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Jeffrey Yasskinbec48772010-01-28 01:14:43 +00007 <title>LLVM 2.7 Release Notes</title>
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9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +000010
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000011<div class="doc_title">LLVM 2.7 Release Notes</div>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000012
Chris Lattner79c3fe12003-10-02 04:57:28 +000013<ol>
Misha Brukman500bc302003-11-22 00:38:41 +000014 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +000015 <li><a href="#subproj">Sub-project Status Update</a></li>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000016 <li><a href="#externalproj">External Projects Using LLVM 2.7</a></li>
17 <li><a href="#whatsnew">What's New in LLVM 2.7?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +000018 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000019 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +000020 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000021 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +000022</ol>
23
Chris Lattner7911ce22004-05-23 21:07:27 +000024<div class="doc_author">
Dan Gohman44aa9212008-10-14 16:23:02 +000025 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +000026</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000027
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000028<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.7
29release.<br>
30You may prefer the
31<a href="http://llvm.org/releases/2.6/docs/ReleaseNotes.html">LLVM 2.6
32Release Notes</a>.</h1>
33
Chris Lattner79c3fe12003-10-02 04:57:28 +000034<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000035<div class="doc_section">
36 <a name="intro">Introduction</a>
37</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000038<!-- *********************************************************************** -->
39
Misha Brukman500bc302003-11-22 00:38:41 +000040<div class="doc_text">
41
Chris Lattnerf6662f92008-10-13 17:57:36 +000042<p>This document contains the release notes for the LLVM Compiler
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000043Infrastructure, release 2.7. Here we describe the status of LLVM, including
Chris Lattnerf6662f92008-10-13 17:57:36 +000044major improvements from the previous release and significant known problems.
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +000045All LLVM releases may be downloaded from the <a
Chris Lattnerf6662f92008-10-13 17:57:36 +000046href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +000047
Chris Lattner7506b1d2004-12-07 08:04:13 +000048<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +000049release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +000050web site</a>. If you have questions or comments, the <a
Chris Lattnerf6662f92008-10-13 17:57:36 +000051href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
52List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +000053
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000054<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +000055main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greiffa933f82008-10-14 11:00:32 +000056current one. To see the release notes for a specific release, please see the
Chris Lattner84977642007-09-21 03:54:09 +000057<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +000058
59</div>
Chris Lattner61358ab2009-10-13 17:48:04 +000060
Chris Lattner79c3fe12003-10-02 04:57:28 +000061
Chris Lattner61358ab2009-10-13 17:48:04 +000062<!--
63Almost dead code.
64 include/llvm/Analysis/LiveValues.h => Dan
65 lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
66 llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
Chris Lattner76ef2982010-01-09 22:30:40 +000067 ABCD, SCCVN, GEPSplitterPass
Chris Lattner048fe3c2010-01-16 21:25:13 +000068 MSIL backend?
Chris Lattner61358ab2009-10-13 17:48:04 +000069-->
70
71
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000072<!-- Features that need text if they're finished for 2.7:
Chris Lattner61358ab2009-10-13 17:48:04 +000073 gcc plugin.
74 strong phi elim
75 variable debug info for optimized code
Chris Lattnerab68e9e2009-02-26 22:33:38 +000076 postalloc scheduler: anti dependence breaking, hazard recognizer?
Chris Lattner61358ab2009-10-13 17:48:04 +000077 metadata
78 loop dependence analysis
79 ELF Writer? How stable?
80 <li>PostRA scheduler improvements, ARM adoption (David Goodwin).</li>
81 2.7 supports the GDB 7.0 jit interfaces for debug info.
82 2.7 eliminates ADT/iterator.h
Chris Lattneracce85d2008-02-10 07:46:44 +000083 -->
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000084
Chris Lattner547a3912008-10-12 19:47:48 +000085 <!-- for announcement email:
Chris Lattner61358ab2009-10-13 17:48:04 +000086 Logo web page.
87 llvm devmtg
88 compiler_rt
89 KLEE web page at klee.llvm.org
90 Many new papers added to /pubs/
91 Mention gcc plugin.
92
Chris Lattner74c80df2009-02-25 06:34:50 +000093 -->
Chris Lattneracce85d2008-02-10 07:46:44 +000094
Chris Lattner96a445e2008-10-13 18:01:01 +000095<!-- *********************************************************************** -->
96<div class="doc_section">
97 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerea34f642008-06-08 21:34:41 +000098</div>
Chris Lattner96a445e2008-10-13 18:01:01 +000099<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000100
101<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000102<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000103The LLVM 2.7 distribution currently consists of code from the core LLVM
Chris Lattner61358ab2009-10-13 17:48:04 +0000104repository (which roughly includes the LLVM optimizers, code generators
105and supporting tools), the Clang repository and the llvm-gcc repository. In
106addition to this code, the LLVM Project includes other sub-projects that are in
107development. Here we include updates on these subprojects.
