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Chris Lattner38ab04c2009-02-25 04:41:31 +00007 <title>LLVM 2.5 Release Notes</title>
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9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +000010
Chris Lattner38ab04c2009-02-25 04:41:31 +000011<div class="doc_title">LLVM 2.5 Release Notes</div>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000012
Chris Lattner79c3fe12003-10-02 04:57:28 +000013<ol>
Misha Brukman500bc302003-11-22 00:38:41 +000014 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +000015 <li><a href="#subproj">Sub-project Status Update</a></li>
16 <li><a href="#whatsnew">What's New in LLVM?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +000017 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000018 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +000019 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000020 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +000021</ol>
22
Chris Lattner7911ce22004-05-23 21:07:27 +000023<div class="doc_author">
Dan Gohman44aa9212008-10-14 16:23:02 +000024 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +000025</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000026
27<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000028<div class="doc_section">
29 <a name="intro">Introduction</a>
30</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000031<!-- *********************************************************************** -->
32
Misha Brukman500bc302003-11-22 00:38:41 +000033<div class="doc_text">
34
Chris Lattnerf6662f92008-10-13 17:57:36 +000035<p>This document contains the release notes for the LLVM Compiler
Chris Lattner38ab04c2009-02-25 04:41:31 +000036Infrastructure, release 2.5. Here we describe the status of LLVM, including
Chris Lattnerf6662f92008-10-13 17:57:36 +000037major improvements from the previous release and significant known problems.
38All LLVM releases may be downloaded from the <a
39href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +000040
Chris Lattner7506b1d2004-12-07 08:04:13 +000041<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +000042release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +000043web site</a>. If you have questions or comments, the <a
Chris Lattnerf6662f92008-10-13 17:57:36 +000044href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
45List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +000046
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000047<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +000048main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greiffa933f82008-10-14 11:00:32 +000049current one. To see the release notes for a specific release, please see the
Chris Lattner84977642007-09-21 03:54:09 +000050<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +000051
52</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000053
Chris Lattner38ab04c2009-02-25 04:41:31 +000054<!-- Unfinished features in 2.5:
Chris Lattneracce85d2008-02-10 07:46:44 +000055 Machine LICM
56 Machine Sinking
Chris Lattner74c80df2009-02-25 06:34:50 +000057 target-specific intrinsics
58 gold lto plugin
Chris Lattner99f375b2009-02-25 07:32:53 +000059 pre-alloc splitter, strong phi elim
Chris Lattner547a3912008-10-12 19:47:48 +000060 llc -enable-value-prop, propagation of value info (sign/zero ext info) from
61 one MBB to another
Chris Lattner74c80df2009-02-25 06:34:50 +000062 debug info for optimized code
Chris Lattner99f375b2009-02-25 07:32:53 +000063
Chris Lattneracce85d2008-02-10 07:46:44 +000064 -->
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000065
Chris Lattner547a3912008-10-12 19:47:48 +000066 <!-- for announcement email:
Chris Lattner74c80df2009-02-25 06:34:50 +000067 -->
Chris Lattneracce85d2008-02-10 07:46:44 +000068
Chris Lattner96a445e2008-10-13 18:01:01 +000069<!-- *********************************************************************** -->
70<div class="doc_section">
71 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerea34f642008-06-08 21:34:41 +000072</div>
Chris Lattner96a445e2008-10-13 18:01:01 +000073<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +000074
75<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +000076<p>
Chris Lattner38ab04c2009-02-25 04:41:31 +000077The LLVM 2.5 distribution currently consists of code from the core LLVM
Chris Lattnerfb97b2d2008-10-13 18:11:54 +000078repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattner8348b472008-06-08 21:58:17 +000079supporting tools) and the llvm-gcc repository. In addition to this code, the
80LLVM Project includes other sub-projects that are in development. The two which
Chris Lattner857fb132008-10-11 18:18:28 +000081are the most actively developed are the <a href="#clang">Clang Project</a> and
Nicolas Geoffray99a4d302008-10-14 19:23:04 +000082the <a href="#vmkit">VMKit Project</a>.
