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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 Lattner0e464a92010-03-17 04:02:39 +000013<img align=right src="http://llvm.org/img/DragonSmall.png"
14 width="136" height="136">
15
Chris Lattner79c3fe12003-10-02 04:57:28 +000016<ol>
Misha Brukman500bc302003-11-22 00:38:41 +000017 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +000018 <li><a href="#subproj">Sub-project Status Update</a></li>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000019 <li><a href="#externalproj">External Projects Using LLVM 2.7</a></li>
20 <li><a href="#whatsnew">What's New in LLVM 2.7?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +000021 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000022 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +000023 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000024 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +000025</ol>
26
Chris Lattner7911ce22004-05-23 21:07:27 +000027<div class="doc_author">
Dan Gohman44aa9212008-10-14 16:23:02 +000028 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +000029</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000030
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000031<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.7
32release.<br>
33You may prefer the
34<a href="http://llvm.org/releases/2.6/docs/ReleaseNotes.html">LLVM 2.6
35Release Notes</a>.</h1>
36
Chris Lattner79c3fe12003-10-02 04:57:28 +000037<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000038<div class="doc_section">
39 <a name="intro">Introduction</a>
40</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000041<!-- *********************************************************************** -->
42
Misha Brukman500bc302003-11-22 00:38:41 +000043<div class="doc_text">
44
Chris Lattnerf6662f92008-10-13 17:57:36 +000045<p>This document contains the release notes for the LLVM Compiler
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000046Infrastructure, release 2.7. Here we describe the status of LLVM, including
Chris Lattnerf6662f92008-10-13 17:57:36 +000047major improvements from the previous release and significant known problems.
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +000048All LLVM releases may be downloaded from the <a
Chris Lattnerf6662f92008-10-13 17:57:36 +000049href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +000050
Chris Lattner7506b1d2004-12-07 08:04:13 +000051<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +000052release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +000053web site</a>. If you have questions or comments, the <a
Chris Lattnerc66bfef2010-03-17 04:41:49 +000054href="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 +000056
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000057<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +000058main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greiffa933f82008-10-14 11:00:32 +000059current one. To see the release notes for a specific release, please see the
Chris Lattner84977642007-09-21 03:54:09 +000060<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +000061
Chris Lattnerc66bfef2010-03-17 04:41:49 +000062
Chris Lattnerdc910082010-03-17 06:41:58 +000063<p>FIXME: llvm.org moved to new server, mention new logo, Ted and Doug new code
64 owners.</p>
Chris Lattnerc66bfef2010-03-17 04:41:49 +000065
Misha Brukman500bc302003-11-22 00:38:41 +000066</div>
Chris Lattner61358ab2009-10-13 17:48:04 +000067
Chris Lattner79c3fe12003-10-02 04:57:28 +000068
Chris Lattner61358ab2009-10-13 17:48:04 +000069<!--
70Almost dead code.
71 include/llvm/Analysis/LiveValues.h => Dan
72 lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
73 llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
Chris Lattner76ef2982010-01-09 22:30:40 +000074 ABCD, SCCVN, GEPSplitterPass
Chris Lattner048fe3c2010-01-16 21:25:13 +000075 MSIL backend?
Chris Lattnerdc910082010-03-17 06:41:58 +000076 lib/Transforms/Utils/SSI.cpp -> ABCD depends on it.
Chris Lattner61358ab2009-10-13 17:48:04 +000077-->
78
79
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000080<!-- Features that need text if they're finished for 2.7:
Chris Lattner61358ab2009-10-13 17:48:04 +000081 gcc plugin.
82 strong phi elim
83 variable debug info for optimized code
Chris Lattnerab68e9e2009-02-26 22:33:38 +000084 postalloc scheduler: anti dependence breaking, hazard recognizer?
Chris Lattner61358ab2009-10-13 17:48:04 +000085 metadata
86 loop dependence analysis
87 ELF Writer? How stable?
88 <li>PostRA scheduler improvements, ARM adoption (David Goodwin).</li>
Chris Lattneracce85d2008-02-10 07:46:44 +000089 -->
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000090
Chris Lattner547a3912008-10-12 19:47:48 +000091 <!-- for announcement email:
Chris Lattner61358ab2009-10-13 17:48:04 +000092 Logo web page.
93 llvm devmtg
94 compiler_rt
95 KLEE web page at klee.llvm.org
96 Many new papers added to /pubs/
Chris Lattnerdc910082010-03-17 06:41:58 +000097 Mention gcc plugin.
Chris Lattner74c80df2009-02-25 06:34:50 +000098 -->
Chris Lattneracce85d2008-02-10 07:46:44 +000099
Chris Lattner96a445e2008-10-13 18:01:01 +0000100<!-- *********************************************************************** -->
101<div class="doc_section">
102 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerea34f642008-06-08 21:34:41 +0000103</div>
Chris Lattner96a445e2008-10-13 18:01:01 +0000104<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000105
106<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000107<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000108The LLVM 2.7 distribution currently consists of code from the core LLVM
Chris Lattner61358ab2009-10-13 17:48:04 +0000109repository (which roughly includes the LLVM optimizers, code generators
110and supporting tools), the Clang repository and the llvm-gcc repository. In
111addition to this code, the LLVM Project includes other sub-projects that are in
112development. Here we include updates on these subprojects.
