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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 Lattnerf6662f92008-10-13 17:57:36 +000054href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
55List</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
62</div>
Chris Lattner61358ab2009-10-13 17:48:04 +000063
Chris Lattner79c3fe12003-10-02 04:57:28 +000064
Chris Lattner61358ab2009-10-13 17:48:04 +000065<!--
66Almost dead code.
67 include/llvm/Analysis/LiveValues.h => Dan
68 lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
69 llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
Chris Lattner76ef2982010-01-09 22:30:40 +000070 ABCD, SCCVN, GEPSplitterPass
Chris Lattner048fe3c2010-01-16 21:25:13 +000071 MSIL backend?
Chris Lattner61358ab2009-10-13 17:48:04 +000072-->
73
74
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000075<!-- Features that need text if they're finished for 2.7:
Chris Lattner61358ab2009-10-13 17:48:04 +000076 gcc plugin.
77 strong phi elim
78 variable debug info for optimized code
Chris Lattnerab68e9e2009-02-26 22:33:38 +000079 postalloc scheduler: anti dependence breaking, hazard recognizer?
Chris Lattner61358ab2009-10-13 17:48:04 +000080 metadata
81 loop dependence analysis
82 ELF Writer? How stable?
83 <li>PostRA scheduler improvements, ARM adoption (David Goodwin).</li>
84 2.7 supports the GDB 7.0 jit interfaces for debug info.
85 2.7 eliminates ADT/iterator.h
Chris Lattneracce85d2008-02-10 07:46:44 +000086 -->
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000087
Chris Lattner547a3912008-10-12 19:47:48 +000088 <!-- for announcement email:
Chris Lattner61358ab2009-10-13 17:48:04 +000089 Logo web page.
90 llvm devmtg
91 compiler_rt
92 KLEE web page at klee.llvm.org
93 Many new papers added to /pubs/
94 Mention gcc plugin.
95
Chris Lattner74c80df2009-02-25 06:34:50 +000096 -->
Chris Lattneracce85d2008-02-10 07:46:44 +000097
Chris Lattner96a445e2008-10-13 18:01:01 +000098<!-- *********************************************************************** -->
99<div class="doc_section">
100 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerea34f642008-06-08 21:34:41 +0000101</div>
Chris Lattner96a445e2008-10-13 18:01:01 +0000102<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000103
104<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000105<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000106The LLVM 2.7 distribution currently consists of code from the core LLVM
Chris Lattner61358ab2009-10-13 17:48:04 +0000107repository (which roughly includes the LLVM optimizers, code generators
108and supporting tools), the Clang repository and the llvm-gcc repository. In
109addition to this code, the LLVM Project includes other sub-projects that are in
110development. Here we include updates on these subprojects.
Bill Wendling63d8c552009-03-02 04:28:57 +0000111</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000112
Chris Lattner8348b472008-06-08 21:58:17 +0000113</div>
114
Chris Lattner96a445e2008-10-13 18:01:01 +0000115
Chris Lattner8348b472008-06-08 21:58:17 +0000116<!--=========================================================================-->
Chris Lattner96a445e2008-10-13 18:01:01 +0000117<div class="doc_subsection">
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000118<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000119</div>
120
121<div class="doc_text">
122
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000123<p>The <a href="http://clang.llvm.org/">Clang project</a> is ...</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000124
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000125<p>In the LLVM 2.7 time-frame, the Clang team has made many improvements:</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000126
Daniel Dunbar13739432008-10-14 23:25:09 +0000127<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000128<li>...</li>
Bill Wendling6bc15282009-03-02 04:28:18 +0000129</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000130</div>
131
132<!--=========================================================================-->
133<div class="doc_subsection">
134<a name="clangsa">Clang Static Analyzer</a>
135</div>
136
137<div class="doc_text">
138
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000139<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 +0000140includes an early stage static source code analysis tool for <a
141href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
Chris Lattner61358ab2009-10-13 17:48:04 +0000142in C and Objective-C programs. The tool performs checks to find
Ted Kremenek8b3894c2009-02-27 07:01:32 +0000143bugs that occur on a specific path within a program.</p>
Chris Lattnercc042612008-10-14 00:52:49 +0000144
Chris Lattner0e464a92010-03-17 04:02:39 +0000145<p>In the LLVM 2.7 time-frame, the analyzer core has sprouted legs and...</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000146
147</div>
148
Chris Lattner96a445e2008-10-13 18:01:01 +0000149<!--=========================================================================-->
150<div class="doc_subsection">
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000151<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner96a445e2008-10-13 18:01:01 +0000152</div>
153
154<div class="doc_text">
155<p>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000156The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner61358ab2009-10-13 17:48:04 +0000157a JVM and a CLI Virtual Machine (Microsoft .NET is an
158implementation of the CLI) using LLVM for static and just-in-time
159compilation.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000160
Chris Lattner61358ab2009-10-13 17:48:04 +0000161<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000162VMKit version ?? builds with LLVM 2.7 and you can find it on its
Chris Lattner61358ab2009-10-13 17:48:04 +0000163<a href="http://vmkit.llvm.org/releases/">web page</a>. The release includes
Nicolas Geoffray56d313d2008-10-15 20:25:04 +0000164bug fixes, cleanup and new features. The major changes are:</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000165
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000166<ul>
167
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000168<li>...</li>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000169
170</ul>
Chris Lattner96a445e2008-10-13 18:01:01 +0000171</div>
172
Chris Lattner61358ab2009-10-13 17:48:04 +0000173
174<!--=========================================================================-->
175<div class="doc_subsection">
176<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
177</div>
178
179<div class="doc_text">
180<p>
181The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
182is a simple library that provides an implementation of the low-level
183target-specific hooks required by code generation and other runtime components.
