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Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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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">
Dan Gohman	b44f6c6	2010-05-03 23:51:05 +0000	[diff] [blame]	7	<title>LLVM 2.8 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
Dan Gohman	b44f6c6	2010-05-03 23:51:05 +0000	[diff] [blame]	11	<div class="doc_title">LLVM 2.8 Release Notes</div>
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>
Dan Gohman	b44f6c6	2010-05-03 23:51:05 +0000	[diff] [blame]	19	<li><a href="#externalproj">External Projects Using LLVM 2.8</a></li>
				20	<li><a href="#whatsnew">What's New in LLVM 2.8?</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">
Dan Gohman	44aa921	2008-10-14 16:23:02 +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	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	30	<!--
Chris Lattner	7b91eda	2010-04-22 05:41:35 +0000	[diff] [blame]	31	<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.8
Jeffrey Yasskin	bec4877	2010-01-28 01:14:43 +0000	[diff] [blame]	32	release.<br>
				33	You may prefer the
Dan Gohman	b44f6c6	2010-05-03 23:51:05 +0000	[diff] [blame]	34	<a href="http://llvm.org/releases/2.7/docs/ReleaseNotes.html">LLVM 2.7
				35	Release Notes</a>.</h1>
Chris Lattner	e07043c	2010-09-29 05:30:03 +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	<!-- *********************************************************************** -->
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	39	<div class="doc_section">
				40	<a name="intro">Introduction</a>
				41	</div>
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
Dan Gohman	7ae3ac8	2010-05-03 23:52:21 +0000	[diff] [blame]	47	Infrastructure, release 2.8. 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	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	65
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	66	<!--
				67	Almost dead code.
				68	include/llvm/Analysis/LiveValues.h => Dan
				69	lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
				70	llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
Chris Lattner	61c70e9	2010-08-28 04:09:24 +0000	[diff] [blame]	71	GEPSplitterPass
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	72	-->
				73
				74
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	75	<!-- Features that need text if they're finished for 2.9:
Chris Lattner	914ce46	2010-04-22 06:28:20 +0000	[diff] [blame]	76	combiner-aa?
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	77	strong phi elim
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	78	loop dependence analysis
Chris Lattner	885b661	2010-08-28 16:33:36 +0000	[diff] [blame]	79	TBAA
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	80	CorrelatedValuePropagation
Chris Lattner	acce85d	2008-02-10 07:46:44 +0000	[diff] [blame]	81	-->
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	82
				83	<!-- Announcement, lldb, libc++ -->
Chris Lattner	afa4163	2010-09-29 07:25:03 +0000	[diff] [blame]	84
				85	<!-- to write:
				86	MachineCSE tuned and on by default.
				87	llvm.dbg.value: variable debug info for optimized code
				88	MC Assembler backend is now real, does relaxation and is bitwise identical
				89	with darwin assembler in huge majority of all cases.
				90	new GHC calling convention
				91	New half float intrinsics LangRef.html#int_fp16
				92	Rewrote tblgen's type inference for backends to be more consistent and
				93	diagnose more target bugs. This also allows limited support for writing
				94	patterns for instructions that return multiple results, e.g. a virtual
				95	register and a flag result. Stuff that used 'parallel' before should use
				96	this.
				97	New ARM/Thumb disassembler support in MC.
				98	New SSEDomainFix pass:
				99	On Nehalem and newer CPUs there is a 2 cycle latency penalty on using a
				100	register in a different domain than where it was defined. Some instructions
				101	have equvivalents for different domains, like por/orps/orpd. The
				102	SSEDomainFix pass tries to minimize the number of domain crossings by
				103	changing between equvivalent opcodes where possible.
				104	Support for the Intel AES instructions in the assembler.
				105	memcpy, memmove, and memset now take address space qualified pointers + volatile.
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	106	per-instruction debug info metadata is much faster and uses less space (new DebugLoc class).
				107	-ffunction-sections and -fdata-sections are supported on ELF targets.
				108	Now iterate function passes when a cgsccpassmanager detects a devirtualization
				109	-momit-leaf-frame-pointer now supported.
				110	New -regalloc=fast, =local got removed
				111	New -regalloc=default option that chooses a register allocator based on the -O optimization level.
				112	New "trap values" concept: http://llvm.org/docs/LangRef.html#trapvalues
				113	Improved trip count analysis for <= and >= loops, and uses sign overflow info.
				114	REMOVED: SCCVN pass.
				115	X86 backend attempts to promote 16-bit integer operations to 32-bits to avoid
				116	0x66 prefixes, which are slow on some microarchitectures and bloat the code
				117	on others.
				118	X87 fp stackifier is global!
				119	LTO debug info support?
				120	NEON: Better performance for QQQQ (4-consecutive Q register) instructions. New reg sequence abstraction?
				121	New support for X86 "thiscall" calling convention (x86_thiscallcc in IR).
				122	ARM: Better scheduling (list-hybrid, hybrid?)
				123	New SubRegIndex tblgen class for targets -> jakob
				124	ARM: Tail call support.
				125	AVX support in the MC assembler. Full compiler support not done yet.
				126	Atomics now get legalized when not natively supported (jim g)
				127	ARM: General performance work and tuning.
Chris Lattner	afa4163	2010-09-29 07:25:03 +0000	[diff] [blame]	128	-->
				129
Chris Lattner	acce85d	2008-02-10 07:46:44 +0000	[diff] [blame]	130
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	131	<!-- *********************************************************************** -->
				132	<div class="doc_section">
				133	<a name="subproj">Sub-project Status Update</a>
Chris Lattner	ea34f64	2008-06-08 21:34:41 +0000	[diff] [blame]	134	</div>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	135	<!-- *********************************************************************** -->
Chris Lattner	ea34f64	2008-06-08 21:34:41 +0000	[diff] [blame]	136
				137	<div class="doc_text">
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	138	<p>
Dan Gohman	b44f6c6	2010-05-03 23:51:05 +0000	[diff] [blame]	139	The LLVM 2.8 distribution currently consists of code from the core LLVM
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	140	repository (which roughly includes the LLVM optimizers, code generators
				141	and supporting tools), the Clang repository and the llvm-gcc repository. In
				142	addition to this code, the LLVM Project includes other sub-projects that are in
				143	development. Here we include updates on these subprojects.
