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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 809d91e306ffc09b3ee5d017bad46310f91dfe26 / . / docs / ReleaseNotes.html
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Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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3<html>
4<head>
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]6 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]7 <title>LLVM 2.3 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]10
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]11<div class="doc_title">LLVM 2.3 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]12
13<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]14 <li><a href="#intro">Introduction</a></li>
15 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]16 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]18 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]19 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]20</ol>
21
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]22<div class="doc_author">
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]23 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]24</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]25
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]26<!-- Done through Week-of-Mon-20080324.txt -->
27
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]28<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]29<div class="doc_section">
30 <a name="intro">Introduction</a>
31</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]32<!-- *********************************************************************** -->
33
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]34<div class="doc_text">
35
36<p>This document contains the release notes for the LLVM compiler
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]37infrastructure, release 2.3. Here we describe the status of LLVM, including
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]38major improvements from the previous release and any known problems. All LLVM
Chris Lattnercaf06342007-05-09 04:58:11 +0000[diff] [blame]39releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]40releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]41
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]42<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]43release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]44web site</a>. If you have questions or comments, the <a
45href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]47
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]48<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]49main LLVM web page, this document applies to the <i>next</i> release, not the
50current one. To see the release notes for a specific releases, please see the
51<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]52
53</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]54
55<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]56<div class="doc_section">
57 <a name="whatsnew">What's New?</a>
58</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]59<!-- *********************************************************************** -->
60
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]61<div class="doc_text">
62
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]63<p>This is the fourteenth public release of the LLVM Compiler Infrastructure.
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]64It includes a large number of features and refinements from LLVM 2.2.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]65
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]66</div>
67
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]68<!-- Unfinished features in 2.3:
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]69 Machine LICM
70 Machine Sinking
71 LegalizeDAGTypes
72 -->
73
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]74<!--=========================================================================-->
Chris Lattner8a458762005-05-15 05:44:51 +0000[diff] [blame]75<div class="doc_subsection">
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]76<a name="changes">Major Changes in LLVM 2.3</a>
Chris Lattnerb4c68cd2008-02-10 07:04:35 +0000[diff] [blame]77</div>
78
79<div class="doc_text">
80
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]81<p>LLVM 2.2 was the last LLVM release to support llvm-gcc 4.0 and llvm-upgrade.
82llvm-gcc 4.0 has been replaced with llvm-gcc 4.2. llvm-upgrade was useful for
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]83upgrading LLVM 1.9 files to LLVM 2.x syntax, but you can always use a previous
84LLVM release to do this. One nice impact of this is that the LLVM regressionn
85test suite no longer depends on llvm-upgrade, which makes it run faster.</p>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]86
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]87<p>LLVM 2.3 renames the LLVMBuilder and LLVMFoldingBuilder classes to
88 IRBuilder.</p>
89
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]90</div>
91
92<!--=========================================================================-->
93<div class="doc_subsection">
94<a name="majorfeatures">Major New Features</a>
95</div>
96
97<div class="doc_text">
98
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]99<p>LLVM 2.3 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]100
101<ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]102<li>Multiple Return Value Support</li>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]103
104
105<li><p>LLVM 2.3 includes a complete reimplementation of the "llvmc" tool. It is
106designed to overcome several problems of the original llvmc and to provide a
107superset of the features as the 'gcc' driver.</p>
108
109<p>The main features of llvmc2 is:</p>
110
111<ul>
112<li>Extended handling of command line options and smart rules for
113dispatching them to different tools.</li>
114<li>Flexible (and extensible) rules for defining different tools.</li>
115<li>The different intermediate steps performed by tools are represented
116as edged in the abstract graph.</li>
117</l>The 'language' for driver behaviour definition is tablegen and thus
118it's relatively easy to add new features.</li>
119<li>The definition of driver is transformed into set of C++ classes, thus
120no runtime interpretation is needed.</li>
121</ul>
122
123</li>
124
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]125<li>Reimplemented <a href="LinkTimeOptimization.html">LTO interface</a> in
126 C.</li>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]127
128
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]129<li>kaleidoscope tutorial in ocaml.</li>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]130
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]131</ul>
132
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]133</div>
134
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]135
136<!--=========================================================================-->
137<div class="doc_subsection">
138<a name="frontends">llvm-gcc 4.2 Improvements and Clang</a>
139</div>
140
141<div class="doc_text">
142
143<p>LLVM 2.3 fully supports llvm-gcc 4.2 front-end.</p>
144
145<p>llvm-gcc 4.2 includes numerous fixes to better support the Objective-C
146front-end. Objective-C now works very well on Mac OS/X.</p>
147
148<p>llvm-gcc 4.2 includes many other fixes which improve conformance with the
149relevant parts of the GCC testsuite.</p>
150
151<p>The <a href="http://clang.llvm.org/">clang project</a> is an effort to build
152a set of new 'llvm native' front-end technologies for the LLVM optimizer
153and code generator. Currently, its C and Objective-C support is maturing
154nicely, and it has advanced source-to-source analysis and transformation
155capabilities. If you are interested in building source-level tools for C and
156Objective-C (and eventually C++), you should take a look. However, note that
157clang is not an official part of the LLVM 2.3 release. If you are interested in
158this project, please see its <a href="http://clang.llvm.org/">web site</a>.</p>
159
160</div>
161
162
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]163<!--=========================================================================-->
164<div class="doc_subsection">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]165<a name="coreimprovements">LLVM Core Improvements</a>
166</div>
167
168<div class="doc_text">
169<p>New features include:
170</p>
171
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]172
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]173Common linkage?