Bill Wendling63d8c552009-03-02 04:28:57 +0000108</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000109
Chris Lattner8348b472008-06-08 21:58:17 +0000110</div>
111
Chris Lattner96a445e2008-10-13 18:01:01 +0000112
Chris Lattner8348b472008-06-08 21:58:17 +0000113<!--=========================================================================-->
Chris Lattner96a445e2008-10-13 18:01:01 +0000114<div class="doc_subsection">
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000115<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000116</div>
117
118<div class="doc_text">
119
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000120<p>The <a href="http://clang.llvm.org/">Clang project</a> is ...</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000121
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000122<p>In the LLVM 2.7 time-frame, the Clang team has made many improvements:</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000123
Daniel Dunbar13739432008-10-14 23:25:09 +0000124<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000125<li>...</li>
Bill Wendling6bc15282009-03-02 04:28:18 +0000126</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000127</div>
128
129<!--=========================================================================-->
130<div class="doc_subsection">
131<a name="clangsa">Clang Static Analyzer</a>
132</div>
133
134<div class="doc_text">
135
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000136<p>Previously announced in the 2.4, 2.5, and 2.6 LLVM releases, the Clang project also
Ted Kremenek8b3894c2009-02-27 07:01:32 +0000137includes an early stage static source code analysis tool for <a
138href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
Chris Lattner61358ab2009-10-13 17:48:04 +0000139in C and Objective-C programs. The tool performs checks to find
Ted Kremenek8b3894c2009-02-27 07:01:32 +0000140bugs that occur on a specific path within a program.</p>
Chris Lattnercc042612008-10-14 00:52:49 +0000141
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000142<p>In the LLVM 2.7 time-frame, the analyzer core has ...</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000143
144</div>
145
Chris Lattner96a445e2008-10-13 18:01:01 +0000146<!--=========================================================================-->
147<div class="doc_subsection">
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000148<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner96a445e2008-10-13 18:01:01 +0000149</div>
150
151<div class="doc_text">
152<p>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000153The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner61358ab2009-10-13 17:48:04 +0000154a JVM and a CLI Virtual Machine (Microsoft .NET is an
155implementation of the CLI) using LLVM for static and just-in-time
156compilation.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000157
Chris Lattner61358ab2009-10-13 17:48:04 +0000158<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000159VMKit version ?? builds with LLVM 2.7 and you can find it on its
Chris Lattner61358ab2009-10-13 17:48:04 +0000160<a href="http://vmkit.llvm.org/releases/">web page</a>. The release includes
Nicolas Geoffray56d313d2008-10-15 20:25:04 +0000161bug fixes, cleanup and new features. The major changes are:</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000162
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000163<ul>
164
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000165<li>...</li>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000166
167</ul>
Chris Lattner96a445e2008-10-13 18:01:01 +0000168</div>
169
Chris Lattner61358ab2009-10-13 17:48:04 +0000170
171<!--=========================================================================-->
172<div class="doc_subsection">
173<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
174</div>
175
176<div class="doc_text">
177<p>
178The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
179is a simple library that provides an implementation of the low-level
180target-specific hooks required by code generation and other runtime components.
181For example, when compiling for a 32-bit target, converting a double to a 64-bit
182unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
183function. The compiler-rt library provides highly optimized implementations of
184this and other low-level routines (some are 3x faster than the equivalent
185libgcc routines).</p>
186
187<p>
188All of the code in the compiler-rt project is available under the standard LLVM
189License, a "BSD-style" license.</p>
190
191</div>
192
193<!--=========================================================================-->
194<div class="doc_subsection">
195<a name="klee">KLEE: Symbolic Execution and Automatic Test Case Generator</a>
196</div>
197
198<div class="doc_text">
199<p>
200The new LLVM <a href="http://klee.llvm.org/">KLEE project</a> is a symbolic
201execution framework for programs in LLVM bitcode form. KLEE tries to
202symbolically evaluate "all" paths through the application and records state
203transitions that lead to fault states. This allows it to construct testcases
204that lead to faults and can even be used to verify algorithms. For more
205details, please see the <a
206href="http://llvm.org/pubs/2008-12-OSDI-KLEE.html">OSDI 2008 paper</a> about
207KLEE.</p>
208
209</div>
210
211<!--=========================================================================-->
212<div class="doc_subsection">
213<a name="dragonegg">DragonEgg: GCC-4.5 as an LLVM frontend</a>
214</div>
215
216<div class="doc_text">
217<p>
218The goal of <a href="http://dragonegg.llvm.org/">DragonEgg</a> is to make
219gcc-4.5 act like llvm-gcc without requiring any gcc modifications whatsoever.
