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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 1efe27eb797144ba4488e7b771fdd9611ee5cd0e / . / docs / ReleaseNotes.html
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Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]8 <title>LLVM 2.9 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]9</head>
10<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]12<h1 class="doc_title">LLVM 2.9 Release Notes</h1>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]13
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]14<img align=right src="http://llvm.org/img/DragonSmall.png"
Gabor Greifee2187a2010-04-22 10:21:43 +0000[diff] [blame]15 width="136" height="136" alt="LLVM Dragon Logo">
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]16
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]17<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]18 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]19 <li><a href="#subproj">Sub-project Status Update</a></li>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]20 <li><a href="#externalproj">External Projects Using LLVM 2.9</a></li>
21 <li><a href="#whatsnew">What's New in LLVM 2.9?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]22 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]23 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]24 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]25</ol>
26
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]27<div class="doc_author">
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]28 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]29</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]30
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]31<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.9
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]32release.<br>
33You may prefer the
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]34<a href="http://llvm.org/releases/2.8/docs/ReleaseNotes.html">LLVM 2.8
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]35Release Notes</a>.</h1>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]36
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]37<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]38<h1>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]39 <a name="intro">Introduction</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]40</h1>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]41<!-- *********************************************************************** -->
42
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]43<div class="doc_text">
44
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]45<p>This document contains the release notes for the LLVM Compiler
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]46Infrastructure, release 2.9. Here we describe the status of LLVM, including
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]47major improvements from the previous release and significant known problems.
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]48All LLVM releases may be downloaded from the <a
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]49href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]50
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]51<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]52release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]53web site</a>. If you have questions or comments, the <a
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000[diff] [blame]54href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's
55Mailing List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]56
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]57<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]58main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greiffa933f82008-10-14 11:00:32 +0000[diff] [blame]59current one. To see the release notes for a specific release, please see the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]60<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]61
62</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]63
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame]64<!-- Features that need text if they're finished for 3.1:
65 ARM EHABI
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]66 combiner-aa?
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]67 strong phi elim
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]68 loop dependence analysis
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]69 CorrelatedValuePropagation
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame]70 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]71 -->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]72
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]73<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]74<h1>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]75 <a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]76</h1>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]77<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]78
79<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]80<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]81The LLVM 2.9 distribution currently consists of code from the core LLVM
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]82repository (which roughly includes the LLVM optimizers, code generators
83and supporting tools), the Clang repository and the llvm-gcc repository. In
84addition to this code, the LLVM Project includes other sub-projects that are in
85development. Here we include updates on these subprojects.
Bill Wendling63d8c552009-03-02 04:28:57 +0000[diff] [blame]86</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]87
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]88</div>
89
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]90
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]91<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]92<h2>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]93<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]94</h2>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]95
96<div class="doc_text">
97
Chris Lattner095539f2010-04-26 17:42:18 +0000[diff] [blame]98<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
99C++, and Objective-C languages. Clang aims to provide a better user experience
100through expressive diagnostics, a high level of conformance to language
101standards, fast compilation, and low memory use. Like LLVM, Clang provides a
102modular, library-based architecture that makes it suitable for creating or
103integrating with other development tools. Clang is considered a
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]104production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]105(32- and 64-bit), and for darwin/arm targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]106
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]107<p>In the LLVM 2.9 time-frame, the Clang team has made many improvements in C,
108C++ and Objective-C support. C++ support is now generally rock solid, has
109been exercised on a broad variety of code, and has several new C++'0x features
110implemented (such as rvalue references and variadic templates). LLVM 2.9 has
111also brought in a large range of bug fixes and minor features (e.g. __label__
112support), and is much more compatible with the Linux Kernel.</p>
113
114<p>If Clang rejects your code that is built with another compiler, please take a
115look at the <a href="http://clang.llvm.org/compatibility.html">language
116compatibility</a> guide to make sure the issue isn't intentional or a known
117issue.
118</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]119
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]120<ul>
121</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]122</div>
123
124<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]125<h2>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]126<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]127</h2>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]128
129<div class="doc_text">
130<p>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]131<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
132<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
133optimizers and code generators with LLVM's.
134Currently it requires a patched version of gcc-4.5.
135The plugin can target the x86-32 and x86-64 processor families and has been
136used successfully on the Darwin, FreeBSD and Linux platforms.
137The Ada, C, C++ and Fortran languages work well.
