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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>
Daniel Dunbar60dadb62010-03-25 16:09:18 +0000130<li>FIXME: C++! Include a link to cxx_compatibility.html</li>
131
132<li>FIXME: Static Analyzer improvements?</li>
133
134<li>CIndex API and Python bindings: Clang now includes a C API as part of the
135CIndex library. Although we make make some changes to the API in the future, it
136is intended to be stable and has been designed for use by external projects. See
137the Clang
138doxygen <a href="http://clang.llvm.org/doxygen/group__CINDEX.html">CIndex</a>
139documentation for more details. The CIndex API also includings an preliminary
140set of Python bindings.</li>
141
142<li>ARM Support: Clang now has ABI support for both the Darwin and Linux ARM
143ABIs. Coupled with many improvements to the LLVM ARM backend, Clang is now
144suitable for use as a a beta quality ARM compiler.</li>
Bill Wendling6bc15282009-03-02 04:28:18 +0000145</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000146</div>
147
148<!--=========================================================================-->
149<div class="doc_subsection">
150<a name="clangsa">Clang Static Analyzer</a>
151</div>
152
153<div class="doc_text">
154
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000155<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 +0000156includes an early stage static source code analysis tool for <a
157href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
Chris Lattner61358ab2009-10-13 17:48:04 +0000158in C and Objective-C programs. The tool performs checks to find
Ted Kremenek8b3894c2009-02-27 07:01:32 +0000159bugs that occur on a specific path within a program.</p>
Chris Lattnercc042612008-10-14 00:52:49 +0000160
Chris Lattner0e464a92010-03-17 04:02:39 +0000161<p>In the LLVM 2.7 time-frame, the analyzer core has sprouted legs and...</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000162
163</div>
164
Chris Lattner96a445e2008-10-13 18:01:01 +0000165<!--=========================================================================-->
166<div class="doc_subsection">
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000167<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner96a445e2008-10-13 18:01:01 +0000168</div>
169
170<div class="doc_text">
171<p>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000172The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner61358ab2009-10-13 17:48:04 +0000173a JVM and a CLI Virtual Machine (Microsoft .NET is an
174implementation of the CLI) using LLVM for static and just-in-time
175compilation.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000176
Chris Lattner61358ab2009-10-13 17:48:04 +0000177<p>
Chris Lattnerbf8e5162010-03-29 18:34:13 +0000178With the release of LLVM 2.7, VMKit has shifted to a great framework for writing
179virtual machines. VMKit now offers precise and efficient garbage collection with
180multi-threading support, thanks to the MMTk memory management toolkit, as well
181as just in time and ahead of time compilation with LLVM. The major changes in
182VMKit 0.27 are:</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000183
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000184<ul>
185
Chris Lattnerbf8e5162010-03-29 18:34:13 +0000186<li>Garbage collection: VMKit now uses the MMTk toolkit for garbage collectors.
187 The first collector to be ported is the MarkSweep collector, which is precise,
188 and drastically improves the performance of VMKit.</li>
189<li>Line number information in the JVM: by using the debug metadata of LLVM, the
190 JVM now supports precise line number information, useful when printing a stack
191 trace.</li>
192<li>Interface calls in the JVM: we implemented a variant of the Interface Method
193 Table technique for interface calls in the JVM.
194</li>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000195
196</ul>
Chris Lattner96a445e2008-10-13 18:01:01 +0000197</div>
198
Chris Lattner61358ab2009-10-13 17:48:04 +0000199
200<!--=========================================================================-->
201<div class="doc_subsection">
202<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
203</div>
204
205<div class="doc_text">
206<p>
207The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
208is a simple library that provides an implementation of the low-level
209target-specific hooks required by code generation and other runtime components.
210For example, when compiling for a 32-bit target, converting a double to a 64-bit
211unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
212function. The compiler-rt library provides highly optimized implementations of
213this and other low-level routines (some are 3x faster than the equivalent
214libgcc routines).</p>
215
216<p>
217All of the code in the compiler-rt project is available under the standard LLVM
218License, a "BSD-style" license.</p>
219
220</div>
221
222<!--=========================================================================-->
223<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000224<a name="dragonegg">DragonEgg: GCC-4.5 as an LLVM frontend</a>
225</div>
226
227<div class="doc_text">
228<p>
229The goal of <a href="http://dragonegg.llvm.org/">DragonEgg</a> is to make
230gcc-4.5 act like llvm-gcc without requiring any gcc modifications whatsoever.
Duncan Sands78a1dcc2009-10-15 08:17:44 +0000231<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a shared library (dragonegg.so)
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000232that is loaded by gcc at runtime. It ...