Duncan Sands78a1dcc2009-10-15 08:17:44 +0000220<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a shared library (dragonegg.so)
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000221that is loaded by gcc at runtime. It ...
Chris Lattner61358ab2009-10-13 17:48:04 +0000222</p>
223
224</div>
225
226
227<!--=========================================================================-->
228<div class="doc_subsection">
229<a name="mc">llvm-mc: Machine Code Toolkit</a>
230</div>
231
232<div class="doc_text">
233<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000234The LLVM Machine Code (MC) Toolkit project is ...
Chris Lattner61358ab2009-10-13 17:48:04 +0000235</p>
236
237</div>
238
239
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000240<!-- *********************************************************************** -->
241<div class="doc_section">
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000242 <a name="externalproj">External Open Source Projects Using LLVM 2.7</a>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000243</div>
244<!-- *********************************************************************** -->
245
Chris Lattner61358ab2009-10-13 17:48:04 +0000246<div class="doc_text">
247
248<p>An exciting aspect of LLVM is that it is used as an enabling technology for
249 a lot of other language and tools projects. This section lists some of the
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000250 projects that have already been updated to work with LLVM 2.7.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000251</div>
252
253
254<!--=========================================================================-->
255<div class="doc_subsection">
256<a name="Rubinius">Rubinius</a>
257</div>
258
259<div class="doc_text">
260<p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment
261for running Ruby code which strives to write as much of the core class
262implementation in Ruby as possible. Combined with a bytecode interpreting VM, it
263uses LLVM to optimize and compile ruby code down to machine code. Techniques
264such as type feedback, method inlining, and uncommon traps are all used to
265remove dynamism from ruby execution and increase performance.</p>
266
267<p>Since LLVM 2.5, Rubinius has made several major leaps forward, implementing
268a counter based JIT, type feedback and speculative method inlining.
269</p>
270
271</div>
272
273<!--=========================================================================-->
274<div class="doc_subsection">
275<a name="macruby">MacRuby</a>
276</div>
277
278<div class="doc_text">
279
280<p>
281<a href="http://macruby.org">MacRuby</a> is an implementation of Ruby on top of
282core Mac OS X technologies, such as the Objective-C common runtime and garbage
283collector and the CoreFoundation framework. It is principally developed by
284Apple and aims at enabling the creation of full-fledged Mac OS X applications.
285</p>
286
287<p>
288MacRuby uses LLVM for optimization passes, JIT and AOT compilation of Ruby
289expressions. It also uses zero-cost DWARF exceptions to implement Ruby exception
290handling.</p>
291
292</div>
293
294
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000295<!--=========================================================================-->
296<div class="doc_subsection">
297<a name="pure">Pure</a>
298</div>
299
300<div class="doc_text">
301<p>
Chris Lattner917cc712009-03-02 02:37:32 +0000302<a href="http://pure-lang.googlecode.com/">Pure</a>
303is an algebraic/functional programming language based on term rewriting.
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000304Programs are collections of equations which are used to evaluate expressions in
305a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000306lexical closures, a hygienic macro system (also based on term rewriting),
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000307built-in list and matrix support (including list and matrix comprehensions) and
308an easy-to-use C interface. The interpreter uses LLVM as a backend to
309 JIT-compile Pure programs to fast native code.</p>
310
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000311<p>Pure versions ??? and later have been tested and are known to work with
312LLVM 2.7 (and continue to work with older LLVM releases >= 2.3 as well).
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000313</p>
314</div>
315
316
317<!--=========================================================================-->
318<div class="doc_subsection">
319<a name="ldc">LLVM D Compiler</a>
320</div>
321
322<div class="doc_text">
323<p>
Chris Lattner917cc712009-03-02 02:37:32 +0000324<a href="http://www.dsource.org/projects/ldc">LDC</a> is an implementation of
325the D Programming Language using the LLVM optimizer and code generator.