138The plugin is capable of compiling plenty of Obj-C, Obj-C++ and Java but it is
139not known whether the compiled code actually works or not!
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]140</p>
141
142<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]143The 2.9 release has the following notable changes:
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]144<ul>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]145<li>The plugin is much more stable when compiling Fortran.</li>
146<li>Inline asm where an asm output is tied to an input of a different size is
147now supported in many more cases.</li>
148<li>Basic support for the __float128 type was added. It is now possible to
149generate LLVM IR from programs using __float128 but code generation does not
150work yet.</li>
151<li>Compiling Java programs no longer systematically crashes the plugin.</li>
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]152</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]153
154</div>
155
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]156<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]157<h2>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]158<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]159</h2>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]160
161<div class="doc_text">
162<p>
163The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
164is a simple library that provides an implementation of the low-level
165target-specific hooks required by code generation and other runtime components.
166For example, when compiling for a 32-bit target, converting a double to a 64-bit
167unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
168function. The compiler-rt library provides highly optimized implementations of
169this and other low-level routines (some are 3x faster than the equivalent
170libgcc routines).</p>
171
172<p>
173All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]174License, a "BSD-style" license.
175
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]176compiler_rt is now dual licensed under MIT and UIUC license
177
178Several minor changes for better ARM support.
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]179
180New in LLVM 2.9, UPDATE</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]181
182</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]183
184<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]185<h2>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]186<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]187</h2>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]188
189<div class="doc_text">
190<p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]191<a href="http://lldb.llvm.org/">LLDB</a> is a brand new member of the LLVM
192umbrella of projects. LLDB is a next generation, high-performance debugger. It
193is built as a set of reusable components which highly leverage existing
194libraries in the larger LLVM Project, such as the Clang expression parser, the
195LLVM disassembler and the LLVM JIT.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]196
197<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]198LLDB is in early development and not included as part of the LLVM 2.9 release,
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]199
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]200
201
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]202<!--
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]203but is mature enough to support basic debugging scenarios on Mac OS X in C,
204Objective-C and C++. We'd really like help extending and expanding LLDB to
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]205support new platforms, new languages, new architectures, and new features.-->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]206</p>
207
208</div>
209
210<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]211<h2>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]212<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]213</h2>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]214
215<div class="doc_text">
216<p>
Tobias Grossercdce44b2010-10-06 21:07:30 +0000[diff] [blame]217<a href="http://libcxx.llvm.org/">libc++</a> is another new member of the LLVM
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]218family. It is an implementation of the C++ standard library, written from the
219ground up to specifically target the forthcoming C++'0X standard and focus on
220delivering great performance.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]221
222<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]223As of the LLVM 2.9 release, UPDATE!
224
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]225libc++ is now dual licensed under MIT and UIUC license
226
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]227<!--libc++ is virtually feature complete, but would
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]228benefit from more testing and better integration with Clang++. It is also
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]229looking forward to the C++ committee finalizing the C++'0x standard.-->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]230</p>
231
232</div>
233
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]234
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]235
236<!--=========================================================================-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]237<!--
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]238<h2>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]239<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]240</h2>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]241
242<div class="doc_text">
243<p>
244<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
245programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
246through the application and records state transitions that lead to fault
247states. This allows it to construct testcases that lead to faults and can even
248be used to verify some algorithms.
249</p>
250
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]251<p>UPDATE!</p>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]252</div>-->
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]253
254
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]255<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]256<h1>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]257 <a name="externalproj">External Open Source Projects Using LLVM 2.9</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]258</h1>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]259<!-- *********************************************************************** -->
260
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]261<div class="doc_text">
262
263<p>An exciting aspect of LLVM is that it is used as an enabling technology for
264 a lot of other language and tools projects. This section lists some of the
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]265 projects that have already been updated to work with LLVM 2.9.</p>
Chris Lattner7c8e7962010-04-26 17:38:10 +0000[diff] [blame]266</div>
267
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]268
269
Chris Lattnere0518442010-10-01 06:34:49 +0000[diff] [blame]270
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]271<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]272<h1>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]273 <a name="whatsnew">What's New in LLVM 2.9?</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]274</h1>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]275<!-- *********************************************************************** -->
276
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]277<div class="doc_text">
278
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]279<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]280minor improvements. Some of the major improvements and new features are listed
281in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]282</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]283
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]284</div>
285
286<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]287<h2>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]288<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]289</h2>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]290
291<div class="doc_text">
292
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]293<p>LLVM 2.9 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]294
295<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]296
297<li>
298 TBAA: On by default in clang. Disable it with -fno-strict-aliasing.
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]299 Could be more aggressive for structs.