Bill Wendling	63d8c55	2009-03-02 04:28:57 +0000	[diff] [blame]	144	</p>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	145
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	146	</div>
				147
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	148
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	149	<!--=========================================================================-->
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	150	<div class="doc_subsection">
Chris Lattner	fb97b2d	2008-10-13 18:11:54 +0000	[diff] [blame]	151	<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	152	</div>
				153
				154	<div class="doc_text">
				155
Chris Lattner	095539f	2010-04-26 17:42:18 +0000	[diff] [blame]	156	<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
				157	C++, and Objective-C languages. Clang aims to provide a better user experience
				158	through expressive diagnostics, a high level of conformance to language
				159	standards, fast compilation, and low memory use. Like LLVM, Clang provides a
				160	modular, library-based architecture that makes it suitable for creating or
				161	integrating with other development tools. Clang is considered a
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	162	production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
				163	(32- and 64-bit), and for darwin-arm targets.</p>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	164
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	165	<p>In the LLVM 2.8 time-frame, the Clang team has made many improvements:</p>
Bill Wendling	741748a	2008-10-27 09:27:33 +0000	[diff] [blame]	166
Daniel Dunbar	1373943	2008-10-14 23:25:09 +0000	[diff] [blame]	167	<ul>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	168	<li>Surely these guys have done something</li>
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	169	<li>X86-64 abi improvements? Did they make it in?</li>
Bill Wendling	6bc1528	2009-03-02 04:28:18 +0000	[diff] [blame]	170	</ul>
Chris Lattner	fb97b2d	2008-10-13 18:11:54 +0000	[diff] [blame]	171	</div>
				172
				173	<!--=========================================================================-->
				174	<div class="doc_subsection">
				175	<a name="clangsa">Clang Static Analyzer</a>
				176	</div>
				177
				178	<div class="doc_text">
				179
Chris Lattner	8cdd793	2010-04-22 06:38:11 +0000	[diff] [blame]	180	<p>The <a href="http://clang-analyzer.llvm.org/">Clang Static Analyzer</a>
				181	project is an effort to use static source code analysis techniques to
				182	automatically find bugs in C and Objective-C programs (and hopefully <a
				183	href="http://clang-analyzer.llvm.org/dev_cxx.html">C++ in the
				184	future</a>!). The tool is very good at finding bugs that occur on specific
				185	paths through code, such as on error conditions.</p>
Chris Lattner	cc04261	2008-10-14 00:52:49 +0000	[diff] [blame]	186
Chris Lattner	2e38c7f	2010-09-30 00:34:43 +0000	[diff] [blame]	187	<p>The LLVM 2.8 release fixes a number of bugs and slightly improves precision
				188	over 2.7, but there are no major new features in the release.
Chris Lattner	8cdd793	2010-04-22 06:38:11 +0000	[diff] [blame]	189	</p>
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	190
				191	</div>
				192
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	193	<!--=========================================================================-->
				194	<div class="doc_subsection">
Nicolas Geoffray	99a4d30	2008-10-14 19:23:04 +0000	[diff] [blame]	195	<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	196	</div>
				197
				198	<div class="doc_text">
				199	<p>
Nicolas Geoffray	99a4d30	2008-10-14 19:23:04 +0000	[diff] [blame]	200	The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	201	a JVM and a CLI Virtual Machine (Microsoft .NET is an
				202	implementation of the CLI) using LLVM for static and just-in-time
				203	compilation.</p>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	204
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	205	<p>With the release of LLVM 2.8, ...</p>
Chris Lattner	96a445e	2008-10-13 18:01:01 +0000	[diff] [blame]	206
				207	</div>
				208
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	209
				210	<!--=========================================================================-->
				211	<div class="doc_subsection">
				212	<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
				213	</div>
				214
				215	<div class="doc_text">
				216	<p>
				217	The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
				218	is a simple library that provides an implementation of the low-level
				219	target-specific hooks required by code generation and other runtime components.
				220	For example, when compiling for a 32-bit target, converting a double to a 64-bit
				221	unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
				222	function. The compiler-rt library provides highly optimized implementations of
				223	this and other low-level routines (some are 3x faster than the equivalent
				224	libgcc routines).</p>
				225
				226	<p>
				227	All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	228	License, a "BSD-style" license. New in LLVM 2.8:
				229
				230	Soft float support
				231	</p>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	232
				233	</div>
				234
				235	<!--=========================================================================-->
				236	<div class="doc_subsection">
Duncan Sands	749fd83	2010-04-02 09:23:15 +0000	[diff] [blame]	237	<a name="dragonegg">DragonEgg: llvm-gcc ported to gcc-4.5</a>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	238	</div>
				239
				240	<div class="doc_text">
				241	<p>
Duncan Sands	749fd83	2010-04-02 09:23:15 +0000	[diff] [blame]	242	<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a port of llvm-gcc to
Duncan Sands	4b1da2b	2010-09-30 17:37:34 +0000	[diff] [blame^]	243	gcc-4.5. Unlike llvm-gcc, dragonegg in theory does not require any gcc-4.5
				244	modifications whatsoever (currently one small patch is needed) thanks to the
				245	new <a href="http://gcc.gnu.org/wiki/plugins">gcc plugin architecture</a>.
				246	DragonEgg is a gcc plugin that makes gcc-4.5 use the LLVM optimizers and code
				247	generators instead of gcc's, just like with llvm-gcc.
Duncan Sands	749fd83	2010-04-02 09:23:15 +0000	[diff] [blame]	248	</p>
				249
				250	<p>
Duncan Sands	4b1da2b	2010-09-30 17:37:34 +0000	[diff] [blame^]	251	DragonEgg is still a work in progress, but it is able to compile a lot of code,
				252	for example all of gcc, LLVM and clang. Currently Ada, C, C++ and Fortran work
				253	well, while all other languages either don't work at all or only work poorly.
				254	For the moment only the x86-32 and x86-64 targets are supported, and only on
				255	linux and darwin (darwin may need additional gcc patches).