Chris Lattner61358ab2009-10-13 17:48:04 +0000233</p>
234
235</div>
236
237
238<!--=========================================================================-->
239<div class="doc_subsection">
240<a name="mc">llvm-mc: Machine Code Toolkit</a>
241</div>
242
243<div class="doc_text">
244<p>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000245The LLVM Machine Code (MC) Toolkit project is ...
Chris Lattner61358ab2009-10-13 17:48:04 +0000246</p>
247
248</div>
249
250
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000251<!-- *********************************************************************** -->
252<div class="doc_section">
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000253 <a name="externalproj">External Open Source Projects Using LLVM 2.7</a>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000254</div>
255<!-- *********************************************************************** -->
256
Chris Lattner61358ab2009-10-13 17:48:04 +0000257<div class="doc_text">
258
259<p>An exciting aspect of LLVM is that it is used as an enabling technology for
260 a lot of other language and tools projects. This section lists some of the
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000261 projects that have already been updated to work with LLVM 2.7.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000262</div>
263
264
265<!--=========================================================================-->
266<div class="doc_subsection">
267<a name="Rubinius">Rubinius</a>
268</div>
269
270<div class="doc_text">
Chris Lattner0e464a92010-03-17 04:02:39 +0000271Need update.
272<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000273<p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment
274for running Ruby code which strives to write as much of the core class
275implementation in Ruby as possible. Combined with a bytecode interpreting VM, it
276uses LLVM to optimize and compile ruby code down to machine code. Techniques
277such as type feedback, method inlining, and uncommon traps are all used to
278remove dynamism from ruby execution and increase performance.</p>
279
280<p>Since LLVM 2.5, Rubinius has made several major leaps forward, implementing
281a counter based JIT, type feedback and speculative method inlining.
Chris Lattner0e464a92010-03-17 04:02:39 +0000282-->
Chris Lattner61358ab2009-10-13 17:48:04 +0000283</p>
284
285</div>
286
287<!--=========================================================================-->
288<div class="doc_subsection">
289<a name="macruby">MacRuby</a>
290</div>
291
292<div class="doc_text">
293
294<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000295Need update.
296<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000297<a href="http://macruby.org">MacRuby</a> is an implementation of Ruby on top of
298core Mac OS X technologies, such as the Objective-C common runtime and garbage
299collector and the CoreFoundation framework. It is principally developed by
300Apple and aims at enabling the creation of full-fledged Mac OS X applications.
301</p>
302
303<p>
304MacRuby uses LLVM for optimization passes, JIT and AOT compilation of Ruby
305expressions. It also uses zero-cost DWARF exceptions to implement Ruby exception
Chris Lattner0e464a92010-03-17 04:02:39 +0000306handling.--> </p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000307
308</div>
309
310
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000311<!--=========================================================================-->
312<div class="doc_subsection">
313<a name="pure">Pure</a>
314</div>
315
316<div class="doc_text">
317<p>
Chris Lattner917cc712009-03-02 02:37:32 +0000318<a href="http://pure-lang.googlecode.com/">Pure</a>
319is an algebraic/functional programming language based on term rewriting.
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000320Programs are collections of equations which are used to evaluate expressions in
321a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000322lexical closures, a hygienic macro system (also based on term rewriting),
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000323built-in list and matrix support (including list and matrix comprehensions) and
324an easy-to-use C interface. The interpreter uses LLVM as a backend to
325 JIT-compile Pure programs to fast native code.</p>
326
Chris Lattner477a1fd2010-03-17 17:25:49 +0000327<p>Pure versions 0.43 and later have been tested and are known to work with
328LLVM 2.7 (and continue to work with older LLVM releases >= 2.5).</p>
329
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000330</div>
331
332
333<!--=========================================================================-->
334<div class="doc_subsection">
335<a name="ldc">LLVM D Compiler</a>
336</div>
337
338<div class="doc_text">
339<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000340Need update.
341<!--
Chris Lattner917cc712009-03-02 02:37:32 +0000342<a href="http://www.dsource.org/projects/ldc">LDC</a> is an implementation of
343the D Programming Language using the LLVM optimizer and code generator.
