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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
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]12<div class="doc_title">LLVM 2.9 Release Notes</div>
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<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]38<div class="doc_section">
39 <a name="intro">Introduction</a>
40</div>
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 Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]63
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]64<!--
65Almost dead code.
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]66 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.0.
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]67-->
68
69
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]70<!-- Features that need text if they're finished for 3.0:
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]71 combiner-aa?
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]72 strong phi elim
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]73 loop dependence analysis
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]74 CorrelatedValuePropagation
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]75 -->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]76
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]77<!-- *********************************************************************** -->
78<div class="doc_section">
79 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]80</div>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]81<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]82
83<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]84<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]85The LLVM 2.9 distribution currently consists of code from the core LLVM
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]86repository (which roughly includes the LLVM optimizers, code generators
87and supporting tools), the Clang repository and the llvm-gcc repository. In
88addition to this code, the LLVM Project includes other sub-projects that are in
89development. Here we include updates on these subprojects.
Bill Wendling63d8c552009-03-02 04:28:57 +0000[diff] [blame]90</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]91
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]92</div>
93
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]94
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]95<!--=========================================================================-->
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]96<div class="doc_subsection">
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]97<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]98</div>
99
100<div class="doc_text">
101
Chris Lattner095539f2010-04-26 17:42:18 +0000[diff] [blame]102<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
103C++, and Objective-C languages. Clang aims to provide a better user experience
104through expressive diagnostics, a high level of conformance to language
105standards, fast compilation, and low memory use. Like LLVM, Clang provides a
106modular, library-based architecture that makes it suitable for creating or
107integrating with other development tools. Clang is considered a
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]108production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
109(32- and 64-bit), and for darwin-arm targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]110
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]111<p>In the LLVM 2.9 time-frame, the Clang team has made many improvements in C,
112C++ and Objective-C support. C++ support is now generally rock solid, has
113been exercised on a broad variety of code, and has several new C++'0x features
114implemented (such as rvalue references and variadic templates). LLVM 2.9 has
115also brought in a large range of bug fixes and minor features (e.g. __label__
116support), and is much more compatible with the Linux Kernel.</p>
117
118<p>If Clang rejects your code that is built with another compiler, please take a
119look at the <a href="http://clang.llvm.org/compatibility.html">language
120compatibility</a> guide to make sure the issue isn't intentional or a known
121issue.
122</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]123
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]124<ul>
125</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]126</div>
127
128<!--=========================================================================-->
129<div class="doc_subsection">
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]130<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]131</div>
132
133<div class="doc_text">
134<p>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]135<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
136<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
137optimizers and code generators with LLVM's.
138Currently it requires a patched version of gcc-4.5.
139The plugin can target the x86-32 and x86-64 processor families and has been
140used successfully on the Darwin, FreeBSD and Linux platforms.
141The Ada, C, C++ and Fortran languages work well.
142The plugin is capable of compiling plenty of Obj-C, Obj-C++ and Java but it is
143not known whether the compiled code actually works or not!
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]144</p>
145
146<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]147The 2.9 release has the following notable changes:
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]148<ul>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]149<li>The plugin is much more stable when compiling Fortran.</li>
150<li>Inline asm where an asm output is tied to an input of a different size is
151now supported in many more cases.</li>
152<li>Basic support for the __float128 type was added. It is now possible to
153generate LLVM IR from programs using __float128 but code generation does not
154work yet.</li>
155<li>Compiling Java programs no longer systematically crashes the plugin.</li>
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]156</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]157
158</div>
159
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]160<!--=========================================================================-->
161<div class="doc_subsection">
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]162<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
163</div>
164
165<div class="doc_text">
166<p>
167The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
168is a simple library that provides an implementation of the low-level
169target-specific hooks required by code generation and other runtime components.
170For example, when compiling for a 32-bit target, converting a double to a 64-bit
171unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
172function. The compiler-rt library provides highly optimized implementations of
173this and other low-level routines (some are 3x faster than the equivalent
174libgcc routines).</p>
175
176<p>
177All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]178License, a "BSD-style" license.