174
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]175Atomic operation support, Alpha, X86, X86-64, PowerPC. "__sync_synchronize"
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]176
177<ul>
Gordon Henriksen1494bcc2008-06-05 12:51:50 +0000[diff] [blame]178<li>The C and Ocaml bindings have received additional improvements. The
179bindings now cover pass managers, several transformation passes, iteration
180over the LLVM IR, target data, and parameter attribute lists.</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]181</ul>
182
183</div>
184
185<!--=========================================================================-->
186<div class="doc_subsection">
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]187<a name="codegen">Code Generator Improvements</a>
188</div>
189
190<div class="doc_text">
191
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]192<p>We put a significant amount of work into the code generator infrastructure,
193which allows us to implement more aggressive algorithms and make it run
194faster:</p>
Chris Lattnerd4298712007-09-26 05:44:21 +0000[diff] [blame]195
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]196<ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]197<li>MemOperand in the code generator: describe me!.</li>
Dan Gohman85765e62008-06-05 15:43:11 +0000[diff] [blame]198<li>Target-independent codegen infastructure now uses LLVM's APInt class for
199 handling integer values, which allow it to support integer types larger
200 than 64 bits. Note that support for such types is also dependent on
201 target-specific support. Use of APInt is also a step toward support for
202 non-power-of-2 integer sizes.</li>
203<li>Support for 128-bit integers on X86-64.</li>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]204<li>Several compile time speedups for code with large basic blocks.</li>
Dan Gohman809d91e2008-06-05 15:46:36 +0000[diff] [blame^]205<li>Several improvements which make llc's <tt>--view-sunit-dags</tt>
206 visualization of scheduling dependency graphs easier to understand.</li>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]207</ul>
208
209</div>
210
211<!--=========================================================================-->
212<div class="doc_subsection">
213<a name="optimizer">Optimizer Improvements</a>
214</div>
215
216<div class="doc_text">
217
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]218<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]219LLVM 2.3 optimizers support a few major enhancements:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]220
221<ul>
222
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]223<li>Loop index set splitting on by default: describe me.</li>
224<li>LLVM includes a new memcpy optimization pass which optimizes out dead
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]225memcpy calls, unneeded copies of aggregates, and handles the return slot
226optimization. The LLVM optimizer now notices long sequences of consequtive
227stores and merges them into memcpy's where profitable.</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]228</ul>
229
230</div>
231
232
233<!--=========================================================================-->
234<div class="doc_subsection">
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]235<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]236</div>
Chris Lattner60893e52007-05-18 06:33:02 +0000[diff] [blame]237
Chris Lattner738bd302006-04-18 06:32:08 +0000[diff] [blame]238<div class="doc_text">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]239<p>New target-specific features include:
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]240</p>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]241
242<ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]243<li>llvm-gcc's X86-64 ABI conformance is far improved, particularly in the
244 area of passing and returning structures by value. llvm-gcc Compiled code
245 now interoperates very well on X86-64 systems with other compilers.</li>
246
247<li>The LLVM X86 backend now supports the support SSE 4.1 instruction set, and
248 the llvm-gcc 4.2 front-end supports the SSE 4.1 compiler builtins.</li>
249
250<li>The X86 backend now does a number of optimizations that aim to avoid
251 converting numbers back and forth from SSE registers to the X87 floating
252 point stack.</li>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]253
254<li>The X86 backend supports stack realignment, which is particularly useful for
255 vector code on OS's without 16-byte aligned stacks.</li>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]256
257<li>The X86 backend now supports the "sseregparm" options in GCC, which allow
258 functions to be tagged as passing floating point values in SSE
259 registers.</li>
260
261<li>Trampolines (taking the address of a nested function) now work on
262 Linux/x86-64.</li>
263
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]264<li><tt>__builtin_prefetch</tt> is now compiled into the appropriate prefetch
265 instructions instead of being ignored.</li>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]266
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000[diff] [blame]267</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]268
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000[diff] [blame]269</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]270
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]271<!--=========================================================================-->
272<div class="doc_subsection">
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]273<a name="targetspecific">Other Target Specific Improvements</a>
274</div>
275
276<div class="doc_text">
277<p>New target-specific features include:
278</p>
279
280<ul>
281<li>The LLVM C backend now supports vectors code.</li>
282
283
284</ul>
285
286</div>
287
288
289
290<!--=========================================================================-->
291<div class="doc_subsection">
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]292<a name="otherimprovements">Other Improvements</a>
293</div>
294
295<div class="doc_text">
296<p>New features include:
297</p>
298
299<ul>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]300<li>LLVM now builds with GCC 4.3.</li>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]301<li>llvm2cpp tool was moved into llc, use llc -march=cpp</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]302</ul>
303
304</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]305
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]306<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]307<div class="doc_section">
308 <a name="portability">Portability and Supported Platforms</a>
309</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]310<!-- *********************************************************************** -->
311
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]312<div class="doc_text">
313
John Criswell0b5b5e92004-12-08 20:35:47 +0000[diff] [blame]314<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]315
316<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]317<li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
Reid Spencer00812e22005-05-17 02:47:27 +0000[diff] [blame]318 (and probably other unix-like systems).</li>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame]319<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]320 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]321<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]322<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