Chris Lattner61358ab2009-10-13 17:48:04 +0000344The LDC project works great with the LLVM 2.6 release. General improvements in
John Criswell524a5dd2009-03-02 15:28:15 +0000345this
Chris Lattner917cc712009-03-02 02:37:32 +0000346cycle have included new inline asm constraint handling, better debug info
Chris Lattner61358ab2009-10-13 17:48:04 +0000347support, general bug fixes and better x86-64 support. This has allowed
348some major improvements in LDC, getting it much closer to being as
Chris Lattner0e464a92010-03-17 04:02:39 +0000349fully featured as the original DMD compiler from DigitalMars.-->
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000350</p>
351</div>
352
Chris Lattnerbc31caf2009-02-28 18:58:01 +0000353<!--=========================================================================-->
354<div class="doc_subsection">
355<a name="RoadsendPHP">Roadsend PHP</a>
356</div>
357
358<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000359<p>
360<a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
Chris Lattnercade8222009-03-02 19:07:24 +0000361source implementation of the PHP programming
Chris Lattner61358ab2009-10-13 17:48:04 +0000362language that uses LLVM for its optimizer, JIT and static compiler. This is a
Chris Lattner0e464a92010-03-17 04:02:39 +0000363reimplementation of an earlier project that is now based on LLVM.
Chris Lattner477a1fd2010-03-17 17:25:49 +0000364</p>
Chris Lattnerbc31caf2009-02-28 18:58:01 +0000365</div>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000366
Chris Lattner61358ab2009-10-13 17:48:04 +0000367<!--=========================================================================-->
368<div class="doc_subsection">
369<a name="UnladenSwallow">Unladen Swallow</a>
370</div>
371
372<div class="doc_text">
373<p>
374<a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a
375branch of <a href="http://python.org/">Python</a> intended to be fully
376compatible and significantly faster. It uses LLVM's optimization passes and JIT
Chris Lattnerb5f6feb2010-03-18 06:52:15 +0000377compiler.
Chris Lattner0e464a92010-03-17 04:02:39 +0000378</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000379</div>
380
381<!--=========================================================================-->
382<div class="doc_subsection">
383<a name="llvm-lua">llvm-lua</a>
384</div>
385
386<div class="doc_text">
387<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000388Need update.
389<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000390<a href="http://code.google.com/p/llvm-lua/">LLVM-Lua</a> uses LLVM to add JIT
391and static compiling support to the Lua VM. Lua bytecode is analyzed to
392remove type checks, then LLVM is used to compile the bytecode down to machine
Chris Lattner0e464a92010-03-17 04:02:39 +0000393code.-->
394</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000395</div>
396
397<!--=========================================================================-->
398<div class="doc_subsection">
399<a name="icedtea">IcedTea Java Virtual Machine Implementation</a>
400</div>
401
402<div class="doc_text">
403<p>
Chris Lattner0e464a92010-03-17 04:02:39 +0000404Need update.
405<!--
Chris Lattner61358ab2009-10-13 17:48:04 +0000406<a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a
407harness to build OpenJDK using only free software build tools and to provide
408replacements for the not-yet free parts of OpenJDK. One of the extensions that
409IcedTea provides is a new JIT compiler named <a
410href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM
411to provide native code generation without introducing processor-dependent
Chris Lattner0e464a92010-03-17 04:02:39 +0000412code.-->
Chris Lattner61358ab2009-10-13 17:48:04 +0000413</p>
414</div>
415
416
Chris Lattner8d4bbbe2010-03-29 17:50:39 +0000417<!--=========================================================================-->
418<div class="doc_subsection">
419<a name="tce">TTA-based Codesign Environment (TCE)</a>
420</div>
421
422<div class="doc_text">
423<p>
424<a href="http://tce.cs.tut.fi/">TCE</a> is a toolset for designing
425application-specific processors (ASP) based on the Transport triggered
426architecture (TTA). The toolset provides a complete co-design flow from C/C++
427programs down to synthesizable VHDL and parallel program binaries. Processor
428customization points include the register files, function units, supported
429operations, and the interconnection network.</p>
430
431<p>TCE uses llvm-gcc/Clang and LLVM for C/C++ language support, target
432independent optimizations and also for parts of code generation. It generates
433new LLVM-based code generators "on the fly" for the designed TTA processors and
434loads them in to the compiler backend as runtime libraries to avoid per-target
435recompilation of larger parts of the compiler chain.</p>
436
437</div>
Chris Lattner8348b472008-06-08 21:58:17 +0000438
439<!-- *********************************************************************** -->
440<div class="doc_section">
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000441 <a name="whatsnew">What's New in LLVM 2.7?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000442</div>
443<!-- *********************************************************************** -->
444
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000445<div class="doc_text">
446
Chris Lattner61358ab2009-10-13 17:48:04 +0000447<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000448minor improvements. Some of the major improvements and new features are listed
449in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000450</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000451
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000452</div>
453
Chris Lattner8348b472008-06-08 21:58:17 +0000454<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000455<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000456<a name="majorfeatures">Major New Features</a>
457</div>
458
459<div class="doc_text">
460
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000461<p>LLVM 2.7 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000462
463<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000464<li>...</li>
Chris Lattner8170c102008-02-10 08:18:42 +0000465</ul>
466
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000467Extensible metadata solid.