Chris Lattner8348b472008-06-08 21:58:17 +000083</p>
Chris Lattner96a445e2008-10-13 18:01:01 +000084
Chris Lattner8348b472008-06-08 21:58:17 +000085</div>
86
Chris Lattner96a445e2008-10-13 18:01:01 +000087
Chris Lattner8348b472008-06-08 21:58:17 +000088<!--=========================================================================-->
Chris Lattner96a445e2008-10-13 18:01:01 +000089<div class="doc_subsection">
Chris Lattnerfb97b2d2008-10-13 18:11:54 +000090<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattner8348b472008-06-08 21:58:17 +000091</div>
92
93<div class="doc_text">
94
95<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
96a set of new 'LLVM native' front-end technologies for the LLVM optimizer
Chris Lattnerf40c40b2009-02-25 05:09:54 +000097and code generator. While Clang is not included in the LLVM 2.5 release, it
98is continuing to make major strides forward in all areas. Its C and Objective-C
99parsing and code generation support is now very solid. For example, it is
100capable of successfully building many real applications for X86-32 and X86-64,
101including the FreeBSD kernel. C++ is also making <a
102href="http://clang.llvm.org/cxx_status.html">incredible progress</a>, and work
103on templates has recently started.</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000104
Chris Lattnerf40c40b2009-02-25 05:09:54 +0000105<p>While Clang is not yet production quality, it is progressing very nicely and
106is quite usable for building many C and Objective-C applications. If you are
107interested in fast compiles and good diagnostics, we encourage you to try it out
Chris Lattner74c80df2009-02-25 06:34:50 +0000108by <a href="http://clang.llvm.org/get_started.html">building from mainline</a>
Chris Lattnerf40c40b2009-02-25 05:09:54 +0000109and reporting any issues you hit to the <a
110href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">Clang front-end mailing
111list</a>.</p>
112
113<p>In the LLVM 2.5 time-frame, the Clang team has made many improvements:</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000114
Daniel Dunbar13739432008-10-14 23:25:09 +0000115<ul>
Chris Lattnerf40c40b2009-02-25 05:09:54 +0000116<li>Clang now has a new driver, which is focused on providing a GCC-compatible
117 interface.</li>
118<li>The X86-64 ABI is now supported.</li>
119<li>Precompiled header support is now implemented.</li>
120<li>Objective-C support is significantly improved beyond LLVM 2.4, supporting
121 many features, such as Objective-C Garbage Collection.</li>
122<li>Many many bugs are fixed.</li>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000123</div>
124
125<!--=========================================================================-->
126<div class="doc_subsection">
127<a name="clangsa">Clang Static Analyzer</a>
128</div>
129
130<div class="doc_text">
131
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000132<p>The Clang project also includes an early stage static source code analysis
133tool for <a href="http://clang.llvm.org/StaticAnalysis.html">automatically
134finding bugs</a> in C and Objective-C programs. The tool performs a growing set
Chris Lattnerc702d162008-10-14 06:02:29 +0000135of checks to find bugs that occur on a specific path within a program. Examples
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000136of bugs the tool finds include logic errors such as null dereferences,
137violations of various API rules, dead code, and potential memory leaks in
Chris Lattnerc702d162008-10-14 06:02:29 +0000138Objective-C programs. Since its inception, public feedback on the tool has been
139extremely positive, and conservative estimates put the number of real bugs it
140has found in industrial-quality software on the order of thousands.</p>
Chris Lattnercc042612008-10-14 00:52:49 +0000141
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000142<p>The tool also provides a simple web GUI to inspect potential bugs found by
Chris Lattnerc702d162008-10-14 06:02:29 +0000143the tool. While still early in development, the GUI illustrates some of the key
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000144features of Clang: accurate source location information, which is used by the
145GUI to highlight specific code expressions that relate to a bug (including those
Bill Wendling741748a2008-10-27 09:27:33 +0000146that span multiple lines); and built-in knowledge of macros, which is used to
Ted Kremenek3c3ec0c2008-10-14 05:14:21 +0000147perform inline expansion of macros within the GUI itself.</p>
148
Chris Lattnerc702d162008-10-14 06:02:29 +0000149<p>The set of checks performed by the static analyzer is gradually expanding,
Bill Wendling741748a2008-10-27 09:27:33 +0000150and future plans for the tool include full source-level inter-procedural
151analysis and deeper checks such as buffer overrun detection. There are many
152opportunities to extend and enhance the static analyzer, and anyone interested
153in working on this project is encouraged to get involved!</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000154
155</div>
156
Chris Lattner96a445e2008-10-13 18:01:01 +0000157<!--=========================================================================-->
158<div class="doc_subsection">
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000159<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner96a445e2008-10-13 18:01:01 +0000160</div>
161
162<div class="doc_text">
163<p>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000164The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner96a445e2008-10-13 18:01:01 +0000165a JVM and a CLI Virtual Machines (Microsoft .NET is an
166implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
167
Chris Lattner1f859862009-02-25 05:45:05 +0000168<p>Following LLVM 2.5, VMKit has its first release ? that you can find on its
Nicolas Geoffray56d313d2008-10-15 20:25:04 +0000169<a href="http://vmkit.llvm.org/releases/">webpage</a>. The release includes
170bug fixes, cleanup and new features. The major changes are:</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000171
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000172<ul>
173
Chris Lattner75e26ca2009-02-26 05:20:36 +0000174<li>Ahead of Time compiler: compiles .class files to llvm .bc. VMKit uses this
175functionality to native compile the standard classes (eg java.lang.String).