184For example, when compiling for a 32-bit target, converting a double to a 64-bit
185unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
186function. The compiler-rt library provides highly optimized implementations of
187this and other low-level routines (some are 3x faster than the equivalent
188libgcc routines).</p>
189
190<p>
191All of the code in the compiler-rt project is available under the standard LLVM
192License, a "BSD-style" license.</p>
193
194</div>
195
196<!--=========================================================================-->
197<div class="doc_subsection">
198<a name="klee">KLEE: Symbolic Execution and Automatic Test Case Generator</a>
199</div>
200
201<div class="doc_text">
202<p>
203The new LLVM <a href="http://klee.llvm.org/">KLEE project</a> is a symbolic
204execution framework for programs in LLVM bitcode form. KLEE tries to
205symbolically evaluate "all" paths through the application and records state
206transitions that lead to fault states. This allows it to construct testcases
207that lead to faults and can even be used to verify algorithms. For more
208details, please see the <a
209href="http://llvm.org/pubs/2008-12-OSDI-KLEE.html">OSDI 2008 paper</a> about
210KLEE.</p>
211
212</div>
213
214<!--=========================================================================-->
215<div class="doc_subsection">
216<a name="dragonegg">DragonEgg: GCC-4.5 as an LLVM frontend</a>
217</div>
218
219<div class="doc_text">
220<p>
221The goal of <a href="http://dragonegg.llvm.org/">DragonEgg</a> is to make
222gcc-4.5 act like llvm-gcc without requiring any gcc modifications whatsoever.
Duncan Sands78a1dcc2009-10-15 08:17:44 +0000223<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a shared library (dragonegg.so)
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000224that is loaded by gcc at runtime. It ...
Chris Lattner61358ab2009-10-13 17:48:04 +0000225</p>
226
227</div>
228
229
230<!--=========================================================================-->
231<div class="doc_subsection">
232<a name="mc">llvm-mc: Machine Code Toolkit</a>
233</div>
234
235<div class="doc_text">
236<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000237The LLVM Machine Code (MC) Toolkit project is ...
Chris Lattner61358ab2009-10-13 17:48:04 +0000238</p>
239
240</div>
241
242
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000243<!-- *********************************************************************** -->
244<div class="doc_section">
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000245 <a name="externalproj">External Open Source Projects Using LLVM 2.7</a>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000246</div>
247<!-- *********************************************************************** -->
248
Chris Lattner61358ab2009-10-13 17:48:04 +0000249<div class="doc_text">
250
251<p>An exciting aspect of LLVM is that it is used as an enabling technology for
252 a lot of other language and tools projects. This section lists some of the
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000253 projects that have already been updated to work with LLVM 2.7.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000254</div>
255
256
257<!--=========================================================================-->
258<div class="doc_subsection">
259<a name="Rubinius">Rubinius</a>
260</div>
261
262<div class="doc_text">
Chris Lattner0e464a92010-03-17 04:02:39 +0000263Need update.
264<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000265<p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment
266for running Ruby code which strives to write as much of the core class
267implementation in Ruby as possible. Combined with a bytecode interpreting VM, it
268uses LLVM to optimize and compile ruby code down to machine code. Techniques
269such as type feedback, method inlining, and uncommon traps are all used to
270remove dynamism from ruby execution and increase performance.</p>
271
272<p>Since LLVM 2.5, Rubinius has made several major leaps forward, implementing
273a counter based JIT, type feedback and speculative method inlining.
