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Reid Spencer	6454ed3	2004-11-18 18:38:58 +0000	[diff] [blame]	5	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	6	<link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	7	<title>LLVM 2.9 Release Notes</title>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	8	</head>
				9	<body>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	10
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	11	<h1 class="doc_title">LLVM 2.9 Release Notes</h1>
Mikhail Glushenkov	ea65d7d	2008-10-13 02:08:34 +0000	[diff] [blame]	12
Chris Lattner	0e464a9	2010-03-17 04:02:39 +0000	[diff] [blame]	13	<img align=right src="http://llvm.org/img/DragonSmall.png"
Gabor Greif	ee2187a	2010-04-22 10:21:43 +0000	[diff] [blame]	14	width="136" height="136" alt="LLVM Dragon Logo">
Chris Lattner	0e464a9	2010-03-17 04:02:39 +0000	[diff] [blame]	15
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	16	<ol>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	17	<li><a href="#intro">Introduction</a></li>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	18	<li><a href="#subproj">Sub-project Status Update</a></li>
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	19	<li><a href="#externalproj">External Projects Using LLVM 2.9</a></li>
				20	<li><a href="#whatsnew">What's New in LLVM 2.9?</a></li>
Chris Lattner	4b538b9	2004-04-30 22:17:12 +0000	[diff] [blame]	21	<li><a href="GettingStarted.html">Installation Instructions</a></li>
Dan Gohman	44aa921	2008-10-14 16:23:02 +0000	[diff] [blame]	22	<li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	23	<li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	24	</ol>
				25
Chris Lattner	7911ce2	2004-05-23 21:07:27 +0000	[diff] [blame]	26	<div class="doc_author">
NAKAMURA Takumi	b9a3363	2011-04-09 02:13:37 +0000	[diff] [blame]	27	<p>Written by the <a href="http://llvm.org/">LLVM Team</a></p>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	28	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	29
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	30	<!--
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	31	<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.9
Jeffrey Yasskin	bec4877	2010-01-28 01:14:43 +0000	[diff] [blame]	32	release.<br>
				33	You may prefer the
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	34	<a href="http://llvm.org/releases/2.8/docs/ReleaseNotes.html">LLVM 2.8
Dan Gohman	b44f6c6	2010-05-03 23:51:05 +0000	[diff] [blame]	35	Release Notes</a>.</h1>
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	36	-->
Jeffrey Yasskin	bec4877	2010-01-28 01:14:43 +0000	[diff] [blame]	37
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	38	<!-- *********************************************************************** -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	39	<h1>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	40	<a name="intro">Introduction</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	41	</h1>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	42	<!-- *********************************************************************** -->
				43
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	44	<div class="doc_text">
				45
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	46	<p>This document contains the release notes for the LLVM Compiler
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	47	Infrastructure, release 2.9. Here we describe the status of LLVM, including
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	48	major improvements from the previous release and significant known problems.
Mikhail Glushenkov	f795ef0	2009-03-01 18:09:47 +0000	[diff] [blame]	49	All LLVM releases may be downloaded from the <a
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	50	href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner	1909261	2003-10-02 16:38:05 +0000	[diff] [blame]	51
Chris Lattner	7506b1d	2004-12-07 08:04:13 +0000	[diff] [blame]	52	<p>For more information about LLVM, including information about the latest
Chris Lattner	c463b27	2005-10-29 07:07:09 +0000	[diff] [blame]	53	release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner	47ad72c	2003-10-07 21:38:31 +0000	[diff] [blame]	54	web site</a>. If you have questions or comments, the <a
Chris Lattner	c66bfef	2010-03-17 04:41:49 +0000	[diff] [blame]	55	href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's
				56	Mailing List</a> is a good place to send them.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	57
Mikhail Glushenkov	ea65d7d	2008-10-13 02:08:34 +0000	[diff] [blame]	58	<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	59	main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greif	fa933f8	2008-10-14 11:00:32 +0000	[diff] [blame]	60	current one. To see the release notes for a specific release, please see the
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	61	<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	62
				63	</div>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	64
Chris Lattner	e4dc196	2011-04-05 23:22:33 +0000	[diff] [blame]	65	<!-- Features that need text if they're finished for 3.1:
				66	ARM EHABI
Chris Lattner	914ce46	2010-04-22 06:28:20 +0000	[diff] [blame]	67	combiner-aa?
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	68	strong phi elim
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	69	loop dependence analysis
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	70	CorrelatedValuePropagation
Chris Lattner	e4dc196	2011-04-05 23:22:33 +0000	[diff] [blame]	71	lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
Chris Lattner	acce85d	2008-02-10 07:46:44 +0000	[diff] [blame]	72	-->
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	73
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	74	<!-- *********************************************************************** -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	75	<h1>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	76	<a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	77	</h1>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	78	<!-- *********************************************************************** -->
Chris Lattner	ea34f64	2008-06-08 21:34:41 +0000	[diff] [blame]	79
				80	<div class="doc_text">
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	81	<p>
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	82	The LLVM 2.9 distribution currently consists of code from the core LLVM
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	83	repository (which roughly includes the LLVM optimizers, code generators
				84	and supporting tools), the Clang repository and the llvm-gcc repository. In
				85	addition to this code, the LLVM Project includes other sub-projects that are in
				86	development. Here we include updates on these subprojects.
Bill Wendling	63d8c55	2009-03-02 04:28:57 +0000	[diff] [blame]	87	</p>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	88
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	89	</div>
				90
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	91
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	92	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	93	<h2>
Chris Lattner	fb97b2d	2008-10-13 18:11:54 +0000	[diff] [blame]	94	<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	95	</h2>
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	96
				97	<div class="doc_text">
				98
Chris Lattner	095539f	2010-04-26 17:42:18 +0000	[diff] [blame]	99	<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
				100	C++, and Objective-C languages. Clang aims to provide a better user experience
				101	through expressive diagnostics, a high level of conformance to language
				102	standards, fast compilation, and low memory use. Like LLVM, Clang provides a
				103	modular, library-based architecture that makes it suitable for creating or
				104	integrating with other development tools. Clang is considered a
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	105	production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	106	(32- and 64-bit), and for darwin/arm targets.</p>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	107
Chris Lattner	0a6f6d5	2011-04-05 07:19:28 +0000	[diff] [blame]	108	<p>In the LLVM 2.9 time-frame, the Clang team has made many improvements in C,
				109	C++ and Objective-C support. C++ support is now generally rock solid, has
Chris Lattner	df448a3	2011-04-06 00:56:12 +0000	[diff] [blame]	110	been exercised on a broad variety of code, and has several new <a
				111	href="http://clang.llvm.org/cxx_status.html#cxx0x">C++'0x features</a>
Chris Lattner	0a6f6d5	2011-04-05 07:19:28 +0000	[diff] [blame]	112	implemented (such as rvalue references and variadic templates). LLVM 2.9 has
				113	also brought in a large range of bug fixes and minor features (e.g. __label__
				114	support), and is much more compatible with the Linux Kernel.</p>
				115
Duncan Sands	f3ba7af	2011-04-06 08:07:40 +0000	[diff] [blame]	116	<p>If Clang rejects your code but another compiler accepts it, please take a
Chris Lattner	0a6f6d5	2011-04-05 07:19:28 +0000	[diff] [blame]	117	look at the <a href="http://clang.llvm.org/compatibility.html">language
Duncan Sands	f3ba7af	2011-04-06 08:07:40 +0000	[diff] [blame]	118	compatibility</a> guide to make sure this is not intentional or a known issue.
