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Chris Lattner857fb132008-10-11 18:18:28 +00007 <title>LLVM 2.4 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +00008</head>
9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +000010
Chris Lattner857fb132008-10-11 18:18:28 +000011<div class="doc_title">LLVM 2.4 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000012
13<ol>
Misha Brukman500bc302003-11-22 00:38:41 +000014 <li><a href="#intro">Introduction</a></li>
Chris Lattner8348b472008-06-08 21:58:17 +000015 <li><a href="#changes">Major Changes and Sub-project Status</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000016 <li><a href="#whatsnew">What's New?</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>
Chris Lattner79c3fe12003-10-02 04:57:28 +000019 <li><a href="#knownproblems">Known Problems</a>
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">
Chris Lattnerc463b272005-10-29 07:07:09 +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
Chris Lattner77d29b12008-06-05 08:02:49 +000027<!-- Done through Week-of-Mon-20080324.txt -->
28
Chris Lattner79c3fe12003-10-02 04:57:28 +000029<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000030<div class="doc_section">
31 <a name="intro">Introduction</a>
32</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000033<!-- *********************************************************************** -->
34
Misha Brukman500bc302003-11-22 00:38:41 +000035<div class="doc_text">
36
37<p>This document contains the release notes for the LLVM compiler
Chris Lattner857fb132008-10-11 18:18:28 +000038infrastructure, release 2.4. Here we describe the status of LLVM, including
Chris Lattner57a460e2007-05-23 04:39:32 +000039major improvements from the previous release and any known problems. All LLVM
Chris Lattnercaf06342007-05-09 04:58:11 +000040releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
Chris Lattner57a460e2007-05-23 04:39:32 +000041releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +000042
Chris Lattner7506b1d2004-12-07 08:04:13 +000043<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +000044release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +000045web site</a>. If you have questions or comments, the <a
46href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +000047list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +000048
Reid Spencer669ed452007-07-09 08:04:31 +000049<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +000050main LLVM web page, this document applies to the <i>next</i> release, not the
51current one. To see the release notes for a specific releases, please see the
52<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +000053
54</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000055
56<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +000057<div class="doc_section">
Chris Lattner8348b472008-06-08 21:58:17 +000058 <a name="changes">Major Changes and Sub-project Status</a>
Misha Brukman500bc302003-11-22 00:38:41 +000059</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000060<!-- *********************************************************************** -->
61
Misha Brukman500bc302003-11-22 00:38:41 +000062<div class="doc_text">
63
Chris Lattner857fb132008-10-11 18:18:28 +000064<p>This is the fifteenth public release of the LLVM Compiler Infrastructure.
65It includes a large number of features and refinements from LLVM 2.3.</p>
Chris Lattnera5099962003-12-06 20:22:41 +000066
Chris Lattner80453c92004-05-24 04:50:25 +000067</div>
68
Chris Lattner857fb132008-10-11 18:18:28 +000069<!-- Unfinished features in 2.4:
Chris Lattneracce85d2008-02-10 07:46:44 +000070 Machine LICM
71 Machine Sinking
72 LegalizeDAGTypes
73 -->
74
Chris Lattnera5099962003-12-06 20:22:41 +000075<!--=========================================================================-->
Chris Lattner8a458762005-05-15 05:44:51 +000076<div class="doc_subsection">
Chris Lattner857fb132008-10-11 18:18:28 +000077<a name="changes">Major Changes in LLVM 2.4</a>
Chris Lattnerb4c68cd2008-02-10 07:04:35 +000078</div>
79
80<div class="doc_text">
81
Chris Lattner857fb132008-10-11 18:18:28 +000082<p>....</p>
Chris Lattnere6e1b352008-06-08 21:19:07 +000083
Chris Lattner0b832202008-06-08 02:45:07 +000084<p>LLVM API Changes:</p>
Chris Lattner77d29b12008-06-05 08:02:49 +000085
Chris Lattner0b832202008-06-08 02:45:07 +000086<ul>
Chris Lattner857fb132008-10-11 18:18:28 +000087<li>....</li>
Chris Lattner0b832202008-06-08 02:45:07 +000088</ul>
Chris Lattner252b83d2008-02-06 18:00:06 +000089</div>
90
91<!--=========================================================================-->
92<div class="doc_subsection">
Chris Lattnerea34f642008-06-08 21:34:41 +000093<a name="otherprojects">Other LLVM Sub-Projects</a>
94</div>
95
96<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +000097<p>
Chris Lattner857fb132008-10-11 18:18:28 +000098The core LLVM 2.4 distribution currently consists of code from the core LLVM
Chris Lattner8348b472008-06-08 21:58:17 +000099repository (which roughly contains the LLVM optimizer, code generators and
100supporting tools) and the llvm-gcc repository. In addition to this code, the
101LLVM Project includes other sub-projects that are in development. The two which
Chris Lattner857fb132008-10-11 18:18:28 +0000102are the most actively developed are the <a href="#clang">Clang Project</a> and
103<a href="#vmkit">vmkit Project</a>.