Chris Lattner0e464a92010-03-17 04:02:39 +0000274-->
Chris Lattner61358ab2009-10-13 17:48:04 +0000275</p>
276
277</div>
278
279<!--=========================================================================-->
280<div class="doc_subsection">
281<a name="macruby">MacRuby</a>
282</div>
283
284<div class="doc_text">
285
286<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000287Need update.
288<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000289<a href="http://macruby.org">MacRuby</a> is an implementation of Ruby on top of
290core Mac OS X technologies, such as the Objective-C common runtime and garbage
291collector and the CoreFoundation framework. It is principally developed by
292Apple and aims at enabling the creation of full-fledged Mac OS X applications.
293</p>
294
295<p>
296MacRuby uses LLVM for optimization passes, JIT and AOT compilation of Ruby
297expressions. It also uses zero-cost DWARF exceptions to implement Ruby exception
Chris Lattner0e464a92010-03-17 04:02:39 +0000298handling.--> </p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000299
300</div>
301
302
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000303<!--=========================================================================-->
304<div class="doc_subsection">
305<a name="pure">Pure</a>
306</div>
307
308<div class="doc_text">
309<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000310Need update.
311<!--
Chris Lattner917cc712009-03-02 02:37:32 +0000312<a href="http://pure-lang.googlecode.com/">Pure</a>
313is an algebraic/functional programming language based on term rewriting.
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000314Programs are collections of equations which are used to evaluate expressions in
315a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000316lexical closures, a hygienic macro system (also based on term rewriting),
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000317built-in list and matrix support (including list and matrix comprehensions) and
318an easy-to-use C interface. The interpreter uses LLVM as a backend to
319 JIT-compile Pure programs to fast native code.</p>
320
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000321<p>Pure versions ??? and later have been tested and are known to work with
322LLVM 2.7 (and continue to work with older LLVM releases >= 2.3 as well).
Chris Lattner0e464a92010-03-17 04:02:39 +0000323--></p>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000324</div>
325
326
327<!--=========================================================================-->
328<div class="doc_subsection">
329<a name="ldc">LLVM D Compiler</a>
330</div>
331
332<div class="doc_text">
333<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000334Need update.
335<!--
Chris Lattner917cc712009-03-02 02:37:32 +0000336<a href="http://www.dsource.org/projects/ldc">LDC</a> is an implementation of
337the D Programming Language using the LLVM optimizer and code generator.
Chris Lattner61358ab2009-10-13 17:48:04 +0000338The LDC project works great with the LLVM 2.6 release. General improvements in
John Criswell524a5dd2009-03-02 15:28:15 +0000339this
Chris Lattner917cc712009-03-02 02:37:32 +0000340cycle have included new inline asm constraint handling, better debug info
Chris Lattner61358ab2009-10-13 17:48:04 +0000341support, general bug fixes and better x86-64 support. This has allowed
342some major improvements in LDC, getting it much closer to being as
Chris Lattner0e464a92010-03-17 04:02:39 +0000343fully featured as the original DMD compiler from DigitalMars.-->
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000344</p>
345</div>
346
Chris Lattnerbc31caf2009-02-28 18:58:01 +0000347<!--=========================================================================-->
348<div class="doc_subsection">
349<a name="RoadsendPHP">Roadsend PHP</a>
350</div>
351
352<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000353<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000354Need update.
355<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000356<a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
Chris Lattnercade8222009-03-02 19:07:24 +0000357source implementation of the PHP programming
Chris Lattner61358ab2009-10-13 17:48:04 +0000358language that uses LLVM for its optimizer, JIT and static compiler. This is a
Chris Lattner0e464a92010-03-17 04:02:39 +0000359reimplementation of an earlier project that is now based on LLVM.
360--> </p>
Chris Lattnerbc31caf2009-02-28 18:58:01 +0000361</div>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000362
Chris Lattner61358ab2009-10-13 17:48:04 +0000363<!--=========================================================================-->
364<div class="doc_subsection">
365<a name="UnladenSwallow">Unladen Swallow</a>
366</div>
367
368<div class="doc_text">
369<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000370Need update.
371<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000372<a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a
373branch of <a href="http://python.org/">Python</a> intended to be fully
374compatible and significantly faster. It uses LLVM's optimization passes and JIT
Chris Lattner0e464a92010-03-17 04:02:39 +0000375compiler.-->
376</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000377</div>
378
379<!--=========================================================================-->
380<div class="doc_subsection">
381<a name="llvm-lua">llvm-lua</a>
382</div>
383
384<div class="doc_text">
385<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000386Need update.