179
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]180compiler_rt is now dual licensed under MIT and UIUC license
181
182Several minor changes for better ARM support.
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]183
184New in LLVM 2.9, UPDATE</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]185
186</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]187
188<!--=========================================================================-->
189<div class="doc_subsection">
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]190<a name="lldb">LLDB: Low Level Debugger</a>
191</div>
192
193<div class="doc_text">
194<p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]195<a href="http://lldb.llvm.org/">LLDB</a> is a brand new member of the LLVM
196umbrella of projects. LLDB is a next generation, high-performance debugger. It
197is built as a set of reusable components which highly leverage existing
198libraries in the larger LLVM Project, such as the Clang expression parser, the
199LLVM disassembler and the LLVM JIT.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]200
201<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]202LLDB 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]203
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]204
205
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]206<!--
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]207but is mature enough to support basic debugging scenarios on Mac OS X in C,
208Objective-C and C++. We'd really like help extending and expanding LLDB to
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]209support new platforms, new languages, new architectures, and new features.-->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]210</p>
211
212</div>
213
214<!--=========================================================================-->
215<div class="doc_subsection">
216<a name="libc++">libc++: C++ Standard Library</a>
217</div>
218
219<div class="doc_text">
220<p>
Tobias Grossercdce44b2010-10-06 21:07:30 +0000[diff] [blame]221<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]222family. It is an implementation of the C++ standard library, written from the
223ground up to specifically target the forthcoming C++'0X standard and focus on
224delivering great performance.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]225
226<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]227As of the LLVM 2.9 release, UPDATE!
228
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]229libc++ is now dual licensed under MIT and UIUC license
230
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]231<!--libc++ is virtually feature complete, but would
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]232benefit from more testing and better integration with Clang++. It is also
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]233looking forward to the C++ committee finalizing the C++'0x standard.-->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]234</p>
235
236</div>
237
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]238
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]239
240<!--=========================================================================-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]241<!--
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]242<div class="doc_subsection">
243<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
244</div>
245
246<div class="doc_text">
247<p>
248<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
249programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
250through the application and records state transitions that lead to fault
251states. This allows it to construct testcases that lead to faults and can even
252be used to verify some algorithms.
253</p>
254
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]255<p>UPDATE!</p>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]256</div>-->
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]257
258
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]259<!-- *********************************************************************** -->
260<div class="doc_section">
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]261 <a name="externalproj">External Open Source Projects Using LLVM 2.9</a>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]262</div>
263<!-- *********************************************************************** -->
264
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]265<div class="doc_text">
266
267<p>An exciting aspect of LLVM is that it is used as an enabling technology for
268 a lot of other language and tools projects. This section lists some of the
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]269 projects that have already been updated to work with LLVM 2.9.</p>
Chris Lattner7c8e7962010-04-26 17:38:10 +0000[diff] [blame]270</div>
271
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]272
273
Chris Lattnere0518442010-10-01 06:34:49 +0000[diff] [blame]274
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]275<!-- *********************************************************************** -->
276<div class="doc_section">
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]277 <a name="whatsnew">What's New in LLVM 2.9?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]278</div>
279<!-- *********************************************************************** -->
280
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]281<div class="doc_text">
282
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]283<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]284minor improvements. Some of the major improvements and new features are listed
285in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]286</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]287
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]288</div>
289
290<!--=========================================================================-->
291<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]292<a name="majorfeatures">Major New Features</a>
293</div>
294
295<div class="doc_text">
296
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]297<p>LLVM 2.9 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]298
299<ul>
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]300<li><pre>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]301 last release for llvm-gcc
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]302TBAA: On by default in clang. Disable it with -fno-strict-aliasing.
303 Could be more aggressive for structs.
304
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]305Triple::normalize is new, llvm triples are always stored in normalized form internally.
306
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]307Triple x86_64--mingw64 is obsoleted. Use x86_64--mingw32 instead.