Bill Wendling63d8c552009-03-02 04:28:57 +0000113</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000114
Chris Lattner8348b472008-06-08 21:58:17 +0000115</div>
116
Chris Lattner96a445e2008-10-13 18:01:01 +0000117
Chris Lattner8348b472008-06-08 21:58:17 +0000118<!--=========================================================================-->
Chris Lattner96a445e2008-10-13 18:01:01 +0000119<div class="doc_subsection">
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000120<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000121</div>
122
123<div class="doc_text">
124
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000125<p>The <a href="http://clang.llvm.org/">Clang project</a> is ...</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000126
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000127<p>In the LLVM 2.7 time-frame, the Clang team has made many improvements:</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000128
Daniel Dunbar13739432008-10-14 23:25:09 +0000129<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000130<li>...</li>
Chris Lattnerdc910082010-03-17 06:41:58 +0000131include a link to cxx_compatibility.html
Bill Wendling6bc15282009-03-02 04:28:18 +0000132</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000133</div>
134
135<!--=========================================================================-->
136<div class="doc_subsection">
137<a name="clangsa">Clang Static Analyzer</a>
138</div>
139
140<div class="doc_text">
141
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000142<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 +0000143includes an early stage static source code analysis tool for <a
144href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
Chris Lattner61358ab2009-10-13 17:48:04 +0000145in C and Objective-C programs. The tool performs checks to find
Ted Kremenek8b3894c2009-02-27 07:01:32 +0000146bugs that occur on a specific path within a program.</p>
Chris Lattnercc042612008-10-14 00:52:49 +0000147
Chris Lattner0e464a92010-03-17 04:02:39 +0000148<p>In the LLVM 2.7 time-frame, the analyzer core has sprouted legs and...</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000149
150</div>
151
Chris Lattner96a445e2008-10-13 18:01:01 +0000152<!--=========================================================================-->
153<div class="doc_subsection">
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000154<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner96a445e2008-10-13 18:01:01 +0000155</div>
156
157<div class="doc_text">
158<p>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000159The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner61358ab2009-10-13 17:48:04 +0000160a JVM and a CLI Virtual Machine (Microsoft .NET is an
161implementation of the CLI) using LLVM for static and just-in-time
162compilation.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000163
Chris Lattner61358ab2009-10-13 17:48:04 +0000164<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000165VMKit version ?? builds with LLVM 2.7 and you can find it on its
Chris Lattner61358ab2009-10-13 17:48:04 +0000166<a href="http://vmkit.llvm.org/releases/">web page</a>. The release includes
Nicolas Geoffray56d313d2008-10-15 20:25:04 +0000167bug fixes, cleanup and new features. The major changes are:</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000168
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000169<ul>
170
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000171<li>...</li>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000172
173</ul>
Chris Lattner96a445e2008-10-13 18:01:01 +0000174</div>
175
Chris Lattner61358ab2009-10-13 17:48:04 +0000176
177<!--=========================================================================-->
178<div class="doc_subsection">
179<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
180</div>
181
182<div class="doc_text">
183<p>
184The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
185is a simple library that provides an implementation of the low-level
186target-specific hooks required by code generation and other runtime components.
187For example, when compiling for a 32-bit target, converting a double to a 64-bit
188unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
189function. The compiler-rt library provides highly optimized implementations of
190this and other low-level routines (some are 3x faster than the equivalent
191libgcc routines).</p>
192
193<p>
194All of the code in the compiler-rt project is available under the standard LLVM
195License, a "BSD-style" license.</p>
196
197</div>
198
199<!--=========================================================================-->
200<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000201<a name="dragonegg">DragonEgg: GCC-4.5 as an LLVM frontend</a>
202</div>
203
204<div class="doc_text">
205<p>
206The goal of <a href="http://dragonegg.llvm.org/">DragonEgg</a> is to make
207gcc-4.5 act like llvm-gcc without requiring any gcc modifications whatsoever.
Duncan Sands78a1dcc2009-10-15 08:17:44 +0000208<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a shared library (dragonegg.so)
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000209that is loaded by gcc at runtime. It ...
Chris Lattner61358ab2009-10-13 17:48:04 +0000210</p>
211
212</div>
213
214
215<!--=========================================================================-->
216<div class="doc_subsection">
217<a name="mc">llvm-mc: Machine Code Toolkit</a>
218</div>
219
220<div class="doc_text">
221<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000222The LLVM Machine Code (MC) Toolkit project is ...