387<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000388<a href="http://code.google.com/p/llvm-lua/">LLVM-Lua</a> uses LLVM to add JIT
389and static compiling support to the Lua VM. Lua bytecode is analyzed to
390remove type checks, then LLVM is used to compile the bytecode down to machine
Chris Lattner0e464a92010-03-17 04:02:39 +0000391code.-->
392</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000393</div>
394
395<!--=========================================================================-->
396<div class="doc_subsection">
397<a name="icedtea">IcedTea Java Virtual Machine Implementation</a>
398</div>
399
400<div class="doc_text">
401<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000402Need update.
403<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000404<a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a
405harness to build OpenJDK using only free software build tools and to provide
406replacements for the not-yet free parts of OpenJDK. One of the extensions that
407IcedTea provides is a new JIT compiler named <a
408href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM
409to provide native code generation without introducing processor-dependent
Chris Lattner0e464a92010-03-17 04:02:39 +0000410code.-->
Chris Lattner61358ab2009-10-13 17:48:04 +0000411</p>
412</div>
413
414
Chris Lattner8348b472008-06-08 21:58:17 +0000415
416<!-- *********************************************************************** -->
417<div class="doc_section">
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000418 <a name="whatsnew">What's New in LLVM 2.7?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000419</div>
420<!-- *********************************************************************** -->
421
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000422<div class="doc_text">
423
Chris Lattner61358ab2009-10-13 17:48:04 +0000424<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000425minor improvements. Some of the major improvements and new features are listed
426in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000427</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000428
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000429</div>
430
Chris Lattner8348b472008-06-08 21:58:17 +0000431<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000432<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000433<a name="majorfeatures">Major New Features</a>
434</div>
435
436<div class="doc_text">
437
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000438<p>LLVM 2.7 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000439
440<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000441<li>...</li>
Chris Lattner8170c102008-02-10 08:18:42 +0000442</ul>
443
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000444</div>
445
Chris Lattner84977642007-09-21 03:54:09 +0000446<!--=========================================================================-->
447<div class="doc_subsection">
Chris Lattner917cc712009-03-02 02:37:32 +0000448<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000449</div>
450
451<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000452<p>LLVM IR has several new features for better support of new targets and that
453expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000454
Chris Lattner791f77b2008-06-05 06:25:56 +0000455<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000456<li>...</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000457</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000458
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000459</div>
460
461<!--=========================================================================-->
462<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000463<a name="optimizer">Optimizer Improvements</a>
464</div>
465
466<div class="doc_text">
467
Chris Lattner61358ab2009-10-13 17:48:04 +0000468<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattnerf3013872008-10-13 21:50:36 +0000469release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000470
471<ul>
472
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000473<li>...</li>
Chris Lattner917cc712009-03-02 02:37:32 +0000474
Chris Lattner61358ab2009-10-13 17:48:04 +0000475</ul>
Chris Lattner917cc712009-03-02 02:37:32 +0000476
Chris Lattnerf2201912010-03-01 19:29:17 +0000477<p>Also, -anders-aa was removed</p>
478
Chris Lattner61358ab2009-10-13 17:48:04 +0000479</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000480
Chris Lattner917cc712009-03-02 02:37:32 +0000481
Chris Lattner61358ab2009-10-13 17:48:04 +0000482<!--=========================================================================-->
483<div class="doc_subsection">
484<a name="executionengine">Interpreter and JIT Improvements</a>
485</div>
Chris Lattnerf3013872008-10-13 21:50:36 +0000486
Chris Lattner61358ab2009-10-13 17:48:04 +0000487<div class="doc_text">
488
489<ul>
Jeffrey Yasskin01eba392010-01-29 19:10:38 +0000490<li>The JIT now <a
491href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
492to compiling eagerly</a> to avoid a race condition in the lazy JIT.
493Clients that still want the lazy JIT can switch it on by calling
494<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
Jeffrey Yasskin40966a72010-02-11 01:07:39 +0000495<li>It is now possible to create more than one JIT instance in the same process.