Duncan Sands	749fd83	2010-04-02 09:23:15 +0000	[diff] [blame]	256	</p>
				257
				258	<p>
Duncan Sands	4b1da2b	2010-09-30 17:37:34 +0000	[diff] [blame^]	259	The 2.8 release has the following notable changes:
				260	<ul>
				261	<li>The plugin loads faster due to exporting fewer symbols.</li>
				262	<li>Additional vector operations such as addps256 are now supported.</li>
				263	<li>Ada global variables with no initial value are no longer zero initialized,
				264	resulting in better optimization.</li>
				265	<li>The '-fplugin-arg-dragonegg-enable-gcc-optzns' flag now runs all gcc
				266	optimizers, rather than just a handful.</li>
				267	<li>Fortran programs using common variables now link correctly.</li>
				268	<li>GNU OMP constructs no longer crash the compiler.</li>
				269	</ul>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	270	</p>
				271
				272	</div>
				273
				274
				275	<!--=========================================================================-->
				276	<div class="doc_subsection">
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	277	<a name="lldb">LLDB: Low Level Debugger</a>
				278	</div>
				279
				280	<div class="doc_text">
				281	<p>
				282	<a href="http://lldb.llvm.org/">LLDB</a> is</p>
				283
				284	<p>
				285	</p>
				286
				287	<p>
				288	2.8 status here.
				289	</p>
				290
				291	</div>
				292
				293	<!--=========================================================================-->
				294	<div class="doc_subsection">
				295	<a name="libc++">libc++: C++ Standard Library</a>
				296	</div>
				297
				298	<div class="doc_text">
				299	<p>
				300	<a href="http://libc++.llvm.org/">libc++</a> is</p>
				301
				302	<p>
				303	</p>
				304
				305	<p>
				306	2.8 status here.
				307	</p>
				308
				309	</div>
				310
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	311
Chris Lattner	ab68e9e	2009-02-26 22:33:38 +0000	[diff] [blame]	312	<!-- *********************************************************************** -->
				313	<div class="doc_section">
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	314	<a name="externalproj">External Open Source Projects Using LLVM 2.8</a>
Chris Lattner	ab68e9e	2009-02-26 22:33:38 +0000	[diff] [blame]	315	</div>
				316	<!-- *********************************************************************** -->
				317
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	318	<div class="doc_text">
				319
				320	<p>An exciting aspect of LLVM is that it is used as an enabling technology for
				321	a lot of other language and tools projects. This section lists some of the
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	322	projects that have already been updated to work with LLVM 2.8.</p>
Chris Lattner	7c8e796	2010-04-26 17:38:10 +0000	[diff] [blame]	323	</div>
				324
Chris Lattner	2e38c7f	2010-09-30 00:34:43 +0000	[diff] [blame]	325	<!--=========================================================================-->
				326	<div class="doc_subsection">
				327	<a name="tce">TTA-based Codesign Environment (TCE)</a>
				328	</div>
				329
				330	<div class="doc_text">
				331	<p>
				332	<a href="http://tce.cs.tut.fi/">TCE</a> is a toolset for designing
				333	application-specific processors (ASP) based on the Transport triggered
				334	architecture (TTA). The toolset provides a complete co-design flow from C/C++
				335	programs down to synthesizable VHDL and parallel program binaries. Processor
				336	customization points include the register files, function units, supported
				337	operations, and the interconnection network.</p>
				338
				339	<p>TCE uses llvm-gcc/Clang and LLVM for C/C++ language support, target
				340	independent optimizations and also for parts of code generation. It generates
				341	new LLVM-based code generators "on the fly" for the designed TTA processors and
				342	loads them in to the compiler backend as runtime libraries to avoid per-target
				343	recompilation of larger parts of the compiler chain.</p>
				344
				345	</div>
				346
				347	<!--=========================================================================-->
				348	<div class="doc_subsection">
				349	<a name="Horizon">Horizon Bytecode Compiler</a>
				350	</div>
				351
				352	<div class="doc_text">
				353	<p>
				354	<a href="http://www.quokforge.org/projects/horizon">Horizon</a> is a bytecode
				355	language and compiler written on top of LLVM, intended for producing
				356	single-address-space managed code operating systems that
				357	run faster than the equivalent multiple-address-space C systems.
				358	More in-depth blurb is available on <a
				359	href="http://www.quokforge.org/projects/horizon/wiki/Wiki">the wiki</a>.</p>
				360
				361	</div>
				362
				363	<!--=========================================================================-->
				364	<div class="doc_subsection">
				365	<a name="clamav">Clam AntiVirus</a>
				366	</div>
				367
				368	<div class="doc_text">
				369	<p>
				370	<a href=http://www.clamav.net>Clam AntiVirus</a> is an open source (GPL)
				371	anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
				372	gateways. Since version 0.96 it has <a
				373	href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
				374	signatures</a> that allow writing detections for complex malware. It
				375	uses LLVM's JIT to speed up the execution of bytecode on
				376	X86,X86-64,PPC32/64, falling back to its own interpreter otherwise.
				377	The git version was updated to work with LLVM 2.8
				378	</p>
				379
				380	<p>The <a
				381	href="http://git.clamav.net/gitweb?p=clamav-bytecode-compiler.git;a=blob_plain;f=docs/user/clambc-user.pdf">
				382	ClamAV bytecode compiler</a> uses Clang and LLVM to compile a C-like
				383	language, insert runtime checks, and generate ClamAV bytecode.</p>
				384
				385	</div>
				386
				387	<!--=========================================================================-->
				388	<div class="doc_subsection">
				389	<a name="pure">Pure</a>
				390	</div>
				391
				392	<div class="doc_text">
				393	<p>
				394	<a href="http://pure-lang.googlecode.com/">Pure</a>
				395	is an algebraic/functional
				396	programming language based on term rewriting. Programs are collections
				397	of equations which are used to evaluate expressions in a symbolic
				398	fashion. Pure offers dynamic typing, eager and lazy evaluation, lexical
				399	closures, a hygienic macro system (also based on term rewriting),
				400	built-in list and matrix support (including list and matrix
				401	comprehensions) and an easy-to-use C interface. The interpreter uses
				402	LLVM as a backend to JIT-compile Pure programs to fast native code.</p>
				403
				404	<p>Pure versions 0.44 and later have been tested and are known to work with
				405	LLVM 2.8 (and continue to work with older LLVM releases >= 2.5).</p>
				406
				407	</div>
				408
				409	<!--=========================================================================-->
				410	<div class="doc_subsection">
				411	<a name="GHC">Glasgow Haskell Compiler (GHC)</a>
				412	</div>
				413
				414	<div class="doc_text">
				415	<p>
				416	<a href="http://www.haskell.org/ghc/">GHC</a> is an open source,
				417	state-of-the-art programming suite for
				418	Haskell, a standard lazy functional programming language. It includes
				419	an optimizing static compiler generating good code for a variety of
				420	platforms, together with an interactive system for convenient, quick
				421	development.</p>
				422
				423	<p>In addition to the existing C and native code generators, GHC 7.0 now
				424	supports an <a
				425	href="http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/Backends/LLVM">LLVM
				426	code generator</a>. GHC supports LLVM 2.7 and later.</p>
				427
				428	</div>
				429
				430	<!--=========================================================================-->
				431	<div class="doc_subsection">
				432	<a name="Clay">Clay Programming Language</a>
				433	</div>
				434
				435	<div class="doc_text">
				436	<p>
Chris Lattner	97fe645	2010-09-30 01:12:09 +0000	[diff] [blame]	437	<a href="http://tachyon.in/clay/">Clay</a> is a new systems programming
Chris Lattner	2e38c7f	2010-09-30 00:34:43 +0000	[diff] [blame]	438	language that is specifically designed for generic programming. It makes
				439	generic programming very concise thanks to whole program type propagation. It
				440	uses LLVM as its backend.</p>
				441
				442	</div>
Chris Lattner	3a1d4cf	2010-04-22 21:34:16 +0000	[diff] [blame]	443
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	444	<!-- *********************************************************************** -->
				445	<div class="doc_section">
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	446	<a name="whatsnew">What's New in LLVM 2.8?</a>
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	447	</div>
				448	<!-- *********************************************************************** -->
				449
Chris Lattner	f8e0b4e	2008-06-08 22:59:35 +0000	[diff] [blame]	450	<div class="doc_text">
				451
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	452	<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]	453	minor improvements. Some of the major improvements and new features are listed
				454	in this section.