176Users can compile AOT .class files into dynamic libraries and run them with the
177help of VMKit.</li>
178
179<li>New exception model: the dwarf exception model is very slow for
180exception-intensive applications, so the JVM has had a new implementation of
181exceptions which check at each function call if an exception happened. There is
182a low performance penalty on applications without exceptions, but it is a big
183gain for exception-intensive applications. For example the jack benchmark in
184Spec JVM98 is 6x faster (performance gain of 83%).</li>
185
186<li>New support for OSX/X64, Linux/X64 (with the Boehm GC), Linux/ppc32.</li>
Nicolas Geoffray99a4d302008-10-14 19:23:04 +0000187
188</ul>
Chris Lattner96a445e2008-10-13 18:01:01 +0000189</div>
190
Chris Lattner8348b472008-06-08 21:58:17 +0000191
192<!-- *********************************************************************** -->
193<div class="doc_section">
Chris Lattner96a445e2008-10-13 18:01:01 +0000194 <a name="whatsnew">What's New in LLVM?</a>
Chris Lattner8348b472008-06-08 21:58:17 +0000195</div>
196<!-- *********************************************************************** -->
197
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000198<div class="doc_text">
199
Bill Wendling741748a2008-10-27 09:27:33 +0000200<p>This release includes a huge number of bug fixes, performance tweaks, and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000201minor improvements. Some of the major improvements and new features are listed
202in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000203</p>
204</div>
205
Chris Lattner8348b472008-06-08 21:58:17 +0000206<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000207<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000208<a name="majorfeatures">Major New Features</a>
209</div>
210
211<div class="doc_text">
212
Chris Lattner38ab04c2009-02-25 04:41:31 +0000213<p>LLVM 2.5 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000214
215<ul>
Duncan Sands8524cb92009-02-25 11:37:39 +0000216<li><p>The code generator now supports arbitrary precision integers.
217Types like <tt>i33</tt> have long been valid in the LLVM IR, but previously
218could only be used with the interpreter.
219Now IR using such types can be compiled to native code on all targets.
220All operations are supported if the integer is not bigger than twice the
221target machine word size.
222Simple operations like loads, stores and shifts by a constant amount are
223supported for integers of any size.
224</p></li>
Chris Lattner74c80df2009-02-25 06:34:50 +0000225
226<!--
227Random stuff:
228
Chris Lattner99f375b2009-02-25 07:32:53 +0000229xcore backend!
230fortran on darwin!
231
Chris Lattner74c80df2009-02-25 06:34:50 +0000232.ll parser rewrite.
233GCC inliner off.
234cmake mature?
235x86 backend FS/GS segment address spaces?
236nocapture
237memdep is faster / more aggressive.
Chris Lattner99f375b2009-02-25 07:32:53 +0000238how to write a backend doc docs/WritingAnLLVMBackend.html
Chris Lattner74c80df2009-02-25 06:34:50 +0000239fastisel + exception handling
240vector widening <3 x float> -> <4 x float>
Chris Lattner99f375b2009-02-25 07:32:53 +0000241arm port improvements? arm jit encoding stuff, constant island support?