496These JITs can generate machine code in parallel,
497although <a href="http://llvm.org/docs/ProgrammersManual.html#jitthreading">you
498still have to obey the other threading restrictions</a>.</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000499</ul>
500
501</div>
502
503<!--=========================================================================-->
504<div class="doc_subsection">
Chris Lattner511433e2009-03-02 03:24:11 +0000505<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0b832202008-06-08 02:45:07 +0000506</div>
507
508<div class="doc_text">
509
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000510<p>We have put a significant amount of work into the code generator
511infrastructure, which allows us to implement more aggressive algorithms and make
512it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000513
514<ul>
Chris Lattner511433e2009-03-02 03:24:11 +0000515
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000516<li>...</li>
Chris Lattner84977642007-09-21 03:54:09 +0000517</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000518</div>
519
Chris Lattner917cc712009-03-02 02:37:32 +0000520<!--=========================================================================-->
521<div class="doc_subsection">
522<a name="x86">X86-32 and X86-64 Target Improvements</a>
523</div>
524
525<div class="doc_text">
526<p>New features of the X86 target include:
527</p>
528
529<ul>
Chris Lattner511433e2009-03-02 03:24:11 +0000530
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000531<li>...</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000532
Chris Lattner917cc712009-03-02 02:37:32 +0000533</ul>
534
Chris Lattner917cc712009-03-02 02:37:32 +0000535</div>
Chris Lattner84977642007-09-21 03:54:09 +0000536
537<!--=========================================================================-->
538<div class="doc_subsection">
Chris Lattner11398992009-02-26 07:32:11 +0000539<a name="pic16">PIC16 Target Improvements</a>
540</div>
541
542<div class="doc_text">
543<p>New features of the PIC16 target include:
544</p>
545
546<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000547<li>...</li>
Chris Lattner11398992009-02-26 07:32:11 +0000548</ul>
549
550<p>Things not yet supported:</p>
551
552<ul>
Chris Lattner11398992009-02-26 07:32:11 +0000553<li>Variable arguments.</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000554<li>Interrupts/programs.</li>
Chris Lattner11398992009-02-26 07:32:11 +0000555</ul>
556
557</div>
558
Chris Lattner11398992009-02-26 07:32:11 +0000559<!--=========================================================================-->
560<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000561<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000562</div>
563
564<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000565<p>New features of the ARM target include:
566</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000567
568<ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000569
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000570<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000571</ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000572
Chris Lattnerc441fb82009-03-01 02:30:21 +0000573
Chris Lattner61358ab2009-10-13 17:48:04 +0000574</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000575
Chris Lattner61358ab2009-10-13 17:48:04 +0000576<!--=========================================================================-->
577<div class="doc_subsection">
578<a name="OtherTarget">Other Target Specific Improvements</a>
579</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000580
Chris Lattner61358ab2009-10-13 17:48:04 +0000581<div class="doc_text">
582<p>New features of other targets include:
583</p>
584
585<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000586<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000587</ul>
588
589</div>
590
591<!--=========================================================================-->
592<div class="doc_subsection">
593<a name="newapis">New Useful APIs</a>
594</div>
595
596<div class="doc_text">
597
598<p>This release includes a number of new APIs that are used internally, which
599 may also be useful for external clients.
600</p>
601
602<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000603<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000604</ul>
605
606
607</div>
608
609<!--=========================================================================-->
610<div class="doc_subsection">
611<a name="otherimprovements">Other Improvements and New Features</a>
612</div>
613
614<div class="doc_text">
615<p>Other miscellaneous features include:</p>
616
617<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000618<li>...</li>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000619</ul>
620
621</div>
622
Chris Lattner77d29b12008-06-05 08:02:49 +0000623
624<!--=========================================================================-->
625<div class="doc_subsection">
Chris Lattnerf6662f92008-10-13 17:57:36 +0000626<a name="changes">Major Changes and Removed Features</a>
627</div>
628
629<div class="doc_text">
630
Chris Lattnereeb4da02008-10-13 22:06:31 +0000631<p>If you're already an LLVM user or developer with out-of-tree changes based
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000632on LLVM 2.6, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000633from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000634
635<ul>
Jeffrey Yasskinbc83d062010-02-09 23:03:44 +0000636<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
637if you have it installed. This makes it more likely that an LLVM built on one
638system will work when copied to a similar system. To use <tt>libffi</tt>,
639configure with <tt>--enable-libffi</tt>.
640</li>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000641</ul>
642
643
644<p>In addition, many APIs have changed in this release. Some of the major LLVM
645API changes are:</p>
646
647<ul>
Jeffrey Yasskin4fcd6072010-01-28 01:41:20 +0000648<li><tt>ModuleProvider</tt> has been <a
649href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
650and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
651Most clients can remove uses of <tt>ExistingModuleProvider</tt>,
652replace <tt>getBitcodeModuleProvider</tt> with
653<tt>getLazyBitcodeModule</tt>, and pass their <tt>Module</tt> to
654functions that used to accept <tt>ModuleProvider</tt>. Clients who
655wrote their own <tt>ModuleProvider</tt>s will need to derive from
656<tt>GVMaterializer</tt> instead and use
657<tt>Module::setMaterializer</tt> to attach it to a
658<tt>Module</tt>.</li>
659
660<li><tt>GhostLinkage</tt> has given up the ghost.