Chris Lattner	0a6f6d5	2011-04-05 07:19:28 +0000	[diff] [blame]	119	</p>
Bill Wendling	741748a	2008-10-27 09:27:33 +0000	[diff] [blame]	120
Chris Lattner	fb97b2d	2008-10-13 18:11:54 +0000	[diff] [blame]	121	</div>
				122
				123	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	124	<h2>
Duncan Sands	528a510	2011-04-04 11:09:08 +0000	[diff] [blame]	125	<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	126	</h2>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	127
				128	<div class="doc_text">
				129	<p>
Duncan Sands	528a510	2011-04-04 11:09:08 +0000	[diff] [blame]	130	<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
				131	<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
				132	optimizers and code generators with LLVM's.
				133	Currently it requires a patched version of gcc-4.5.
				134	The plugin can target the x86-32 and x86-64 processor families and has been
				135	used successfully on the Darwin, FreeBSD and Linux platforms.
				136	The Ada, C, C++ and Fortran languages work well.
				137	The plugin is capable of compiling plenty of Obj-C, Obj-C++ and Java but it is
				138	not known whether the compiled code actually works or not!
Duncan Sands	749fd83	2010-04-02 09:23:15 +0000	[diff] [blame]	139	</p>
				140
				141	<p>
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	142	The 2.9 release has the following notable changes:
Duncan Sands	4b1da2b	2010-09-30 17:37:34 +0000	[diff] [blame]	143	<ul>
Duncan Sands	528a510	2011-04-04 11:09:08 +0000	[diff] [blame]	144	<li>The plugin is much more stable when compiling Fortran.</li>
Chris Lattner	df448a3	2011-04-06 00:56:12 +0000	[diff] [blame]	145	<li>Inline assembly where an asm output is tied to an input of a different size
				146	is now supported in many more cases.</li>
Duncan Sands	528a510	2011-04-04 11:09:08 +0000	[diff] [blame]	147	<li>Basic support for the __float128 type was added. It is now possible to
				148	generate LLVM IR from programs using __float128 but code generation does not
				149	work yet.</li>
				150	<li>Compiling Java programs no longer systematically crashes the plugin.</li>
Duncan Sands	4b1da2b	2010-09-30 17:37:34 +0000	[diff] [blame]	151	</ul>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	152
				153	</div>
				154
Chris Lattner	7554771	2010-10-03 23:49:06 +0000	[diff] [blame]	155	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	156	<h2>
Chris Lattner	7554771	2010-10-03 23:49:06 +0000	[diff] [blame]	157	<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	158	</h2>
Chris Lattner	7554771	2010-10-03 23:49:06 +0000	[diff] [blame]	159
				160	<div class="doc_text">
				161	<p>
				162	The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
				163	is a simple library that provides an implementation of the low-level
				164	target-specific hooks required by code generation and other runtime components.
				165	For example, when compiling for a 32-bit target, converting a double to a 64-bit
				166	unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
				167	function. The compiler-rt library provides highly optimized implementations of
				168	this and other low-level routines (some are 3x faster than the equivalent
				169	libgcc routines).</p>
				170
Chris Lattner	df448a3	2011-04-06 00:56:12 +0000	[diff] [blame]	171	<p>In the LLVM 2.9 timeframe, compiler_rt has had several minor changes for
				172	better ARM support, and a fairly major license change. All of the code in the
				173	compiler-rt project is now <a href="DeveloperPolicy.html#license">dual
				174	licensed</a> under MIT and UIUC license, which allows you to use compiler-rt
				175	in applications without the binary copyright reproduction clause. If you
				176	prefer the LLVM/UIUC license, you are free to continue using it under that
				177	license as well.</p>
Chris Lattner	7554771	2010-10-03 23:49:06 +0000	[diff] [blame]	178
				179	</div>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	180
				181	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	182	<h2>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	183	<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	184	</h2>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	185
				186	<div class="doc_text">
				187	<p>
Chris Lattner	7554771	2010-10-03 23:49:06 +0000	[diff] [blame]	188	<a href="http://lldb.llvm.org/">LLDB</a> is a brand new member of the LLVM
				189	umbrella of projects. LLDB is a next generation, high-performance debugger. It
				190	is built as a set of reusable components which highly leverage existing
				191	libraries in the larger LLVM Project, such as the Clang expression parser, the
				192	LLVM disassembler and the LLVM JIT.</p>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	193
				194	<p>
Chris Lattner	df448a3	2011-04-06 00:56:12 +0000	[diff] [blame]	195	LLDB is has advanced by leaps and bounds in the 2.9 timeframe. It is
				196	dramatically more stable and useful, and includes both a new <a
				197	href="http://lldb.llvm.org/tutorial.html">tutorial</a> and a <a
				198	href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
				199	GDB</a>.</p>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	200
				201	</div>
				202
				203	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	204	<h2>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	205	<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	206	</h2>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	207
				208	<div class="doc_text">
				209	<p>
Tobias Grosser	cdce44b	2010-10-06 21:07:30 +0000	[diff] [blame]	210	<a href="http://libcxx.llvm.org/">libc++</a> is another new member of the LLVM
Chris Lattner	7554771	2010-10-03 23:49:06 +0000	[diff] [blame]	211	family. It is an implementation of the C++ standard library, written from the
				212	ground up to specifically target the forthcoming C++'0X standard and focus on
				213	delivering great performance.</p>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	214
				215	<p>
Chris Lattner	2009c49	2011-04-06 00:59:18 +0000	[diff] [blame]	216	In the LLVM 2.9 timeframe, libc++ has had numerous bugs fixed, and is now being
				217	co-developed with Clang's C++'0x mode.</p>
Chris Lattner	0a6f6d5	2011-04-05 07:19:28 +0000	[diff] [blame]	218
Chris Lattner	2009c49	2011-04-06 00:59:18 +0000	[diff] [blame]	219	<p>
				220	Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
				221	licensed</a> under the MIT and UIUC license, allowing it to be used more
				222	permissively.