468
469Debug info improvements: using metadata instead of llvm.dbg global variables.
470This brings several enhancements including improved compile times.
471
472New instruction selector.
473GHC Haskell ABI/ calling conv support.
474Pre-Alpha support for unions in IR.
475New InlineHint and StackAlignment function attributes
476Code generator MC'ized except for debug info and EH.
477New SCEV AA pass: -scev-aa
478Inliner reuses arrays allocas when inlining multiple callers to reduce stack usage.
479MC encoding and disassembler apis.
480Optimal Edge Profiling?
481Instcombine is now a library, has its own IRBuilder to simplify itself.
482New llvm/Support/Regex.h API. FileCheck now does regex's
Chris Lattnerdc910082010-03-17 06:41:58 +0000483Many subtle pointer invalidation bugs in Callgraph have been fixed and it now uses asserting value handles.
484MC Disassembler (with blog post), MCInstPrinter. Many X86 backend and AsmPrinter simplifications
485Various tools like llc and opt now read either .ll or .bc files as input.
Chris Lattner8e7f1b12010-03-29 18:42:42 +0000486Malloc and free instructions got removed, along with LowerAllocations pass.
Chris Lattnerdc910082010-03-17 06:41:58 +0000487compiler-rt support for ARM.
488completely llvm-gcc NEON support.
489Can transcode from GAS to intel syntax with "llvm-mc foo.s -output-asm-variant=1"
490JIT debug information with GDB 7.0
Chris Lattnerf04bdc52010-03-17 18:15:52 +0000491New CodeGen Level CSE
Chris Lattnerdc910082010-03-17 06:41:58 +0000492CMake can now run tests, what other improvements?
Chris Lattnerf04bdc52010-03-17 18:15:52 +0000493ARM/Thumb using reg scavenging for stack object address materialization (PEI).
Chris Lattnerdc910082010-03-17 06:41:58 +0000494New SSAUpdater and MachineSSAUpdater classes for unstructured ssa updating,
495 changed jump threading, GVN, etc to use it which simplified them and speed
496 them up.
Chris Lattner15a06112010-03-17 06:42:25 +0000497Combiner-AA improvements, why not on by default?
Chris Lattnerf04bdc52010-03-17 18:15:52 +0000498Pre-regalloc tail duplication
499x86 sibcall optimization
500New LSR with full strength reduction mode
501The most awesome sext / zext optimization pass. ?
502
Chris Lattnerb22060d2010-03-29 18:39:28 +0000503The ARM backend now has good support for ARMv4 backend (tested on StrongARM
504 hardware), previously only supported ARMv4T and newer.
505
Chris Lattnerf04bdc52010-03-17 18:15:52 +0000506
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000507
Chris Lattner8e7f1b12010-03-29 18:42:42 +0000508Defaults to RTTI off, packagers should build with make REQUIRE_RTTI=1.
Chris Lattnerdc910082010-03-17 06:41:58 +0000509CondProp pass removed (functionality merged into jump threading).
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000510AndersAA got removed (from 2.7 or mainline?)
Chris Lattnerdc910082010-03-17 06:41:58 +0000511PredSimplify, LoopVR, GVNPRE got removed.
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000512LLVM command line tools now overwrite their output, before they would only do this with -f.
513DOUT removed, use DEBUG(errs() instead.
514Much stuff converted to use raw_ostream instead of std::ostream.
515TargetAsmInfo renamed to MCAsmInfo
516llvm/ADT/iterator.h gone.
517
Chris Lattnerdc910082010-03-17 06:41:58 +0000518
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000519</div>
520
Chris Lattner84977642007-09-21 03:54:09 +0000521<!--=========================================================================-->
522<div class="doc_subsection">
Chris Lattner917cc712009-03-02 02:37:32 +0000523<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000524</div>
525
526<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000527<p>LLVM IR has several new features for better support of new targets and that
528expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000529
Chris Lattner791f77b2008-06-05 06:25:56 +0000530<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000531<li>...</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000532</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000533
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000534</div>
535
536<!--=========================================================================-->
537<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000538<a name="optimizer">Optimizer Improvements</a>
539</div>
540
541<div class="doc_text">
542
Chris Lattner61358ab2009-10-13 17:48:04 +0000543<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattnerf3013872008-10-13 21:50:36 +0000544release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000545
546<ul>
547
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000548<li>...</li>
Chris Lattner917cc712009-03-02 02:37:32 +0000549
Chris Lattner61358ab2009-10-13 17:48:04 +0000550</ul>
Chris Lattner917cc712009-03-02 02:37:32 +0000551
Chris Lattnerf2201912010-03-01 19:29:17 +0000552<p>Also, -anders-aa was removed</p>
553
Chris Lattner61358ab2009-10-13 17:48:04 +0000554</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000555
Chris Lattner917cc712009-03-02 02:37:32 +0000556
Chris Lattner61358ab2009-10-13 17:48:04 +0000557<!--=========================================================================-->
558<div class="doc_subsection">
559<a name="executionengine">Interpreter and JIT Improvements</a>
560</div>
Chris Lattnerf3013872008-10-13 21:50:36 +0000561
Chris Lattner61358ab2009-10-13 17:48:04 +0000562<div class="doc_text">
563
564<ul>
Jeffrey Yasskin01eba392010-01-29 19:10:38 +0000565<li>The JIT now <a
566href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
567to compiling eagerly</a> to avoid a race condition in the lazy JIT.