Chris Lattner	f8e0b4e	2008-06-08 22:59:35 +0000	[diff] [blame]	455	</p>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	456
Chris Lattner	914ce46	2010-04-22 06:28:20 +0000	[diff] [blame]	457	</div>
				458
				459	<!--=========================================================================-->
				460	<div class="doc_subsection">
				461	<a name="orgchanges">LLVM Community Changes</a>
				462	</div>
				463
				464	<div class="doc_text">
				465
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	466	<p>In addition to changes to the code, between LLVM 2.7 and 2.8, a number of
Chris Lattner	b7c85b4	2010-04-21 05:17:40 +0000	[diff] [blame]	467	organization changes have happened:
				468	</p>
				469
				470	<ul>
Chris Lattner	e07043c	2010-09-29 05:30:03 +0000	[diff] [blame]	471	<li>libc++ and lldb are new</li>
Chris Lattner	afa4163	2010-09-29 07:25:03 +0000	[diff] [blame]	472	<li>Debugging optimized code support.</li>
Chris Lattner	b7c85b4	2010-04-21 05:17:40 +0000	[diff] [blame]	473	</ul>
Chris Lattner	f8e0b4e	2008-06-08 22:59:35 +0000	[diff] [blame]	474	</div>
				475
Chris Lattner	8348b47	2008-06-08 21:58:17 +0000	[diff] [blame]	476	<!--=========================================================================-->
Chris Lattner	ea34f64	2008-06-08 21:34:41 +0000	[diff] [blame]	477	<div class="doc_subsection">
Chris Lattner	252b83d	2008-02-06 18:00:06 +0000	[diff] [blame]	478	<a name="majorfeatures">Major New Features</a>
				479	</div>
				480
				481	<div class="doc_text">
				482
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	483	<p>LLVM 2.8 includes several major new capabilities:</p>
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	484
				485	<ul>
Chris Lattner	8dc5faf	2010-09-05 20:49:45 +0000	[diff] [blame]	486	<li>atomic lowering pass.</li>
				487	<li>RegionInfo pass: opt -regions analyze" or "opt -view-regions".
				488	<!-- Tobias Grosser --></li>
				489	<li>ARMGlobalMerge: <!-- Anton --> </li>
Chris Lattner	702f2d4	2010-09-06 19:14:40 +0000	[diff] [blame]	490	<li>llvm-diff</li>
Chris Lattner	8170c10	2008-02-10 08:18:42 +0000	[diff] [blame]	491	</ul>
Chris Lattner	dc91008	2010-03-17 06:41:58 +0000	[diff] [blame]	492
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	493	</div>
				494
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	495	<!--=========================================================================-->
				496	<div class="doc_subsection">
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	497	<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattner	f304ffc	2008-02-10 08:17:19 +0000	[diff] [blame]	498	</div>
				499
				500	<div class="doc_text">
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	501	<p>LLVM IR has several new features for better support of new targets and that
				502	expose new optimization opportunities:</p>
Chris Lattner	f304ffc	2008-02-10 08:17:19 +0000	[diff] [blame]	503
Chris Lattner	791f77b	2008-06-05 06:25:56 +0000	[diff] [blame]	504	<ul>
Gabor Greif	17b59fe	2010-07-21 10:20:08 +0000	[diff] [blame]	505
				506	<li>LLVM 2.8 changes the internal order of operands in <a
				507	href="http://llvm.org/doxygen/classllvm_1_1InvokeInst.html"><tt>InvokeInst</tt></a>
				508	and <a href="http://llvm.org/doxygen/classllvm_1_1CallInst.html"><tt>CallInst</tt></a>.
				509	To be portable across releases, resort to <tt>CallSite</tt> and the
Gabor Greif	50fb330	2010-07-21 10:22:41 +0000	[diff] [blame]	510	high-level accessors, such as <tt>getCalledValue</tt> and <tt>setUnwindDest</tt>.
Gabor Greif	17b59fe	2010-07-21 10:20:08 +0000	[diff] [blame]	511	</li>
Gabor Greif	05006e2	2010-07-26 18:48:07 +0000	[diff] [blame]	512	<li>
				513	You can no longer pass use_iterators directly to cast<> (and similar), because
				514	these routines tend to perform costly dereference operations more than once. You
				515	have to dereference the iterators yourself and pass them in.
				516	</li>
Torok Edwin	7c46cf0	2010-08-04 12:43:22 +0000	[diff] [blame]	517	<li>
				518	llvm.memcpy., llvm.memset., llvm.memmove.* (and possibly other?) intrinsics
				519	take an extra parameter now (i1 isVolatile), totaling 5 parameters.