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	223	</p>
				224
				225	</div>
				226
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	227
Chris Lattner	3d6a80a	2011-04-07 03:08:22 +0000	[diff] [blame]	228	<!--=========================================================================-->
				229	<h2>
				230	<a name="LLBrowse">LLBrowse: IR Browser</a>
				231	</h2>
Daniel Dunbar	97b01a8	2010-10-04 17:39:47 +0000	[diff] [blame]	232
Chris Lattner	3d6a80a	2011-04-07 03:08:22 +0000	[diff] [blame]	233	<div class="doc_text">
				234	<p>
				235	<a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
				236	LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
				237	module and displays its contents as an expandable tree view, facilitating an
				238	easy way to inspect types, functions, global variables, or metadata nodes. It
				239	is fully cross-platform, being based on the popular wxWidgets GUI toolkit.
				240	</p>
				241	</div>
				242
				243	<!--=========================================================================-->
				244	<h2>
				245	<a name="vmkit">VMKit</a>
				246	</h2>
				247
				248	<div class="doc_text">
				249	<p>The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation
				250	of a Java Virtual Machine (Java VM or JVM) that uses LLVM for static and
				251	just-in-time compilation. As of LLVM 2.9, VMKit now supports generational
				252	garbage collectors. The garbage collectors are provided by the MMTk framework,
				253	and VMKit can be configured to use one of the numerous implemented collectors
				254	of MMTk.
				255	</p>
				256	</div>
				257
				258
Daniel Dunbar	97b01a8	2010-10-04 17:39:47 +0000	[diff] [blame]	259	<!--=========================================================================-->
Chris Lattner	7a8e6c5	2011-04-05 18:38:45 +0000	[diff] [blame]	260	<!--
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	261	<h2>
Daniel Dunbar	97b01a8	2010-10-04 17:39:47 +0000	[diff] [blame]	262	<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	263	</h2>
Daniel Dunbar	97b01a8	2010-10-04 17:39:47 +0000	[diff] [blame]	264
				265	<div class="doc_text">
				266	<p>
				267	<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
				268	programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
				269	through the application and records state transitions that lead to fault
				270	states. This allows it to construct testcases that lead to faults and can even
				271	be used to verify some algorithms.
				272	</p>
				273
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	274	<p>UPDATE!</p>
Chris Lattner	7a8e6c5	2011-04-05 18:38:45 +0000	[diff] [blame]	275	</div>-->
Daniel Dunbar	97b01a8	2010-10-04 17:39:47 +0000	[diff] [blame]	276
				277
Chris Lattner	ab68e9e	2009-02-26 22:33:38 +0000	[diff] [blame]	278	<!-- *********************************************************************** -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	279	<h1>
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	280	<a name="externalproj">External Open Source Projects Using LLVM 2.9</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	281	</h1>
Chris Lattner	ab68e9e	2009-02-26 22:33:38 +0000	[diff] [blame]	282	<!-- *********************************************************************** -->
				283
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	284	<div class="doc_text">
				285
				286	<p>An exciting aspect of LLVM is that it is used as an enabling technology for
				287	a lot of other language and tools projects. This section lists some of the
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	288	projects that have already been updated to work with LLVM 2.9.</p>
Chris Lattner	7c8e796	2010-04-26 17:38:10 +0000	[diff] [blame]	289	</div>
				290
Chris Lattner	7554771	2010-10-03 23:49:06 +0000	[diff] [blame]	291
Chris Lattner	3bfe57e	2011-04-06 01:13:49 +0000	[diff] [blame]	292	<!--=========================================================================-->
				293	<h2>Crack Programming Language</h2>
				294
				295	<div class="doc_text">
				296	<p>
				297	<a href="http://code.google.com/p/crack-language/">Crack</a> aims to provide the
				298	ease of development of a scripting language with the performance of a compiled
				299	language. The language derives concepts from C++, Java and Python, incorporating
				300	object-oriented programming, operator overloading and strong typing.</p>
				301	</div>
				302
				303
				304	<!--=========================================================================-->
				305	<h2>TTA-based Codesign Environment (TCE)</h2>
				306
				307	<div class="doc_text">
				308	<p>TCE is a toolset for designing application-specific processors (ASP) based on
				309	the Transport triggered architecture (TTA). The toolset provides a complete
				310	co-design flow from C/C++ programs down to synthesizable VHDL and parallel
				311	program binaries. Processor customization points include the register files,
				312	function units, supported operations, and the interconnection network.</p>
				313
				314	<p>TCE uses Clang and LLVM for C/C++ language support, target independent
				315	optimizations and also for parts of code generation. It generates new LLVM-based
				316	code generators "on the fly" for the designed TTA processors and loads them in
				317	to the compiler backend as runtime libraries to avoid per-target recompilation
				318	of larger parts of the compiler chain.</p>
				319	</div>
				320
				321
				322
				323	<!--=========================================================================-->
				324	<h2>PinaVM</h2>
				325
				326	<div class="doc_text">
				327	<p><a href="http://gitorious.org/pinavm/pages/Home">PinaVM</a> is an open
				328	source, <a href="http://www.systemc.org/">SystemC</a> front-end. Unlike many
				329	other front-ends, PinaVM actually executes the elaboration of the
				330	program analyzed using LLVM's JIT infrastructure. It later enriches the
				331	bitcode with SystemC-specific information.</p>
				332	</div>
				333
				334	<!--=========================================================================-->
				335	<h2>Pure</h2>
				336
				337	<div class="doc_text">
				338	<p><a href="http://pure-lang.googlecode.com/">Pure</a> is an
				339	algebraic/functional
				340	programming language based on term rewriting. Programs are collections
				341	of equations which are used to evaluate expressions in a symbolic
				342	fashion. The interpreter uses LLVM as a backend to JIT-compile Pure
				343	programs to fast native code. Pure offers dynamic typing, eager and lazy
				344	evaluation, lexical closures, a hygienic macro system (also based on
				345	term rewriting), built-in list and matrix support (including list and
				346	matrix comprehensions) and an easy-to-use interface to C and other
				347	programming languages (including the ability to load LLVM bitcode
				348	modules, and inline C, C++, Fortran and Faust code in Pure programs if
				349	the corresponding LLVM-enabled compilers are installed).</p>
				350
				351	<p>Pure version 0.47 has been tested and is known to work with LLVM 2.9
				352	(and continues to work with older LLVM releases >= 2.5).</p>
				353	</div>
				354
				355	<!--=========================================================================-->
				356	<h2 id="icedtea">IcedTea Java Virtual Machine Implementation</h2>
				357
				358	<div class="doc_text">
				359	<p>
				360	<a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a
				361	harness to build OpenJDK using only free software build tools and to provide
				362	replacements for the not-yet free parts of OpenJDK. One of the extensions that
				363	IcedTea provides is a new JIT compiler named <a
				364	href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM
				365	to provide native code generation without introducing processor-dependent
				366	code.