661<tt>GlobalValue</tt>s that have not yet been read from their backing
662storage have the same linkage they will have after being read in.
663Clients must replace calls to
664<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
665<tt>GlobalValue::isMaterializable</tt>.</li>
Daniel Dunbar4acdede2010-02-10 04:09:52 +0000666
667<li>FIXME: Debug info has been totally redone. Add pointers to new APIs. Substantial caveats about compatibility of .ll and .bc files.</li>
668
Daniel Dunbarca1c8162010-02-14 01:47:19 +0000669<li>The <tt>llvm/Support/DataTypes.h</tt> header has moved
670to <tt>llvm/System/DataTypes.h</tt>.</li>
671
Duncan Sands411432d2010-02-17 17:20:17 +0000672<li>The <tt>isInteger</tt>, <tt>isIntOrIntVector</tt>, <tt>isFloatingPoint</tt>,
673<tt>isFPOrFPVector</tt> and <tt>isFPOrFPVector</tt> methods have been renamed
674<tt>isIntegerTy</tt>, <tt>isIntOrIntVectorTy</tt>, <tt>isFloatingPointTy</tt>,
675<tt>isFPOrFPVectorTy</tt> and <tt>isFPOrFPVectorTy</tt> respectively.</li>
Devang Patelb34dd132008-10-14 20:03:43 +0000676</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000677
Chris Lattnerf6662f92008-10-13 17:57:36 +0000678</div>
679
680
681
Chris Lattner19092612003-10-02 16:38:05 +0000682<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000683<div class="doc_section">
684 <a name="portability">Portability and Supported Platforms</a>
685</div>
Chris Lattner19092612003-10-02 16:38:05 +0000686<!-- *********************************************************************** -->
687
Misha Brukman500bc302003-11-22 00:38:41 +0000688<div class="doc_text">
689
John Criswell0b5b5e92004-12-08 20:35:47 +0000690<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000691
692<ul>
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000693<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
Chris Lattner61358ab2009-10-13 17:48:04 +0000694 Linux, Fedora Core, FreeBSD and AuroraUX (and probably other unix-like
695 systems).</li>
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000696<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
Chris Lattner61358ab2009-10-13 17:48:04 +0000697 and 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000698<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000699<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
700 support is available for native builds with Visual C++).</li>
Chris Lattner7e23d6e2009-10-16 16:30:58 +0000701<li>Sun x86 and AMD64 machines running Solaris 10, OpenSolaris 0906.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000702<li>Alpha-based machines running Debian GNU/Linux.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000703</ul>
704
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000705<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000706to the machine and operating system on which it is built. However, minor
707porting may be required to get LLVM to work on new platforms. We welcome your
708portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000709
Misha Brukman500bc302003-11-22 00:38:41 +0000710</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000711
712<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000713<div class="doc_section">
714 <a name="knownproblems">Known Problems</a>
715</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000716<!-- *********************************************************************** -->
717
Misha Brukman500bc302003-11-22 00:38:41 +0000718<div class="doc_text">
719
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000720<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000721listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000722href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000723there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000724
Chris Lattner61358ab2009-10-13 17:48:04 +0000725<ul>
726<li>The llvm-gcc bootstrap will fail with some versions of binutils (e.g. 2.15)
727 with a message of "<tt><a href="http://llvm.org/PR5004">Error: can not do 8
728 byte pc-relative relocation</a></tt>" when building C++ code. We intend to
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000729 fix this on mainline, but a workaround is to upgrade to binutils 2.17 or
730 later.</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000731
732<li>LLVM will not correctly compile on Solaris and/or OpenSolaris
733using the stock GCC 3.x.x series 'out the box',
Chris Lattner554ee4a2009-11-03 21:50:09 +0000734See: <a href="GettingStarted.html#brokengcc">Broken versions of GCC and other tools</a>.