Chris Lattner61358ab2009-10-13 17:48:04 +0000223</p>
224
225</div>
226
227
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000228<!-- *********************************************************************** -->
229<div class="doc_section">
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000230 <a name="externalproj">External Open Source Projects Using LLVM 2.7</a>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000231</div>
232<!-- *********************************************************************** -->
233
Chris Lattner61358ab2009-10-13 17:48:04 +0000234<div class="doc_text">
235
236<p>An exciting aspect of LLVM is that it is used as an enabling technology for
237 a lot of other language and tools projects. This section lists some of the
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000238 projects that have already been updated to work with LLVM 2.7.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000239</div>
240
241
242<!--=========================================================================-->
243<div class="doc_subsection">
244<a name="Rubinius">Rubinius</a>
245</div>
246
247<div class="doc_text">
Chris Lattner0e464a92010-03-17 04:02:39 +0000248Need update.
249<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000250<p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment
251for running Ruby code which strives to write as much of the core class
252implementation in Ruby as possible. Combined with a bytecode interpreting VM, it
253uses LLVM to optimize and compile ruby code down to machine code. Techniques
254such as type feedback, method inlining, and uncommon traps are all used to
255remove dynamism from ruby execution and increase performance.</p>
256
257<p>Since LLVM 2.5, Rubinius has made several major leaps forward, implementing
258a counter based JIT, type feedback and speculative method inlining.
Chris Lattner0e464a92010-03-17 04:02:39 +0000259-->
Chris Lattner61358ab2009-10-13 17:48:04 +0000260</p>
261
262</div>
263
264<!--=========================================================================-->
265<div class="doc_subsection">
266<a name="macruby">MacRuby</a>
267</div>
268
269<div class="doc_text">
270
271<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000272Need update.
273<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000274<a href="http://macruby.org">MacRuby</a> is an implementation of Ruby on top of
275core Mac OS X technologies, such as the Objective-C common runtime and garbage
276collector and the CoreFoundation framework. It is principally developed by
277Apple and aims at enabling the creation of full-fledged Mac OS X applications.
278</p>
279
280<p>
281MacRuby uses LLVM for optimization passes, JIT and AOT compilation of Ruby
282expressions. It also uses zero-cost DWARF exceptions to implement Ruby exception
Chris Lattner0e464a92010-03-17 04:02:39 +0000283handling.--> </p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000284
285</div>
286
287
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000288<!--=========================================================================-->
289<div class="doc_subsection">
290<a name="pure">Pure</a>
291</div>
292
293<div class="doc_text">
294<p>
Chris Lattner917cc712009-03-02 02:37:32 +0000295<a href="http://pure-lang.googlecode.com/">Pure</a>
296is an algebraic/functional programming language based on term rewriting.
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000297Programs are collections of equations which are used to evaluate expressions in
298a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000299lexical closures, a hygienic macro system (also based on term rewriting),
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000300built-in list and matrix support (including list and matrix comprehensions) and
301an easy-to-use C interface. The interpreter uses LLVM as a backend to
302 JIT-compile Pure programs to fast native code.</p>
303
Chris Lattner477a1fd2010-03-17 17:25:49 +0000304<p>Pure versions 0.43 and later have been tested and are known to work with
305LLVM 2.7 (and continue to work with older LLVM releases >= 2.5).</p>
306
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000307</div>
308
309
310<!--=========================================================================-->
311<div class="doc_subsection">
312<a name="ldc">LLVM D Compiler</a>
313</div>
314
315<div class="doc_text">
316<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000317Need update.
318<!--
Chris Lattner917cc712009-03-02 02:37:32 +0000319<a href="http://www.dsource.org/projects/ldc">LDC</a> is an implementation of
320the D Programming Language using the LLVM optimizer and code generator.
Chris Lattner61358ab2009-10-13 17:48:04 +0000321The LDC project works great with the LLVM 2.6 release. General improvements in
John Criswell524a5dd2009-03-02 15:28:15 +0000322this
Chris Lattner917cc712009-03-02 02:37:32 +0000323cycle have included new inline asm constraint handling, better debug info
Chris Lattner61358ab2009-10-13 17:48:04 +0000324support, general bug fixes and better x86-64 support. This has allowed
325some major improvements in LDC, getting it much closer to being as
Chris Lattner0e464a92010-03-17 04:02:39 +0000326fully featured as the original DMD compiler from DigitalMars.-->
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000327</p>
328</div>
329
Chris Lattnerbc31caf2009-02-28 18:58:01 +0000330<!--=========================================================================-->
331<div class="doc_subsection">
332<a name="RoadsendPHP">Roadsend PHP</a>
333</div>
334
335<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000336<p>
337<a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
Chris Lattnercade8222009-03-02 19:07:24 +0000338source implementation of the PHP programming
Chris Lattner61358ab2009-10-13 17:48:04 +0000339language that uses LLVM for its optimizer, JIT and static compiler. This is a
Chris Lattner0e464a92010-03-17 04:02:39 +0000340reimplementation of an earlier project that is now based on LLVM.