Chris Lattner75e26ca2009-02-26 05:20:36 +0000242JIT TLS support on x86-32.
Chris Lattner99f375b2009-02-25 07:32:53 +0000243mem2reg now faster on code with huge basic blocks
244stack protectors/stack canaries, -fstack-protector, controllable on a
245 per-function basis with attributes.
246shufflevector is generalized to allow different shuffle mask width than its
247 input vectors.
248loop optimizer improves floating point induction variables
249llvm/Analysis/DebugInfo.h classes, llvm-gcc and clang and codegen use them.
250asmprinters seperate from targets for jits
Chris Lattner75e26ca2009-02-26 05:20:36 +0000251PBQP register allocator now supports register coalescing.
252
Chris Lattner74c80df2009-02-25 06:34:50 +0000253-->
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000254
Chris Lattner8170c102008-02-10 08:18:42 +0000255</ul>
256
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000257</div>
258
Chris Lattner791f77b2008-06-05 06:25:56 +0000259
260<!--=========================================================================-->
261<div class="doc_subsection">
Chris Lattnerea34f642008-06-08 21:34:41 +0000262<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattner791f77b2008-06-05 06:25:56 +0000263</div>
264
265<div class="doc_text">
266
Chris Lattnerb82eb062008-10-13 20:47:20 +0000267<p>LLVM fully supports the llvm-gcc 4.2 front-end, which marries the GCC
268front-ends and driver with the LLVM optimizer and code generator. It currently
269includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattner791f77b2008-06-05 06:25:56 +0000270
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000271<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000272<li>?</li>
Gabor Greifa3bd11d2008-06-09 06:06:18 +0000273</ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000274
Chris Lattner791f77b2008-06-05 06:25:56 +0000275</div>
276
277
Chris Lattner84977642007-09-21 03:54:09 +0000278<!--=========================================================================-->
279<div class="doc_subsection">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000280<a name="coreimprovements">LLVM Core Improvements</a>
281</div>
282
283<div class="doc_text">
Bill Wendling741748a2008-10-27 09:27:33 +0000284<p>New features include:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000285
Chris Lattner791f77b2008-06-05 06:25:56 +0000286<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000287<li>?</li>
Chris Lattner7752d1a2008-10-13 20:59:32 +0000288
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000289</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000290
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000291</div>
292
293<!--=========================================================================-->
294<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000295<a name="optimizer">Optimizer Improvements</a>
296</div>
297
298<div class="doc_text">
299
Chris Lattnerf3013872008-10-13 21:50:36 +0000300<p>In addition to a huge array of bug fixes and minor performance tweaks, this
301release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000302
303<ul>
304
Chris Lattner38ab04c2009-02-25 04:41:31 +0000305<li>?</li>
Chris Lattnerf3013872008-10-13 21:50:36 +0000306
Chris Lattner0b832202008-06-08 02:45:07 +0000307</ul>
308
309</div>
310
311<!--=========================================================================-->
312<div class="doc_subsection">
313<a name="codegen">Code Generator Improvements</a>
314</div>
315
316<div class="doc_text">
317
Gabor Greifa8b84902008-10-14 11:31:14 +0000318<p>We have put a significant amount of work into the code generator infrastructure,
Chris Lattner0b832202008-06-08 02:45:07 +0000319which allows us to implement more aggressive algorithms and make it run
320faster:</p>
321
322<ul>
Duncan Sands07636ea2009-02-25 11:50:08 +0000323<li>The type legalization logic has been completely rewritten, and is now
324more powerful (it supports arbitrary precision integer types for example)
325and hopefully more correct.
326The type legalizer converts operations on types that are not natively
327supported by the target machine into equivalent code sequences that only use
328natively supported types.
329The old type legalizer is still available and will be used if
330<tt>-disable-legalize-types</tt> is passed to <tt>llc</tt>.