				367	</p>
				368
				369	<p> OpenJDK 7 b112, IcedTea6 1.9 and IcedTea7 1.13 and later have been tested
				370	and are known to work with LLVM 2.9 (and continue to work with older LLVM
				371	releases >= 2.6 as well).</p>
				372	</div>
				373
				374	<!--=========================================================================-->
				375	<h2>Glasgow Haskell Compiler (GHC)</h2>
				376
				377	<div class="doc_text">
				378	<p>GHC is an open source, state-of-the-art programming suite for Haskell,
				379	a standard lazy functional programming language. It includes an
				380	optimizing static compiler generating good code for a variety of
				381	platforms, together with an interactive system for convenient, quick
				382	development.</p>
				383
				384	<p>In addition to the existing C and native code generators, GHC 7.0 now
				385	supports an LLVM code generator. GHC supports LLVM 2.7 and later.</p>
				386	</div>
				387
				388	<!--=========================================================================-->
				389	<h2>Polly - Polyhedral optimizations for LLVM</h2>
				390
				391	<div class="doc_text">
				392	<p>Polly is a project that aims to provide advanced memory access optimizations
				393	to better take advantage of SIMD units, cache hierarchies, multiple cores or
				394	even vector accelerators for LLVM. Built around an abstract mathematical
				395	description based on Z-polyhedra, it provides the infrastructure to develop
				396	advanced optimizations in LLVM and to connect complex external optimizers. In
				397	its first year of existence Polly already provides an exact value-based
				398	dependency analysis as well as basic SIMD and OpenMP code generation support.
				399	Furthermore, Polly can use PoCC(Pluto) an advanced optimizer for data-locality
				400	and parallelism.</p>
				401	</div>
Chris Lattner	7554771	2010-10-03 23:49:06 +0000	[diff] [blame]	402
Chris Lattner	0fa5da9	2011-04-06 16:14:25 +0000	[diff] [blame]	403	<!--=========================================================================-->
				404	<h2>Rubinius</h2>
				405
				406	<div class="doc_text">
				407	<p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment
				408	for running Ruby code which strives to write as much of the implementation in
				409	Ruby as possible. Combined with a bytecode interpreting VM, it uses LLVM to
				410	optimize and compile ruby code down to machine code. Techniques such as type
				411	feedback, method inlining, and deoptimization are all used to remove dynamism
				412	from ruby execution and increase performance.</p>
				413	</div>
				414
				415
Chris Lattner	a844a3e	2011-04-07 03:09:21 +0000	[diff] [blame]	416	<!--=========================================================================-->
				417	<div class="doc_subsection">
				418	<a name="FAUST">FAUST Real-Time Audio Signal Processing Language</a>
				419	</div>
Chris Lattner	e051844	2010-10-01 06:34:49 +0000	[diff] [blame]	420
Chris Lattner	a844a3e	2011-04-07 03:09:21 +0000	[diff] [blame]	421	<div class="doc_text">
				422	<p>
				423	<a href="http://faust.grame.fr">FAUST</a> is a compiled language for real-time
				424	audio signal processing. The name FAUST stands for Functional AUdio STream. Its
				425	programming model combines two approaches: functional programming and block
				426	diagram composition. In addition with the C, C++, JAVA output formats, the
				427	Faust compiler can now generate LLVM bitcode, and works with LLVM 2.7-2.9.</p>
				428
				429	</div>
				430
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	431	<!-- *********************************************************************** -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	432	<h1>
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	433	<a name="whatsnew">What's New in LLVM 2.9?</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	434	</h1>
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	435	<!-- *********************************************************************** -->
				436
Chris Lattner	f8e0b4e	2008-06-08 22:59:35 +0000	[diff] [blame]	437	<div class="doc_text">
				438
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	439	<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	440	minor improvements. Some of the major improvements and new features are listed
				441	in this section.
Chris Lattner	f8e0b4e	2008-06-08 22:59:35 +0000	[diff] [blame]	442	</p>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	443
Chris Lattner	914ce46	2010-04-22 06:28:20 +0000	[diff] [blame]	444	</div>
				445
				446	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	447	<h2>
Chris Lattner	252b83d	2008-02-06 18:00:06 +0000	[diff] [blame]	448	<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	449	</h2>
Chris Lattner	252b83d	2008-02-06 18:00:06 +0000	[diff] [blame]	450
				451	<div class="doc_text">
				452
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	453	<p>LLVM 2.9 includes several major new capabilities:</p>
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	454
				455	<ul>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	456
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	457	<li>Type Based Alias Analysis (TBAA) is now implemented and turned on by default
				458	in Clang. This allows substantially better load/store optimization in some
				459	cases. TBAA can be disabled by passing -fno-strict-aliasing.
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	460	</li>
				461
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	462	<li>This release has seen a continued focus on quality of debug information.
				463	LLVM now generates much higher fidelity debug information, particularly when
				464	debugging optimized code.</li>
				465
				466	<li>Inline assembly now supports multiple alternative constraints.</li>
				467
				468	<li>A new backend for the NVIDIA PTX virtual ISA (used to target its GPUs) is
				469	under rapid development. It is not generally useful in 2.9, but is making
				470	rapid progress.</li>
Chris Lattner	7a8e6c5	2011-04-05 18:38:45 +0000	[diff] [blame]	471
Chris Lattner	8170c10	2008-02-10 08:18:42 +0000	[diff] [blame]	472	</ul>
Chris Lattner	0a6f6d5	2011-04-05 07:19:28 +0000	[diff] [blame]	473
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	474	</div>
				475
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	476	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	477	<h2>
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	478	<a name="coreimprovements">LLVM IR and Core Improvements</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	479	</h2>
Chris Lattner	f304ffc	2008-02-10 08:17:19 +0000	[diff] [blame]	480
				481	<div class="doc_text">
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	482	<p>LLVM IR has several new features for better support of new targets and that
				483	expose new optimization opportunities:</p>
Chris Lattner	f304ffc	2008-02-10 08:17:19 +0000	[diff] [blame]	484
Chris Lattner	791f77b	2008-06-05 06:25:56 +0000	[diff] [blame]	485	<ul>
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	486	<li>The <a href="LangRef.html#bitwiseops">udiv, ashr, lshr, and shl</a>
				487	instructions now have support exact and nuw/nsw bits to indicate that they
				488	don't overflow or shift out bits. This is useful for optimization of <a
				489	href="http://llvm.org/PR8862">pointer differences</a> and other cases.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	490
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	491	<li>LLVM IR now supports the <a href="LangRef.html#globalvars">unnamed_addr</a>
				492	attribute to indicate that constant global variables with identical
				493	initializers can be merged. This fixed <a href="http://llvm.org/PR8927">an
				494	issue</a> where LLVM would incorrectly merge two globals which were supposed
				495	to have distinct addresses.</li>
				496
				497	<li>The new <a href="LangRef.html#fnattrs">hotpatch attribute</a> has been added
				498	to allow runtime patching of functions.</li>
Chris Lattner	f304ffc	2008-02-10 08:17:19 +0000	[diff] [blame]	499	</ul>
Mikhail Glushenkov	ea65d7d	2008-10-13 02:08:34 +0000	[diff] [blame]	500
Chris Lattner	f304ffc	2008-02-10 08:17:19 +0000	[diff] [blame]	501	</div>
				502
				503	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	504	<h2>
Chris Lattner	acce85d	2008-02-10 07:46:44 +0000	[diff] [blame]	505	<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	506	</h2>
Chris Lattner	acce85d	2008-02-10 07:46:44 +0000	[diff] [blame]	507
				508	<div class="doc_text">
				509
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	510	<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattner	f301387	2008-10-13 21:50:36 +0000	[diff] [blame]	511	release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner	acce85d	2008-02-10 07:46:44 +0000	[diff] [blame]	512
				513	<ul>
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	514	<li>Link Time Optimization (LTO) has been improved to use MC for parsing inline
				515	assembly and now can build large programs like Firefox 4 on both Mac OS X and
				516	Linux.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	517
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	518	<li>The new -loop-idiom pass recognizes memset/memcpy loops (and memset_pattern
				519	on darwin), turning them into library calls, which are typically better
				520	optimized than inline code. If you are building a libc and notice that your
				521	memcpy and memset functions are compiled into infinite recursion, please build
				522	with -ffreestanding or -fno-builtin to disable this pass.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	523
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	524	<li>A new -early-cse pass does a fast pass over functions to fold constants,
				525	simplify expressions, perform simple dead store elimination, and perform
				526	common subexpression elimination. It does a good job at catching some of the
				527	trivial redundancies that exist in unoptimized code, making later passes more
Roman Divacky	77b42e9	2011-04-06 19:12:21 +0000	[diff] [blame]	528	effective.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	529
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	530	<li>A new -loop-instsimplify pass is used to clean up loop bodies in the loop
				531	optimizer.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	532
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	533	<li>The new TargetLibraryInfo interface allows mid-level optimizations to know
				534	whether the current target's runtime library has certain functions. For
				535	example, the optimizer can now transform integer-only printf calls to call
				536	iprintf, allowing reduced code size for embedded C libraries (e.g. newlib).
