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Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]7 <title>LLVM 2.4 Release Notes</title>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]8</head>
9<body>
10
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]11<div class="doc_title">LLVM 2.4 Release Notes</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]12
13<ol>
14 <li><a href="#intro">Introduction</a></li>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]15 <li><a href="#changes">Major Changes and Sub-project Status</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]16 <li><a href="#whatsnew">What's New?</a></li>
17 <li><a href="GettingStarted.html">Installation Instructions</a></li>
18 <li><a href="#portability">Portability and Supported Platforms</a></li>
19 <li><a href="#knownproblems">Known Problems</a>
20 <li><a href="#additionalinfo">Additional Information</a></li>
21</ol>
22
23<div class="doc_author">
24 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
25</div>
26
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]27<!-- Done through Week-of-Mon-20080324.txt -->
28
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]29<!-- *********************************************************************** -->
30<div class="doc_section">
31 <a name="intro">Introduction</a>
32</div>
33<!-- *********************************************************************** -->
34
35<div class="doc_text">
36
37<p>This document contains the release notes for the LLVM compiler
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]38infrastructure, release 2.4. Here we describe the status of LLVM, including
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]39major improvements from the previous release and any known problems. All LLVM
40releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
41releases web site</a>.</p>
42
43<p>For more information about LLVM, including information about the latest
44release, please check out the <a href="http://llvm.org/">main LLVM
45web site</a>. If you have questions or comments, the <a
46href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
47list</a> is a good place to send them.</p>
48
49<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]50main 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>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]53
54</div>
55
56<!-- *********************************************************************** -->
57<div class="doc_section">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]58 <a name="changes">Major Changes and Sub-project Status</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]59</div>
60<!-- *********************************************************************** -->
61
62<div class="doc_text">
63
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]64<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>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]66
67</div>
68
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]69<!-- Unfinished features in 2.4:
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]70 Machine LICM
71 Machine Sinking
72 LegalizeDAGTypes
73 -->
74
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]75<!--=========================================================================-->
76<div class="doc_subsection">
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]77<a name="changes">Major Changes in LLVM 2.4</a>
Chris Lattner41bf8e92008-02-10 07:04:35 +0000[diff] [blame]78</div>
79
80<div class="doc_text">
81
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]82<p>....</p>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]83
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]84<p>LLVM API Changes:</p>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]85
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]86<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]87<li>....</li>
Daniel Dunbardcb129a2008-10-11 21:26:56 +0000[diff] [blame]88
89<li>... Attributes changes ... </li>
90
91<li>The <tt>DbgStopPointInst</tt> methods <tt>getDirectory</tt> and <tt>getFileName</tt> now return <tt>Value*</tt> instead of strings. These can be converted to strings using <tt>llvm::GetConstantStringInfo</tt> defined via "llvm/Analysis/ValueTracking.h".
92
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]93</ul>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]94</div>
95
96<!--=========================================================================-->
97<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]98<a name="otherprojects">Other LLVM Sub-Projects</a>
99</div>
100
101<div class="doc_text">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]102<p>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]103The core LLVM 2.4 distribution currently consists of code from the core LLVM
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]104repository (which roughly contains the LLVM optimizer, code generators and
105supporting tools) and the llvm-gcc repository. In addition to this code, the
106LLVM Project includes other sub-projects that are in development. The two which
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]107are the most actively developed are the <a href="#clang">Clang Project</a> and
108<a href="#vmkit">vmkit Project</a>.
