-- _______________________________________________________________________ -->
				6961	<div class="doc_subsubsection">
				6962	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6963	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6964	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6965	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6966
				6967	</div>
				6968	<div class="doc_text">
				6969	<h5>Syntax:</h5>
				6970	<p>
				6971	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6972	<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]	6973	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6974	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6975	support all bit widths however.</p>
				6976	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6977	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6978	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6979	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6980	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]	6981
				6982	</pre>
				6983
				6984	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6985	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6986	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6987	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6988	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]	6989
				6990	</pre>
				6991
				6992	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6993	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6994	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6995	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6996	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]	6997
				6998	</pre>
				6999
				7000	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7001	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				7002	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				7003	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				7004	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]	7005
				7006	</pre>
				7007	<h5>Overview:</h5>
				7008	<p>
				7009	These intrinsics takes the signed or unsigned minimum or maximum of
				7010	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				7011	original value at <tt>ptr</tt>.
				7012	</p>
				7013	<h5>Arguments:</h5>
				7014	<p>
				7015
				7016	These intrinsics take two arguments, the first a pointer to an integer value
				7017	and the second an integer value. The result is also an integer value. These
				7018	integer types can have any bit width, but they must all have the same bit
				7019	width. The targets may only lower integer representations they support.
				7020	</p>
				7021	<h5>Semantics:</h5>
				7022	<p>
				7023	These intrinsics does a series of operations atomically. They first load the
				7024	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				7025	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				7026	the original value stored at <tt>ptr</tt>.
				7027	</p>
				7028
				7029	<h5>Examples:</h5>
				7030	<pre>
				7031	%ptr = malloc i32
				7032	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7033	%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]	7034	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7035	%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]	7036	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7037	%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]	7038	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7039	%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]	7040	<i>; yields {i32}:result3 = 8</i>
				7041	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				7042	</pre>
				7043	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	7044
				7045	<!-- ======================================================================= -->
				7046	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7047	<a name="int_general">General Intrinsics</a>
				7048	</div>
				7049
				7050	<div class="doc_text">
				7051	<p> This class of intrinsics is designed to be generic and has
				7052	no specific purpose. </p>
				7053	</div>
				7054
				7055	<!-- _______________________________________________________________________ -->
				7056	<div class="doc_subsubsection">
				7057	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				7058	</div>
				7059
				7060	<div class="doc_text">
				7061
				7062	<h5>Syntax:</h5>
				7063	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	7064	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]	7065	</pre>
				7066
				7067	<h5>Overview:</h5>
				7068
				7069	<p>
				7070	The '<tt>llvm.var.annotation</tt>' intrinsic
				7071	</p>
				7072
				7073	<h5>Arguments:</h5>
				7074
				7075	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	7076	The first argument is a pointer to a value, the second is a pointer to a
				7077	global string, the third is a pointer to a global string which is the source
				7078	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7079	</p>
				7080
				7081	<h5>Semantics:</h5>
				7082
				7083	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	7084	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7085	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]	7086	annotations. These have no other defined use, they are ignored by code
				7087	generation and optimization.
				7088	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7089	</div>
				7090
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7091	<!-- _______________________________________________________________________ -->
				7092	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	7093	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7094	</div>
				7095
				7096	<div class="doc_text">
				7097
				7098	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	7099	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				7100	any integer bit width.
				7101	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7102	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	7103	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				7104	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				7105	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				7106	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				7107	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]	7108	</pre>
				7109
				7110	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	7111
				7112	<p>
				7113	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7114	</p>
				7115
				7116	<h5>Arguments:</h5>
				7117
				7118	<p>
				7119	The first argument is an integer value (result of some expression),
				7120	the second is a pointer to a global string, the third is a pointer to a global
				7121	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]	7122	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7123	</p>
				7124
				7125	<h5>Semantics:</h5>
				7126
				7127	<p>
				7128	This intrinsic allows annotations to be put on arbitrary expressions
				7129	with arbitrary strings. This can be useful for special purpose optimizations
				7130	that want to look for these annotations. These have no other defined use, they
				7131	are ignored by code generation and optimization.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	7132	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7133	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	7134
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	7135	<!-- _______________________________________________________________________ -->
				7136	<div class="doc_subsubsection">
				7137	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7138	</div>
				7139
				7140	<div class="doc_text">
				7141
				7142	<h5>Syntax:</h5>
				7143	<pre>
				7144	declare void @llvm.trap()
				7145	</pre>
				7146
				7147	<h5>Overview:</h5>
				7148
				7149	<p>
				7150	The '<tt>llvm.trap</tt>' intrinsic
				7151	</p>
				7152
				7153	<h5>Arguments:</h5>
				7154
				7155	<p>
				7156	None
				7157	</p>
				7158
				7159	<h5>Semantics:</h5>
				7160
				7161	<p>
				7162	This intrinsics is lowered to the target dependent trap instruction. If the
				7163	target does not have a trap instruction, this intrinsic will be lowered to the
				7164	call of the abort() function.
				7165	</p>
				7166	</div>
				7167
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7168	<!-- _______________________________________________________________________ -->
				7169	<div class="doc_subsubsection">
Misha Brukman	50de2b2	2008-11-22 23:55:29 +0000	[diff] [blame]	7170	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7171	</div>
				7172	<div class="doc_text">
				7173	<h5>Syntax:</h5>
				7174	<pre>
				7175	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7176
				7177	</pre>
				7178	<h5>Overview:</h5>
				7179	<p>
				7180	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7181	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7182	it is placed on the stack before local variables.
				7183	</p>
				7184	<h5>Arguments:</h5>
				7185	<p>
				7186	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7187	first argument is the value loaded from the stack guard
				7188	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7189	has enough space to hold the value of the guard.
				7190	</p>
				7191	<h5>Semantics:</h5>
				7192	<p>
				7193	This intrinsic causes the prologue/epilogue inserter to force the position of
				7194	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7195	stack. This is to ensure that if a local variable on the stack is overwritten,
				7196	it will destroy the value of the guard. When the function exits, the guard on
				7197	the stack is checked against the original guard. If they're different, then
				7198	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7199	</p>
				7200	</div>
				7201
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7202	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7203	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7204	<address>
				7205	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7206	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]	7207	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7208	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]	7209
				7210	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	7211	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7212	Last modified: $Date$
				7213	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	7214
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	7215	</body>
				7216	</html>