				537	</li>
				538
				539	<li>LLVM has a new <a href="WritingAnLLVMPass.html#RegionPass">RegionPass</a>
				540	infrastructure for region-based optimizations.</li>
				541
				542	<li>Several optimizer passes have been substantially sped up:
				543	GVN is much faster on functions with deep dominator trees and lots of basic
				544	blocks. The dominator tree and dominance frontier passes are much faster to
				545	compute, and preserved by more passes (so they are computed less often). The
				546	-scalar-repl pass is also much faster and doesn't use DominanceFrontier.
				547	</li>
				548
				549	<li>The Dead Store Elimination pass is more aggressive optimizing stores of
				550	different types: e.g. a large store following a small one to the same address.
				551	The MemCpyOptimizer pass handles several new forms of memcpy elimination.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	552
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	553	<li>LLVM now optimizes various idioms for overflow detection into check of the
				554	flag register on various CPUs. For example, we now compile:
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	555
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	556	<pre>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	557	unsigned long t = a+b;
				558	if (t < a) ...
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	559	</pre>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	560	into:
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	561	<pre>
				562	addq %rdi, %rbx
				563	jno LBB0_2
				564	</pre>
				565	</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	566
Chris Lattner	11b6611	2010-10-04 02:42:39 +0000	[diff] [blame]	567	</ul>
				568
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	569	</div>
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	570
Chris Lattner	0b83220	2008-06-08 02:45:07 +0000	[diff] [blame]	571	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	572	<h2>
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	573	<a name="mc">MC Level Improvements</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	574	</h2>
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	575
				576	<div class="doc_text">
				577	<p>
Chris Lattner	7d9b6b4	2010-10-02 21:59:30 +0000	[diff] [blame]	578	The LLVM Machine Code (aka MC) subsystem was created to solve a number
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	579	of problems in the realm of assembly, disassembly, object file format handling,
				580	and a number of other related areas that CPU instruction-set level tools work
Chris Lattner	7d9b6b4	2010-10-02 21:59:30 +0000	[diff] [blame]	581	in.</p>
				582
Chris Lattner	7d9b6b4	2010-10-02 21:59:30 +0000	[diff] [blame]	583	<ul>
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	584	<li>ELF MC support has matured enough for the integrated assembler to be turned
				585	on by default in Clang on X86-32 and X86-64 ELF systems.</li>
				586
				587	<li>MC supports and CodeGen uses the <tt>.file</tt> and <tt>.loc</tt> directives
				588	for producing line number debug info. This produces more compact line
				589	tables and easier to read .s files.</li>
				590
				591	<li>MC supports the <tt>.cfi_*</tt> directives for producing DWARF
Rafael Espindola	a26f36c	2011-03-18 04:07:44 +0000	[diff] [blame]	592	frame information, but it is still not used by CodeGen by default.</li>
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	593
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	594
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	595	<li>The MC assembler now generates much better diagnostics for common errors,
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	596	is much faster at matching instructions, is much more bug-compatible with
				597	the GAS assembler, and is now generally useful for a broad range of X86
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	598	assembly.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	599
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	600	<li>We now have some basic <a href="CodeGenerator.html#mc">internals
				601	documentation</a> for MC.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	602
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	603	<li>.td files can now specify assembler aliases directly with the <a
				604	href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
				605	tblgen classes.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	606
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	607	<li>LLVM now has an experimental format-independent object file manipulation
				608	library (lib/Object). It supports both PE/COFF and ELF. The llvm-nm tool has
				609	been extended to work with native object files, and the new llvm-objdump tool
				610	supports disassembly of object files (but no relocations are displayed yet).
				611	</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	612
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	613	<li>Win32 PE-COFF support in the MC assembler has made a lot of progress in the
				614	2.9 timeframe, but is still not generally useful.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	615
Chris Lattner	7d9b6b4	2010-10-02 21:59:30 +0000	[diff] [blame]	616	</ul>
				617
				618	<p>For more information, please see the <a
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	619	href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
				620	LLVM MC Project Blog Post</a>.
				621	</p>
				622
NAKAMURA Takumi	45c435a	2011-04-05 08:24:22 +0000	[diff] [blame]	623	</div>
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	624
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	625	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	626	<h2>
Chris Lattner	511433e	2009-03-02 03:24:11 +0000	[diff] [blame]	627	<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	628	</h2>
Chris Lattner	0b83220	2008-06-08 02:45:07 +0000	[diff] [blame]	629
				630	<div class="doc_text">
				631
Mikhail Glushenkov	f795ef0	2009-03-01 18:09:47 +0000	[diff] [blame]	632	<p>We have put a significant amount of work into the code generator
				633	infrastructure, which allows us to implement more aggressive algorithms and make
				634	it run faster:</p>
Chris Lattner	0b83220	2008-06-08 02:45:07 +0000	[diff] [blame]	635
				636	<ul>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	637	<li>The pre-register-allocation (preRA) instruction scheduler models register
				638	pressure much more accurately in some cases. This allows the adoption of more
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	639	aggressive scheduling heuristics without causing spills to be generated.