Chris Lattner61358ab2009-10-13 17:48:04 +0000326The LDC project works great with the LLVM 2.6 release. General improvements in
John Criswell524a5dd2009-03-02 15:28:15 +0000327this
Chris Lattner917cc712009-03-02 02:37:32 +0000328cycle have included new inline asm constraint handling, better debug info
Chris Lattner61358ab2009-10-13 17:48:04 +0000329support, general bug fixes and better x86-64 support. This has allowed
330some major improvements in LDC, getting it much closer to being as
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000331fully featured as the original DMD compiler from DigitalMars.
332</p>
333</div>
334
Chris Lattnerbc31caf2009-02-28 18:58:01 +0000335<!--=========================================================================-->
336<div class="doc_subsection">
337<a name="RoadsendPHP">Roadsend PHP</a>
338</div>
339
340<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000341<p>
342<a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
Chris Lattnercade8222009-03-02 19:07:24 +0000343source implementation of the PHP programming
Chris Lattner61358ab2009-10-13 17:48:04 +0000344language that uses LLVM for its optimizer, JIT and static compiler. This is a
Chris Lattnercade8222009-03-02 19:07:24 +0000345reimplementation of an earlier project that is now based on LLVM.</p>
Chris Lattnerbc31caf2009-02-28 18:58:01 +0000346</div>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000347
Chris Lattner61358ab2009-10-13 17:48:04 +0000348<!--=========================================================================-->
349<div class="doc_subsection">
350<a name="UnladenSwallow">Unladen Swallow</a>
351</div>
352
353<div class="doc_text">
354<p>
355<a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a
356branch of <a href="http://python.org/">Python</a> intended to be fully
357compatible and significantly faster. It uses LLVM's optimization passes and JIT
358compiler.</p>
359</div>
360
361<!--=========================================================================-->
362<div class="doc_subsection">
363<a name="llvm-lua">llvm-lua</a>
364</div>
365
366<div class="doc_text">
367<p>
368<a href="http://code.google.com/p/llvm-lua/">LLVM-Lua</a> uses LLVM to add JIT
369and static compiling support to the Lua VM. Lua bytecode is analyzed to
370remove type checks, then LLVM is used to compile the bytecode down to machine
371code.</p>
372</div>
373
374<!--=========================================================================-->
375<div class="doc_subsection">
376<a name="icedtea">IcedTea Java Virtual Machine Implementation</a>
377</div>
378
379<div class="doc_text">
380<p>
381<a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a
382harness to build OpenJDK using only free software build tools and to provide
383replacements for the not-yet free parts of OpenJDK. One of the extensions that
384IcedTea provides is a new JIT compiler named <a
385href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM
386to provide native code generation without introducing processor-dependent
387code.
388</p>
389</div>
390
391
Chris Lattner8348b472008-06-08 21:58:17 +0000392
393<!-- *********************************************************************** -->
394<div class="doc_section">
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000395 <a name="whatsnew">What's New in LLVM 2.7?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000396</div>
397<!-- *********************************************************************** -->
398
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000399<div class="doc_text">
400
Chris Lattner61358ab2009-10-13 17:48:04 +0000401<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000402minor improvements. Some of the major improvements and new features are listed
403in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000404</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000405
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000406</div>
407
Chris Lattner8348b472008-06-08 21:58:17 +0000408<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000409<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000410<a name="majorfeatures">Major New Features</a>
411</div>
412
413<div class="doc_text">
414
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000415<p>LLVM 2.7 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000416
417<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000418<li>...</li>
Chris Lattner8170c102008-02-10 08:18:42 +0000419</ul>
420
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000421</div>
422
Chris Lattner84977642007-09-21 03:54:09 +0000423<!--=========================================================================-->
424<div class="doc_subsection">
Chris Lattner917cc712009-03-02 02:37:32 +0000425<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000426</div>
427
428<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000429<p>LLVM IR has several new features for better support of new targets and that
430expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000431
Chris Lattner791f77b2008-06-05 06:25:56 +0000432<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000433<li>...</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000434</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000435
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000436</div>
437
438<!--=========================================================================-->
439<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000440<a name="optimizer">Optimizer Improvements</a>
441</div>
442
443<div class="doc_text">
444
Chris Lattner61358ab2009-10-13 17:48:04 +0000445<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattnerf3013872008-10-13 21:50:36 +0000446release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000447
448<ul>
449
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000450<li>...</li>
Chris Lattner917cc712009-03-02 02:37:32 +0000451
Chris Lattner61358ab2009-10-13 17:48:04 +0000452</ul>
Chris Lattner917cc712009-03-02 02:37:32 +0000453
Chris Lattner61358ab2009-10-13 17:48:04 +0000454</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000455
Chris Lattner917cc712009-03-02 02:37:32 +0000456
Chris Lattner61358ab2009-10-13 17:48:04 +0000457<!--=========================================================================-->
458<div class="doc_subsection">
459<a name="executionengine">Interpreter and JIT Improvements</a>
460</div>
Chris Lattnerf3013872008-10-13 21:50:36 +0000461
Chris Lattner61358ab2009-10-13 17:48:04 +0000462<div class="doc_text">
463
464<ul>
Jeffrey Yasskin01eba392010-01-29 19:10:38 +0000465<li>The JIT now <a
466href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
467to compiling eagerly</a> to avoid a race condition in the lazy JIT.