Chris Lattner477a1fd2010-03-17 17:25:49 +0000341</p>
Chris Lattnerbc31caf2009-02-28 18:58:01 +0000342</div>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000343
Chris Lattner61358ab2009-10-13 17:48:04 +0000344<!--=========================================================================-->
345<div class="doc_subsection">
346<a name="UnladenSwallow">Unladen Swallow</a>
347</div>
348
349<div class="doc_text">
350<p>
351<a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a
352branch of <a href="http://python.org/">Python</a> intended to be fully
353compatible and significantly faster. It uses LLVM's optimization passes and JIT
Chris Lattnerb5f6feb2010-03-18 06:52:15 +0000354compiler.
Chris Lattner0e464a92010-03-17 04:02:39 +0000355</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000356</div>
357
358<!--=========================================================================-->
359<div class="doc_subsection">
360<a name="llvm-lua">llvm-lua</a>
361</div>
362
363<div class="doc_text">
364<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000365Need update.
366<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000367<a href="http://code.google.com/p/llvm-lua/">LLVM-Lua</a> uses LLVM to add JIT
368and static compiling support to the Lua VM. Lua bytecode is analyzed to
369remove type checks, then LLVM is used to compile the bytecode down to machine
Chris Lattner0e464a92010-03-17 04:02:39 +0000370code.-->
371</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000372</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>
Chris Lattner0e464a92010-03-17 04:02:39 +0000381Need update.
382<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000383<a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a
384harness to build OpenJDK using only free software build tools and to provide
385replacements for the not-yet free parts of OpenJDK. One of the extensions that
386IcedTea provides is a new JIT compiler named <a
387href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM
388to provide native code generation without introducing processor-dependent
Chris Lattner0e464a92010-03-17 04:02:39 +0000389code.-->
Chris Lattner61358ab2009-10-13 17:48:04 +0000390</p>
391</div>
392
393
Chris Lattner8348b472008-06-08 21:58:17 +0000394
395<!-- *********************************************************************** -->
396<div class="doc_section">
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000397 <a name="whatsnew">What's New in LLVM 2.7?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000398</div>
399<!-- *********************************************************************** -->
400
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000401<div class="doc_text">
402
Chris Lattner61358ab2009-10-13 17:48:04 +0000403<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000404minor improvements. Some of the major improvements and new features are listed
405in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000406</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000407
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000408</div>
409
Chris Lattner8348b472008-06-08 21:58:17 +0000410<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000411<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000412<a name="majorfeatures">Major New Features</a>
413</div>
414
415<div class="doc_text">
416
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000417<p>LLVM 2.7 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000418
419<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000420<li>...</li>
Chris Lattner8170c102008-02-10 08:18:42 +0000421</ul>
422
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000423Extensible metadata solid.
424
425Debug info improvements: using metadata instead of llvm.dbg global variables.
426This brings several enhancements including improved compile times.
427
428New instruction selector.
429GHC Haskell ABI/ calling conv support.
430Pre-Alpha support for unions in IR.
431New InlineHint and StackAlignment function attributes
432Code generator MC'ized except for debug info and EH.
433New SCEV AA pass: -scev-aa
434Inliner reuses arrays allocas when inlining multiple callers to reduce stack usage.
435MC encoding and disassembler apis.
436Optimal Edge Profiling?
437Instcombine is now a library, has its own IRBuilder to simplify itself.
438New llvm/Support/Regex.h API. FileCheck now does regex's
Chris Lattnerdc910082010-03-17 06:41:58 +0000439Many subtle pointer invalidation bugs in Callgraph have been fixed and it now uses asserting value handles.
440MC Disassembler (with blog post), MCInstPrinter. Many X86 backend and AsmPrinter simplifications
441Various tools like llc and opt now read either .ll or .bc files as input.
442Malloc and free instructions got removed.
443compiler-rt support for ARM.
444completely llvm-gcc NEON support.
445Can transcode from GAS to intel syntax with "llvm-mc foo.s -output-asm-variant=1"
446JIT debug information with GDB 7.0
Chris Lattnerf04bdc52010-03-17 18:15:52 +0000447New CodeGen Level CSE
Chris Lattnerdc910082010-03-17 06:41:58 +0000448CMake can now run tests, what other improvements?
Chris Lattnerf04bdc52010-03-17 18:15:52 +0000449ARM/Thumb using reg scavenging for stack object address materialization (PEI).
Chris Lattnerdc910082010-03-17 06:41:58 +0000450New SSAUpdater and MachineSSAUpdater classes for unstructured ssa updating,
451 changed jump threading, GVN, etc to use it which simplified them and speed
452 them up.
Chris Lattner15a06112010-03-17 06:42:25 +0000453Combiner-AA improvements, why not on by default?
Chris Lattnerf04bdc52010-03-17 18:15:52 +0000454Pre-regalloc tail duplication
455x86 sibcall optimization
456New LSR with full strength reduction mode
457The most awesome sext / zext optimization pass. ?
458
459
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000460
Chris Lattnerdc910082010-03-17 06:41:58 +0000461CondProp pass removed (functionality merged into jump threading).
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000462AndersAA got removed (from 2.7 or mainline?)
Chris Lattnerdc910082010-03-17 06:41:58 +0000463PredSimplify, LoopVR, GVNPRE got removed.
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000464LLVM command line tools now overwrite their output, before they would only do this with -f.