568Clients that still want the lazy JIT can switch it on by calling
569<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
Jeffrey Yasskin40966a72010-02-11 01:07:39 +0000570<li>It is now possible to create more than one JIT instance in the same process.
571These JITs can generate machine code in parallel,
572although <a href="http://llvm.org/docs/ProgrammersManual.html#jitthreading">you
573still have to obey the other threading restrictions</a>.</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000574</ul>
575
576</div>
577
578<!--=========================================================================-->
579<div class="doc_subsection">
Chris Lattner511433e2009-03-02 03:24:11 +0000580<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0b832202008-06-08 02:45:07 +0000581</div>
582
583<div class="doc_text">
584
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000585<p>We have put a significant amount of work into the code generator
586infrastructure, which allows us to implement more aggressive algorithms and make
587it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000588
589<ul>
Chris Lattner511433e2009-03-02 03:24:11 +0000590
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000591<li>...</li>
Chris Lattner84977642007-09-21 03:54:09 +0000592</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000593</div>
594
Chris Lattner917cc712009-03-02 02:37:32 +0000595<!--=========================================================================-->
596<div class="doc_subsection">
597<a name="x86">X86-32 and X86-64 Target Improvements</a>
598</div>
599
600<div class="doc_text">
601<p>New features of the X86 target include:
602</p>
603
604<ul>
Chris Lattner511433e2009-03-02 03:24:11 +0000605
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000606<li>...</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000607
Chris Lattner917cc712009-03-02 02:37:32 +0000608</ul>
609
Chris Lattner917cc712009-03-02 02:37:32 +0000610</div>
Chris Lattner84977642007-09-21 03:54:09 +0000611
612<!--=========================================================================-->
613<div class="doc_subsection">
Chris Lattner11398992009-02-26 07:32:11 +0000614<a name="pic16">PIC16 Target Improvements</a>
615</div>
616
617<div class="doc_text">
618<p>New features of the PIC16 target include:
619</p>
620
621<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000622<li>...</li>
Chris Lattner11398992009-02-26 07:32:11 +0000623</ul>
624
625<p>Things not yet supported:</p>
626
627<ul>
Chris Lattner11398992009-02-26 07:32:11 +0000628<li>Variable arguments.</li>
Chris Lattner511433e2009-03-02 03:24:11 +0000629<li>Interrupts/programs.</li>
Chris Lattner11398992009-02-26 07:32:11 +0000630</ul>
631
632</div>
633
Chris Lattner11398992009-02-26 07:32:11 +0000634<!--=========================================================================-->
635<div class="doc_subsection">
Chris Lattner61358ab2009-10-13 17:48:04 +0000636<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000637</div>
638
639<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000640<p>New features of the ARM target include:
641</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000642
643<ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000644
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000645<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000646</ul>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000647
Chris Lattnerc441fb82009-03-01 02:30:21 +0000648
Chris Lattner61358ab2009-10-13 17:48:04 +0000649</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000650
Chris Lattner61358ab2009-10-13 17:48:04 +0000651<!--=========================================================================-->
652<div class="doc_subsection">
653<a name="OtherTarget">Other Target Specific Improvements</a>
654</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000655
Chris Lattner61358ab2009-10-13 17:48:04 +0000656<div class="doc_text">
657<p>New features of other targets include:
658</p>
659
660<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000661<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000662</ul>
663
664</div>
665
666<!--=========================================================================-->
667<div class="doc_subsection">
668<a name="newapis">New Useful APIs</a>
669</div>
670
671<div class="doc_text">
672
673<p>This release includes a number of new APIs that are used internally, which
674 may also be useful for external clients.