323 support is available for native builds with Visual C++).</li>
324<li>Sun UltraSPARC workstations running Solaris 8.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000[diff] [blame]325<li>Alpha-based machines running Debian GNU/Linux.</li>
326<li>Itanium-based machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]327</ul>
328
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000[diff] [blame]329<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]330to the machine and operating system on which it is built. However, minor
331porting may be required to get LLVM to work on new platforms. We welcome your
332portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]333
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]334</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]335
336<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]337<div class="doc_section">
338 <a name="knownproblems">Known Problems</a>
339</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]340<!-- *********************************************************************** -->
341
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]342<div class="doc_text">
343
344<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]345component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]346sections. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]347href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]348there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]349
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]350</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]351
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]352<!-- ======================================================================= -->
353<div class="doc_subsection">
354 <a name="experimental">Experimental features included with this release</a>
355</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]356
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]357<div class="doc_text">
358
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]359<p>The following components of this LLVM release are either untested, known to
360be broken or unreliable, or are in early development. These components should
361not be relied on, and bugs should not be filed against them, but they may be
362useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]363components, please contact us on the <a
364href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]365
366<ul>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]367<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame]368<li>The LLC "<tt>-filetype=asm</tt>" (the default) is the only supported
369 value for this option.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]370</ul>
371
372</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]373
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]374<!-- ======================================================================= -->
375<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]376 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]377</div>
378
379<div class="doc_text">
380
381<ul>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]382<li>The X86 backend does not yet support all <a
383 href="http://llvm.org/PR879">inline assembly that uses the X86 floating
384 point stack</a>. It supports the 'f' and 't' constraints, but not 'u'.</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]385<li>The X86 backend generates inefficient floating point code when configured to
386 generate code for systems that don't have SSE2.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]387</ul>
388
389</div>
390
391<!-- ======================================================================= -->
392<div class="doc_subsection">
393 <a name="ppc-be">Known problems with the PowerPC back-end</a>
394</div>
395
396<div class="doc_text">
397
398<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]399<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]400compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]401</ul>
402
403</div>
404
405<!-- ======================================================================= -->
406<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]407 <a name="arm-be">Known problems with the ARM back-end</a>
408</div>
409
410<div class="doc_text">
411
412<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]413<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]414processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]415results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]416<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
417</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]418<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly execute
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]419programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]420</ul>
421
422</div>
423
424<!-- ======================================================================= -->
425<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]426 <a name="sparc-be">Known problems with the SPARC back-end</a>
427</div>
428
429<div class="doc_text">
430
431<ul>
432<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
433 support the 64-bit SPARC ABI (-m64).</li>
434</ul>
435
436</div>
437
438<!-- ======================================================================= -->
439<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]440 <a name="alpha-be">Known problems with the Alpha back-end</a>
441</div>
442
443<div class="doc_text">
444
445<ul>
446
447<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
448appropriate nops inserted to ensure restartability.</li>
449
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]450</ul>
451</div>
452
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]453<!-- ======================================================================= -->
454<div class="doc_subsection">
455 <a name="ia64-be">Known problems with the IA64 back-end</a>
456</div>
457
458<div class="doc_text">
459
460<ul>
461
462<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
463made where the argument is not 16-byte aligned, as required on IA64. (Strictly
464speaking this is not a bug in the IA64 back-end; it will also be encountered
465when building C++ programs using the C back-end.)</li>
466
467<li>The C++ front-end does not use <a href="http://llvm.org/PR406">IA64
468ABI compliant layout of v-tables</a>. In particular, it just stores function
469pointers instead of function descriptors in the vtable. This bug prevents
470mixing C++ code compiled with LLVM with C++ objects compiled by other C++
471compilers.</li>
472
473<li>There are a few ABI violations which will lead to problems when mixing LLVM
474output with code built with other compilers, particularly for floating-point
475programs.</li>
476
477<li>Defining vararg functions is not supported (but calling them is ok).</li>
478
Chris Lattnercaf06342007-05-09 04:58:11 +0000[diff] [blame]479<li>The Itanium backend has bitrotted somewhat.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]480</ul>
481
482</div>
483
484<!-- ======================================================================= -->
485<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]486 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]487</div>
488
489<div class="doc_text">
490
491<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]492<li><a href="http://llvm.org/PR802">The C backend has only basic support for
493 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]494<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