				520	If you were creating these intrinsic calls and prototypes yourself (as opposed
				521	to using Intrinsic::getDeclaration), you can use UpgradeIntrinsicFunction/UpgradeIntrinsicCall
				522	to be portable accross releases.
				523	Note that you cannot use Intrinsic::getDeclaration() in a backwards compatible
				524	way (needs 2/3 types now, in 2.7 it needed just 1).
				525	</li>
				526	<li>
				527	SetCurrentDebugLocation takes a DebugLoc now instead of a MDNode.
				528	Change your code to use
				529	SetCurrentDebugLocation(DebugLoc::getFromDILocation(...)).
				530	</li>
				531	<li>
				532	VISIBILITY_HIDDEN is gone.
				533	</li>
				534	<li>
Owen Anderson	87ebbc0	2010-08-04 18:27:08 +0000	[diff] [blame]	535	The <tt>RegisterPass</tt> and <tt>RegisterAnalysisGroup</tt> templates are
				536	considered deprecated, but continue to function in LLVM 2.8. Clients are
				537	strongly advised to use the upcoming <tt>INITIALIZE_PASS()</tt> and
				538	<tt>INITIALIZE_AG_PASS()</tt> macros instead.
				539	<li>
Torok Edwin	7c46cf0	2010-08-04 12:43:22 +0000	[diff] [blame]	540	SMDiagnostic takes different parameters now. //FIXME: how to upgrade?
				541	</li>
				542	<li>
Duncan Sands	12881e7	2010-08-30 10:57:54 +0000	[diff] [blame]	543	The constructor for the Triple class no longer tries to understand odd triple
				544	specifications. Frontends should ensure that they only pass valid triples to
				545	LLVM. The Triple::normalize utility method has been added to help front-ends
				546	deal with funky triples.
				547	<li>
Torok Edwin	7c46cf0	2010-08-04 12:43:22 +0000	[diff] [blame]	548	Some APIs got renamed:
				549	<ul>
				550	<li>llvm_report_error -> report_fatal_error</li>
				551	<li>llvm_install_error_handler -> install_fatal_error_handler</li>
				552	<li>llvm::DwarfExceptionHandling -> llvm::JITExceptionHandling</li>
				553	</ul>
				554	</li>
Chris Lattner	f304ffc	2008-02-10 08:17:19 +0000	[diff] [blame]	555	</ul>
Mikhail Glushenkov	ea65d7d	2008-10-13 02:08:34 +0000	[diff] [blame]	556
Chris Lattner	f304ffc	2008-02-10 08:17:19 +0000	[diff] [blame]	557	</div>
				558
				559	<!--=========================================================================-->
				560	<div class="doc_subsection">
Chris Lattner	acce85d	2008-02-10 07:46:44 +0000	[diff] [blame]	561	<a name="optimizer">Optimizer Improvements</a>
				562	</div>
				563
				564	<div class="doc_text">
				565
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	566	<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]	567	release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner	acce85d	2008-02-10 07:46:44 +0000	[diff] [blame]	568
				569	<ul>
				570
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	571	<li></li>
Chris Lattner	a54c1f7	2010-04-21 06:42:24 +0000	[diff] [blame]	572
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	573	</ul>
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	574
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	575	</div>
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	576
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	577
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	578	<!--=========================================================================-->
				579	<div class="doc_subsection">
				580	<a name="executionengine">Interpreter and JIT Improvements</a>
				581	</div>
Chris Lattner	f301387	2008-10-13 21:50:36 +0000	[diff] [blame]	582
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	583	<div class="doc_text">
				584
				585	<ul>
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	586	<li></li>
Chris Lattner	b7c85b4	2010-04-21 05:17:40 +0000	[diff] [blame]	587
Chris Lattner	0b83220	2008-06-08 02:45:07 +0000	[diff] [blame]	588	</ul>
				589
				590	</div>
				591
				592	<!--=========================================================================-->
				593	<div class="doc_subsection">
Chris Lattner	4ba2b65	2010-09-30 16:31:33 +0000	[diff] [blame]	594	<a name="mc">MC Level Improvements</a>
				595	</div>
				596
				597	<div class="doc_text">
				598	<p>
				599	FIXME: Rewrite.
				600
				601	The LLVM Machine Code (aka MC) sub-project of LLVM was created to solve a number
				602	of problems in the realm of assembly, disassembly, object file format handling,
				603	and a number of other related areas that CPU instruction-set level tools work
				604	in. It is a sub-project of LLVM which provides it with a number of advantages
				605	over other compilers that do not have tightly integrated assembly-level tools.
				606	For a gentle introduction, please see the <a
				607	href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
				608	LLVM MC Project Blog Post</a>.
				609	</p>
				610
				611	<p>2.8 status here. Basic correctness, some obscure missing instructions on
				612	mainline, on by default in clang.
				613	Entire compiler backend converted to use mcstreamer.
				614	</p>
				615	</div>
				616
				617
				618
				619	<!--=========================================================================-->
				620	<div class="doc_subsection">
Chris Lattner	511433e	2009-03-02 03:24:11 +0000	[diff] [blame]	621	<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner	0b83220	2008-06-08 02:45:07 +0000	[diff] [blame]	622	</div>
				623
				624	<div class="doc_text">
				625
Mikhail Glushenkov	f795ef0	2009-03-01 18:09:47 +0000	[diff] [blame]	626	<p>We have put a significant amount of work into the code generator
				627	infrastructure, which allows us to implement more aggressive algorithms and make
				628	it run faster:</p>
Chris Lattner	0b83220	2008-06-08 02:45:07 +0000	[diff] [blame]	629
				630	<ul>
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	631	<li>MachO writer works.</li>
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	632	</ul>
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	633	</div>
				634
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	635	<!--=========================================================================-->
				636	<div class="doc_subsection">
				637	<a name="x86">X86-32 and X86-64 Target Improvements</a>
				638	</div>
				639
				640	<div class="doc_text">
				641	<p>New features of the X86 target include:
				642	</p>
				643
				644	<ul>
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	645	<li>The X86 backend now supports holding X87 floating point stack values
				646	in registers across basic blocks, dramatically improving performance of code
				647	that uses long double, and when targetting CPUs that don't support SSE.</li>
Chris Lattner	511433e	2009-03-02 03:24:11 +0000	[diff] [blame]	648
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	649	</ul>
				650
Chris Lattner	917cc71	2009-03-02 02:37:32 +0000	[diff] [blame]	651	</div>
Chris Lattner	8497764	2007-09-21 03:54:09 +0000	[diff] [blame]	652
				653	<!--=========================================================================-->
				654	<div class="doc_subsection">
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	655	<a name="ARM">ARM Target Improvements</a>
Chris Lattner	c441fb8	2009-03-01 02:30:21 +0000	[diff] [blame]	656	</div>
				657
				658	<div class="doc_text">
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	659	<p>New features of the ARM target include:
				660	</p>
Chris Lattner	c441fb8	2009-03-01 02:30:21 +0000	[diff] [blame]	661
				662	<ul>
Chris Lattner	c441fb8	2009-03-01 02:30:21 +0000	[diff] [blame]	663
Bob Wilson	5b2fb95	2010-09-13 17:37:55 +0000	[diff] [blame]	664	<li>
				665	All of the NEON load and store intrinsics (llvm.arm.neon.vld* and
				666	llvm.arm.neon.vst*) take an extra parameter to specify the alignment in bytes
				667	of the memory being accessed.