675</p>
676
677<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000678<li>...</li>
Chris Lattner61358ab2009-10-13 17:48:04 +0000679</ul>
680
681
682</div>
683
684<!--=========================================================================-->
685<div class="doc_subsection">
686<a name="otherimprovements">Other Improvements and New Features</a>
687</div>
688
689<div class="doc_text">
690<p>Other miscellaneous features include:</p>
691
692<ul>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000693<li>...</li>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000694</ul>
695
696</div>
697
Chris Lattner77d29b12008-06-05 08:02:49 +0000698
699<!--=========================================================================-->
700<div class="doc_subsection">
Chris Lattnerf6662f92008-10-13 17:57:36 +0000701<a name="changes">Major Changes and Removed Features</a>
702</div>
703
704<div class="doc_text">
705
Chris Lattnereeb4da02008-10-13 22:06:31 +0000706<p>If you're already an LLVM user or developer with out-of-tree changes based
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000707on LLVM 2.6, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000708from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000709
710<ul>
Jeffrey Yasskinbc83d062010-02-09 23:03:44 +0000711<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
712if you have it installed. This makes it more likely that an LLVM built on one
713system will work when copied to a similar system. To use <tt>libffi</tt>,
714configure with <tt>--enable-libffi</tt>.
715</li>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000716</ul>
717
718
719<p>In addition, many APIs have changed in this release. Some of the major LLVM
720API changes are:</p>
721
722<ul>
Jeffrey Yasskin4fcd6072010-01-28 01:41:20 +0000723<li><tt>ModuleProvider</tt> has been <a
724href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
725and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
726Most clients can remove uses of <tt>ExistingModuleProvider</tt>,
727replace <tt>getBitcodeModuleProvider</tt> with
728<tt>getLazyBitcodeModule</tt>, and pass their <tt>Module</tt> to
729functions that used to accept <tt>ModuleProvider</tt>. Clients who
730wrote their own <tt>ModuleProvider</tt>s will need to derive from
731<tt>GVMaterializer</tt> instead and use
732<tt>Module::setMaterializer</tt> to attach it to a
733<tt>Module</tt>.</li>
734
735<li><tt>GhostLinkage</tt> has given up the ghost.
736<tt>GlobalValue</tt>s that have not yet been read from their backing
737storage have the same linkage they will have after being read in.
738Clients must replace calls to
739<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
740<tt>GlobalValue::isMaterializable</tt>.</li>
Daniel Dunbar4acdede2010-02-10 04:09:52 +0000741
742<li>FIXME: Debug info has been totally redone. Add pointers to new APIs. Substantial caveats about compatibility of .ll and .bc files.</li>
743
Daniel Dunbarca1c8162010-02-14 01:47:19 +0000744<li>The <tt>llvm/Support/DataTypes.h</tt> header has moved
745to <tt>llvm/System/DataTypes.h</tt>.</li>
746
Duncan Sands411432d2010-02-17 17:20:17 +0000747<li>The <tt>isInteger</tt>, <tt>isIntOrIntVector</tt>, <tt>isFloatingPoint</tt>,
748<tt>isFPOrFPVector</tt> and <tt>isFPOrFPVector</tt> methods have been renamed
749<tt>isIntegerTy</tt>, <tt>isIntOrIntVectorTy</tt>, <tt>isFloatingPointTy</tt>,
750<tt>isFPOrFPVectorTy</tt> and <tt>isFPOrFPVectorTy</tt> respectively.</li>
Devang Patelb34dd132008-10-14 20:03:43 +0000751</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000752
Chris Lattnerf6662f92008-10-13 17:57:36 +0000753</div>
754
755
756
Chris Lattner19092612003-10-02 16:38:05 +0000757<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000758<div class="doc_section">
759 <a name="portability">Portability and Supported Platforms</a>
760</div>
Chris Lattner19092612003-10-02 16:38:05 +0000761<!-- *********************************************************************** -->
762
Misha Brukman500bc302003-11-22 00:38:41 +0000763<div class="doc_text">
764
John Criswell0b5b5e92004-12-08 20:35:47 +0000765<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000766
767<ul>
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000768<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
Chris Lattner61358ab2009-10-13 17:48:04 +0000769 Linux, Fedora Core, FreeBSD and AuroraUX (and probably other unix-like
770 systems).</li>
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000771<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
Chris Lattner61358ab2009-10-13 17:48:04 +0000772 and 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000773<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000774<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
775 support is available for native builds with Visual C++).</li>
Chris Lattner7e23d6e2009-10-16 16:30:58 +0000776<li>Sun x86 and AMD64 machines running Solaris 10, OpenSolaris 0906.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000777<li>Alpha-based machines running Debian GNU/Linux.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000778</ul>
779
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000780<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000781to the machine and operating system on which it is built. However, minor
782porting may be required to get LLVM to work on new platforms. We welcome your
783portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000784
Misha Brukman500bc302003-11-22 00:38:41 +0000785</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000786
787<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000788<div class="doc_section">
789 <a name="knownproblems">Known Problems</a>
790</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000791<!-- *********************************************************************** -->
792
Misha Brukman500bc302003-11-22 00:38:41 +0000793<div class="doc_text">
794
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000795<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000796listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000797href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000798there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000799
Chris Lattner477a1fd2010-03-17 17:25:49 +0000800<ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000801<li>LLVM will not correctly compile on Solaris and/or OpenSolaris
802using the stock GCC 3.x.x series 'out the box',
Chris Lattner554ee4a2009-11-03 21:50:09 +0000803See: <a href="GettingStarted.html#brokengcc">Broken versions of GCC and other tools</a>.