465DOUT removed, use DEBUG(errs() instead.
466Much stuff converted to use raw_ostream instead of std::ostream.
467TargetAsmInfo renamed to MCAsmInfo
468llvm/ADT/iterator.h gone.
469
Chris Lattnerdc910082010-03-17 06:41:58 +0000470
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000471</div>
472
Chris Lattner84977642007-09-21 03:54:09 +0000473<!--=========================================================================-->
474<div class="doc_subsection">
Chris Lattner917cc712009-03-02 02:37:32 +0000475<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000476</div>
477
478<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000479<p>LLVM IR has several new features for better support of new targets and that
480expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000481
Chris Lattner791f77b2008-06-05 06:25:56 +0000482<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000483<li>...</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000484</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000485
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000486</div>
487
488<!--=========================================================================-->
489<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000490<a name="optimizer">Optimizer Improvements</a>
491</div>
492
493<div class="doc_text">
494
Chris Lattner61358ab2009-10-13 17:48:04 +0000495<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattnerf3013872008-10-13 21:50:36 +0000496release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000497
498<ul>
499
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000500<li>...</li>
Chris Lattner917cc712009-03-02 02:37:32 +0000501
Chris Lattner61358ab2009-10-13 17:48:04 +0000502</ul>
Chris Lattner917cc712009-03-02 02:37:32 +0000503
Chris Lattnerf2201912010-03-01 19:29:17 +0000504<p>Also, -anders-aa was removed</p>
505
Chris Lattner61358ab2009-10-13 17:48:04 +0000506</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000507
Chris Lattner917cc712009-03-02 02:37:32 +0000508
Chris Lattner61358ab2009-10-13 17:48:04 +0000509<!--=========================================================================-->
510<div class="doc_subsection">
511<a name="executionengine">Interpreter and JIT Improvements</a>
512</div>
Chris Lattnerf3013872008-10-13 21:50:36 +0000513
Chris Lattner61358ab2009-10-13 17:48:04 +0000514<div class="doc_text">
515
516<ul>
Jeffrey Yasskin01eba392010-01-29 19:10:38 +0000517<li>The JIT now <a
518href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
519to compiling eagerly</a> to avoid a race condition in the lazy JIT.
520Clients that still want the lazy JIT can switch it on by calling
521<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
Jeffrey Yasskin40966a72010-02-11 01:07:39 +0000522<li>It is now possible to create more than one JIT instance in the same process.
523These JITs can generate machine code in parallel,
524although <a href="http://llvm.org/docs/ProgrammersManual.html#jitthreading">you
525still have to obey the other threading restrictions</a>.</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000526</ul>
527
528</div>
529
530<!--=========================================================================-->
531<div class="doc_subsection">
Chris Lattner511433e2009-03-02 03:24:11 +0000532<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0b832202008-06-08 02:45:07 +0000533</div>
534
535<div class="doc_text">
536
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000537<p>We have put a significant amount of work into the code generator
538infrastructure, which allows us to implement more aggressive algorithms and make
539it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000540
541<ul>
Chris Lattner511433e2009-03-02 03:24:11 +0000542
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000543<li>...</li>
Chris Lattner84977642007-09-21 03:54:09 +0000544</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000545</div>
546
Chris Lattner917cc712009-03-02 02:37:32 +0000547<!--=========================================================================-->
548<div class="doc_subsection">
549<a name="x86">X86-32 and X86-64 Target Improvements</a>
550</div>
551
552<div class="doc_text">
553<p>New features of the X86 target include:
554</p>
555
556<ul>
Chris Lattner511433e2009-03-02 03:24:11 +0000557
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000558<li>...</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000559
Chris Lattner917cc712009-03-02 02:37:32 +0000560</ul>
561
Chris Lattner917cc712009-03-02 02:37:32 +0000562</div>
Chris Lattner84977642007-09-21 03:54:09 +0000563
564<!--=========================================================================-->
565<div class="doc_subsection">
Chris Lattner11398992009-02-26 07:32:11 +0000566<a name="pic16">PIC16 Target Improvements</a>
567</div>
568
569<div class="doc_text">
570<p>New features of the PIC16 target include:
571</p>
572
573<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000574<li>...</li>
Chris Lattner11398992009-02-26 07:32:11 +0000575</ul>
576
577<p>Things not yet supported:</p>
578
579<ul>
Chris Lattner11398992009-02-26 07:32:11 +0000580<li>Variable arguments.</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000581<li>Interrupts/programs.</li>
Chris Lattner11398992009-02-26 07:32:11 +0000582</ul>
583
584</div>
585
Chris Lattner11398992009-02-26 07:32:11 +0000586<!--=========================================================================-->
587<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000588<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000589</div>
590
591<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000592<p>New features of the ARM target include:
593</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000594
595<ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000596
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000597<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000598</ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000599
Chris Lattnerc441fb82009-03-01 02:30:21 +0000600
Chris Lattner61358ab2009-10-13 17:48:04 +0000601</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000602
Chris Lattner61358ab2009-10-13 17:48:04 +0000603<!--=========================================================================-->
604<div class="doc_subsection">
605<a name="OtherTarget">Other Target Specific Improvements</a>
606</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000607
Chris Lattner61358ab2009-10-13 17:48:04 +0000608<div class="doc_text">
609<p>New features of other targets include:
610</p>
611
612<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000613<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000614</ul>
615
616</div>
617
618<!--=========================================================================-->
619<div class="doc_subsection">
620<a name="newapis">New Useful APIs</a>
621</div>
622
623<div class="doc_text">
624
625<p>This release includes a number of new APIs that are used internally, which
626 may also be useful for external clients.