Chris Lattner61358ab2009-10-13 17:48:04 +0000735However, A <a href="http://pkg.auroraux.org/GCC">Modern GCC Build</a>
736for x86/x86-64 has been made available from the third party AuroraUX Project
737that has been meticulously tested for bootstrapping LLVM &amp; Clang.</li>
738</ul>
739
Misha Brukman500bc302003-11-22 00:38:41 +0000740</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000741
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000742<!-- ======================================================================= -->
743<div class="doc_subsection">
744 <a name="experimental">Experimental features included with this release</a>
745</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000746
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000747<div class="doc_text">
748
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000749<p>The following components of this LLVM release are either untested, known to
750be broken or unreliable, or are in early development. These components should
751not be relied on, and bugs should not be filed against them, but they may be
752useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000753components, please contact us on the <a
754href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000755
756<ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000757<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430 and SystemZ backends are
758 experimental.</li>
Bill Wendling99dac472009-03-02 07:54:14 +0000759<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattner61358ab2009-10-13 17:48:04 +0000760 supported value for this option. The ELF writer is experimental.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000761</ul>
762
763</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000764
Misha Brukman500bc302003-11-22 00:38:41 +0000765<!-- ======================================================================= -->
766<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000767 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000768</div>
769
770<div class="doc_text">
771
772<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000773 <li>The X86 backend does not yet support
774 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
775 floating point stack</a>. It supports the 'f' and 't' constraints, but not
776 'u'.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000777 <li>The X86 backend generates inefficient floating point code when configured
778 to generate code for systems that don't have SSE2.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000779 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswell524a5dd2009-03-02 15:28:15 +0000780 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
781 runtime currently due
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000782 to <a href="http://llvm.org/PR2255">several</a>
John Criswell524a5dd2009-03-02 15:28:15 +0000783 <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for
784 the
785 'u' inline assembly constraint and for X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000786 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner917cc712009-03-02 02:37:32 +0000787 <tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000788 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000789</ul>
790
791</div>
792
793<!-- ======================================================================= -->
794<div class="doc_subsection">
795 <a name="ppc-be">Known problems with the PowerPC back-end</a>
796</div>
797
798<div class="doc_text">
799
800<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000801<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000802compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000803</ul>
804
805</div>
806
807<!-- ======================================================================= -->
808<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000809 <a name="arm-be">Known problems with the ARM back-end</a>
810</div>
811
812<div class="doc_text">
813
814<ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000815<li>Support for the Advanced SIMD (Neon) instruction set is still incomplete
816and not well tested. Some features may not work at all, and the code quality
817may be poor in some cases.</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000818<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000819processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000820results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000821<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000822</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000823</ul>
824
825</div>
826
827<!-- ======================================================================= -->
828<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000829 <a name="sparc-be">Known problems with the SPARC back-end</a>
830</div>
831
832<div class="doc_text">
833
834<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000835<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattner26299222006-11-18 07:51:14 +0000836 support the 64-bit SPARC ABI (-m64).</li>
837</ul>
838
839</div>
840
841<!-- ======================================================================= -->
842<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000843 <a name="mips-be">Known problems with the MIPS back-end</a>
844</div>
845
846<div class="doc_text">
847
848<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000849<li>64-bit MIPS targets are not supported yet.</li>
850</ul>
851
852</div>
853
854<!-- ======================================================================= -->
855<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000856 <a name="alpha-be">Known problems with the Alpha back-end</a>
857</div>
858
859<div class="doc_text">
860
861<ul>
862
863<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
864appropriate nops inserted to ensure restartability.</li>
865
John Criswellc0c186d2005-11-08 21:11:33 +0000866</ul>
867</div>
868
Chris Lattner26299222006-11-18 07:51:14 +0000869<!-- ======================================================================= -->
870<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000871 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000872</div>
873
874<div class="doc_text">
875
876<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000877<li><a href="http://llvm.org/PR802">The C backend has only basic support for
878 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000879<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
880 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif4906abe2009-03-02 12:02:51 +0000881 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000882<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000883<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000884</ul>
885
886</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000887
Misha Brukman500bc302003-11-22 00:38:41 +0000888
889<!-- ======================================================================= -->
890<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000891 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000892</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000893
Misha Brukman500bc302003-11-22 00:38:41 +0000894<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000895
Chris Lattner5733b272008-06-05 06:35:40 +0000896<p>The only major language feature of GCC not supported by llvm-gcc is
897 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
898 are only supported on some targets. For example, trampolines are only
Duncan Sands27aff872008-06-08 20:18:35 +0000899 supported on some targets (these are used when you take the address of a
900 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000901
Chris Lattner5733b272008-06-05 06:35:40 +0000902<p>If you run into GCC extensions which are not supported, please let us know.
