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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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Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]13 <li><a href="#intro">Introduction</a></li>
14 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]21 <li><a href="#core">Known problems with the LLVM Core</a>
22 <li><a href="#c-fe">Known problems with the C Front-end</a>
23 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
24 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
25 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]31<div class="doc_author">
32 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]41<div class="doc_text">
42
43<p>This document contains the release notes for the LLVM compiler
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]47href="http://llvm.cs.uiuc.edu/releases/1.3/">LLVM 1.3 web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]52current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
53web site</a>. If you have questions or comments, the <a
54href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]57<p>Note that if you are reading this file from CVS, this document applies
58to the <i>next</i> release, not the current one. To see the release notes for
59the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]73release primarily improves the <a href="#codequality">performance of the
74code</a> produced by all aspects of the LLVM compiler and adds some <a
75href="#newfeatures">new features</a>, though it does <a href="#bugfix">fix a few
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]76bugs</a> as well.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]77
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]78<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
79SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It
80has also been used to compile <b>many</b> other programs. LLVM now also works
81with a broad variety of C++ programs, though it has still received less testing
82than the C front-end.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]84</div>
85
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]86<!--=========================================================================-->
87<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]88<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]89</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]90
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]91<div class="doc_text">
92
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]93<ol>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]94<li>The LLVM <a href="LangRef.html#i_select"><tt>select</tt></a> instruction is
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]95now fully implemented and supported by all transformations, native code
96generators, and the interpreter.</li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]97<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
98before it could only narrow them down to a function being miscompiled.</li>
Brian Gaeke43be3112004-05-04 21:22:57 +0000[diff] [blame]99<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
100modes of llc</a> and lli, by passing them command line flags (e.g.,
101<tt>-regalloc=linearscan</tt>, <tt>-enable-correct-eh-support</tt>, etc.) </li>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]102<li>The Control Flow Graph in the native code generators is no longer
103constrained to be the same as the CFG for the LLVM input code.</li>
104<li>The LLVM induction variable analysis routines have been rewritten.</li>
105<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
106<li>The induction variable substitution pass performs linear function test
107replacement and exit value replacement optimizations.</li>
Chris Lattner39491a72004-05-24 04:45:52 +0000[diff] [blame]108<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
109Garbage Collection</a>, enabling the use of aggressive copying and generational
110collectors.</li>
111<li>LLVM now includes an implementation of Andersen's interprocedural alias
112analysis algorithm.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]113</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]114
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]115</div>
116
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]117
118<!--=========================================================================-->
119<div class="doc_subsubsection">
120In this release, the following missing features were implemented:
121</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]122
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]123<div class="doc_text">
124
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]125<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]126<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
127more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]128<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
129non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]130<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
131with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]132<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
133uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]134</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]135
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]136</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]137
138<!--=========================================================================-->
139<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]140<a name="qualityofimp">In this release, the following Quality of Implementation
141issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]142</div>
143
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]144<div class="doc_text">
145
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]146<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]147<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
148bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]149<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
150for structure typedefs</a></li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]151</ol>
152
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]153</div>
154
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]155<!--=========================================================================-->
156<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]157In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]158</div>
159
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]160<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]161<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]162<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
163-disable/enable-povray and -disable-spec</a></li>
164<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
165work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]166</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]167</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]168
169<!--=========================================================================-->
170<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]171<a name="codequality">This release includes the following Code Quality
172improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]173</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]174
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]175<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]176<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]177<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
178due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]179
180<li>The X86 backend now generates substantially better code for 64-bit integer
181and floating point operations.</li>
182
183<li>The -inline pass no longer inlines mutually recursive functions until it
184hits the inlining threshold.</li>
185
186<li>The -inline pass no longer misses obvious inlining opportunities just
187because the callee eventually calls into an external function.</li>
188
189<li>The -simplifycfg pass can now "if convert" simple statements into the new
190<tt>select</tt> instruction.</li>
191
192<li>The -loopsimplify pass can now break <a
193href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
194into multiple nested loops. This enables a variety of subsequent
195optimizations.</li>
196
197<li>The -adce pass can now eliminate calls to functions that do not not write to
198memory.</li>
199
200<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]201exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]202
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]203<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
204"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
205operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
206&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
207
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]208<li>LLVM now has infrastructure for (simple and sparse conditional) constant
209propagation of function calls. It currently supports a few math library
210functions like sqrt/sin/cos/etc.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]211</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]212</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]213
214<!--=========================================================================-->
215<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]216<a name="bugfix">In this release, the following bugs in the previous release
217were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]218</div>
219
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]220<div class="doc_text">
221
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]222<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]223
224<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]225<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
226asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]227<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
228incorrectly updates dominator information</a></li>
229<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
230breaks SSA form</a></li>
231<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
232to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]233<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
234code that unwinds</a></li>
235<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
236of the same name, both having constant pools</a></li>
237<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
238physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]239<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]240</ol>
241
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]242<p>Bugs in the C/C++ front-end:</p>
243
244<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]245<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
246enum type</a></li>
247<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
248indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]249</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]250</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]251
252<!--=========================================================================-->
253<div class="doc_subsubsection">
254<a name="misc">This release includes the following miscellaneous
255improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]256</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]257
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]258<div class="doc_text">
259
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]260<p>Documentation Improvements</p>
261<ol>
262<li><a href="BytecodeFormat.html">Documentation of the LLVM Bytecode file format
263was added.</a></li>
264<li>All documentation was brought up to HTML 4.01 (Strict) level.</li>
265</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]266</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]267
268
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]269<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]270<div class="doc_section">
271 <a name="portability">Portability and Supported Platforms</a>
272</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]273<!-- *********************************************************************** -->
274
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]275<div class="doc_text">
276
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]277<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
278Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
279workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
280above, but only with the C backend and interpreter; no native machine-code
281generator for the PowerPC is available yet.</p>
282
283<p>The core LLVM infrastructure uses
284<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
285to the machine and operating system on which it is built. However, minor
286porting may be required to get LLVM to work on new platforms. We welcome your
287portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]288
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]289</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]290
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]291<!--=========================================================================-->
292<div class="doc_subsection">
293In this release, the following portability problems were fixed:
294</div>
295
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]296<div class="doc_text">
297
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]298<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]299<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
300on Mac OS X</a></li>
301<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
302understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]303</ol>
304
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame^]305</div>
306
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]307<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]308<div class="doc_section">
309 <a name="knownproblems">Known Problems</a>
310</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]311<!-- *********************************************************************** -->
312
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]313<div class="doc_text">
314
315<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]316component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]317sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]318href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]319there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]320
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]321</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]322
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]323<!-- ======================================================================= -->
324<div class="doc_subsection">
325 <a name="experimental">Experimental features included with this release</a>
326</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]327
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]328<div class="doc_text">
329
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]330<p>The following components of this LLVM release are either untested, known to
331be broken or unreliable, or are in early development. These components should
332not be relied on, and bugs should not be filed against them, but they may be
333useful to some people. In particular, if you would like to work on one of these
334components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]335
336<ul>
337<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
338 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
339
340<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
341 it should) and not thoroughly tested.</li>
342<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
343<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
344</ul>
345
346</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]347
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]348<!-- ======================================================================= -->
349<div class="doc_subsection">
350 <a name="core">Known problems with the LLVM Core</a>
351</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]352
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]353<div class="doc_text">
354
355<ul>
356
357<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
358work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]359
360<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]361such, execution of a threaded program could cause these data structures to be
362corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]363
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]364<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]365
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]366<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]367table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]368
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]369<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
370objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]371
372<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswelld46c6962004-03-12 21:29:42 +0000[diff] [blame]373values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]374targets whose setjmp/longjmp libraries do not save and restore the entire
375register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]376</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]377</div>
378
379<!-- ======================================================================= -->
380<div class="doc_subsection">
381 <a name="c-fe">Known problems with the C front-end</a>
382</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]383
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]384<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]385<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]386
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]387<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]388<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]389<li>C99 Variable sized arrays do not release stack memory when they go out of
390 scope. Thus, the following program may run out of stack space:
391<pre>
392 for (i = 0; i != 1000000; ++i) {
393 int X[n];
394 foo(X);
395 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]396</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]397
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]398<li>Initialization of global union variables can only be done <a
399href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
400member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]401
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]402<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
403external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]404
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]405</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]406</div>
407
408<!-- _______________________________________________________________________ -->
409<div class="doc_subsubsection">
410 Notes
411</div>
412
413<div class="doc_text">
414
415<ul>
416
417<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]418
419<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]420support for floating point data types of any size other than 32 and 64
421bits.</li>
422
423<li>The following Unix system functionality has not been tested and may not
424work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]425 <ol>
426 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
427 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
428 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
429 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
430 - These functions have not been tested.