Chris Lattner61358ab2009-10-13 17:48:04 +0000804However, A <a href="http://pkg.auroraux.org/GCC">Modern GCC Build</a>
805for x86/x86-64 has been made available from the third party AuroraUX Project
806that has been meticulously tested for bootstrapping LLVM &amp; Clang.</li>
807</ul>
808
Misha Brukman500bc302003-11-22 00:38:41 +0000809</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000810
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000811<!-- ======================================================================= -->
812<div class="doc_subsection">
813 <a name="experimental">Experimental features included with this release</a>
814</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000815
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000816<div class="doc_text">
817
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000818<p>The following components of this LLVM release are either untested, known to
819be broken or unreliable, or are in early development. These components should
820not be relied on, and bugs should not be filed against them, but they may be
821useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000822components, please contact us on the <a
823href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000824
825<ul>
Wesley Peck7c4a1212010-03-18 14:31:30 +0000826<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
827 backends are experimental.</li>
Bill Wendling99dac472009-03-02 07:54:14 +0000828<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000829 supported value for this option. The MachO writer is experimental, and
830 works much better in mainline SVN.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000831</ul>
832
833</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000834
Misha Brukman500bc302003-11-22 00:38:41 +0000835<!-- ======================================================================= -->
836<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000837 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000838</div>
839
840<div class="doc_text">
841
842<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000843 <li>The X86 backend does not yet support
844 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
845 floating point stack</a>. It supports the 'f' and 't' constraints, but not
846 'u'.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000847 <li>The X86 backend generates inefficient floating point code when configured
848 to generate code for systems that don't have SSE2.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000849 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswell524a5dd2009-03-02 15:28:15 +0000850 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
851 runtime currently due
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000852 to <a href="http://llvm.org/PR2255">several</a>
John Criswell524a5dd2009-03-02 15:28:15 +0000853 <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for
854 the
855 'u' inline assembly constraint and for X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000856 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner917cc712009-03-02 02:37:32 +0000857 <tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000858 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000859</ul>
860
861</div>
862
863<!-- ======================================================================= -->
864<div class="doc_subsection">
865 <a name="ppc-be">Known problems with the PowerPC back-end</a>
866</div>
867
868<div class="doc_text">
869
870<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000871<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000872compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000873</ul>
874
875</div>
876
877<!-- ======================================================================= -->
878<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000879 <a name="arm-be">Known problems with the ARM back-end</a>
880</div>
881
882<div class="doc_text">
883
884<ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000885<li>Support for the Advanced SIMD (Neon) instruction set is still incomplete
886and not well tested. Some features may not work at all, and the code quality
887may be poor in some cases.</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000888<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000889processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000890results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000891<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000892</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000893</ul>
894
895</div>
896
897<!-- ======================================================================= -->
898<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000899 <a name="sparc-be">Known problems with the SPARC back-end</a>
900</div>
901
902<div class="doc_text">
903
904<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000905<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattner26299222006-11-18 07:51:14 +0000906 support the 64-bit SPARC ABI (-m64).</li>
907</ul>
908
909</div>
910
911<!-- ======================================================================= -->
912<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000913 <a name="mips-be">Known problems with the MIPS back-end</a>
914</div>
915
916<div class="doc_text">
917
918<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000919<li>64-bit MIPS targets are not supported yet.</li>
920</ul>
921
922</div>
923
924<!-- ======================================================================= -->
925<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000926 <a name="alpha-be">Known problems with the Alpha back-end</a>
927</div>
928
929<div class="doc_text">
930
931<ul>
932
933<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
934appropriate nops inserted to ensure restartability.</li>
935
John Criswellc0c186d2005-11-08 21:11:33 +0000936</ul>
937</div>
938
Chris Lattner26299222006-11-18 07:51:14 +0000939<!-- ======================================================================= -->
940<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000941 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000942</div>
943
944<div class="doc_text">
945
946<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000947<li><a href="http://llvm.org/PR802">The C backend has only basic support for
948 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000949<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
950 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif4906abe2009-03-02 12:02:51 +0000951 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000952<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000953<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000954</ul>
955
956</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000957
Misha Brukman500bc302003-11-22 00:38:41 +0000958
959<!-- ======================================================================= -->
960<div class="doc_subsection">
Chris Lattnerc66bfef2010-03-17 04:41:49 +0000961 <a name="c-fe">Known problems with the llvm-gcc C and C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000962</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000963
Misha Brukman500bc302003-11-22 00:38:41 +0000964<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000965
Chris Lattner5733b272008-06-05 06:35:40 +0000966<p>The only major language feature of GCC not supported by llvm-gcc is
967 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
968 are only supported on some targets. For example, trampolines are only
Duncan Sands27aff872008-06-08 20:18:35 +0000969 supported on some targets (these are used when you take the address of a
970 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000971
Chris Lattner5733b272008-06-05 06:35:40 +0000972<p>If you run into GCC extensions which are not supported, please let us know.