308
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]309MC Assembler: X86 now generates much better diagnostics for common errors,
310 is much faster at matching instructions, is much more bug-compatible with
311 the GAS assembler, and is now generally useful for a broad range of X86
312 assembly.
313
314New Nvidia PTX backend, not generally useful in 2.9 though.
315
316Much better debug info generated, particularly in optimized code situations.
317
318ARM Fast ISel
319
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]320ELF MC support: on by default in clang. There are still known missing features
321 for human written assembly.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]322
323X86: Reimplemented all of MMX to introduce a new LLVM IR x86_mmx type. Now
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]324 random types like &lt;2 x i32&gt; are not iseld to mmx without emms. The
325 -disable-mmx flag is gone now.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]326
327Some basic <a href="CodeGenerator.html#mc">internals documentation</a> for MC.
328
329MC Assembler support for .file and .loc.
330
331
332inline asm multiple alternative constraint support.
333
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]334LoopIdiom: memset/memcpy formation. Build with -ffreestanding or -fno-builtin
335 if your memcpy is being compiled into infinite recursion.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]336
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]337
338TargetLibraryInfo
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]339
340X86 support for FS/GS relative loads and stores using address space 256/257 are
341 reliable now.
342
343ARM: New code placement pass.
344
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]345unnamed_addr + PR8927
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]346
347PointerTracking has been removed from mainline, moved to ClamAV.
348
349EarlyCSE pass.
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]350LoopInstSimplify pass.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]351
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]352- DIBuilder provides simpler interface for front ends like Clang to encode debug info in LLVM IR.
353 - This interface hides implementation details (e.g. DIDerivedType, existence of compile unit etc..) that any front end should not know about.
354 For example,
355 Ty = DebugFactory.CreateDerivedType(DW_TAG_volatile_type,
356 findRegion(TYPE_CONTEXT(type)),
357 StringRef(),
358 getOrCreateFile(main_input_filename),
359 0 /*line no*/,
360 NodeSizeInBits(type),
361 NodeAlignInBits(type),
362 0 /*offset */,
363 0 /* flags */,
364 MainTy);
365 can be replaced by
366 DbgTy = DBuilder.createQualifiedType(DW_TAG_volatile_type, MainTy);
367
368PPC: Switched to MCInstPrinter, and MCCodeEmitter. Ready to implement support
369 for directly writing out mach-o object files, but noone seems interested.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]370
371ARM: Improved code generation for Cortex-A8 and Cortex-A9 CPUs.
372
373Scheduler now models operand latency and pipeline forwarding.
374
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]375error_code + libsystem + PathV2 changes
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]376 The system_error header from C++0x was added.
377 * Use if (error_code ec = function()) to check for error conditions
378 from functions which return it.
379 * error_code::message returns a human readable description of the error.
380
381 PathV1 has been deprecated in favor of PathV2 (sorry I didn't finish
382 this before the release).
383 * No Path class, use a r-value convertible to a twine instead.
384 * Assumes all paths are UTF-8.
385
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]386new macho-dump tool
387
388Major regalloc rewrite, not on by default for 2.9 and not advised to use it.
389 * New basic register allocator that can be used as a safe fallback when
390 debugging. Enable with -regalloc=basic.
391 * New infrastructure for live range splitting. SplitKit can break a live
392 interval into smaller pieces while preserving SSA form, and SpillPlacement
393 can help find the best split points. This is a work in progress so the API
394 is changing quickly.
395 * The inline spiller has learned to clean up after live range splitting. It
396 can hoist spills out of loops, and it can eliminate redundant spills.
397 Rematerialization works with live range splitting.
398 * New greedy register allocator using live range splitting. This will be the
399 default register allocator in the next LLVM release, but it is not turned on
400 by default in 2.9.
401
402ARM: __builtin_prefetch turns into prefetch instructions.
403
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]404MC assembler support for 3dNow! and 3DNowA instructions.
405
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]406tblgen support for assembler aliases: <a
407 href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
408
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]409LoopIndexSplit pass was removed, unmaintained.