495 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
496 C++ code compiled with LLC or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]497<li>The C backend does not support all exception handling constructs.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]498</ul>
499
500</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]501
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]502
503<!-- ======================================================================= -->
504<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]505 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]506</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]507
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]508<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]509<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]510
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]511<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]512
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]513<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
514Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]515llvmdev mailing list if you are interested.</p>
Chris Lattnerd9ea0172006-08-08 17:27:28 +0000[diff] [blame]516
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]517<p>The only major language feature of GCC not supported by llvm-gcc is
518 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
519 are only supported on some targets. For example, trampolines are only
520 supported on some targets, which are used when you take the address of a
521 nested function.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]522
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]523<p>If you run into GCC extensions which are not supported, please let us know.
524</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]525
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]526</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]527
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]528<!-- ======================================================================= -->
529<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]530 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]531</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533<div class="doc_text">
534
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]535<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]536tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]537itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]538
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]539<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]540<li>Exception handling works well on the X86 and PowerPC targets, including
541x86-64 darwin. This works when linking to a libstdc++ compiled by GCC. It is
542supported on x86-64 linux, but that is disabled by default in this release.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]543</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]544
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]545</div>
546
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]547
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]548<!-- ======================================================================= -->
549<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]550 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]551</div>
552
553<div class="doc_text">
554The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
555technology and problems should be expected.
556<ul>
557<li>The Ada front-end currently only builds on x86-32. This is mainly due
558to lack of trampoline support (pointers to nested functions) on other platforms,
559however it <a href="http://llvm.org/PR2006">also fails to build on x86-64</a>
560which does support trampolines.</li>
561<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
562Workaround: configure with --disable-bootstrap.</li>
563<li>The c380004 and <a href="http://llvm.org/PR2010">c393010</a> ACATS tests
564fail (c380004 also fails with gcc-4.2 mainline).</li>
565<li>Many gcc specific Ada tests continue to crash the compiler.</li>
566<li>The -E binder option (exception backtraces)
567<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
568crashing if an exception is raised. Workaround: do not use -E.</li>
569<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
570or finish at a non-byte offset</a> in a record. Workaround: do not pack records
571or use representation clauses that result in a field of a non-discrete type
572starting or finishing in the middle of a byte.</li>
573<li>The lli interpreter <a href="http://llvm.org/PR2009">considers 'main'
574as generated by the Ada binder to be invalid</a>.
575Workaround: hand edit the file to use pointers for argv and envp rather than
576integers.</li>
577<li>The -fstack-check option <a href="http://llvm.org/PR2008">is ignored</a>.</li>
578</ul>
579</div>
580
581<!-- ======================================================================= -->
582<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame]583 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]584</div>
585
586<div class="doc_text">
587
588<ul>
589<li>The llvm-gcc 4.2 gfortran front-end supports a broad range of Fortran code, but does
590<a href="http://llvm.org/PR1971">not support EQUIVALENCE yet</a>.</li>
591</ul>
592</div>
593
594
Chris Lattner98a493c2005-05-15 16:01:20 +0000[diff] [blame]595
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]596<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]597<div class="doc_section">
598 <a name="additionalinfo">Additional Information</a>
599</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]600<!-- *********************************************************************** -->
601
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]602<div class="doc_text">
603
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]604<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]605href="http://llvm.org">LLVM web page</a>, in particular in the <a
606href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]607contains versions of the API documentation which is up-to-date with the
608Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]609You can access versions of these documents specific to this release by going
610into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]611
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]612<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]613us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]614lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]615
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]616</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]617
618<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]619
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]620<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]621<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]622 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]623 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
624 <a href="http://validator.w3.org/check/referer"><img
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]625 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]626
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]627 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]628 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]629</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]630
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]631</body>
632</html>