Chris Lattner8348b472008-06-08 21:58:17 +0000104</p>
105</div>
106
107<!--=========================================================================-->
108<div class="doc_subsubsection">
109<a name="vmkit">vmkit</a>
110</div>
111
112<div class="doc_text">
113<p>
Chris Lattner857fb132008-10-11 18:18:28 +0000114The <a href="http://vmkit.llvm.org/">"vmkit" project</a> is an implementation of
115a JVM and a CLI Virtual Machines (Microsoft .NET is an
Chris Lattner8348b472008-06-08 21:58:17 +0000116implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
117
Chris Lattner857fb132008-10-11 18:18:28 +0000118<p>...</p>
Chris Lattnerea34f642008-06-08 21:34:41 +0000119
120</div>
121
122<!--=========================================================================-->
Chris Lattner8348b472008-06-08 21:58:17 +0000123<div class="doc_subsubsection">
124<a name="clang">Clang</a>
125</div>
126
127<div class="doc_text">
128
129<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
130a set of new 'LLVM native' front-end technologies for the LLVM optimizer
131and code generator. Clang is continuing to make major strides forward in all
132areas. Its C and Objective-C parsing support is very solid, and the code
133generation support is far enough along to build many C applications. While not
134yet production quality, it is progressing very nicely. In addition, C++
135front-end work has started to make significant progress.</p>
136
Chris Lattner857fb132008-10-11 18:18:28 +0000137<p>Codegen progress/state
138</p>
139
140<p>
141<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
142</p>
Chris Lattner8348b472008-06-08 21:58:17 +0000143
144</div>
145
146
147<!-- *********************************************************************** -->
148<div class="doc_section">
149 <a name="whatsnew">What's New?</a>
150</div>
151<!-- *********************************************************************** -->
152
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000153<div class="doc_text">
154
Chris Lattner857fb132008-10-11 18:18:28 +0000155<p>LLVM 2.4 includes a huge number of bug fixes, performance tweaks and minor
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000156improvements. Some of the major improvements and new features are listed in
157this section.
158</p>
159</div>
160
Chris Lattner8348b472008-06-08 21:58:17 +0000161<!--=========================================================================-->
Chris Lattnerea34f642008-06-08 21:34:41 +0000162<div class="doc_subsection">
Chris Lattner252b83d2008-02-06 18:00:06 +0000163<a name="majorfeatures">Major New Features</a>
164</div>
165
166<div class="doc_text">
167
Chris Lattner857fb132008-10-11 18:18:28 +0000168<p>LLVM 2.4 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000169
170<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000171<li>
172 <p>MRVs got generalized to FCAs.</p>
173 </li>
174
175<li><p>fast isel, -O0 compile times</p></li>
Chris Lattnerea34f642008-06-08 21:34:41 +0000176
Chris Lattner857fb132008-10-11 18:18:28 +0000177<li><p>Attrs changes?</p></li>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000178
Chris Lattner857fb132008-10-11 18:18:28 +0000179<li><p>...</p></li>
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000180
Chris Lattner8170c102008-02-10 08:18:42 +0000181</ul>
182
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000183</div>
184
Chris Lattner791f77b2008-06-05 06:25:56 +0000185
186<!--=========================================================================-->
187<div class="doc_subsection">
Chris Lattnerea34f642008-06-08 21:34:41 +0000188<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattner791f77b2008-06-05 06:25:56 +0000189</div>
190
191<div class="doc_text">
192
Chris Lattner857fb132008-10-11 18:18:28 +0000193<p>LLVM 2.4 fully supports the llvm-gcc 4.2 front-end, and includes support
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000194for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattner791f77b2008-06-05 06:25:56 +0000195
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000196<p>
197<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000198<li>...</li>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000199
Gabor Greifa3bd11d2008-06-09 06:06:18 +0000200</ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000201
Chris Lattner791f77b2008-06-05 06:25:56 +0000202</div>
203
204
Chris Lattner84977642007-09-21 03:54:09 +0000205<!--=========================================================================-->
206<div class="doc_subsection">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000207<a name="coreimprovements">LLVM Core Improvements</a>
208</div>
209
210<div class="doc_text">
211<p>New features include:
212</p>
213
Chris Lattner791f77b2008-06-05 06:25:56 +0000214<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000215<li>...</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000216</ul>
217
218</div>
219
220<!--=========================================================================-->
221<div class="doc_subsection">
Chris Lattneracce85d2008-02-10 07:46:44 +0000222<a name="optimizer">Optimizer Improvements</a>
223</div>
224
225<div class="doc_text">
226
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000227<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattner857fb132008-10-11 18:18:28 +0000228LLVM 2.4 optimizers support a few major enhancements:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000229
230<ul>
231
Chris Lattner857fb132008-10-11 18:18:28 +0000232<li>.</li>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000233
Chris Lattner0b832202008-06-08 02:45:07 +0000234</ul>
235
236</div>
237
238<!--=========================================================================-->
239<div class="doc_subsection">
240<a name="codegen">Code Generator Improvements</a>
241</div>
242
243<div class="doc_text">
244
245<p>We put a significant amount of work into the code generator infrastructure,
246which allows us to implement more aggressive algorithms and make it run
247faster:</p>
248
249<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000250<li>Selection dag speedups</li>
251<li>...</li>
Chris Lattner0b832202008-06-08 02:45:07 +0000252