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]300</li>
301
302<li>New Nvidia PTX backend, not generally useful in 2.9 though.</li>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]303
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]304<li>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]305Much better debug info generated, particularly in optimized code situations.
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]306</li>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]307
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]308<li>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]309inline asm multiple alternative constraint support.
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]310</li>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]311
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]312<li>
313 New naming rules in coding standards: CodingStandards.html#ll_naming
314</li>
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]315
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]316</ul>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]317
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]318</div>
319
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]320<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]321<h2>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]322<a name="coreimprovements">LLVM IR and Core Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]323</h2>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]324
325<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]326<p>LLVM IR has several new features for better support of new targets and that
327expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]328
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]329<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]330<li>udiv, ashr, lshr, shl now have exact and nuw/nsw bits:
331 PR8862 / LangRef.html</li>
332
333 unnamed_addr + PR8927
334
335 new 'hotpatch' attribute: LangRef.html#fnattrs
336
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]337</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]338
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]339</div>
340
341<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]342<h2>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]343<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]344</h2>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]345
346<div class="doc_text">
347
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]348<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattnerf3013872008-10-13 21:50:36 +0000[diff] [blame]349release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]350
351<ul>
Rafael Espindolaa26f36c2011-03-18 04:07:44 +0000[diff] [blame]352 <li>LTO has been improved to use MC for parsing inline asm and now
353 can build large programs like Firefox 4 on both OS X and Linux.</li>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]354
355
356 LoopIdiom: memset/memcpy formation and memset_pattern on darwin. Build with
357 -ffreestanding or -fno-builtin if your memcpy is being compiled into infinite
358 recursion.
359
360 TargetLibraryInfo
361
362 EarlyCSE pass.
363 LoopInstSimplify pass.
364
365New <a href="WritingAnLLVMPass.html#RegionPass">RegionPass</a> infrastructure
366 for region-based optimizations.
367
368 Can optimize printf to iprintf when no floating point is used, for embedded
369 targets with smaller iprintf implementation.
370
371Speedups to various mid-level passes:
372 GVN is much faster on functions with deep dominator trees / lots of BBs.
373 DomTree and DominatorFrontier are much faster to compute, and preserved by
374 more passes (so they are computed less often)
375 SRoA is also much faster and doesn't use DominanceFrontier.
376
377DSE is more aggressive with stores of different types: e.g. a large store
378 following a small one to the same address.
379
380
381We now optimize various idioms for overflow detection into check of the flag
382 register on various CPUs, e.g.:
383 unsigned long t = a+b;
384 if (t &lt; a) ...
385 into:
386 addq %rdi, %rbx
387 jno LBB0_2
388
389
Chris Lattner11b66112010-10-04 02:42:39 +0000[diff] [blame]390</ul>
391
392<!--
393<p>In addition to these features that are done in 2.8, there is preliminary
394 support in the release for Type Based Alias Analysis
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]395 Preliminary work on TBAA but not usable in 2.8.
396 New CorrelatedValuePropagation pass, not on by default in 2.8 yet.
Chris Lattner11b66112010-10-04 02:42:39 +0000[diff] [blame]397-->
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]398
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]399</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]400
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]401<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]402<h2>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]403<a name="mc">MC Level Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]404</h2>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]405
406<div class="doc_text">
407<p>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]408The LLVM Machine Code (aka MC) subsystem was created to solve a number
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]409of problems in the realm of assembly, disassembly, object file format handling,
410and a number of other related areas that CPU instruction-set level tools work
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]411in.</p>
412
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]413<ul>
Rafael Espindolaa26f36c2011-03-18 04:07:44 +0000[diff] [blame]414 <li>MC is now used by default for ELF systems on x86 and
415 x86-64.</li>
416 <li>MC supports and CodeGen uses the <tt>.loc</tt> directives for
417 producing line number debug info. This produces more compact line
418 tables.</li>
419 <li>MC supports the <tt>.cfi_*</tt> directives for producing DWARF
420 frame information, but it is still not used by CodeGen by default.</li>
421 <li>COFF support?</li>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]422
423
424 MC Assembler: X86 now generates much better diagnostics for common errors,
425 is much faster at matching instructions, is much more bug-compatible with
426 the GAS assembler, and is now generally useful for a broad range of X86
427 assembly.