627</p>
628
629<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000630<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000631</ul>
632
633
634</div>
635
636<!--=========================================================================-->
637<div class="doc_subsection">
638<a name="otherimprovements">Other Improvements and New Features</a>
639</div>
640
641<div class="doc_text">
642<p>Other miscellaneous features include:</p>
643
644<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000645<li>...</li>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000646</ul>
647
648</div>
649
Chris Lattner77d29b12008-06-05 08:02:49 +0000650
651<!--=========================================================================-->
652<div class="doc_subsection">
Chris Lattnerf6662f92008-10-13 17:57:36 +0000653<a name="changes">Major Changes and Removed Features</a>
654</div>
655
656<div class="doc_text">
657
Chris Lattnereeb4da02008-10-13 22:06:31 +0000658<p>If you're already an LLVM user or developer with out-of-tree changes based
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000659on LLVM 2.6, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000660from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000661
662<ul>
Jeffrey Yasskinbc83d062010-02-09 23:03:44 +0000663<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
664if you have it installed. This makes it more likely that an LLVM built on one
665system will work when copied to a similar system. To use <tt>libffi</tt>,
666configure with <tt>--enable-libffi</tt>.
667</li>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000668</ul>
669
670
671<p>In addition, many APIs have changed in this release. Some of the major LLVM
672API changes are:</p>
673
674<ul>
Jeffrey Yasskin4fcd6072010-01-28 01:41:20 +0000675<li><tt>ModuleProvider</tt> has been <a
676href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
677and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
678Most clients can remove uses of <tt>ExistingModuleProvider</tt>,
679replace <tt>getBitcodeModuleProvider</tt> with
680<tt>getLazyBitcodeModule</tt>, and pass their <tt>Module</tt> to
681functions that used to accept <tt>ModuleProvider</tt>. Clients who
682wrote their own <tt>ModuleProvider</tt>s will need to derive from
683<tt>GVMaterializer</tt> instead and use
684<tt>Module::setMaterializer</tt> to attach it to a
685<tt>Module</tt>.</li>
686
687<li><tt>GhostLinkage</tt> has given up the ghost.
688<tt>GlobalValue</tt>s that have not yet been read from their backing
689storage have the same linkage they will have after being read in.
690Clients must replace calls to
691<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
692<tt>GlobalValue::isMaterializable</tt>.</li>
Daniel Dunbar4acdede2010-02-10 04:09:52 +0000693
694<li>FIXME: Debug info has been totally redone. Add pointers to new APIs. Substantial caveats about compatibility of .ll and .bc files.</li>
695
Daniel Dunbarca1c8162010-02-14 01:47:19 +0000696<li>The <tt>llvm/Support/DataTypes.h</tt> header has moved
697to <tt>llvm/System/DataTypes.h</tt>.</li>
698
Duncan Sands411432d2010-02-17 17:20:17 +0000699<li>The <tt>isInteger</tt>, <tt>isIntOrIntVector</tt>, <tt>isFloatingPoint</tt>,
700<tt>isFPOrFPVector</tt> and <tt>isFPOrFPVector</tt> methods have been renamed
701<tt>isIntegerTy</tt>, <tt>isIntOrIntVectorTy</tt>, <tt>isFloatingPointTy</tt>,
702<tt>isFPOrFPVectorTy</tt> and <tt>isFPOrFPVectorTy</tt> respectively.</li>
Devang Patelb34dd132008-10-14 20:03:43 +0000703</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000704
Chris Lattnerf6662f92008-10-13 17:57:36 +0000705</div>
706
707
708
Chris Lattner19092612003-10-02 16:38:05 +0000709<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000710<div class="doc_section">
711 <a name="portability">Portability and Supported Platforms</a>
712</div>
Chris Lattner19092612003-10-02 16:38:05 +0000713<!-- *********************************************************************** -->
714
Misha Brukman500bc302003-11-22 00:38:41 +0000715<div class="doc_text">
716
John Criswell0b5b5e92004-12-08 20:35:47 +0000717<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000718
719<ul>
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000720<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
Chris Lattner61358ab2009-10-13 17:48:04 +0000721 Linux, Fedora Core, FreeBSD and AuroraUX (and probably other unix-like
722 systems).</li>
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000723<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
Chris Lattner61358ab2009-10-13 17:48:04 +0000724 and 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000725<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000726<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
727 support is available for native builds with Visual C++).</li>
Chris Lattner7e23d6e2009-10-16 16:30:58 +0000728<li>Sun x86 and AMD64 machines running Solaris 10, OpenSolaris 0906.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000729<li>Alpha-based machines running Debian GNU/Linux.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000730</ul>
731
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000732<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000733to the machine and operating system on which it is built. However, minor
734porting may be required to get LLVM to work on new platforms. We welcome your
735portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000736
Misha Brukman500bc302003-11-22 00:38:41 +0000737</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000738
739<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000740<div class="doc_section">
741 <a name="knownproblems">Known Problems</a>
742</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000743<!-- *********************************************************************** -->
744
Misha Brukman500bc302003-11-22 00:38:41 +0000745<div class="doc_text">
746
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000747<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000748listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000749href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000750there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000751
Chris Lattner477a1fd2010-03-17 17:25:49 +0000752<ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000753<li>LLVM will not correctly compile on Solaris and/or OpenSolaris
754using the stock GCC 3.x.x series 'out the box',
Chris Lattner554ee4a2009-11-03 21:50:09 +0000755See: <a href="GettingStarted.html#brokengcc">Broken versions of GCC and other tools</a>.