903</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000904
Misha Brukman500bc302003-11-22 00:38:41 +0000905</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000906
Misha Brukman500bc302003-11-22 00:38:41 +0000907<!-- ======================================================================= -->
908<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000909 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000910</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000911
Misha Brukman500bc302003-11-22 00:38:41 +0000912<div class="doc_text">
913
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000914<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000915tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000916itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000917
Misha Brukman500bc302003-11-22 00:38:41 +0000918<ul>
Anton Korobeynikov0021fc12008-10-11 18:27:16 +0000919<li>Exception handling works well on the X86 and PowerPC targets. Currently
Chris Lattnere18b32e2008-11-10 05:40:34 +0000920 only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000921</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000922
Misha Brukman500bc302003-11-22 00:38:41 +0000923</div>
924
Chris Lattner1eb4df62008-10-30 03:58:13 +0000925<!-- ======================================================================= -->
926<div class="doc_subsection">
927 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
928</div>
929
930<div class="doc_text">
Gabor Greifba10fe02008-11-04 21:50:59 +0000931<ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000932<li>Fortran support generally works, but there are still several unresolved bugs
Chris Lattner61358ab2009-10-13 17:48:04 +0000933 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
934 tools/gfortran component for details.</li>
Gabor Greifba10fe02008-11-04 21:50:59 +0000935</ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000936</div>
Misha Brukman500bc302003-11-22 00:38:41 +0000937
Chris Lattner2b659ef2008-02-12 06:29:45 +0000938<!-- ======================================================================= -->
939<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000940 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000941</div>
942
943<div class="doc_text">
John Criswell524a5dd2009-03-02 15:28:15 +0000944The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
945technology, and problems should be expected.
Chris Lattner2b659ef2008-02-12 06:29:45 +0000946<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000947<li>The Ada front-end currently only builds on X86-32. This is mainly due
John Criswell524a5dd2009-03-02 15:28:15 +0000948to lack of trampoline support (pointers to nested functions) on other platforms.
949However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000950which does support trampolines.</li>
951<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sands326a4982009-02-25 11:59:06 +0000952This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
953exception handling, which is used internally by the compiler.
Chris Lattner61358ab2009-10-13 17:48:04 +0000954Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000955<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
956and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands326a4982009-02-25 11:59:06 +0000957(c380004 also fails with gcc-4.2 mainline).
958If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
959causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsdd3e6722009-03-02 16:35:57 +0000960<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000961<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattner2b659ef2008-02-12 06:29:45 +0000962<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
Chris Lattner61358ab2009-10-13 17:48:04 +0000963crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000964<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
965or finish at a non-byte offset</a> in a record. Workaround: do not pack records
966or use representation clauses that result in a field of a non-discrete type
967starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000968<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
969'main' as generated by the Ada binder to be invalid</a>.
970Workaround: hand edit the file to use pointers for <tt>argv</tt> and
971<tt>envp</tt> rather than integers.</li>
972<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
973ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000974</ul>
975</div>
976
Chris Lattner61358ab2009-10-13 17:48:04 +0000977<!-- ======================================================================= -->
978<div class="doc_subsection">
979 <a name="ocaml-bindings">Known problems with the O'Caml bindings</a>
980</div>
981
982<div class="doc_text">
983
984<p>The <tt>Llvm.Linkage</tt> module is broken, and has incorrect values. Only
985<tt>Llvm.Linkage.External</tt>, <tt>Llvm.Linkage.Available_externally</tt>, and
986<tt>Llvm.Linkage.Link_once</tt> will be correct. If you need any of the other linkage
987modes, you'll have to write an external C library in order to expose the
988functionality. This has been fixed in the trunk.</p>
989</div>
990
Chris Lattner79c3fe12003-10-02 04:57:28 +0000991<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000992<div class="doc_section">
993 <a name="additionalinfo">Additional Information</a>
994</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000995<!-- *********************************************************************** -->
996
Misha Brukman500bc302003-11-22 00:38:41 +0000997<div class="doc_text">
998
Chris Lattner416db102005-05-16 17:13:10 +0000999<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +00001000href="http://llvm.org">LLVM web page</a>, in particular in the <a
1001href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +00001002contains versions of the API documentation which is up-to-date with the
1003Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +00001004You can access versions of these documents specific to this release by going
1005into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001006
Misha Brukman500bc302003-11-22 00:38:41 +00001007<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +00001008us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +00001009lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001010
Misha Brukman500bc302003-11-22 00:38:41 +00001011</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001012
1013<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +00001014
Misha Brukman500bc302003-11-22 00:38:41 +00001015<hr>
Misha Brukman2061e892003-11-22 01:23:39 +00001016<address>
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Chris Lattnerb4b0ce72007-05-18 00:44:29 +00001022 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
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