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	640	</li>
				641
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	642	<li>LiveDebugVariables is a new pass that keeps track of debugging information
				643	for user variables that are promoted to registers in optimized builds.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	644
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	645	<li>The scheduler now models operand latency and pipeline forwarding.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	646
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	647	<li>A major register allocator infrastructure rewrite is underway. It is not on
				648	by default for 2.9 and you are not advised to use it, but it has made
				649	substantial progress in the 2.9 timeframe:
				650	<ul>
				651	<li>A new -regalloc=basic "basic" register allocator can be used as a simple
				652	fallback when debugging. It uses the new infrastructure.</li>
				653	<li>New infrastructure is in place for live range splitting. "SplitKit" can
				654	break a live interval into smaller pieces while preserving SSA form, and
				655	SpillPlacement can help find the best split points. This is a work in
				656	progress so the API is changing quickly.</li>
				657	<li>The inline spiller has learned to clean up after live range splitting. It
				658	can hoist spills out of loops, and it can eliminate redundant spills.</li>
				659	<li>Rematerialization works with live range splitting.</li>
				660	<li>The new "greedy" register allocator using live range splitting. This will
				661	be the default register allocator in the next LLVM release, but it is not
				662	turned on by default in 2.9.</li>
				663	</ul>
				664	</li>
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	665	</ul>
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	666	</div>
				667
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	668	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	669	<h2>
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	670	<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	671	</h2>
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	672
				673	<div class="doc_text">
Chris Lattner	7714c91	2010-10-04 04:39:25 +0000	[diff] [blame]	674	<p>New features and major changes in the X86 target include:
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	675	</p>
				676
				677	<ul>
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	678	<li>LLVM 2.9 includes a complete reimplementation of the MMX instruction set.
				679	The reimplementation uses a new LLVM IR <a
				680	href="LangRef.html#t_x86mmx">x86_mmx</a> type to ensure that MMX operations
				681	are <em>only</em> generated from source that uses MMX builtin operations. With
Duncan Sands	f3ba7af	2011-04-06 08:07:40 +0000	[diff] [blame]	682	this, random types like <2 x i32> are not turned into MMX operations
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	683	(which can be catastrophic without proper "emms" insertion). Because the X86
				684	code generator always generates reliable code, the -disable-mmx flag is now
				685	removed.
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	686	</li>
				687
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	688	<li>X86 support for FS/GS relative loads and stores using <a
Jay Foad	cb88ec3	2011-04-06 07:55:30 +0000	[diff] [blame]	689	href="CodeGenerator.html#x86_memory">address space 256/257</a> works reliably
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	690	now.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	691
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	692	<li>LLVM 2.9 generates much better code in several cases by using adc/sbb to
				693	avoid generation of conditional move instructions for conditional increment
				694	and other idioms.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	695
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	696	<li>The X86 backend has adopted a new preRA scheduling mode, "list-ilp", to
				697	shorten the height of instruction schedules without inducing register spills.
				698	</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	699
Jay Foad	cb88ec3	2011-04-06 07:55:30 +0000	[diff] [blame]	700	<li>The MC assembler supports 3dNow! and 3DNowA instructions.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	701
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	702	<li>Several bugs have been fixed for Windows x64 code generator.</li>
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	703	</ul>
				704
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	705	</div>
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	706
				707	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	708	<h2>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	709	<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	710	</h2>
Chris Lattner	c441fb8	2009-03-01 02:30:21 +0000	[diff] [blame]	711
				712	<div class="doc_text">
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	713	<p>New features of the ARM target include:
				714	</p>
Chris Lattner	c441fb8	2009-03-01 02:30:21 +0000	[diff] [blame]	715
				716	<ul>
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	717	<li>The ARM backend now has a fast instruction selector, which dramatically
				718	improves -O0 compile times.</li>
				719	<li>The ARM backend has new tuning for Cortex-A8 and Cortex-A9 CPUs.</li>
				720	<li>The __builtin_prefetch builtin (and llvm.prefetch intrinsic) is compiled
				721	into prefetch instructions instead of being discarded.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	722
				723	<li> The ARM backend preRA scheduler now models machine resources at cycle
				724	granularity. This allows the scheduler to both accurately model
				725	instruction latency and avoid overcommitting functional units.</li>
				726
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	727	<li>Countless ARM microoptimizations have landed in LLVM 2.9.</li>
Bob Wilson	e847277	2010-09-13 17:39:35 +0000	[diff] [blame]	728	</ul>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	729	</div>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	730
				731	<!--=========================================================================-->
				732	<h2>
				733	<a name="OtherTS">Other Target Specific Improvements</a>
				734	</h2>
Chris Lattner	c441fb8	2009-03-01 02:30:21 +0000	[diff] [blame]	735
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	736	<div class="doc_text">
				737	<ul>
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	738	<li>MicroBlaze: major updates for aggressive delay slot filler, MC-based
				739	assembly printing, assembly instruction parsing, ELF .o file emission, and MC
				740	instruction disassembler have landed.</li>
				741
				742	<li>SPARC: Many improvements, including using the Y registers for
				743	multiplications and addition of a simple delay slot filler.</li>
				744
				745	<li>PowerPC: The backend has been largely MC'ized and is ready to support
Duncan Sands	f3ba7af	2011-04-06 08:07:40 +0000	[diff] [blame]	746	directly writing out mach-o object files. No one seems interested in finishing
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	747	this final step though.</li>
Bruno Cardoso Lopes	3dcac71	2011-04-08 03:06:22 +0000	[diff] [blame]	748
				749	<li>Mips: Improved o32 ABI support, including better varags handling.