331</li>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000332<li>?</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000333
Chris Lattner84977642007-09-21 03:54:09 +0000334</ul>
335
336</div>
337
338
339<!--=========================================================================-->
340<div class="doc_subsection">
Chris Lattnereeb4da02008-10-13 22:06:31 +0000341<a name="targetspecific">Target Specific Improvements</a>
Chris Lattner84977642007-09-21 03:54:09 +0000342</div>
Chris Lattner60893e52007-05-18 06:33:02 +0000343
Chris Lattner738bd302006-04-18 06:32:08 +0000344<div class="doc_text">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000345<p>New target-specific features include:
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000346</p>
Chris Lattner26299222006-11-18 07:51:14 +0000347
348<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000349<li>?</li>
Chris Lattner77d29b12008-06-05 08:02:49 +0000350</ul>
Chris Lattner77d29b12008-06-05 08:02:49 +0000351
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000352</div>
Chris Lattner77d29b12008-06-05 08:02:49 +0000353
354
355<!--=========================================================================-->
356<div class="doc_subsection">
Chris Lattner84977642007-09-21 03:54:09 +0000357<a name="otherimprovements">Other Improvements</a>
358</div>
359
360<div class="doc_text">
361<p>New features include:
362</p>
363
364<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000365<li>?</li>
Tanya Lattnera7ec7062008-11-04 18:40:27 +0000366
Chris Lattner84977642007-09-21 03:54:09 +0000367</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000368
Chris Lattner84977642007-09-21 03:54:09 +0000369</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000370
Chris Lattnerf6662f92008-10-13 17:57:36 +0000371<!--=========================================================================-->
372<div class="doc_subsection">
373<a name="changes">Major Changes and Removed Features</a>
374</div>
375
376<div class="doc_text">
377
Chris Lattnereeb4da02008-10-13 22:06:31 +0000378<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattner38ab04c2009-02-25 04:41:31 +0000379on LLVM 2.4, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000380from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000381
382<ul>
383
Chris Lattner38ab04c2009-02-25 04:41:31 +0000384<li>?</li>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000385</ul>
386
387
388<p>In addition, many APIs have changed in this release. Some of the major LLVM
389API changes are:</p>
390
391<ul>
Chris Lattner38ab04c2009-02-25 04:41:31 +0000392<li>?</li>
Devang Patelb34dd132008-10-14 20:03:43 +0000393</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000394
Chris Lattner38ab04c2009-02-25 04:41:31 +0000395<li>?</li>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000396</ul>
397
398</div>
399
400
401
Chris Lattner19092612003-10-02 16:38:05 +0000402<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000403<div class="doc_section">
404 <a name="portability">Portability and Supported Platforms</a>
405</div>
Chris Lattner19092612003-10-02 16:38:05 +0000406<!-- *********************************************************************** -->
407
Misha Brukman500bc302003-11-22 00:38:41 +0000408<div class="doc_text">
409
John Criswell0b5b5e92004-12-08 20:35:47 +0000410<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000411
412<ul>
Chris Lattnere18b32e2008-11-10 05:40:34 +0000413<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
414Linux, Fedora Core and FreeBSD (and probably other unix-like systems).</li>
415<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
416and 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000417<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000418<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
419 support is available for native builds with Visual C++).</li>
Gabor Greif96a89c72008-06-05 18:39:01 +0000420<li>Sun UltraSPARC workstations running Solaris 10.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000421<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif96a89c72008-06-05 18:39:01 +0000422<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000423</ul>
424
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000425<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000426to the machine and operating system on which it is built. However, minor
427porting may be required to get LLVM to work on new platforms. We welcome your
428portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000429
Misha Brukman500bc302003-11-22 00:38:41 +0000430</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000431
432<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000433<div class="doc_section">
434 <a name="knownproblems">Known Problems</a>
435</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000436<!-- *********************************************************************** -->
437
Misha Brukman500bc302003-11-22 00:38:41 +0000438<div class="doc_text">
439
Chris Lattnere18b32e2008-11-10 05:40:34 +0000440<p>This section contains significant known problems with the LLVM system,
441listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000442href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000443there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000444
Misha Brukman500bc302003-11-22 00:38:41 +0000445</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000446
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000447<!-- ======================================================================= -->
448<div class="doc_subsection">
449 <a name="experimental">Experimental features included with this release</a>
450</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000451
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000452<div class="doc_text">
453
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000454<p>The following components of this LLVM release are either untested, known to
455be broken or unreliable, or are in early development. These components should
456not be relied on, and bugs should not be filed against them, but they may be
457useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000458components, please contact us on the <a
459href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000460
461<ul>
Gabor Greifa8b84902008-10-14 11:31:14 +0000462<li>The MSIL, IA64, Alpha, SPU, MIPS, and PIC16 backends are experimental.</li>
Duncan Sands27aff872008-06-08 20:18:35 +0000463<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattner000c73b2008-02-06 06:30:34 +0000464 value for this option.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000465</ul>
466
467</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000468