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]109</p>
110</div>
111
112<!--=========================================================================-->
113<div class="doc_subsubsection">
114<a name="vmkit">vmkit</a>
115</div>
116
117<div class="doc_text">
118<p>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]119The <a href="http://vmkit.llvm.org/">"vmkit" project</a> is an implementation of
120a JVM and a CLI Virtual Machines (Microsoft .NET is an
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]121implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
122
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]123<p>...</p>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]124
125</div>
126
127<!--=========================================================================-->
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]128<div class="doc_subsubsection">
129<a name="clang">Clang</a>
130</div>
131
132<div class="doc_text">
133
134<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
135a set of new 'LLVM native' front-end technologies for the LLVM optimizer
136and code generator. Clang is continuing to make major strides forward in all
137areas. Its C and Objective-C parsing support is very solid, and the code
138generation support is far enough along to build many C applications. While not
139yet production quality, it is progressing very nicely. In addition, C++
140front-end work has started to make significant progress.</p>
141
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]142<p>Codegen progress/state
143</p>
144
145<p>
146<a href="http://clang.llvm.org/StaticAnalysis.html">static analysis tool</a>
147</p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]148
149</div>
150
151
152<!-- *********************************************************************** -->
153<div class="doc_section">
154 <a name="whatsnew">What's New?</a>
155</div>
156<!-- *********************************************************************** -->
157
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]158<div class="doc_text">
159
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]160<p>LLVM 2.4 includes a huge number of bug fixes, performance tweaks and minor
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]161improvements. Some of the major improvements and new features are listed in
162this section.
163</p>
164</div>
165
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]166<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]167<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]168<a name="majorfeatures">Major New Features</a>
169</div>
170
171<div class="doc_text">
172
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]173<p>LLVM 2.4 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]174
175<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]176<li>
177 <p>MRVs got generalized to FCAs.</p>
178 </li>
179
180<li><p>fast isel, -O0 compile times</p></li>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]181
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]182<li><p>Attrs changes?</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]183
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]184<li><p>...</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]185
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]186</ul>
187
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]188</div>
189
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]190
191<!--=========================================================================-->
192<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]193<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]194</div>
195
196<div class="doc_text">
197
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]198<p>LLVM 2.4 fully supports the llvm-gcc 4.2 front-end, and includes support
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]199for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]200
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]201<p>
202<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]203<li>...</li>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]204
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame]205</ul>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]206
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]207</div>
208
209
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]210<!--=========================================================================-->
211<div class="doc_subsection">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]212<a name="coreimprovements">LLVM Core Improvements</a>
213</div>
214
215<div class="doc_text">
216<p>New features include:
217</p>
218
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]219<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]220<li>...</li>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]221</ul>
222
223</div>
224
225<!--=========================================================================-->
226<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]227<a name="optimizer">Optimizer Improvements</a>
228</div>
229
230<div class="doc_text">
231
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]232<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]233LLVM 2.4 optimizers support a few major enhancements:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]234
235<ul>
236
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]237<li>.</li>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]238
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]239</ul>
240
241</div>
242
243<!--=========================================================================-->
244<div class="doc_subsection">
245<a name="codegen">Code Generator Improvements</a>
246</div>
247
248<div class="doc_text">
249
250<p>We put a significant amount of work into the code generator infrastructure,
251which allows us to implement more aggressive algorithms and make it run
252faster:</p>
253
254<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]255<li>Selection dag speedups</li>
256<li>...</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]257
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]258</ul>
259
260</div>
261
262
263<!--=========================================================================-->
264<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]265<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]266</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]267
268<div class="doc_text">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]269<p>New target-specific features include:
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]270</p>
271
272<ul>
Anton Korobeynikovd9a17932008-10-11 18:27:16 +0000[diff] [blame]273<li>Exception handling is supported by default on x86-64 linux platform.</li>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]274<li>...</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]275