973</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000974
Misha Brukman500bc302003-11-22 00:38:41 +0000975</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000976
Misha Brukman500bc302003-11-22 00:38:41 +0000977<!-- ======================================================================= -->
978<div class="doc_subsection">
Chris Lattner1eb4df62008-10-30 03:58:13 +0000979 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
980</div>
981
982<div class="doc_text">
Gabor Greifba10fe02008-11-04 21:50:59 +0000983<ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000984<li>Fortran support generally works, but there are still several unresolved bugs
Chris Lattner61358ab2009-10-13 17:48:04 +0000985 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
986 tools/gfortran component for details.</li>
Gabor Greifba10fe02008-11-04 21:50:59 +0000987</ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000988</div>
Misha Brukman500bc302003-11-22 00:38:41 +0000989
Chris Lattner2b659ef2008-02-12 06:29:45 +0000990<!-- ======================================================================= -->
991<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000992 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000993</div>
994
995<div class="doc_text">
John Criswell524a5dd2009-03-02 15:28:15 +0000996The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
997technology, and problems should be expected.
Chris Lattner2b659ef2008-02-12 06:29:45 +0000998<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000999<li>The Ada front-end currently only builds on X86-32. This is mainly due
John Criswell524a5dd2009-03-02 15:28:15 +00001000to lack of trampoline support (pointers to nested functions) on other platforms.
1001However, it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +00001002which does support trampolines.</li>
1003<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sands326a4982009-02-25 11:59:06 +00001004This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
1005exception handling, which is used internally by the compiler.
Chris Lattner61358ab2009-10-13 17:48:04 +00001006Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +00001007<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
1008and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands326a4982009-02-25 11:59:06 +00001009(c380004 also fails with gcc-4.2 mainline).
1010If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
1011causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsdd3e6722009-03-02 16:35:57 +00001012<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner61358ab2009-10-13 17:48:04 +00001013<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattner2b659ef2008-02-12 06:29:45 +00001014<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
Chris Lattner61358ab2009-10-13 17:48:04 +00001015crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +00001016<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
1017or finish at a non-byte offset</a> in a record. Workaround: do not pack records
1018or use representation clauses that result in a field of a non-discrete type
1019starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +00001020<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
1021'main' as generated by the Ada binder to be invalid</a>.
1022Workaround: hand edit the file to use pointers for <tt>argv</tt> and
1023<tt>envp</tt> rather than integers.</li>
1024<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
1025ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +00001026</ul>
1027</div>
1028
Chris Lattner79c3fe12003-10-02 04:57:28 +00001029<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +00001030<div class="doc_section">
1031 <a name="additionalinfo">Additional Information</a>
1032</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001033<!-- *********************************************************************** -->
1034
Misha Brukman500bc302003-11-22 00:38:41 +00001035<div class="doc_text">
1036
Chris Lattner416db102005-05-16 17:13:10 +00001037<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +00001038href="http://llvm.org">LLVM web page</a>, in particular in the <a
1039href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +00001040contains versions of the API documentation which is up-to-date with the
1041Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +00001042You can access versions of these documents specific to this release by going
1043into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001044
Misha Brukman500bc302003-11-22 00:38:41 +00001045<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +00001046us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +00001047lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001048
Misha Brukman500bc302003-11-22 00:38:41 +00001049</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001050
1051<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +00001052
Misha Brukman500bc302003-11-22 00:38:41 +00001053<hr>
Misha Brukman2061e892003-11-22 01:23:39 +00001054<address>
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Chris Lattnerb4b0ce72007-05-18 00:44:29 +00001060 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
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