Chris Lattner84977642007-09-21 03:54:09 +0000253</ul>
254
255</div>
256
257
258<!--=========================================================================-->
259<div class="doc_subsection">
Chris Lattner77d29b12008-06-05 08:02:49 +0000260<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattner84977642007-09-21 03:54:09 +0000261</div>
Chris Lattner60893e52007-05-18 06:33:02 +0000262
Chris Lattner738bd302006-04-18 06:32:08 +0000263<div class="doc_text">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000264<p>New target-specific features include:
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000265</p>
Chris Lattner26299222006-11-18 07:51:14 +0000266
267<ul>
Anton Korobeynikov0021fc12008-10-11 18:27:16 +0000268<li>Exception handling is supported by default on x86-64 linux platform.</li>
Chris Lattner857fb132008-10-11 18:18:28 +0000269<li>...</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000270
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000271</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000272
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000273</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000274
Chris Lattner84977642007-09-21 03:54:09 +0000275<!--=========================================================================-->
276<div class="doc_subsection">
Chris Lattner77d29b12008-06-05 08:02:49 +0000277<a name="targetspecific">Other Target Specific Improvements</a>
278</div>
279
280<div class="doc_text">
281<p>New target-specific features include:
282</p>
283
284<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000285<li>....</li>
Chris Lattner77d29b12008-06-05 08:02:49 +0000286</ul>
287
288</div>
289
290
291
292<!--=========================================================================-->
293<div class="doc_subsection">
Chris Lattner84977642007-09-21 03:54:09 +0000294<a name="otherimprovements">Other Improvements</a>
295</div>
296
297<div class="doc_text">
298<p>New features include:
299</p>
300
301<ul>
Chris Lattner857fb132008-10-11 18:18:28 +0000302<li>...</li>
Chris Lattner84977642007-09-21 03:54:09 +0000303</ul>
304
305</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000306
Chris Lattner19092612003-10-02 16:38:05 +0000307<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000308<div class="doc_section">
309 <a name="portability">Portability and Supported Platforms</a>
310</div>
Chris Lattner19092612003-10-02 16:38:05 +0000311<!-- *********************************************************************** -->
312
Misha Brukman500bc302003-11-22 00:38:41 +0000313<div class="doc_text">
314
John Criswell0b5b5e92004-12-08 20:35:47 +0000315<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000316
317<ul>
Gabor Greif96a89c72008-06-05 18:39:01 +0000318<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Reid Spencer00812e22005-05-17 02:47:27 +0000319 (and probably other unix-like systems).</li>
Chris Lattner000c73b2008-02-06 06:30:34 +0000320<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 +0000321 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000322<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000323<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
324 support is available for native builds with Visual C++).</li>
Gabor Greif96a89c72008-06-05 18:39:01 +0000325<li>Sun UltraSPARC workstations running Solaris 10.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000326<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif96a89c72008-06-05 18:39:01 +0000327<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000328</ul>
329
Chris Lattnerbc5786b2008-06-05 06:57:39 +0000330<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000331to the machine and operating system on which it is built. However, minor
332porting may be required to get LLVM to work on new platforms. We welcome your
333portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000334
Misha Brukman500bc302003-11-22 00:38:41 +0000335</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000336
337<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000338<div class="doc_section">
339 <a name="knownproblems">Known Problems</a>
340</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000341<!-- *********************************************************************** -->
342
Misha Brukman500bc302003-11-22 00:38:41 +0000343<div class="doc_text">
344
345<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000346component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000347sections. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000348href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000349there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000350
Misha Brukman500bc302003-11-22 00:38:41 +0000351</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000352
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000353<!-- ======================================================================= -->
354<div class="doc_subsection">
355 <a name="experimental">Experimental features included with this release</a>
356</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000357
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000358<div class="doc_text">
359
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000360<p>The following components of this LLVM release are either untested, known to
361be broken or unreliable, or are in early development. These components should
362not be relied on, and bugs should not be filed against them, but they may be
363useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000364components, please contact us on the <a
365href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000366
367<ul>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000368<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sands27aff872008-06-08 20:18:35 +0000369<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattner000c73b2008-02-06 06:30:34 +0000370 value for this option.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000371</ul>
372
373</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000374
Misha Brukman500bc302003-11-22 00:38:41 +0000375<!-- ======================================================================= -->