Misha Brukman500bc302003-11-22 00:38:41 +0000469<!-- ======================================================================= -->
470<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000471 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000472</div>
473
474<div class="doc_text">
475
476<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000477 <li>The X86 backend does not yet support
478 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
479 floating point stack</a>. It supports the 'f' and 't' constraints, but not
480 'u'.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000481 <li>The X86 backend generates inefficient floating point code when configured
482 to generate code for systems that don't have SSE2.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000483 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000484 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
485 currently due
486 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattner04af7cb2008-06-08 23:12:47 +0000487 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
488 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000489 <li>The X86-64 backend does not yet support the LLVM IR instruction
490 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
491 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000492</ul>
493
494</div>
495
496<!-- ======================================================================= -->
497<div class="doc_subsection">
498 <a name="ppc-be">Known problems with the PowerPC back-end</a>
499</div>
500
501<div class="doc_text">
502
503<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000504<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000505compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000506</ul>
507
508</div>
509
510<!-- ======================================================================= -->
511<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000512 <a name="arm-be">Known problems with the ARM back-end</a>
513</div>
514
515<div class="doc_text">
516
517<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000518<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000519processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000520results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000521<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
522</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000523<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
524 execute
Chris Lattner57a460e2007-05-23 04:39:32 +0000525programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000526</ul>
527
528</div>
529
530<!-- ======================================================================= -->
531<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000532 <a name="sparc-be">Known problems with the SPARC back-end</a>
533</div>
534
535<div class="doc_text">
536
537<ul>
538<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
539 support the 64-bit SPARC ABI (-m64).</li>
540</ul>
541
542</div>
543
544<!-- ======================================================================= -->
545<div class="doc_subsection">
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000546 <a name="mips-be">Known problems with the MIPS back-end</a>
547</div>
548
549<div class="doc_text">
550
551<ul>
552<li>The O32 ABI is not fully supported.</li>
553<li>64-bit MIPS targets are not supported yet.</li>
554</ul>
555
556</div>
557
558<!-- ======================================================================= -->
559<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000560 <a name="alpha-be">Known problems with the Alpha back-end</a>
561</div>
562
563<div class="doc_text">
564
565<ul>
566
567<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
568appropriate nops inserted to ensure restartability.</li>
569
John Criswellc0c186d2005-11-08 21:11:33 +0000570</ul>
571</div>
572
Chris Lattner26299222006-11-18 07:51:14 +0000573<!-- ======================================================================= -->
574<div class="doc_subsection">
575 <a name="ia64-be">Known problems with the IA64 back-end</a>
576</div>
577
578<div class="doc_text">
579
580<ul>
Chris Lattner04af7cb2008-06-08 23:12:47 +0000581<li>The Itanium backend is highly experimental, and has a number of known
582 issues. We are looking for a maintainer for the Itanium backend. If you
Gabor Greif3bd3a262008-10-15 10:47:24 +0000583 are interested, please contact the LLVMdev mailing list.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000584</ul>
585
586</div>
587
588<!-- ======================================================================= -->
589<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000590 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000591</div>
592
593<div class="doc_text">
594
595<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000596<li><a href="http://llvm.org/PR802">The C backend has only basic support for
597 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000598<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
599 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sands27aff872008-06-08 20:18:35 +0000600 C++ code compiled with llc or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000601<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000602<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000603</ul>
604
605</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000606
Misha Brukman500bc302003-11-22 00:38:41 +0000607
608<!-- ======================================================================= -->
609<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000610 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000611</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000612
Misha Brukman500bc302003-11-22 00:38:41 +0000613<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000614
Chris Lattner252b83d2008-02-06 18:00:06 +0000615<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
616Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Gabor Greif3bd3a262008-10-15 10:47:24 +0000617LLVMdev mailing list if you are interested.</p>
Chris Lattnerd9ea0172006-08-08 17:27:28 +0000618
Chris Lattner5733b272008-06-05 06:35:40 +0000619<p>The only major language feature of GCC not supported by llvm-gcc is
620 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
621 are only supported on some targets. For example, trampolines are only
Duncan Sands27aff872008-06-08 20:18:35 +0000622 supported on some targets (these are used when you take the address of a
623 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000624
Chris Lattner5733b272008-06-05 06:35:40 +0000625<p>If you run into GCC extensions which are not supported, please let us know.