Chris Lattner61358ab2009-10-13 17:48:04 +0000756However, A <a href="http://pkg.auroraux.org/GCC">Modern GCC Build</a>
757for x86/x86-64 has been made available from the third party AuroraUX Project
758that has been meticulously tested for bootstrapping LLVM &amp; Clang.</li>
759</ul>
760
Misha Brukman500bc302003-11-22 00:38:41 +0000761</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000762
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000763<!-- ======================================================================= -->
764<div class="doc_subsection">
765 <a name="experimental">Experimental features included with this release</a>
766</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000767
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000768<div class="doc_text">
769
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000770<p>The following components of this LLVM release are either untested, known to
771be broken or unreliable, or are in early development. These components should
772not be relied on, and bugs should not be filed against them, but they may be
773useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000774components, please contact us on the <a
775href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000776
777<ul>
Wesley Peck7c4a1212010-03-18 14:31:30 +0000778<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
779 backends are experimental.</li>
Bill Wendling99dac472009-03-02 07:54:14 +0000780<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000781 supported value for this option. The MachO writer is experimental, and
782 works much better in mainline SVN.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000783</ul>
784
785</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000786
Misha Brukman500bc302003-11-22 00:38:41 +0000787<!-- ======================================================================= -->
788<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000789 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000790</div>
791
792<div class="doc_text">
793
794<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000795 <li>The X86 backend does not yet support
796 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
797 floating point stack</a>. It supports the 'f' and 't' constraints, but not
798 'u'.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000799 <li>The X86 backend generates inefficient floating point code when configured
800 to generate code for systems that don't have SSE2.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000801 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswell524a5dd2009-03-02 15:28:15 +0000802 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
803 runtime currently due
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000804 to <a href="http://llvm.org/PR2255">several</a>
John Criswell524a5dd2009-03-02 15:28:15 +0000805 <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for
806 the
807 'u' inline assembly constraint and for X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000808 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner917cc712009-03-02 02:37:32 +0000809 <tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000810 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000811</ul>
812
813</div>
814
815<!-- ======================================================================= -->
816<div class="doc_subsection">
817 <a name="ppc-be">Known problems with the PowerPC back-end</a>
818</div>
819
820<div class="doc_text">
821
822<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000823<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000824compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000825</ul>
826
827</div>
828
829<!-- ======================================================================= -->
830<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000831 <a name="arm-be">Known problems with the ARM back-end</a>
832</div>
833
834<div class="doc_text">
835
836<ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000837<li>Support for the Advanced SIMD (Neon) instruction set is still incomplete
838and not well tested. Some features may not work at all, and the code quality
839may be poor in some cases.</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000840<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000841processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000842results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000843<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000844</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000845</ul>
846
847</div>
848
849<!-- ======================================================================= -->
850<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000851 <a name="sparc-be">Known problems with the SPARC back-end</a>
852</div>
853
854<div class="doc_text">
855
856<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000857<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattner26299222006-11-18 07:51:14 +0000858 support the 64-bit SPARC ABI (-m64).</li>
859</ul>
860
861</div>
862
863<!-- ======================================================================= -->
864<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000865 <a name="mips-be">Known problems with the MIPS back-end</a>
866</div>
867
868<div class="doc_text">
869
870<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000871<li>64-bit MIPS targets are not supported yet.</li>
872</ul>
873
874</div>
875
876<!-- ======================================================================= -->
877<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000878 <a name="alpha-be">Known problems with the Alpha back-end</a>
879</div>
880
881<div class="doc_text">
882
883<ul>
884
885<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
886appropriate nops inserted to ensure restartability.</li>
887
John Criswellc0c186d2005-11-08 21:11:33 +0000888</ul>
889</div>
890
Chris Lattner26299222006-11-18 07:51:14 +0000891<!-- ======================================================================= -->
892<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000893 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000894</div>
895
896<div class="doc_text">
897
898<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000899<li><a href="http://llvm.org/PR802">The C backend has only basic support for
900 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000901<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
902 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif4906abe2009-03-02 12:02:51 +0000903 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000904<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000905<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000906</ul>
907
908</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000909
Misha Brukman500bc302003-11-22 00:38:41 +0000910
911<!-- ======================================================================= -->
912<div class="doc_subsection">
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000913 <a name="c-fe">Known problems with the llvm-gcc C and C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000914</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000915
Misha Brukman500bc302003-11-22 00:38:41 +0000916<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000917
Chris Lattner5733b272008-06-05 06:35:40 +0000918<p>The only major language feature of GCC not supported by llvm-gcc is
919 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
920 are only supported on some targets. For example, trampolines are only
Duncan Sands27aff872008-06-08 20:18:35 +0000921 supported on some targets (these are used when you take the address of a
922 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000923
Chris Lattner5733b272008-06-05 06:35:40 +0000924<p>If you run into GCC extensions which are not supported, please let us know.