376<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000377 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000378</div>
379
380<div class="doc_text">
381
382<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000383 <li>The X86 backend does not yet support
384 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
385 floating point stack</a>. It supports the 'f' and 't' constraints, but not
386 'u'.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000387 <li>The X86 backend generates inefficient floating point code when configured
388 to generate code for systems that don't have SSE2.</li>
Duncan Sands47eff2b2008-06-08 19:38:43 +0000389 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikova6094be2008-06-08 10:24:13 +0000390 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
391 currently due
392 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattner04af7cb2008-06-08 23:12:47 +0000393 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
394 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman8207ba92008-06-08 23:05:11 +0000395 <li>The X86-64 backend does not yet support the LLVM IR instruction
396 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
397 argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000398</ul>
399
400</div>
401
402<!-- ======================================================================= -->
403<div class="doc_subsection">
404 <a name="ppc-be">Known problems with the PowerPC back-end</a>
405</div>
406
407<div class="doc_text">
408
409<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000410<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000411compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000412</ul>
413
414</div>
415
416<!-- ======================================================================= -->
417<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000418 <a name="arm-be">Known problems with the ARM back-end</a>
419</div>
420
421<div class="doc_text">
422
423<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000424<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000425processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000426results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000427<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
428</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000429<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
430 execute
Chris Lattner57a460e2007-05-23 04:39:32 +0000431programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000432</ul>
433
434</div>
435
436<!-- ======================================================================= -->
437<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000438 <a name="sparc-be">Known problems with the SPARC back-end</a>
439</div>
440
441<div class="doc_text">
442
443<ul>
444<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
445 support the 64-bit SPARC ABI (-m64).</li>
446</ul>
447
448</div>
449
450<!-- ======================================================================= -->
451<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000452 <a name="alpha-be">Known problems with the Alpha back-end</a>
453</div>
454
455<div class="doc_text">
456
457<ul>
458
459<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
460appropriate nops inserted to ensure restartability.</li>
461
John Criswellc0c186d2005-11-08 21:11:33 +0000462</ul>
463</div>
464
Chris Lattner26299222006-11-18 07:51:14 +0000465<!-- ======================================================================= -->
466<div class="doc_subsection">
467 <a name="ia64-be">Known problems with the IA64 back-end</a>
468</div>
469
470<div class="doc_text">
471
472<ul>
Chris Lattner04af7cb2008-06-08 23:12:47 +0000473<li>The Itanium backend is highly experimental, and has a number of known
474 issues. We are looking for a maintainer for the Itanium backend. If you
475 are interested, please contact the llvmdev mailing list.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000476</ul>
477
478</div>
479
480<!-- ======================================================================= -->
481<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000482 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000483</div>
484
485<div class="doc_text">
486
487<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000488<li><a href="http://llvm.org/PR802">The C backend has only basic support for
489 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000490<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
491 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sands27aff872008-06-08 20:18:35 +0000492 C++ code compiled with llc or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000493<li>The C backend does not support all exception handling constructs.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000494</ul>
495
496</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000497
Misha Brukman500bc302003-11-22 00:38:41 +0000498
499<!-- ======================================================================= -->
500<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000501 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000502</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000503
Misha Brukman500bc302003-11-22 00:38:41 +0000504<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000505
Chris Lattner252b83d2008-02-06 18:00:06 +0000506<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
507Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000508llvmdev mailing list if you are interested.</p>
Chris Lattnerd9ea0172006-08-08 17:27:28 +0000509
Chris Lattner5733b272008-06-05 06:35:40 +0000510<p>The only major language feature of GCC not supported by llvm-gcc is
511 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
512 are only supported on some targets. For example, trampolines are only
Duncan Sands27aff872008-06-08 20:18:35 +0000513 supported on some targets (these are used when you take the address of a
514 nested function).</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000515
Chris Lattner5733b272008-06-05 06:35:40 +0000516<p>If you run into GCC extensions which are not supported, please let us know.