468Clients that still want the lazy JIT can switch it on by calling
469<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000470</ul>
471
472</div>
473
474<!--=========================================================================-->
475<div class="doc_subsection">
Chris Lattner511433e2009-03-02 03:24:11 +0000476<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0b832202008-06-08 02:45:07 +0000477</div>
478
479<div class="doc_text">
480
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000481<p>We have put a significant amount of work into the code generator
482infrastructure, which allows us to implement more aggressive algorithms and make
483it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000484
485<ul>
Chris Lattner511433e2009-03-02 03:24:11 +0000486
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000487<li>...</li>
Chris Lattner84977642007-09-21 03:54:09 +0000488</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000489</div>
490
Chris Lattner917cc712009-03-02 02:37:32 +0000491<!--=========================================================================-->
492<div class="doc_subsection">
493<a name="x86">X86-32 and X86-64 Target Improvements</a>
494</div>
495
496<div class="doc_text">
497<p>New features of the X86 target include:
498</p>
499
500<ul>
Chris Lattner511433e2009-03-02 03:24:11 +0000501
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000502<li>...</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000503
Chris Lattner917cc712009-03-02 02:37:32 +0000504</ul>
505
Chris Lattner917cc712009-03-02 02:37:32 +0000506</div>
Chris Lattner84977642007-09-21 03:54:09 +0000507
508<!--=========================================================================-->
509<div class="doc_subsection">
Chris Lattner11398992009-02-26 07:32:11 +0000510<a name="pic16">PIC16 Target Improvements</a>
511</div>
512
513<div class="doc_text">
514<p>New features of the PIC16 target include:
515</p>
516
517<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000518<li>...</li>
Chris Lattner11398992009-02-26 07:32:11 +0000519</ul>
520
521<p>Things not yet supported:</p>
522
523<ul>
Chris Lattner11398992009-02-26 07:32:11 +0000524<li>Variable arguments.</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000525<li>Interrupts/programs.</li>
Chris Lattner11398992009-02-26 07:32:11 +0000526</ul>
527
528</div>
529
Chris Lattner11398992009-02-26 07:32:11 +0000530<!--=========================================================================-->
531<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000532<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000533</div>
534
535<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000536<p>New features of the ARM target include:
537</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000538
539<ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000540
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000541<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000542</ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000543
Chris Lattnerc441fb82009-03-01 02:30:21 +0000544
Chris Lattner61358ab2009-10-13 17:48:04 +0000545</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000546
Chris Lattner61358ab2009-10-13 17:48:04 +0000547<!--=========================================================================-->
548<div class="doc_subsection">
549<a name="OtherTarget">Other Target Specific Improvements</a>
550</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000551
Chris Lattner61358ab2009-10-13 17:48:04 +0000552<div class="doc_text">
553<p>New features of other targets include:
554</p>
555
556<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000557<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000558</ul>
559
560</div>
561
562<!--=========================================================================-->
563<div class="doc_subsection">
564<a name="newapis">New Useful APIs</a>
565</div>
566
567<div class="doc_text">
568
569<p>This release includes a number of new APIs that are used internally, which
570 may also be useful for external clients.
571</p>
572
573<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000574<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000575</ul>
576
577
578</div>
579
580<!--=========================================================================-->
581<div class="doc_subsection">
582<a name="otherimprovements">Other Improvements and New Features</a>
583</div>
584
585<div class="doc_text">
586<p>Other miscellaneous features include:</p>
587
588<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000589<li>...</li>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000590</ul>
591
592</div>
593
Chris Lattner77d29b12008-06-05 08:02:49 +0000594
595<!--=========================================================================-->
596<div class="doc_subsection">
Chris Lattnerf6662f92008-10-13 17:57:36 +0000597<a name="changes">Major Changes and Removed Features</a>
598</div>
599
600<div class="doc_text">
601
Chris Lattnereeb4da02008-10-13 22:06:31 +0000602<p>If you're already an LLVM user or developer with out-of-tree changes based
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000603on LLVM 2.6, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000604from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000605
606<ul>
Jeffrey Yasskinbc83d062010-02-09 23:03:44 +0000607<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
608if you have it installed. This makes it more likely that an LLVM built on one
609system will work when copied to a similar system. To use <tt>libffi</tt>,
610configure with <tt>--enable-libffi</tt>.