				668	</li>
				669	<li>
				670	The llvm.arm.neon.vaba intrinsic (vector absolute difference and
				671	accumulate) has been removed. This operation is now represented using
				672	the llvm.arm.neon.vabd intrinsic (vector absolute difference) followed by a
				673	vector add.
Bob Wilson	e847277	2010-09-13 17:39:35 +0000	[diff] [blame]	674	</li>
Bob Wilson	5b2fb95	2010-09-13 17:37:55 +0000	[diff] [blame]	675	<li>
				676	The llvm.arm.neon.vabdl and llvm.arm.neon.vabal intrinsics (lengthening
				677	vector absolute difference with and without accumlation) have been removed.
				678	They are represented using the llvm.arm.neon.vabd intrinsic (vector absolute
				679	difference) followed by a vector zero-extend operation, and for vabal,
				680	a vector add.
				681	</li>
				682	<li>
				683	The llvm.arm.neon.vmovn intrinsic has been removed. Calls of this intrinsic
				684	are now replaced by vector truncate operations.
				685	</li>
				686	<li>
				687	The llvm.arm.neon.vmovls and llvm.arm.neon.vmovlu intrinsics have been
				688	removed. They are now represented as vector sign-extend (vmovls) and
				689	zero-extend (vmovlu) operations.
				690	</li>
				691	<li>
				692	The llvm.arm.neon.vaddl, llvm.arm.neon.vaddw, llvm.arm.neon.vsubl*, and
				693	llvm.arm.neon.vsubw* intrinsics (lengthening vector add and subtract) have
				694	been removed. They are replaced by vector add and vector subtract operations
				695	where one (vaddw, vsubw) or both (vaddl, vsubl) of the operands are either
				696	sign-extended or zero-extended.
				697	</li>
				698	<li>
				699	The llvm.arm.neon.vmulls, llvm.arm.neon.vmullu, llvm.arm.neon.vmlal*, and
				700	llvm.arm.neon.vmlsl* intrinsics (lengthening vector multiply with and without
				701	accumulation and subtraction) have been removed. These operations are now
				702	represented as vector multiplications where the operands are either
				703	sign-extended or zero-extended, followed by a vector add for vmlal or a
				704	vector subtract for vmlsl. Note that the polynomial vector multiply
				705	intrinsic, llvm.arm.neon.vmullp, remains unchanged.
				706	</li>
Bob Wilson	e847277	2010-09-13 17:39:35 +0000	[diff] [blame]	707
				708	</ul>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	709	</div>
Chris Lattner	c441fb8	2009-03-01 02:30:21 +0000	[diff] [blame]	710
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	711	<!--=========================================================================-->
				712	<div class="doc_subsection">
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	713	<a name="newapis">New Useful APIs</a>
				714	</div>
				715
				716	<div class="doc_text">
				717
				718	<p>This release includes a number of new APIs that are used internally, which
				719	may also be useful for external clients.
				720	</p>
				721
				722	<ul>
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	723	<li></li>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	724	</ul>
				725
				726
				727	</div>
				728
				729	<!--=========================================================================-->
				730	<div class="doc_subsection">
				731	<a name="otherimprovements">Other Improvements and New Features</a>
				732	</div>
				733
				734	<div class="doc_text">
				735	<p>Other miscellaneous features include:</p>
				736
				737	<ul>
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	738	<li></li>
Chris Lattner	c441fb8	2009-03-01 02:30:21 +0000	[diff] [blame]	739	</ul>
				740
				741	</div>
				742
Chris Lattner	77d29b1	2008-06-05 08:02:49 +0000	[diff] [blame]	743
				744	<!--=========================================================================-->
				745	<div class="doc_subsection">
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	746	<a name="changes">Major Changes and Removed Features</a>
				747	</div>
				748
				749	<div class="doc_text">
				750
Chris Lattner	eeb4da0	2008-10-13 22:06:31 +0000	[diff] [blame]	751	<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	752	on LLVM 2.7, this section lists some "gotchas" that you may run into upgrading
Chris Lattner	eeb4da0	2008-10-13 22:06:31 +0000	[diff] [blame]	753	from the previous release.</p>
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	754
				755	<ul>
Chris Lattner	2295b5a	2010-09-02 23:22:50 +0000	[diff] [blame]	756	<li>.ll file doesn't produce #uses comments anymore, to get them, run a .bc file
				757	through "llvm-dis --show-annotations".</li>
Chris Lattner	885b661	2010-08-28 16:33:36 +0000	[diff] [blame]	758	<li>MSIL Backend removed.</li>
				759	<li>ABCD and SSI passes removed.</li>
				760	<li>'Union' LLVM IR feature removed.</li>
Chris Lattner	b7c85b4	2010-04-21 05:17:40 +0000	[diff] [blame]	761	</ul>
Chris Lattner	eeb4da0	2008-10-13 22:06:31 +0000	[diff] [blame]	762
				763	<p>In addition, many APIs have changed in this release. Some of the major LLVM
				764	API changes are:</p>
				765
				766	<ul>
Devang Patel	b34dd13	2008-10-14 20:03:43 +0000	[diff] [blame]	767	</ul>
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	768
Chris Lattner	f6662f9	2008-10-13 17:57:36 +0000	[diff] [blame]	769	</div>
				770
				771
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	772	<!-- *********************************************************************** -->
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	773	<div class="doc_section">
				774	<a name="knownproblems">Known Problems</a>
				775	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	776	<!-- *********************************************************************** -->
				777
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	778	<div class="doc_text">
				779
Mikhail Glushenkov	f795ef0	2009-03-01 18:09:47 +0000	[diff] [blame]	780	<p>This section contains significant known problems with the LLVM system,
Chris Lattner	e18b32e	2008-11-10 05:40:34 +0000	[diff] [blame]	781	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]	782	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]	783	there isn't already one.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	784
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	785	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	786
Chris Lattner	f5ee170	2004-03-14 02:03:02 +0000	[diff] [blame]	787	<!-- ======================================================================= -->
				788	<div class="doc_subsection">