				750	More instructions supported in codegen: madd, msub, rotr, rotrv and clo.
				751	It also now supports lowering block addresses.</li>
				752
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	753	</ul>
				754	</div>
Chris Lattner	77d29b1	2008-06-05 08:02:49 +0000	[diff] [blame]	755
				756	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	757	<h2>
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	758	<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	759	</h2>
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	760
				761	<div class="doc_text">
				762
Chris Lattner	eeb4da0	2008-10-13 22:06:31 +0000	[diff] [blame]	763	<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	764	on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading
Chris Lattner	eeb4da0	2008-10-13 22:06:31 +0000	[diff] [blame]	765	from the previous release.</p>
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	766
				767	<ul>
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	768	<li><b>This is the last release to support the llvm-gcc frontend.</b></li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	769
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	770	<li>LLVM has a new <a href="CodingStandards.html#ll_naming">naming
				771	convention standard</a>, though the codebase hasn't fully adopted it yet.</li>
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	772
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	773	<li>The new DIBuilder class provides a simpler interface for front ends to
				774	encode debug info in LLVM IR, and has replaced DIFactory.</li>
Chris Lattner	c5ac61d	2011-04-06 05:50:04 +0000	[diff] [blame]	775
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	776	<li>LLVM IR and other tools always work on normalized target triples (which have
				777	been run through <tt>Triple::normalize</tt>).</li>
				778
				779	<li>The target triple x86_64--mingw64 is obsoleted. Use x86_64--mingw32
				780	instead.</li>
				781
				782	<li>The PointerTracking pass has been removed from mainline, and moved to The
				783	ClamAV project (its only client).</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	784
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	785	<li>The LoopIndexSplit, LiveValues, SimplifyHalfPowrLibCalls, GEPSplitter, and
				786	PartialSpecialization passes were removed. They were unmaintained,
Duncan Sands	f3ba7af	2011-04-06 08:07:40 +0000	[diff] [blame]	787	buggy, or deemed to be a bad idea.</li>
Devang Patel	b34dd13	2008-10-14 20:03:43 +0000	[diff] [blame]	788	</ul>
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	789
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	790	</div>
				791
Daniel Dunbar	f0233c6	2010-10-04 20:11:41 +0000	[diff] [blame]	792	<!--=========================================================================-->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	793	<h2>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	794	<a name="api_changes">Internal API Changes</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	795	</h2>
Daniel Dunbar	f0233c6	2010-10-04 20:11:41 +0000	[diff] [blame]	796
				797	<div class="doc_text">
				798
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	799	<p>In addition, many APIs have changed in this release. Some of the major
				800	LLVM API changes are:</p>
Daniel Dunbar	f0233c6	2010-10-04 20:11:41 +0000	[diff] [blame]	801
				802	<ul>
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	803	<li>include/llvm/System merged into include/llvm/Support.</li>
				804	<li>The <a href="http://llvm.org/PR5207">llvm::APInt API</a> was significantly
				805	cleaned up.</li>
Chris Lattner	1efe27e	2011-04-06 00:45:11 +0000	[diff] [blame]	806
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	807	<li>In the code generator, MVT::Flag was renamed to MVT::Glue to more accurately
				808	describe its behavior.</li>
				809
				810	<li>The system_error header from C++0x was added, and is now pervasively used to
				811	capture and handle i/o and other errors in LLVM.</li>
				812
				813	<li>The old sys::Path API has been deprecated in favor of the new PathV2 API,
				814	which is more efficient and flexible.</li>
Daniel Dunbar	f0233c6	2010-10-04 20:11:41 +0000	[diff] [blame]	815	</ul>
				816	</div>
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	817
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	818	<!-- *********************************************************************** -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	819	<h1>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	820	<a name="knownproblems">Known Problems</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	821	</h1>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	822	<!-- *********************************************************************** -->
				823
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	824	<div class="doc_text">
				825
Mikhail Glushenkov	f795ef0	2009-03-01 18:09:47 +0000	[diff] [blame]	826	<p>This section contains significant known problems with the LLVM system,
Chris Lattner	e18b32e	2008-11-10 05:40:34 +0000	[diff] [blame]	827	listed by component. If you run into a problem, please check the <a
Chris Lattner	c463b27	2005-10-29 07:07:09 +0000	[diff] [blame]	828	href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner	5eccca4	2003-12-12 21:22:16 +0000	[diff] [blame]	829	there isn't already one.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	830
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	831	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	832
Chris Lattner	f5ee170	2004-03-14 02:03:02 +0000	[diff] [blame]	833	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	834	<h2>
Chris Lattner	f5ee170	2004-03-14 02:03:02 +0000	[diff] [blame]	835	<a name="experimental">Experimental features included with this release</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	836	</h2>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	837
Chris Lattner	f5ee170	2004-03-14 02:03:02 +0000	[diff] [blame]	838	<div class="doc_text">
				839
Misha Brukman	6df9e2c	2004-05-12 21:46:05 +0000	[diff] [blame]	840	<p>The following components of this LLVM release are either untested, known to
				841	be broken or unreliable, or are in early development. These components should
				842	not be relied on, and bugs should not be filed against them, but they may be
				843	useful to some people. In particular, if you would like to work on one of these
Chris Lattner	2b659ef	2008-02-12 06:29:45 +0000	[diff] [blame]	844	components, please contact us on the <a
				845	href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattner	f5ee170	2004-03-14 02:03:02 +0000	[diff] [blame]	846
				847	<ul>
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	848	<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ
Chris Lattner	bb11771	2010-10-04 01:29:06 +0000	[diff] [blame]	849	and XCore backends are experimental.</li>
Chris Lattner	7d9b6b4	2010-10-02 21:59:30 +0000	[diff] [blame]	850	<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	851	other than darwin and ELF X86 systems.</li>
Chris Lattner	be2e1b5	2011-03-10 07:43:44 +0000	[diff] [blame]	852
Chris Lattner	f5ee170	2004-03-14 02:03:02 +0000	[diff] [blame]	853	</ul>
				854
				855	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	856
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	857	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	858	<h2>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	859	<a name="x86-be">Known problems with the X86 back-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	860	</h2>
John Criswell	c0c186d	2005-11-08 21:11:33 +0000	[diff] [blame]	861
				862	<div class="doc_text">
				863
				864	<ul>
Anton Korobeynikov	a6094be	2008-06-08 10:24:13 +0000	[diff] [blame]	865	<li>The X86 backend does not yet support
				866	all <a href="http://llvm.org/PR879">inline assembly that uses the X86
				867	floating point stack</a>. It supports the 'f' and 't' constraints, but not
				868	'u'.</li>
Dan Gohman	8207ba9	2008-06-08 23:05:11 +0000	[diff] [blame]	869	<li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner	914ce46	2010-04-22 06:28:20 +0000	[diff] [blame]	870	<tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman	8207ba9	2008-06-08 23:05:11 +0000	[diff] [blame]	871	argument constructs on X86-64 by lowering them manually.</li>
NAKAMURA Takumi	45c435a	2011-04-05 08:24:22 +0000	[diff] [blame]	872	<li>Windows x64 (aka Win64) code generator has a few issues.