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]276</ul>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]277
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]278</div>
279
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]280<!--=========================================================================-->
281<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]282<a name="targetspecific">Other Target Specific Improvements</a>
283</div>
284
285<div class="doc_text">
286<p>New target-specific features include:
287</p>
288
289<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]290<li>....</li>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]291</ul>
292
293</div>
294
295
296
297<!--=========================================================================-->
298<div class="doc_subsection">
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]299<a name="otherimprovements">Other Improvements</a>
300</div>
301
302<div class="doc_text">
303<p>New features include:
304</p>
305
306<ul>
Chris Lattner2c3ef982008-10-11 18:18:28 +0000[diff] [blame]307<li>...</li>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]308</ul>
309
310</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]311
312<!-- *********************************************************************** -->
313<div class="doc_section">
314 <a name="portability">Portability and Supported Platforms</a>
315</div>
316<!-- *********************************************************************** -->
317
318<div class="doc_text">
319
320<p>LLVM is known to work on the following platforms:</p>
321
322<ul>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]323<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]324 (and probably other unix-like systems).</li>
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]325<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]326 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]327<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]328<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
329 support is available for native builds with Visual C++).</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]330<li>Sun UltraSPARC workstations running Solaris 10.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]331<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]332<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]333</ul>
334
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]335<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]336to the machine and operating system on which it is built. However, minor
337porting may be required to get LLVM to work on new platforms. We welcome your
338portability patches and reports of successful builds or error messages.</p>
339
340</div>
341
342<!-- *********************************************************************** -->
343<div class="doc_section">
344 <a name="knownproblems">Known Problems</a>
345</div>
346<!-- *********************************************************************** -->
347
348<div class="doc_text">
349
350<p>This section contains all known problems with the LLVM system, listed by
351component. As new problems are discovered, they will be added to these
352sections. If you run into a problem, please check the <a
353href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
354there isn't already one.</p>
355
356</div>
357
358<!-- ======================================================================= -->
359<div class="doc_subsection">
360 <a name="experimental">Experimental features included with this release</a>
361</div>
362
363<div class="doc_text">
364
365<p>The following components of this LLVM release are either untested, known to
366be broken or unreliable, or are in early development. These components should
367not be relied on, and bugs should not be filed against them, but they may be
368useful to some people. In particular, if you would like to work on one of these
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]369components, please contact us on the <a
370href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]371
372<ul>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]373<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]374<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]375 value for this option.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]376</ul>
377
378</div>
379
380<!-- ======================================================================= -->
381<div class="doc_subsection">
382 <a name="x86-be">Known problems with the X86 back-end</a>
383</div>
384
385<div class="doc_text">
386
387<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]388 <li>The X86 backend does not yet support
389 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
390 floating point stack</a>. It supports the 'f' and 't' constraints, but not
391 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]392 <li>The X86 backend generates inefficient floating point code when configured
393 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]394 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]395 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
396 currently due
397 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]398 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
399 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]400 <li>The X86-64 backend does not yet support the LLVM IR instruction
401 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
402 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]403</ul>
404
405</div>
406
407<!-- ======================================================================= -->
408<div class="doc_subsection">
409 <a name="ppc-be">Known problems with the PowerPC back-end</a>
410</div>
411
412<div class="doc_text">
413
414<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]415<li>The Linux PPC32/ABI support needs testing for the interpreter and static
416compilation, and lacks support for debug information.</li>
417</ul>
418
419</div>
420
421<!-- ======================================================================= -->
422<div class="doc_subsection">
423 <a name="arm-be">Known problems with the ARM back-end</a>
424</div>
425
426<div class="doc_text">
427
428<ul>
429<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]430processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]431results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
432<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
433</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]434<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
435 execute
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]436programs compiled with LLVM. Please use more recent versions of QEMU.</li>
437</ul>
438
439</div>
440
441<!-- ======================================================================= -->
442<div class="doc_subsection">
443 <a name="sparc-be">Known problems with the SPARC back-end</a>
444</div>
445
446<div class="doc_text">