428
429
430 ELF MC support: on by default in clang. There are still known missing features
431 for human written assembly.
432
433
434 Some basic <a href="CodeGenerator.html#mc">internals documentation</a> for MC.
435
436 MC Assembler support for .file and .loc.
437
438 tblgen support for assembler aliases: <a
439 href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
440
441 Win32 PE-COFF support in the MC assembler has made a lot of progress in the 2.9
442 timeframe, but is still not generally useful. Please see
443 "http://llvm.org/bugs/showdependencytree.cgi?id=9100&amp;hide_resolved=1" for open bugs?
444
445
446 lib/Object and llvm-objdump
447 Experimental format independent object file manipulation library.
448 * Supports PE/COFF and ELF.
449 * llvm-nm extended to work with object files. Exactly matches
450 binutils-nm for the files I've tested.
451 * llvm-objdump added with support for disassembly (no relocations displayed).
452
453
454
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]455</ul>
456
457<p>For more information, please see the <a
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]458href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
459LLVM MC Project Blog Post</a>.
460</p>
461
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]462</div>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]463
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]464<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]465<h2>
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]466<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]467</h2>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]468
469<div class="doc_text">
470
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]471<p>We have put a significant amount of work into the code generator
472infrastructure, which allows us to implement more aggressive algorithms and make
473it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]474
475<ul>
Chris Lattner3bdcda12010-10-04 03:58:12 +0000[diff] [blame]476<!-- SplitKit -->
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]477
478<li>The pre-register-allocation (preRA) instruction scheduler models register
479 pressure much more accurately in some cases. This allows the adoption of more
480 aggressive scheduling heuristics.
481</li>
482
483 LiveDebugVariables is a new pass that keeps track of debugging information for
484 user variables that are kept in registers in optimized builds.
485
486
487Scheduler now models operand latency and pipeline forwarding.
488
489Major regalloc rewrite, not on by default for 2.9 and not advised to use it.
490 * New basic register allocator that can be used as a safe fallback when
491 debugging. Enable with -regalloc=basic.
492 * New infrastructure for live range splitting. SplitKit can break a live
493 interval into smaller pieces while preserving SSA form, and SpillPlacement
494 can help find the best split points. This is a work in progress so the API
495 is changing quickly.
496 * The inline spiller has learned to clean up after live range splitting. It
497 can hoist spills out of loops, and it can eliminate redundant spills.
498 Rematerialization works with live range splitting.
499 * New greedy register allocator using live range splitting. This will be the
500 default register allocator in the next LLVM release, but it is not turned on
501 by default in 2.9.
502
503
504
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]505</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]506</div>
507
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]508<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]509<h2>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]510<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]511</h2>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]512
513<div class="doc_text">
Chris Lattner7714c912010-10-04 04:39:25 +0000[diff] [blame]514<p>New features and major changes in the X86 target include:
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]515</p>
516
517<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]518<li>
519X86: Reimplemented all of MMX to introduce a new LLVM IR x86_mmx type. Now
520 random types like &lt;2 x i32&gt; are not iseld to mmx without emms. The
521 -disable-mmx flag is gone now.
522</li>
523
524 <li>
525X86 support for FS/GS relative loads and stores using address space 256/257 are
526 reliable now.
527 </li>
528
529 <li>
530X86: Much better codegen for several cases using adc/sbb instead of cmovs for
531 conditional increment and other idioms.
532 </li>
533
534 <li>
535 The X86 backend has adopted a new preRA scheduling
536 mode, "list-ilp", to shorten the height of instruction schedules
537 without inducing register spills.
538 </li>
539
540 MC assembler support for 3dNow! and 3DNowA instructions.
541
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]542 <li>Several bugs have been fixed for Windows x64 code generator.</li>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]543</ul>
544
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]545</div>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]546
547<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]548<h2>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]549<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]550</h2>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]551
552<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]553<p>New features of the ARM target include:
554</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]555
556<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]557<li>ARM Fast ISel</li>
558<li>ARM: New code placement pass.</li>
559<li>ARM: Improved code generation for Cortex-A8 and Cortex-A9 CPUs.</li>
560<li>ARM: __builtin_prefetch turns into prefetch instructions.</li>
561<li>Countless ARM microoptimizations.</li>
562
563<li> The ARM backend preRA scheduler now models machine resources at cycle
564 granularity. This allows the scheduler to both accurately model
565 instruction latency and avoid overcommitting functional units.</li>
566
567
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]568</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]569</div>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]570
571<!--=========================================================================-->
572<h2>
573<a name="OtherTS">Other Target Specific Improvements</a>
574</h2>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]575
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]576<div class="doc_text">
577<ul>
578 PPC: Switched to MCInstPrinter, and MCCodeEmitter. Ready to implement support
579 for directly writing out mach-o object files, but noone seems interested.