410
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]411include/llvm/System merged into include/llvm/Support.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]412
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]413Win32 PE-COFF support in the MC assembler has made a lot of progress in the 2.9
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]414 timeframe, but is still not generally useful. Please see
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]415 "http://llvm.org/bugs/showdependencytree.cgi?id=9100&amp;hide_resolved=1" for open bugs?
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]416
417New <a href="WritingAnLLVMPass.html#RegionPass">RegionPass</a> infrastructure
418 for region-based optimizations.
419
420MicroBlaze: major updates for aggressive delay slot filler, MC-based assembly
421 printing, assembly instruction parsing, ELF .o file emission, and MC
422 instruction disassembler.
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]423
424Countless ARM microoptimizations.
425
426Speedups to various mid-level passes:
427 GVN is much faster on functions with deep dominator trees / lots of BBs.
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]428 DomTree and DominatorFrontier are much faster to compute, and preserved by
429 more passes (so they are computed less often)
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]430
431
432new 'hotpatch' attribute: LangRef.html#fnattrs
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]433
434APInt API changes, see PR5207.
435
436DSE is more aggressive with stores of different types: e.g. a large store
437 following a small one to the same address.
438
439New naming rules in coding standards: CodingStandards.html#ll_naming
440
441LiveDebugVariables is a new pass that keeps track of debugging information for
442 user variables that are kept in registers in optimized builds.
443
444We now optimize various idioms for overflow detection into check of the flag
445 register on various CPUs, e.g.:
446 unsigned long t = a+b;
447 if (t &lt; a) ...
448 into:
449 addq %rdi, %rbx
450 jno LBB0_2
451
452X86: Much better codegen for several cases using adc/sbb instead of cmovs for
453 conditional increment and other idioms.
454
455MVT::Flag renamed to MVT::Glue
456
457Removed the PartialSpecialization pass, it was unmaintained and buggy.
458
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]459</pre></li>
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]460</ul>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]461
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]462Still todo: [110117-110228]
Chris Lattnerdc910082010-03-17 06:41:58 +0000[diff] [blame]463
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]464
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]465</div>
466
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]467<!--=========================================================================-->
468<div class="doc_subsection">
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]469<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]470</div>
471
472<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]473<p>LLVM IR has several new features for better support of new targets and that
474expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]475
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]476<ul>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]477</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]478
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]479</div>
480
481<!--=========================================================================-->
482<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]483<a name="optimizer">Optimizer Improvements</a>
484</div>
485
486<div class="doc_text">
487
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]488<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]489release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]490
491<ul>
Rafael Espindolaa26f36c2011-03-18 04:07:44 +0000[diff] [blame]492 <li>TBAA.</li>
493 <li>LTO has been improved to use MC for parsing inline asm and now
494 can build large programs like Firefox 4 on both OS X and Linux.</li>
Chris Lattner11b66112010-10-04 02:42:39 +0000[diff] [blame]495</ul>
496
497<!--
498<p>In addition to these features that are done in 2.8, there is preliminary
499 support in the release for Type Based Alias Analysis
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]500 Preliminary work on TBAA but not usable in 2.8.
501 New CorrelatedValuePropagation pass, not on by default in 2.8 yet.
Chris Lattner11b66112010-10-04 02:42:39 +0000[diff] [blame]502-->
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]503
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]504</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]505
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]506<!--=========================================================================-->
507<div class="doc_subsection">
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]508<a name="mc">MC Level Improvements</a>
509</div>
510
511<div class="doc_text">
512<p>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]513The LLVM Machine Code (aka MC) subsystem was created to solve a number
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]514of problems in the realm of assembly, disassembly, object file format handling,
515and a number of other related areas that CPU instruction-set level tools work
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]516in.</p>
517
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]518<ul>
Rafael Espindolaa26f36c2011-03-18 04:07:44 +0000[diff] [blame]519 <li>MC is now used by default for ELF systems on x86 and
520 x86-64.</li>
521 <li>MC supports and CodeGen uses the <tt>.loc</tt> directives for
522 producing line number debug info. This produces more compact line
523 tables.</li>
524 <li>MC supports the <tt>.cfi_*</tt> directives for producing DWARF
525 frame information, but it is still not used by CodeGen by default.</li>
526 <li>COFF support?</li>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]527</ul>
528
529<p>For more information, please see the <a
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]530href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
531LLVM MC Project Blog Post</a>.