447
448<ul>
449<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
450 support the 64-bit SPARC ABI (-m64).</li>
451</ul>
452
453</div>
454
455<!-- ======================================================================= -->
456<div class="doc_subsection">
457 <a name="alpha-be">Known problems with the Alpha back-end</a>
458</div>
459
460<div class="doc_text">
461
462<ul>
463
464<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
465appropriate nops inserted to ensure restartability.</li>
466
467</ul>
468</div>
469
470<!-- ======================================================================= -->
471<div class="doc_subsection">
472 <a name="ia64-be">Known problems with the IA64 back-end</a>
473</div>
474
475<div class="doc_text">
476
477<ul>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]478<li>The Itanium backend is highly experimental, and has a number of known
479 issues. We are looking for a maintainer for the Itanium backend. If you
480 are interested, please contact the llvmdev mailing list.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]481</ul>
482
483</div>
484
485<!-- ======================================================================= -->
486<div class="doc_subsection">
487 <a name="c-be">Known problems with the C back-end</a>
488</div>
489
490<div class="doc_text">
491
492<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]493<li><a href="http://llvm.org/PR802">The C backend has only basic support for
494 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]495<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
496 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]497 C++ code compiled with llc or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]498<li>The C backend does not support all exception handling constructs.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]499</ul>
500
501</div>
502
503
504<!-- ======================================================================= -->
505<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]506 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]507</div>
508
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]509<div class="doc_text">
510
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]511<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
512Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]513llvmdev mailing list if you are interested.</p>
514
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]515<p>The only major language feature of GCC not supported by llvm-gcc is
516 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
517 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]518 supported on some targets (these are used when you take the address of a
519 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]520
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]521<p>If you run into GCC extensions which are not supported, please let us know.
522</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]523
524</div>
525
526<!-- ======================================================================= -->
527<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]528 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]529</div>
530
531<div class="doc_text">
532
533<p>The C++ front-end is considered to be fully
534tested and works for a number of non-trivial programs, including LLVM
535itself, Qt, Mozilla, etc.</p>
536
537<ul>
Anton Korobeynikovd9a17932008-10-11 18:27:16 +0000[diff] [blame]538<li>Exception handling works well on the X86 and PowerPC targets. Currently
539 only linux and darwin targets are supported (both 32 and 64 bit).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]540</ul>
541
542</div>
543
544
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]545<!-- ======================================================================= -->
546<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]547 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]548</div>
549
550<div class="doc_text">
551The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
552technology and problems should be expected.
553<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]554<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]555to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]556however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]557which does support trampolines.</li>
558<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
559Workaround: configure with --disable-bootstrap.</li>
560<li>The c380004 and <a href="http://llvm.org/PR2010">c393010</a> ACATS tests
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]561fail (c380004 also fails with gcc-4.2 mainline). When built at -O3, the
562<a href="http://llvm.org/PR2421">cxg2021</a> ACATS test also fails.</li>
563<li>Some gcc specific Ada tests continue to crash the compiler. The testsuite
564reports most tests as having failed even though they pass.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]565<li>The -E binder option (exception backtraces)
566<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
567crashing if an exception is raised. Workaround: do not use -E.</li>
568<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
569or finish at a non-byte offset</a> in a record. Workaround: do not pack records
570or use representation clauses that result in a field of a non-discrete type
571starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]572<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
573'main' as generated by the Ada binder to be invalid</a>.
574Workaround: hand edit the file to use pointers for <tt>argv</tt> and
575<tt>envp</tt> rather than integers.</li>
576<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
577ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]578</ul>
579</div>
580
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]581<!-- *********************************************************************** -->
582<div class="doc_section">
583 <a name="additionalinfo">Additional Information</a>
584</div>
585<!-- *********************************************************************** -->
586
587<div class="doc_text">
588
589<p>A wide variety of additional information is available on the <a
590href="http://llvm.org">LLVM web page</a>, in particular in the <a
591href="http://llvm.org/docs/">documentation</a> section. The web page also
592contains versions of the API documentation which is up-to-date with the
593Subversion version of the source code.
594You can access versions of these documents specific to this release by going
595into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
596
597<p>If you have any questions or comments about LLVM, please feel free to contact
598us via the <a href="http://llvm.org/docs/#maillist"> mailing
599lists</a>.</p>
600
601</div>
602
603<!-- *********************************************************************** -->
604
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