580
581 MicroBlaze: major updates for aggressive delay slot filler, MC-based assembly
582 printing, assembly instruction parsing, ELF .o file emission, and MC
583 instruction disassembler.
584
585 SPARC: Many improvements, including using the Y registers for multiplications
586 and addition of a simple delay slot filler.
587
588</ul>
589</div>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]590
591<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]592<h2>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]593<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]594</h2>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]595
596<div class="doc_text">
597
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]598<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]599on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]600from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]601
602<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]603 last release for llvm-gcc
604
605- DIBuilder provides simpler interface for front ends like Clang to encode debug info in LLVM IR.
606 - This interface hides implementation details (e.g. DIDerivedType, existence of compile unit etc..) that any front end should not know about.
607 For example, DIFactory DebugFactory;
608 Ty = DebugFactory.CreateDerivedType(DW_TAG_volatile_type,
609 findRegion(TYPE_CONTEXT(type)),
610 StringRef(),
611 getOrCreateFile(main_input_filename),
612 0 /*line no*/,
613 NodeSizeInBits(type),
614 NodeAlignInBits(type),
615 0 /*offset */,
616 0 /* flags */,
617 MainTy);
618 can be replaced by
619 DbgTy = DBuilder.createQualifiedType(DW_TAG_volatile_type, MainTy);
620DIFactory is gone now.
621
622
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]623
Chris Lattnerbb117712010-10-04 01:29:06 +0000[diff] [blame]624
625
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]626
627 LoopIndexSplit pass was removed, unmaintained.
628 LiveValues, SimplifyHalfPowrLibCalls, and GEPSplitter were removed.
629 Removed the PartialSpecialization pass, it was unmaintained and buggy.
630
631 DIFactory removed, use DIBuilder instead.
632
633 Triple::normalize is new, llvm triples are always stored in normalized form internally.
634
635 Triple x86_64--mingw64 is obsoleted. Use x86_64--mingw32 instead.
636
637 PointerTracking has been removed from mainline, moved to ClamAV.
638
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]639</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]640
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]641</div>
642
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]643<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]644<h2>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]645<a name="api_changes">Internal API Changes</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]646</h2>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]647
648<div class="doc_text">
649
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]650<p>In addition, many APIs have changed in this release. Some of the major
651 LLVM API changes are:</p>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]652
653<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame^]654
655 include/llvm/System merged into include/llvm/Support.
656
657
658 APInt API changes, see PR5207.
659
660 MVT::Flag renamed to MVT::Glue
661
662
663 error_code + libsystem + PathV2 changes
664 The system_error header from C++0x was added.
665 * Use if (error_code ec = function()) to check for error conditions
666 from functions which return it.
667 * error_code::message returns a human readable description of the error.
668
669 PathV1 has been deprecated in favor of PathV2 (sorry I didn't finish
670 this before the release).
671 * No Path class, use a r-value convertible to a twine instead.
672 * Assumes all paths are UTF-8.
673
674
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]675</ul>
676</div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]677
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]678<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]679<h1>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]680 <a name="knownproblems">Known Problems</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]681</h1>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]682<!-- *********************************************************************** -->
683
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]684<div class="doc_text">
685
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]686<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000[diff] [blame]687listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]688href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]689there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]690
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]691</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]692
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]693<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]694<h2>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]695 <a name="experimental">Experimental features included with this release</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]696</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]697
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]698<div class="doc_text">
699
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]700<p>The following components of this LLVM release are either untested, known to
701be broken or unreliable, or are in early development. These components should
702not be relied on, and bugs should not be filed against them, but they may be
703useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]704components, please contact us on the <a
705href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]706
707<ul>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]708<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ
Chris Lattnerbb117712010-10-04 01:29:06 +0000[diff] [blame]709 and XCore backends are experimental.</li>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]710<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]711 other than darwin-i386 and darwin-x86_64. FIXME: Not true on ELF anymore?</li>
712
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]713</ul>
714
715</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]716
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]717<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]718<h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]719 <a name="x86-be">Known problems with the X86 back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]720</h2>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]721
722<div class="doc_text">
723
724<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000[diff] [blame]725 <li>The X86 backend does not yet support
726 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
727 floating point stack</a>. It supports the 'f' and 't' constraints, but not
728 'u'.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]729 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]730 <tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]731 argument constructs on X86-64 by lowering them manually.</li>
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]732 <li>Windows x64 (aka Win64) code generator has a few issues.