				789	<a name="experimental">Experimental features included with this release</a>
				790	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	791
Chris Lattner	f5ee170	2004-03-14 02:03:02 +0000	[diff] [blame]	792	<div class="doc_text">
				793
Misha Brukman	6df9e2c	2004-05-12 21:46:05 +0000	[diff] [blame]	794	<p>The following components of this LLVM release are either untested, known to
				795	be broken or unreliable, or are in early development. These components should
				796	not be relied on, and bugs should not be filed against them, but they may be
				797	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]	798	components, please contact us on the <a
				799	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]	800
				801	<ul>
Chris Lattner	885b661	2010-08-28 16:33:36 +0000	[diff] [blame]	802	<li>The Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
Wesley Peck	7c4a121	2010-03-18 14:31:30 +0000	[diff] [blame]	803	backends are experimental.</li>
Chris Lattner	914ce46	2010-04-22 06:28:20 +0000	[diff] [blame]	804	<li><tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattner	922d00f	2010-07-21 15:57:40 +0000	[diff] [blame]	805	supported value for this option. XXX Update me</li>
Chris Lattner	f5ee170	2004-03-14 02:03:02 +0000	[diff] [blame]	806	</ul>
				807
				808	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	809
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	810	<!-- ======================================================================= -->
				811	<div class="doc_subsection">
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	812	<a name="x86-be">Known problems with the X86 back-end</a>
John Criswell	c0c186d	2005-11-08 21:11:33 +0000	[diff] [blame]	813	</div>
				814
				815	<div class="doc_text">
				816
				817	<ul>
Anton Korobeynikov	a6094be	2008-06-08 10:24:13 +0000	[diff] [blame]	818	<li>The X86 backend does not yet support
				819	all <a href="http://llvm.org/PR879">inline assembly that uses the X86
				820	floating point stack</a>. It supports the 'f' and 't' constraints, but not
				821	'u'.</li>
Duncan Sands	47eff2b	2008-06-08 19:38:43 +0000	[diff] [blame]	822	<li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswell	524a5dd	2009-03-02 15:28:15 +0000	[diff] [blame]	823	expect small issues to happen. Also, llvm-gcc cannot build the mingw64
Chris Lattner	914ce46	2010-04-22 06:28:20 +0000	[diff] [blame]	824	runtime currently due to lack of support for the 'u' inline assembly
				825	constraint and for X87 floating point inline assembly.</li>
Dan Gohman	8207ba9	2008-06-08 23:05:11 +0000	[diff] [blame]	826	<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]	827	<tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman	8207ba9	2008-06-08 23:05:11 +0000	[diff] [blame]	828	argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	829	</ul>
				830
				831	</div>
				832
				833	<!-- ======================================================================= -->
				834	<div class="doc_subsection">
				835	<a name="ppc-be">Known problems with the PowerPC back-end</a>
				836	</div>
				837
				838	<div class="doc_text">
				839
				840	<ul>
Nicolas Geoffray	e4285dc	2007-05-15 09:21:28 +0000	[diff] [blame]	841	<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]	842	compilation, and lacks support for debug information.</li>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	843	</ul>
				844
				845	</div>
				846
				847	<!-- ======================================================================= -->
				848	<div class="doc_subsection">
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	849	<a name="arm-be">Known problems with the ARM back-end</a>
				850	</div>
				851
				852	<div class="doc_text">
				853
				854	<ul>
Chris Lattner	57a460e	2007-05-23 04:39:32 +0000	[diff] [blame]	855	<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]	856	processors, thumb programs can crash or produce wrong
Chris Lattner	57a460e	2007-05-23 04:39:32 +0000	[diff] [blame]	857	results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell	524a5dd	2009-03-02 15:28:15 +0000	[diff] [blame]	858	<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]	859	</li>
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	860	</ul>
				861
				862	</div>
				863
				864	<!-- ======================================================================= -->
				865	<div class="doc_subsection">
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	866	<a name="sparc-be">Known problems with the SPARC back-end</a>
				867	</div>
				868
				869	<div class="doc_text">
				870
				871	<ul>
John Criswell	524a5dd	2009-03-02 15:28:15 +0000	[diff] [blame]	872	<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]	873	support the 64-bit SPARC ABI (-m64).</li>
				874	</ul>
				875
				876	</div>
				877
				878	<!-- ======================================================================= -->
				879	<div class="doc_subsection">
Bruno Cardoso Lopes	b7e1a4f	2008-10-25 14:56:26 +0000	[diff] [blame]	880	<a name="mips-be">Known problems with the MIPS back-end</a>
				881	</div>
				882
				883	<div class="doc_text">
				884
				885	<ul>
Bruno Cardoso Lopes	b7e1a4f	2008-10-25 14:56:26 +0000	[diff] [blame]	886	<li>64-bit MIPS targets are not supported yet.</li>
				887	</ul>
				888
				889	</div>
				890
				891	<!-- ======================================================================= -->
				892	<div class="doc_subsection">
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	893	<a name="alpha-be">Known problems with the Alpha back-end</a>
				894	</div>
				895
				896	<div class="doc_text">
				897
				898	<ul>
				899
				900	<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
				901	appropriate nops inserted to ensure restartability.</li>
				902
John Criswell	c0c186d	2005-11-08 21:11:33 +0000	[diff] [blame]	903	</ul>
				904	</div>
				905
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	906	<!-- ======================================================================= -->
				907	<div class="doc_subsection">
Chris Lattner	f3e5bc6	2007-05-14 06:56:09 +0000	[diff] [blame]	908	<a name="c-be">Known problems with the C back-end</a>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	909	</div>
				910
				911	<div class="doc_text">
				912
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	913	<p>The C backend has numerous problems and is not being actively maintained.