431 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]432
433<li>Although many GCC extensions are supported, some are not. In particular,
434 the following extensions are known to <b>not be</b> supported:
435 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]436 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]437 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>: As in Algol and Pascal, lexical scoping of functions.</li>
438 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
439 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]440 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]441 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Asm-Labels.html#Asm%20Labels">Asm Labels</a>: Specifying the assembler name to use for a C symbol.</li>
442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]443 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html#Vector%20Extensions">Vector Extensions</a>: Using vector instructions through built-in functions.</li>
444 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Target-Builtins.html#Target%20Builtins">Target Builtins</a>: Built-in functions specific to particular targets.</li>
445 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
446 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]447 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]448
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]449 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]450 attribute means that the LLVM compiler ignores the presence of the attribute,
451 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]452 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]453 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]454
455 <ol>
456 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
457 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]458 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]459
460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]461
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]462 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]463 return.<br>
464
465 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
466 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
467 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
468
469 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
470 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
471 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
472
473 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
474 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
475 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]476
477 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
478 Specifying attributes of variables.<br>
479 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
480 <tt>deprecated</tt>, <tt>transparent_union</tt>,
481 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]482
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]483 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
484 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
485 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]486 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]487
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]488 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]489 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]490 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]491
492 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
493 all target specific attributes.</li>
494
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]495 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
496 Other built-in functions.<br>
497 We support all builtins which have a C language equivalent (e.g.,
498 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
499 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]501
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]502 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]503
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]504 <p>The following extensions <b>are</b> known to be supported:</p>
505
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]506 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]508 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
509 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
510 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
511 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variadic-Macros.html#Variadic%20Macros">Variadic Macros</a>: Macros with a variable number of arguments.</li>
518 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]520 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]521 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]522 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
523or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]524 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]525 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]526 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
528 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
529 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
530 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Character-Escapes.html#Character%20Escapes">Character Escapes</a>: <code>\e</code> stands for the character &lt;ESC&gt;.</li>
532 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
533 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
534 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html#Alternate%20Keywords">Alternate Keywords</a>:<code>__const__</code>, <code>__asm__</code>, etc., for header files.</li>
535 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Incomplete-Enums.html#Incomplete%20Enums">Incomplete Enums</a>: <code>enum foo;</code>, with details to follow.</li>
536 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner25795bc2004-02-14 04:08:29 +0000[diff] [blame]537 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]538 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed%20Fields">Unnamed Fields</a>: Unnamed struct/union fields within structs/unions.</li>
539 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]540 </ol></li>
541
542</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]543
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]544<p>If you run into GCC extensions which have not been included in any of these
545lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]546
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]547</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]548
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]549<!-- ======================================================================= -->
550<div class="doc_subsection">
551 <a name="c++-fe">Known problems with the C++ front-end</a>
552</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]553
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]554<div class="doc_text">
555
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]556<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]557has not been tested as thoroughly as the C front-end. It has been tested and
558works for a number of non-trivial programs, but there may be lurking bugs.
559Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]560
561</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]562
563<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]564<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]565
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]566<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]567
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]568<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]569<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]570 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]571</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]572</div>
573
574<!-- _______________________________________________________________________ -->
575<div class="doc_subsubsection">
576 Notes
577</div>
578
579<div class="doc_text">
580
581<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]582
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]583<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
584parser is significantly more standards compliant (and picky) than prior GCC
585versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]586href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]587
588<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]589 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]590 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]591 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]592 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]593
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]594<li>The LLVM C++ front-end follows the <a
595 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
596 This document, which is not Itanium specific, specifies a standard for name
597 mangling, class layout, v-table layout, RTTI formats, and other C++
598 representation issues. Because we use this API, code generated by the LLVM
599 compilers should be binary compatible with machine code generated by other
600 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
601 <i>However</i>, the exception handling mechanism used by LLVM is very
602 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]603 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]604
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]605</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]606
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]607</div>
608
609<!-- ======================================================================= -->
610<div class="doc_subsection">
611 <a name="x86-be">Known problems with the X86 back-end</a>
612</div>
613
614<div class="doc_text">
615
616<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]617<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]618</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]619
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]620</div>
621
622<!-- ======================================================================= -->
623<div class="doc_subsection">
624 <a name="sparc-be">Known problems with the Sparc back-end</a>
625</div>
626
627<div class="doc_text">
628
629<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]630<li>There are several programs in the LLVM testsuite that the Sparc code generator is known to miscompile.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]631</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]632
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]633</div>
634
635<!-- ======================================================================= -->
636<div class="doc_subsection">
637 <a name="c-be">Known problems with the C back-end</a>
638</div>
639
640<div class="doc_text">
641
642<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]643
644<li>The C back-end produces code that violates the ANSI C Type-Based Alias
645Analysis rules. As such, special options may be necessary to compile the code
646(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]648
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]649<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]650cannot include special floating point numbers like Not-A-Number or
651Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]652
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]653<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]654supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]655frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]656
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]657</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]658
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]659</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]660
661<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]662<div class="doc_section">
663 <a name="additionalinfo">Additional Information</a>
664</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]665<!-- *********************************************************************** -->
666
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]667<div class="doc_text">
668
669<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]670including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]671implemented in LLVM. The web page also contains versions of the API
672documentation which is up-to-date with the CVS version of the source code. You
673can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]674the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]675
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]676<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]677us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
678lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]679
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]680</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]681
682<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]683
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]684<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]685<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]686 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]687 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
688 <a href="http://validator.w3.org/check/referer"><img
689 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
690
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]691 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]692 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]693</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]694
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]695</body>
696</html>