517</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000518
Misha Brukman500bc302003-11-22 00:38:41 +0000519</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000520
Misha Brukman500bc302003-11-22 00:38:41 +0000521<!-- ======================================================================= -->
522<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000523 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000524</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000525
Misha Brukman500bc302003-11-22 00:38:41 +0000526<div class="doc_text">
527
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000528<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000529tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000530itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000531
Misha Brukman500bc302003-11-22 00:38:41 +0000532<ul>
Anton Korobeynikov0021fc12008-10-11 18:27:16 +0000533<li>Exception handling works well on the X86 and PowerPC targets. Currently
534 only linux and darwin targets are supported (both 32 and 64 bit).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000535</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000536
Misha Brukman500bc302003-11-22 00:38:41 +0000537</div>
538
Misha Brukman500bc302003-11-22 00:38:41 +0000539
Chris Lattner2b659ef2008-02-12 06:29:45 +0000540<!-- ======================================================================= -->
541<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000542 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000543</div>
544
545<div class="doc_text">
546The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
547technology and problems should be expected.
548<ul>
Duncan Sands27aff872008-06-08 20:18:35 +0000549<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattner2b659ef2008-02-12 06:29:45 +0000550to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sands27aff872008-06-08 20:18:35 +0000551however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000552which does support trampolines.</li>
553<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
554Workaround: configure with --disable-bootstrap.</li>
555<li>The c380004 and <a href="http://llvm.org/PR2010">c393010</a> ACATS tests
Duncan Sands27aff872008-06-08 20:18:35 +0000556fail (c380004 also fails with gcc-4.2 mainline). When built at -O3, the
557<a href="http://llvm.org/PR2421">cxg2021</a> ACATS test also fails.</li>
558<li>Some gcc specific Ada tests continue to crash the compiler. The testsuite
559reports most tests as having failed even though they pass.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000560<li>The -E binder option (exception backtraces)
561<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
562crashing if an exception is raised. Workaround: do not use -E.</li>
563<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
564or finish at a non-byte offset</a> in a record. Workaround: do not pack records
565or use representation clauses that result in a field of a non-discrete type
566starting or finishing in the middle of a byte.</li>
Chris Lattnere6e1b352008-06-08 21:19:07 +0000567<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
568'main' as generated by the Ada binder to be invalid</a>.
569Workaround: hand edit the file to use pointers for <tt>argv</tt> and
570<tt>envp</tt> rather than integers.</li>
571<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
572ignored</a>.</li>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000573</ul>
574</div>
575
Chris Lattner79c3fe12003-10-02 04:57:28 +0000576<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000577<div class="doc_section">
578 <a name="additionalinfo">Additional Information</a>
579</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000580<!-- *********************************************************************** -->
581
Misha Brukman500bc302003-11-22 00:38:41 +0000582<div class="doc_text">
583
Chris Lattner416db102005-05-16 17:13:10 +0000584<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000585href="http://llvm.org">LLVM web page</a>, in particular in the <a
586href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000587contains versions of the API documentation which is up-to-date with the
588Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000589You can access versions of these documents specific to this release by going
590into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000591
Misha Brukman500bc302003-11-22 00:38:41 +0000592<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000593us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000594lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000595
Misha Brukman500bc302003-11-22 00:38:41 +0000596</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000597
598<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000599
Misha Brukman500bc302003-11-22 00:38:41 +0000600<hr>
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