611</li>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000612</ul>
613
614
615<p>In addition, many APIs have changed in this release. Some of the major LLVM
616API changes are:</p>
617
618<ul>
Jeffrey Yasskin4fcd6072010-01-28 01:41:20 +0000619<li><tt>ModuleProvider</tt> has been <a
620href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
621and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
622Most clients can remove uses of <tt>ExistingModuleProvider</tt>,
623replace <tt>getBitcodeModuleProvider</tt> with
624<tt>getLazyBitcodeModule</tt>, and pass their <tt>Module</tt> to
625functions that used to accept <tt>ModuleProvider</tt>. Clients who
626wrote their own <tt>ModuleProvider</tt>s will need to derive from
627<tt>GVMaterializer</tt> instead and use
628<tt>Module::setMaterializer</tt> to attach it to a
629<tt>Module</tt>.</li>
630
631<li><tt>GhostLinkage</tt> has given up the ghost.
632<tt>GlobalValue</tt>s that have not yet been read from their backing
633storage have the same linkage they will have after being read in.
634Clients must replace calls to
635<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
636<tt>GlobalValue::isMaterializable</tt>.</li>
Daniel Dunbar4acdede2010-02-10 04:09:52 +0000637
638<li>FIXME: Debug info has been totally redone. Add pointers to new APIs. Substantial caveats about compatibility of .ll and .bc files.</li>
639
Devang Patelb34dd132008-10-14 20:03:43 +0000640</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000641
Chris Lattnerf6662f92008-10-13 17:57:36 +0000642</div>
643
644
645
Chris Lattner19092612003-10-02 16:38:05 +0000646<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000647<div class="doc_section">
648 <a name="portability">Portability and Supported Platforms</a>
649</div>
Chris Lattner19092612003-10-02 16:38:05 +0000650<!-- *********************************************************************** -->
651
Misha Brukman500bc302003-11-22 00:38:41 +0000652<div class="doc_text">
653
John Criswell0b5b5e92004-12-08 20:35:47 +0000654<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000655
656<ul>
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000657<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
Chris Lattner61358ab2009-10-13 17:48:04 +0000658 Linux, Fedora Core, FreeBSD and AuroraUX (and probably other unix-like
659 systems).</li>
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000660<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
Chris Lattner61358ab2009-10-13 17:48:04 +0000661 and 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000662<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000663<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
664 support is available for native builds with Visual C++).</li>
Chris Lattner7e23d6e2009-10-16 16:30:58 +0000665<li>Sun x86 and AMD64 machines running Solaris 10, OpenSolaris 0906.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000666<li>Alpha-based machines running Debian GNU/Linux.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000667</ul>
668
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000669<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000670to the machine and operating system on which it is built. However, minor
671porting may be required to get LLVM to work on new platforms. We welcome your
672portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000673
Misha Brukman500bc302003-11-22 00:38:41 +0000674</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000675
676<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000677<div class="doc_section">
678 <a name="knownproblems">Known Problems</a>
679</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000680<!-- *********************************************************************** -->
681
Misha Brukman500bc302003-11-22 00:38:41 +0000682<div class="doc_text">
683
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000684<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000685listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000686href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000687there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000688
Chris Lattner61358ab2009-10-13 17:48:04 +0000689<ul>
690<li>The llvm-gcc bootstrap will fail with some versions of binutils (e.g. 2.15)
691 with a message of "<tt><a href="http://llvm.org/PR5004">Error: can not do 8
692 byte pc-relative relocation</a></tt>" when building C++ code. We intend to
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000693 fix this on mainline, but a workaround is to upgrade to binutils 2.17 or
694 later.</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000695
696<li>LLVM will not correctly compile on Solaris and/or OpenSolaris
697using the stock GCC 3.x.x series 'out the box',
Chris Lattner554ee4a2009-11-03 21:50:09 +0000698See: <a href="GettingStarted.html#brokengcc">Broken versions of GCC and other tools</a>.