733 <ul>
734 <li>llvm-gcc cannot build the mingw-w64 runtime currently
735 due to lack of support for the 'u' inline assembly
736 constraint and for X87 floating point inline assembly.</li>
737 <li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt>
738 due to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
739 It is fixed in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
740 <li>Miss-aligned MOVDQA might crash your program. It is due to
741 <a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>,
742 lack of handling aligned internal globals.</li>
743 </ul>
744 </li>
745
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]746</ul>
747
748</div>
749
750<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]751<h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]752 <a name="ppc-be">Known problems with the PowerPC back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]753</h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]754
755<div class="doc_text">
756
757<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]758<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]759compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]760</ul>
761
762</div>
763
764<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]765<h2>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]766 <a name="arm-be">Known problems with the ARM back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]767</h2>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]768
769<div class="doc_text">
770
771<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]772<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]773processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]774results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]775<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]776</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]777</ul>
778
779</div>
780
781<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]782<h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]783 <a name="sparc-be">Known problems with the SPARC back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]784</h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]785
786<div class="doc_text">
787
788<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]789<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]790 support the 64-bit SPARC ABI (-m64).</li>
791</ul>
792
793</div>
794
795<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]796<h2>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]797 <a name="mips-be">Known problems with the MIPS back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]798</h2>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]799
800<div class="doc_text">
801
802<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]803<li>64-bit MIPS targets are not supported yet.</li>
804</ul>
805
806</div>
807
808<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]809<h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]810 <a name="alpha-be">Known problems with the Alpha back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]811</h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]812
813<div class="doc_text">
814
815<ul>
816
817<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
818appropriate nops inserted to ensure restartability.</li>
819
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]820</ul>
821</div>
822
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]823<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]824<h2>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]825 <a name="c-be">Known problems with the C back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]826</h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]827
828<div class="doc_text">
829
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]830<p>The C backend has numerous problems and is not being actively maintained.
831Depending on it for anything serious is not advised.</p>
832
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]833<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]834<li><a href="http://llvm.org/PR802">The C backend has only basic support for
835 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]836<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
837 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif4906abe2009-03-02 12:02:51 +0000[diff] [blame]838 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]839<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000[diff] [blame]840<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]841</ul>
842
843</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]844
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]845
846<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]847<h2>
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]848 <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]849</h2>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]850
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]851<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]852
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]853<p>llvm-gcc is generally very stable for the C family of languages. The only
854 major language feature of GCC not supported by llvm-gcc is the
855 <tt>__builtin_apply</tt> family of builtins. However, some extensions
856 are only supported on some targets. For example, trampolines are only
857 supported on some targets (these are used when you take the address of a
858 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]859
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]860<p>Fortran support generally works, but there are still several unresolved bugs
861 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
862 tools/gfortran component for details. Note that llvm-gcc is missing major
863 Fortran performance work in the frontend and library that went into GCC after
864 4.2. If you are interested in Fortran, we recommend that you consider using
865 <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]866
Duncan Sands3af96332010-10-04 10:06:56 +0000[diff] [blame]867<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
868actively maintained. If you are interested in Ada, we recommend that you
869consider using <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]870</div>
871
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]872<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]873<h1>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]874 <a name="additionalinfo">Additional Information</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]875</h1>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]876<!-- *********************************************************************** -->
877
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]878<div class="doc_text">
879
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]880<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]881href="http://llvm.org">LLVM web page</a>, in particular in the <a
882href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]883contains versions of the API documentation which is up-to-date with the
884Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]885You can access versions of these documents specific to this release by going
886into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]887
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]888<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]889us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]890lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]891
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]892</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]893
894<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]895
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]896<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]897<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]898 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]899 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]900 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]901 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]902
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]903 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]904 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]905</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]906
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]907</body>
908</html>