626</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000627
Misha Brukman500bc302003-11-22 00:38:41 +0000628</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000629
Misha Brukman500bc302003-11-22 00:38:41 +0000630<!-- ======================================================================= -->
631<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000632 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000633</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000634
Misha Brukman500bc302003-11-22 00:38:41 +0000635<div class="doc_text">
636
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000637<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000638tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000639itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000640
Misha Brukman500bc302003-11-22 00:38:41 +0000641<ul>
Anton Korobeynikov0021fc12008-10-11 18:27:16 +0000642<li>Exception handling works well on the X86 and PowerPC targets. Currently
Chris Lattnere18b32e2008-11-10 05:40:34 +0000643 only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000644</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000645
Misha Brukman500bc302003-11-22 00:38:41 +0000646</div>
647
Chris Lattner1eb4df62008-10-30 03:58:13 +0000648<!-- ======================================================================= -->
649<div class="doc_subsection">
650 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
651</div>
652
653<div class="doc_text">
Gabor Greifba10fe02008-11-04 21:50:59 +0000654<ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000655<li>Fortran support generally works, but there are still several unresolved bugs
656 in Bugzilla. Please see the tools/gfortran component for details.</li>
657
658<li>The Fortran front-end currently does not build on Darwin (without tweaks)
659 due to unresolved dependencies on the C front-end.</li>
Gabor Greifba10fe02008-11-04 21:50:59 +0000660</ul>
Chris Lattner1eb4df62008-10-30 03:58:13 +0000661</div>
Misha Brukman500bc302003-11-22 00:38:41 +0000662
Chris Lattner2b659ef2008-02-12 06:29:45 +0000663<!-- ======================================================================= -->
664<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000665 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000666</div>
667
668<div class="doc_text">
669The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
670technology and problems should be expected.
671<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000672<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattner2b659ef2008-02-12 06:29:45 +0000673to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sands27aff872008-06-08 20:18:35 +0000674however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000675which does support trampolines.</li>
676<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sands326a4982009-02-25 11:59:06 +0000677This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
678exception handling, which is used internally by the compiler.
Chris Lattner2b659ef2008-02-12 06:29:45 +0000679Workaround: configure with --disable-bootstrap.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000680<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
681and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sands326a4982009-02-25 11:59:06 +0000682(c380004 also fails with gcc-4.2 mainline).
683If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
684causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sands978bcee2008-10-13 17:27:23 +0000685<li>Some gcc specific Ada tests continue to crash the compiler.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000686<li>The -E binder option (exception backtraces)
687<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
688crashing if an exception is raised. Workaround: do not use -E.</li>
689<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
690or finish at a non-byte offset</a> in a record. Workaround: do not pack records
691or use representation clauses that result in a field of a non-discrete type
692starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000693<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
694'main' as generated by the Ada binder to be invalid</a>.
695Workaround: hand edit the file to use pointers for <tt>argv</tt> and
696<tt>envp</tt> rather than integers.</li>
697<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
698ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000699</ul>
700</div>
701
Chris Lattner79c3fe12003-10-02 04:57:28 +0000702<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000703<div class="doc_section">
704 <a name="additionalinfo">Additional Information</a>
705</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000706<!-- *********************************************************************** -->
707
Misha Brukman500bc302003-11-22 00:38:41 +0000708<div class="doc_text">
709
Chris Lattner416db102005-05-16 17:13:10 +0000710<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000711href="http://llvm.org">LLVM web page</a>, in particular in the <a
712href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000713contains versions of the API documentation which is up-to-date with the
714Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000715You can access versions of these documents specific to this release by going
716into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000717
Misha Brukman500bc302003-11-22 00:38:41 +0000718<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000719us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000720lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000721
Misha Brukman500bc302003-11-22 00:38:41 +0000722</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000723
724<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000725
Misha Brukman500bc302003-11-22 00:38:41 +0000726<hr>
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Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000733 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
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