532</p>
533
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]534</div>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]535
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]536<!--=========================================================================-->
537<div class="doc_subsection">
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]538<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]539</div>
540
541<div class="doc_text">
542
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]543<p>We have put a significant amount of work into the code generator
544infrastructure, which allows us to implement more aggressive algorithms and make
545it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]546
547<ul>
Chris Lattner3bdcda12010-10-04 03:58:12 +0000[diff] [blame]548<!-- SplitKit -->
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]549FastISel for ARM.
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]550</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]551</div>
552
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]553<!--=========================================================================-->
554<div class="doc_subsection">
555<a name="x86">X86-32 and X86-64 Target Improvements</a>
556</div>
557
558<div class="doc_text">
Chris Lattner7714c912010-10-04 04:39:25 +0000[diff] [blame]559<p>New features and major changes in the X86 target include:
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]560</p>
561
562<ul>
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]563 <li>Several bugs have been fixed for Windows x64 code generator.</li>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]564</ul>
565
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]566</div>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]567
568<!--=========================================================================-->
569<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]570<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]571</div>
572
573<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]574<p>New features of the ARM target include:
575</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]576
577<ul>
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]578</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]579</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]580
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]581
582<!--=========================================================================-->
583<div class="doc_subsection">
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]584<a name="changes">Major Changes and Removed Features</a>
585</div>
586
587<div class="doc_text">
588
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]589<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]590on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]591from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]592
593<ul>
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]594</ul>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]595
Chris Lattnerbb117712010-10-04 01:29:06 +0000[diff] [blame]596
597
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]598<p>In addition, many APIs have changed in this release. Some of the major LLVM
599API changes are:</p>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]600<ul>
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]601</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]602
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]603</div>
604
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]605<!--=========================================================================-->
606<div class="doc_subsection">
607<a name="devtree_changes">Development Infrastructure Changes</a>
608</div>
609
610<div class="doc_text">
611
612<p>This section lists changes to the LLVM development infrastructure. This
613mostly impacts users who actively work on LLVM or follow development on
614mainline, but may also impact users who leverage the LLVM build infrastructure
615or are interested in LLVM qualification.</p>
616
617<ul>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]618</ul>
619</div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]620
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]621<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]622<div class="doc_section">
623 <a name="knownproblems">Known Problems</a>
624</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]625<!-- *********************************************************************** -->
626
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]627<div class="doc_text">
628
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]629<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000[diff] [blame]630listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]631href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]632there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]634</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]635
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]636<!-- ======================================================================= -->
637<div class="doc_subsection">
638 <a name="experimental">Experimental features included with this release</a>
639</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]640
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]641<div class="doc_text">
642
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]643<p>The following components of this LLVM release are either untested, known to
644be broken or unreliable, or are in early development. These components should
645not be relied on, and bugs should not be filed against them, but they may be
646useful 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]647components, please contact us on the <a
648href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]649
650<ul>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]651<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ
Chris Lattnerbb117712010-10-04 01:29:06 +0000[diff] [blame]652 and XCore backends are experimental.</li>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]653<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]654 other than darwin-i386 and darwin-x86_64. FIXME: Not true on ELF anymore?</li>
655
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]656</ul>
657
658</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]659
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]660<!-- ======================================================================= -->
661<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]662 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]663</div>
664
665<div class="doc_text">
666
667<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000[diff] [blame]668 <li>The X86 backend does not yet support
669 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
670 floating point stack</a>. It supports the 'f' and 't' constraints, but not
671 'u'.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]672 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]673 <tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]674 argument constructs on X86-64 by lowering them manually.</li>
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]675 <li>Windows x64 (aka Win64) code generator has a few issues.