Chris Lattner61358ab2009-10-13 17:48:04 +0000699However, A <a href="http://pkg.auroraux.org/GCC">Modern GCC Build</a>
700for x86/x86-64 has been made available from the third party AuroraUX Project
701that has been meticulously tested for bootstrapping LLVM &amp; Clang.</li>
702</ul>
703
Misha Brukman500bc302003-11-22 00:38:41 +0000704</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000705
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000706<!-- ======================================================================= -->
707<div class="doc_subsection">
708 <a name="experimental">Experimental features included with this release</a>
709</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000710
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000711<div class="doc_text">
712
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000713<p>The following components of this LLVM release are either untested, known to
714be broken or unreliable, or are in early development. These components should
715not be relied on, and bugs should not be filed against them, but they may be
716useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000717components, please contact us on the <a
718href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000719
720<ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000721<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430 and SystemZ backends are
722 experimental.</li>
Bill Wendling99dac472009-03-02 07:54:14 +0000723<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattner61358ab2009-10-13 17:48:04 +0000724 supported value for this option. The ELF writer is experimental.</li>
725<li>The implementation of Andersen's Alias Analysis has many known bugs.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000726</ul>
727
728</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000729
Misha Brukman500bc302003-11-22 00:38:41 +0000730<!-- ======================================================================= -->
731<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000732 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000733</div>
734
735<div class="doc_text">
736
737<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000738 <li>The X86 backend does not yet support
739 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
740 floating point stack</a>. It supports the 'f' and 't' constraints, but not
741 'u'.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000742 <li>The X86 backend generates inefficient floating point code when configured
743 to generate code for systems that don't have SSE2.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000744 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswell524a5dd2009-03-02 15:28:15 +0000745 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
746 runtime currently due
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000747 to <a href="http://llvm.org/PR2255">several</a>
John Criswell524a5dd2009-03-02 15:28:15 +0000748 <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for
749 the
750 'u' inline assembly constraint and for X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000751 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner917cc712009-03-02 02:37:32 +0000752 <tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000753 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000754</ul>
755
756</div>
757
758<!-- ======================================================================= -->
759<div class="doc_subsection">
760 <a name="ppc-be">Known problems with the PowerPC back-end</a>
761</div>
762
763<div class="doc_text">
764
765<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000766<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000767compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000768</ul>
769
770</div>
771
772<!-- ======================================================================= -->
773<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000774 <a name="arm-be">Known problems with the ARM back-end</a>
775</div>
776
777<div class="doc_text">
778
779<ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000780<li>Support for the Advanced SIMD (Neon) instruction set is still incomplete
781and not well tested. Some features may not work at all, and the code quality
782may be poor in some cases.</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000783<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000784processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000785results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000786<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000787</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000788</ul>
789
790</div>
791
792<!-- ======================================================================= -->
793<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000794 <a name="sparc-be">Known problems with the SPARC back-end</a>
795</div>
796
797<div class="doc_text">
798
799<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000800<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattner26299222006-11-18 07:51:14 +0000801 support the 64-bit SPARC ABI (-m64).</li>
802</ul>
803
804</div>
805
806<!-- ======================================================================= -->
807<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000808 <a name="mips-be">Known problems with the MIPS back-end</a>
809</div>
810
811<div class="doc_text">
812
813<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000814<li>64-bit MIPS targets are not supported yet.</li>
815</ul>
816
817</div>
818
819<!-- ======================================================================= -->
820<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000821 <a name="alpha-be">Known problems with the Alpha back-end</a>
822</div>
823
824<div class="doc_text">
825
826<ul>
827
828<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
829appropriate nops inserted to ensure restartability.</li>
830
John Criswellc0c186d2005-11-08 21:11:33 +0000831</ul>
832</div>
833
Chris Lattner26299222006-11-18 07:51:14 +0000834<!-- ======================================================================= -->
835<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000836 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000837</div>
838
839<div class="doc_text">
840
841<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000842<li><a href="http://llvm.org/PR802">The C backend has only basic support for
843 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000844<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
845 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif4906abe2009-03-02 12:02:51 +0000846 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000847<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000848<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000849</ul>
850
851</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000852
Misha Brukman500bc302003-11-22 00:38:41 +0000853
854<!-- ======================================================================= -->
855<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000856 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000857</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000858
Misha Brukman500bc302003-11-22 00:38:41 +0000859<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000860
Chris Lattner5733b272008-06-05 06:35:40 +0000861<p>The only major language feature of GCC not supported by llvm-gcc is
862 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
863 are only supported on some targets. For example, trampolines are only
Duncan Sands27aff872008-06-08 20:18:35 +0000864 supported on some targets (these are used when you take the address of a
865 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000866
Chris Lattner5733b272008-06-05 06:35:40 +0000867<p>If you run into GCC extensions which are not supported, please let us know.