925</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000926
Misha Brukman500bc302003-11-22 00:38:41 +0000927</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000928
Misha Brukman500bc302003-11-22 00:38:41 +0000929<!-- ======================================================================= -->
930<div class="doc_subsection">
Chris Lattner1eb4df62008-10-30 03:58:13 +0000931 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
932</div>
933
934<div class="doc_text">
Gabor Greifba10fe02008-11-04 21:50:59 +0000935<ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000936<li>Fortran support generally works, but there are still several unresolved bugs
Chris Lattner61358ab2009-10-13 17:48:04 +0000937 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
938 tools/gfortran component for details.</li>
Gabor Greifba10fe02008-11-04 21:50:59 +0000939</ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000940</div>
Misha Brukman500bc302003-11-22 00:38:41 +0000941
Chris Lattner2b659ef2008-02-12 06:29:45 +0000942<!-- ======================================================================= -->
943<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000944 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000945</div>
946
947<div class="doc_text">
John Criswell524a5dd2009-03-02 15:28:15 +0000948The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
949technology, and problems should be expected.
Chris Lattner2b659ef2008-02-12 06:29:45 +0000950<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000951<li>The Ada front-end currently only builds on X86-32. This is mainly due
John Criswell524a5dd2009-03-02 15:28:15 +0000952to lack of trampoline support (pointers to nested functions) on other platforms.
953However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000954which does support trampolines.</li>
955<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sands326a4982009-02-25 11:59:06 +0000956This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
957exception handling, which is used internally by the compiler.
Chris Lattner61358ab2009-10-13 17:48:04 +0000958Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000959<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
960and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands326a4982009-02-25 11:59:06 +0000961(c380004 also fails with gcc-4.2 mainline).
962If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
963causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsdd3e6722009-03-02 16:35:57 +0000964<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000965<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattner2b659ef2008-02-12 06:29:45 +0000966<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
Chris Lattner61358ab2009-10-13 17:48:04 +0000967crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000968<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
969or finish at a non-byte offset</a> in a record. Workaround: do not pack records
970or use representation clauses that result in a field of a non-discrete type
971starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000972<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
973'main' as generated by the Ada binder to be invalid</a>.
974Workaround: hand edit the file to use pointers for <tt>argv</tt> and
975<tt>envp</tt> rather than integers.</li>
976<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
977ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000978</ul>
979</div>
980
Chris Lattner61358ab2009-10-13 17:48:04 +0000981<!-- ======================================================================= -->
982<div class="doc_subsection">
983 <a name="ocaml-bindings">Known problems with the O'Caml bindings</a>
984</div>
985
986<div class="doc_text">
987
988<p>The <tt>Llvm.Linkage</tt> module is broken, and has incorrect values. Only
989<tt>Llvm.Linkage.External</tt>, <tt>Llvm.Linkage.Available_externally</tt>, and
990<tt>Llvm.Linkage.Link_once</tt> will be correct. If you need any of the other linkage
991modes, you'll have to write an external C library in order to expose the
992functionality. This has been fixed in the trunk.</p>
993</div>
994
Chris Lattner79c3fe12003-10-02 04:57:28 +0000995<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000996<div class="doc_section">
997 <a name="additionalinfo">Additional Information</a>
998</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000999<!-- *********************************************************************** -->
1000
Misha Brukman500bc302003-11-22 00:38:41 +00001001<div class="doc_text">
1002
Chris Lattner416db102005-05-16 17:13:10 +00001003<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +00001004href="http://llvm.org">LLVM web page</a>, in particular in the <a
1005href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +00001006contains versions of the API documentation which is up-to-date with the
1007Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +00001008You can access versions of these documents specific to this release by going
1009into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001010
Misha Brukman500bc302003-11-22 00:38:41 +00001011<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +00001012us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +00001013lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001014
Misha Brukman500bc302003-11-22 00:38:41 +00001015</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001016
1017<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +00001018
Misha Brukman500bc302003-11-22 00:38:41 +00001019<hr>
Misha Brukman2061e892003-11-22 01:23:39 +00001020<address>
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Chris Lattnerb4b0ce72007-05-18 00:44:29 +00001026 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
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