676 <ul>
677 <li>llvm-gcc cannot build the mingw-w64 runtime currently
678 due to lack of support for the 'u' inline assembly
679 constraint and for X87 floating point inline assembly.</li>
680 <li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt>
681 due to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
682 It is fixed in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
683 <li>Miss-aligned MOVDQA might crash your program. It is due to
684 <a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>,
685 lack of handling aligned internal globals.</li>
686 </ul>
687 </li>
688
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]689</ul>
690
691</div>
692
693<!-- ======================================================================= -->
694<div class="doc_subsection">
695 <a name="ppc-be">Known problems with the PowerPC back-end</a>
696</div>
697
698<div class="doc_text">
699
700<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]701<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]702compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]703</ul>
704
705</div>
706
707<!-- ======================================================================= -->
708<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]709 <a name="arm-be">Known problems with the ARM back-end</a>
710</div>
711
712<div class="doc_text">
713
714<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]715<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]716processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]717results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]718<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]719</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]720</ul>
721
722</div>
723
724<!-- ======================================================================= -->
725<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]726 <a name="sparc-be">Known problems with the SPARC back-end</a>
727</div>
728
729<div class="doc_text">
730
731<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]732<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]733 support the 64-bit SPARC ABI (-m64).</li>
734</ul>
735
736</div>
737
738<!-- ======================================================================= -->
739<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]740 <a name="mips-be">Known problems with the MIPS back-end</a>
741</div>
742
743<div class="doc_text">
744
745<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]746<li>64-bit MIPS targets are not supported yet.</li>
747</ul>
748
749</div>
750
751<!-- ======================================================================= -->
752<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]753 <a name="alpha-be">Known problems with the Alpha back-end</a>
754</div>
755
756<div class="doc_text">
757
758<ul>
759
760<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
761appropriate nops inserted to ensure restartability.</li>
762
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]763</ul>
764</div>
765
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]766<!-- ======================================================================= -->
767<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]768 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]769</div>
770
771<div class="doc_text">
772
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]773<p>The C backend has numerous problems and is not being actively maintained.
774Depending on it for anything serious is not advised.</p>
775
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]776<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]777<li><a href="http://llvm.org/PR802">The C backend has only basic support for
778 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]779<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
780 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif4906abe2009-03-02 12:02:51 +0000[diff] [blame]781 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]782<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000[diff] [blame]783<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]784</ul>
785
786</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]787
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]788
789<!-- ======================================================================= -->
790<div class="doc_subsection">
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]791 <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]792</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]793
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]794<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]795
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]796<p>llvm-gcc is generally very stable for the C family of languages. The only
797 major language feature of GCC not supported by llvm-gcc is the
798 <tt>__builtin_apply</tt> family of builtins. However, some extensions
799 are only supported on some targets. For example, trampolines are only
800 supported on some targets (these are used when you take the address of a
801 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]802
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]803<p>Fortran support generally works, but there are still several unresolved bugs
804 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
805 tools/gfortran component for details. Note that llvm-gcc is missing major
806 Fortran performance work in the frontend and library that went into GCC after
807 4.2. If you are interested in Fortran, we recommend that you consider using
808 <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]809
Duncan Sands3af96332010-10-04 10:06:56 +0000[diff] [blame]810<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
811actively maintained. If you are interested in Ada, we recommend that you
812consider using <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]813</div>
814
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]815<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]816<div class="doc_section">
817 <a name="additionalinfo">Additional Information</a>
818</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]819<!-- *********************************************************************** -->
820
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]821<div class="doc_text">
822
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]823<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]824href="http://llvm.org">LLVM web page</a>, in particular in the <a
825href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]826contains versions of the API documentation which is up-to-date with the
827Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]828You can access versions of these documents specific to this release by going
829into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]830
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]831<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]832us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]833lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]834
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]835</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]836
837<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]838
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]839<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]840<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]841 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]842 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]843 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]844 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]845
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]846 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]847 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]848</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]849
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]850</body>
851</html>