868</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000869
Misha Brukman500bc302003-11-22 00:38:41 +0000870</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000871
Misha Brukman500bc302003-11-22 00:38:41 +0000872<!-- ======================================================================= -->
873<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000874 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000875</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000876
Misha Brukman500bc302003-11-22 00:38:41 +0000877<div class="doc_text">
878
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000879<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000880tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000881itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000882
Misha Brukman500bc302003-11-22 00:38:41 +0000883<ul>
Anton Korobeynikov0021fc12008-10-11 18:27:16 +0000884<li>Exception handling works well on the X86 and PowerPC targets. Currently
Chris Lattnere18b32e2008-11-10 05:40:34 +0000885 only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000886</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000887
Misha Brukman500bc302003-11-22 00:38:41 +0000888</div>
889
Chris Lattner1eb4df62008-10-30 03:58:13 +0000890<!-- ======================================================================= -->
891<div class="doc_subsection">
892 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
893</div>
894
895<div class="doc_text">
Gabor Greifba10fe02008-11-04 21:50:59 +0000896<ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000897<li>Fortran support generally works, but there are still several unresolved bugs
Chris Lattner61358ab2009-10-13 17:48:04 +0000898 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
899 tools/gfortran component for details.</li>
Gabor Greifba10fe02008-11-04 21:50:59 +0000900</ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000901</div>
Misha Brukman500bc302003-11-22 00:38:41 +0000902
Chris Lattner2b659ef2008-02-12 06:29:45 +0000903<!-- ======================================================================= -->
904<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000905 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000906</div>
907
908<div class="doc_text">
John Criswell524a5dd2009-03-02 15:28:15 +0000909The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
910technology, and problems should be expected.
Chris Lattner2b659ef2008-02-12 06:29:45 +0000911<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000912<li>The Ada front-end currently only builds on X86-32. This is mainly due
John Criswell524a5dd2009-03-02 15:28:15 +0000913to lack of trampoline support (pointers to nested functions) on other platforms.
914However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000915which does support trampolines.</li>
916<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sands326a4982009-02-25 11:59:06 +0000917This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
918exception handling, which is used internally by the compiler.
Chris Lattner61358ab2009-10-13 17:48:04 +0000919Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000920<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
921and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands326a4982009-02-25 11:59:06 +0000922(c380004 also fails with gcc-4.2 mainline).
923If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
924causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsdd3e6722009-03-02 16:35:57 +0000925<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000926<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattner2b659ef2008-02-12 06:29:45 +0000927<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
Chris Lattner61358ab2009-10-13 17:48:04 +0000928crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000929<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
930or finish at a non-byte offset</a> in a record. Workaround: do not pack records
931or use representation clauses that result in a field of a non-discrete type
932starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000933<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
934'main' as generated by the Ada binder to be invalid</a>.
935Workaround: hand edit the file to use pointers for <tt>argv</tt> and
936<tt>envp</tt> rather than integers.</li>
937<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
938ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000939</ul>
940</div>
941
Chris Lattner61358ab2009-10-13 17:48:04 +0000942<!-- ======================================================================= -->
943<div class="doc_subsection">
944 <a name="ocaml-bindings">Known problems with the O'Caml bindings</a>
945</div>
946
947<div class="doc_text">
948
949<p>The <tt>Llvm.Linkage</tt> module is broken, and has incorrect values. Only
950<tt>Llvm.Linkage.External</tt>, <tt>Llvm.Linkage.Available_externally</tt>, and
951<tt>Llvm.Linkage.Link_once</tt> will be correct. If you need any of the other linkage
952modes, you'll have to write an external C library in order to expose the
953functionality. This has been fixed in the trunk.</p>
954</div>
955
Chris Lattner79c3fe12003-10-02 04:57:28 +0000956<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000957<div class="doc_section">
958 <a name="additionalinfo">Additional Information</a>
959</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000960<!-- *********************************************************************** -->
961
Misha Brukman500bc302003-11-22 00:38:41 +0000962<div class="doc_text">
963
Chris Lattner416db102005-05-16 17:13:10 +0000964<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000965href="http://llvm.org">LLVM web page</a>, in particular in the <a
966href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000967contains versions of the API documentation which is up-to-date with the
968Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000969You can access versions of these documents specific to this release by going
970into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000971
Misha Brukman500bc302003-11-22 00:38:41 +0000972<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000973us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000974lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000975
Misha Brukman500bc302003-11-22 00:38:41 +0000976</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000977
978<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000979
Misha Brukman500bc302003-11-22 00:38:41 +0000980<hr>
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Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000987 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
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Misha Brukman2061e892003-11-22 01:23:39 +0000989</address>
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