				873	<ul>
				874	<li>llvm-gcc cannot build the mingw-w64 runtime currently
				875	due to lack of support for the 'u' inline assembly
				876	constraint and for X87 floating point inline assembly.</li>
				877	<li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt>
				878	due to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
				879	It is fixed in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
				880	<li>Miss-aligned MOVDQA might crash your program. It is due to
				881	<a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>,
				882	lack of handling aligned internal globals.</li>
				883	</ul>
				884	</li>
				885
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	886	</ul>
				887
				888	</div>
				889
				890	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	891	<h2>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	892	<a name="ppc-be">Known problems with the PowerPC back-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	893	</h2>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	894
				895	<div class="doc_text">
				896
				897	<ul>
Nicolas Geoffray	e4285dc	2007-05-15 09:21:28 +0000	[diff] [blame]	898	<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner	57a460e	2007-05-23 04:39:32 +0000	[diff] [blame]	899	compilation, and lacks support for debug information.</li>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	900	</ul>
				901
				902	</div>
				903
				904	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	905	<h2>
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	906	<a name="arm-be">Known problems with the ARM back-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	907	</h2>
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	908
				909	<div class="doc_text">
				910
				911	<ul>
Chris Lattner	57a460e	2007-05-23 04:39:32 +0000	[diff] [blame]	912	<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands	c90d68b	2007-09-26 15:59:54 +0000	[diff] [blame]	913	processors, thumb programs can crash or produce wrong
Chris Lattner	57a460e	2007-05-23 04:39:32 +0000	[diff] [blame]	914	results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell	524a5dd	2009-03-02 15:28:15 +0000	[diff] [blame]	915	<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	916	</li>
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	917	</ul>
				918
				919	</div>
				920
				921	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	922	<h2>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	923	<a name="sparc-be">Known problems with the SPARC back-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	924	</h2>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	925
				926	<div class="doc_text">
				927
				928	<ul>
John Criswell	524a5dd	2009-03-02 15:28:15 +0000	[diff] [blame]	929	<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	930	support the 64-bit SPARC ABI (-m64).</li>
				931	</ul>
				932
				933	</div>
				934
				935	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	936	<h2>
Bruno Cardoso Lopes	b7e1a4f	2008-10-25 14:56:26 +0000	[diff] [blame]	937	<a name="mips-be">Known problems with the MIPS back-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	938	</h2>
Bruno Cardoso Lopes	b7e1a4f	2008-10-25 14:56:26 +0000	[diff] [blame]	939
				940	<div class="doc_text">
				941
				942	<ul>
Bruno Cardoso Lopes	b7e1a4f	2008-10-25 14:56:26 +0000	[diff] [blame]	943	<li>64-bit MIPS targets are not supported yet.</li>
				944	</ul>
				945
				946	</div>
				947
				948	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	949	<h2>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	950	<a name="alpha-be">Known problems with the Alpha back-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	951	</h2>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	952
				953	<div class="doc_text">
				954
				955	<ul>
				956
				957	<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
				958	appropriate nops inserted to ensure restartability.</li>
				959
John Criswell	c0c186d	2005-11-08 21:11:33 +0000	[diff] [blame]	960	</ul>
				961	</div>
				962
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	963	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	964	<h2>
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	965	<a name="c-be">Known problems with the C back-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	966	</h2>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	967
				968	<div class="doc_text">
				969
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	970	<p>The C backend has numerous problems and is not being actively maintained.
				971	Depending on it for anything serious is not advised.</p>
				972
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	973	<ul>
Chris Lattner	5733b27	2008-06-05 06:35:40 +0000	[diff] [blame]	974	<li><a href="http://llvm.org/PR802">The C backend has only basic support for
				975	inline assembly code</a>.</li>
Chris Lattner	725a0d8	2007-09-26 06:01:35 +0000	[diff] [blame]	976	<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
				977	C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif	4906abe	2009-03-02 12:02:51 +0000	[diff] [blame]	978	C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sands	f74c0cc	2008-02-10 13:40:55 +0000	[diff] [blame]	979	<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands	50723a9	2009-02-25 11:51:54 +0000	[diff] [blame]	980	<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	981	</ul>
				982
				983	</div>
John Criswell	c0c186d	2005-11-08 21:11:33 +0000	[diff] [blame]	984
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	985
				986	<!-- ======================================================================= -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	987	<h2>
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	988	<a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	989	</h2>
Chris Lattner	47588f9	2003-10-02 05:07:23 +0000	[diff] [blame]	990
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	991	<div class="doc_text">
Chris Lattner	c5d658a	2006-03-03 00:34:26 +0000	[diff] [blame]	992
Chris Lattner	49123fd	2011-04-06 06:29:50 +0000	[diff] [blame]	993	<p><b>LLVM 2.9 will be the last release of llvm-gcc.</b></p>
				994
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	995	<p>llvm-gcc is generally very stable for the C family of languages. The only
				996	major language feature of GCC not supported by llvm-gcc is the
				997	<tt>__builtin_apply</tt> family of builtins. However, some extensions
				998	are only supported on some targets. For example, trampolines are only
				999	supported on some targets (these are used when you take the address of a
				1000	nested function).</p>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1001
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	1002	<p>Fortran support generally works, but there are still several unresolved bugs
				1003	in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
				1004	tools/gfortran component for details. Note that llvm-gcc is missing major
				1005	Fortran performance work in the frontend and library that went into GCC after
				1006	4.2. If you are interested in Fortran, we recommend that you consider using
				1007	<a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1008
Duncan Sands	3af9633	2010-10-04 10:06:56 +0000	[diff] [blame]	1009	<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
				1010	actively maintained. If you are interested in Ada, we recommend that you
				1011	consider using <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner	2b659ef	2008-02-12 06:29:45 +0000	[diff] [blame]	1012	</div>
				1013
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1014	<!-- *********************************************************************** -->
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	1015	<h1>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1016	<a name="additionalinfo">Additional Information</a>
NAKAMURA Takumi	c631931	2011-04-05 21:55:14 +0000	[diff] [blame]	1017	</h1>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1018	<!-- *********************************************************************** -->
				1019
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1020	<div class="doc_text">
				1021
Chris Lattner	416db10	2005-05-16 17:13:10 +0000	[diff] [blame]	1022	<p>A wide variety of additional information is available on the <a
NAKAMURA Takumi	b9a3363	2011-04-09 02:13:37 +0000	[diff] [blame]	1023	href="http://llvm.org/">LLVM web page</a>, in particular in the <a
Chris Lattner	b4b0ce7	2007-05-18 00:44:29 +0000	[diff] [blame]	1024	href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer	669ed45	2007-07-09 08:04:31 +0000	[diff] [blame]	1025	contains versions of the API documentation which is up-to-date with the
				1026	Subversion version of the source code.
Misha Brukman	109d9e8	2005-03-30 19:14:24 +0000	[diff] [blame]	1027	You can access versions of these documents specific to this release by going
				1028	into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1029
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1030	<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattner	c463b27	2005-10-29 07:07:09 +0000	[diff] [blame]	1031	us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner	5eccca4	2003-12-12 21:22:16 +0000	[diff] [blame]	1032	lists</a>.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1033
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1034	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1035
				1036	<!-- *********************************************************************** -->
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1037
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1038	<hr>
Misha Brukman	2061e89	2003-11-22 01:23:39 +0000	[diff] [blame]	1039	<address>
Misha Brukman	38847d5	2003-12-21 22:53:21 +0000	[diff] [blame]	1040	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	1041	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	2061e89	2003-11-22 01:23:39 +0000	[diff] [blame]	1042	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	1043	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	2061e89	2003-11-22 01:23:39 +0000	[diff] [blame]	1044
Chris Lattner	b4b0ce7	2007-05-18 00:44:29 +0000	[diff] [blame]	1045	<a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1046	Last modified: $Date$
Misha Brukman	2061e89	2003-11-22 01:23:39 +0000	[diff] [blame]	1047	</address>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1048
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1049	</body>
				1050	</html>