				914	Depending on it for anything serious is not advised.</p>
				915
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	916	<ul>
Chris Lattner	5733b27	2008-06-05 06:35:40 +0000	[diff] [blame]	917	<li><a href="http://llvm.org/PR802">The C backend has only basic support for
				918	inline assembly code</a>.</li>
Chris Lattner	725a0d8	2007-09-26 06:01:35 +0000	[diff] [blame]	919	<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
				920	C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif	4906abe	2009-03-02 12:02:51 +0000	[diff] [blame]	921	C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sands	f74c0cc	2008-02-10 13:40:55 +0000	[diff] [blame]	922	<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands	50723a9	2009-02-25 11:51:54 +0000	[diff] [blame]	923	<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner	2629922	2006-11-18 07:51:14 +0000	[diff] [blame]	924	</ul>
				925
				926	</div>
John Criswell	c0c186d	2005-11-08 21:11:33 +0000	[diff] [blame]	927
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	928
				929	<!-- ======================================================================= -->
				930	<div class="doc_subsection">
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	931	<a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	932	</div>
Chris Lattner	47588f9	2003-10-02 05:07:23 +0000	[diff] [blame]	933
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	934	<div class="doc_text">
Chris Lattner	c5d658a	2006-03-03 00:34:26 +0000	[diff] [blame]	935
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	936	<p>llvm-gcc is generally very stable for the C family of languages. The only
				937	major language feature of GCC not supported by llvm-gcc is the
				938	<tt>__builtin_apply</tt> family of builtins. However, some extensions
				939	are only supported on some targets. For example, trampolines are only
				940	supported on some targets (these are used when you take the address of a
				941	nested function).</p>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	942
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	943	<p>Fortran support generally works, but there are still several unresolved bugs
				944	in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
				945	tools/gfortran component for details. Note that llvm-gcc is missing major
				946	Fortran performance work in the frontend and library that went into GCC after
				947	4.2. If you are interested in Fortran, we recommend that you consider using
				948	<a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	949
Chris Lattner	3016ee9	2010-09-29 05:34:42 +0000	[diff] [blame]	950	<p>The llvm-gcc 4.2 Ada compiler has basic functionality. However, this is not a
				951	mature technology, and problems should be expected. For example:</p>
Chris Lattner	2b659ef	2008-02-12 06:29:45 +0000	[diff] [blame]	952	<ul>
Duncan Sands	27aff87	2008-06-08 20:18:35 +0000	[diff] [blame]	953	<li>The Ada front-end currently only builds on X86-32. This is mainly due
John Criswell	524a5dd	2009-03-02 15:28:15 +0000	[diff] [blame]	954	to lack of trampoline support (pointers to nested functions) on other platforms.
				955	However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner	2b659ef	2008-02-12 06:29:45 +0000	[diff] [blame]	956	which does support trampolines.</li>
				957	<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sands	326a498	2009-02-25 11:59:06 +0000	[diff] [blame]	958	This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
				959	exception handling, which is used internally by the compiler.
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	960	Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands	978bcee	2008-10-13 17:27:23 +0000	[diff] [blame]	961	<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
				962	and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands	326a498	2009-02-25 11:59:06 +0000	[diff] [blame]	963	(c380004 also fails with gcc-4.2 mainline).
				964	If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
				965	causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sands	dd3e672	2009-03-02 16:35:57 +0000	[diff] [blame]	966	<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	967	<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattner	2b659ef	2008-02-12 06:29:45 +0000	[diff] [blame]	968	<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
Chris Lattner	61358ab	2009-10-13 17:48:04 +0000	[diff] [blame]	969	crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattner	2b659ef	2008-02-12 06:29:45 +0000	[diff] [blame]	970	<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
				971	or finish at a non-byte offset</a> in a record. Workaround: do not pack records
				972	or use representation clauses that result in a field of a non-discrete type
				973	starting or finishing in the middle of a byte.</li>
Chris Lattner	e6e1b35	2008-06-08 21:19:07 +0000	[diff] [blame]	974	<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
				975	'main' as generated by the Ada binder to be invalid</a>.
				976	Workaround: hand edit the file to use pointers for <tt>argv</tt> and
				977	<tt>envp</tt> rather than integers.</li>
				978	<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
				979	ignored</a>.</li>
Chris Lattner	2b659ef	2008-02-12 06:29:45 +0000	[diff] [blame]	980	</ul>
				981	</div>
				982
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	983	<!-- *********************************************************************** -->
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	984	<div class="doc_section">
				985	<a name="additionalinfo">Additional Information</a>
				986	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	987	<!-- *********************************************************************** -->
				988
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	989	<div class="doc_text">
				990
Chris Lattner	416db10	2005-05-16 17:13:10 +0000	[diff] [blame]	991	<p>A wide variety of additional information is available on the <a
Chris Lattner	b4b0ce7	2007-05-18 00:44:29 +0000	[diff] [blame]	992	href="http://llvm.org">LLVM web page</a>, in particular in the <a
				993	href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer	669ed45	2007-07-09 08:04:31 +0000	[diff] [blame]	994	contains versions of the API documentation which is up-to-date with the
				995	Subversion version of the source code.
Misha Brukman	109d9e8	2005-03-30 19:14:24 +0000	[diff] [blame]	996	You can access versions of these documents specific to this release by going
				997	into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	998
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	999	<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]	1000	us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner	5eccca4	2003-12-12 21:22:16 +0000	[diff] [blame]	1001	lists</a>.</p>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1002
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1003	</div>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1004
				1005	<!-- *********************************************************************** -->
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1006
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1007	<hr>
Misha Brukman	2061e89	2003-11-22 01:23:39 +0000	[diff] [blame]	1008	<address>
Misha Brukman	38847d5	2003-12-21 22:53:21 +0000	[diff] [blame]	1009	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	1010	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]	1011	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	1012	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]	1013
Chris Lattner	b4b0ce7	2007-05-18 00:44:29 +0000	[diff] [blame]	1014	<a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1015	Last modified: $Date$
Misha Brukman	2061e89	2003-11-22 01:23:39 +0000	[diff] [blame]	1016	</address>
Chris Lattner	79c3fe1	2003-10-02 04:57:28 +0000	[diff] [blame]	1017
Misha Brukman	500bc30	2003-11-22 00:38:41 +0000	[diff] [blame]	1018	</body>
				1019	</html>