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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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4<head>
5 <link rel="stylesheet" href="llvm.css" type="text/css">
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 Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]108<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame^]109 documented.</li>
Chris Lattner39491a72004-05-24 04:45:52 +0000[diff] [blame]110<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
111Garbage Collection</a>, enabling the use of aggressive copying and generational
112collectors.</li>
113<li>LLVM now includes an implementation of Andersen's interprocedural alias
114analysis algorithm.</li>
Chris Lattner14cd5392004-05-24 05:34:32 +0000[diff] [blame]115<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
116basic blocks</a> to track down reduce miscompilation testcases.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame^]117<li>LLVM and the C front-end now work under Win32 using the cygnus libraries.
118This includes the JIT compiler.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]119</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]120
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]121</div>
122
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]123
124<!--=========================================================================-->
125<div class="doc_subsubsection">
126In this release, the following missing features were implemented:
127</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]128
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]129<div class="doc_text">
130
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]131<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]132<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
133more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]134<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
135non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]136<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
137with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]138<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
139uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]140</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]141
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]142</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]143
144<!--=========================================================================-->
145<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]146<a name="qualityofimp">In this release, the following Quality of Implementation
147issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]148</div>
149
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]150<div class="doc_text">
151
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]152<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]153<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
154bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]155<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
156for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]157<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]158</ol>
159
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]160</div>
161
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]162<!--=========================================================================-->
163<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]164In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]165</div>
166
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]167<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]168<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]169<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
170-disable/enable-povray and -disable-spec</a></li>
171<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
172work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]173</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]174</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]175
176<!--=========================================================================-->
177<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]178<a name="codequality">This release includes the following Code Quality
179improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]180</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]181
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]182<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]183<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]184<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
185due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]186
187<li>The X86 backend now generates substantially better code for 64-bit integer
188and floating point operations.</li>
189
190<li>The -inline pass no longer inlines mutually recursive functions until it
191hits the inlining threshold.</li>
192
193<li>The -inline pass no longer misses obvious inlining opportunities just
194because the callee eventually calls into an external function.</li>
195
196<li>The -simplifycfg pass can now "if convert" simple statements into the new
197<tt>select</tt> instruction.</li>
198
199<li>The -loopsimplify pass can now break <a
200href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
201into multiple nested loops. This enables a variety of subsequent
202optimizations.</li>
203
204<li>The -adce pass can now eliminate calls to functions that do not not write to
205memory.</li>
206
207<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]208exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]209
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]210<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
211"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
212operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
213&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
214
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]215<li>LLVM now has infrastructure for (simple and sparse conditional) constant
216propagation of function calls. It currently supports a few math library
217functions like sqrt/sin/cos/etc.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]218</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]219</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]220
221<!--=========================================================================-->
222<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]223<a name="bugfix">In this release, the following bugs in the previous release
224were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]225</div>
226
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]227<div class="doc_text">
228
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]229<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]230
231<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]232<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
233asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]234<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
235incorrectly updates dominator information</a></li>
236<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
237breaks SSA form</a></li>
238<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
239to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]240<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
241code that unwinds</a></li>
242<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
243of the same name, both having constant pools</a></li>
244<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
245physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]246<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]247</ol>
248
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]249<p>Bugs in the C/C++ front-end:</p>
250
251<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]252<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
253enum type</a></li>
254<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
255indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]256</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]257</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]258
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]259<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]260<div class="doc_section">
261 <a name="portability">Portability and Supported Platforms</a>
262</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]263<!-- *********************************************************************** -->
264
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]265<div class="doc_text">
266
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame^]267<p>LLVM is known to work in the following platforms:</p>
268
269<ul>
270<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
271 other unix-like systems).</li>
272<li>Sun UltraSPARC workstations running Solaris 8.</li>
273<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
274 interpreter only, no native codegen is available yet).</li>
275<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
276</ul>
277
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]278
279<p>The core LLVM infrastructure uses
280<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
281to the machine and operating system on which it is built. However, minor
282porting may be required to get LLVM to work on new platforms. We welcome your
283portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]284
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame^]285<p>Note that the LLVM build system does not currently support directories with
286spaces on them when running on Win32/cygwin. We strongly recommend running
287LLVM and the C frontend out of a top-level directory without spaces (e.g.,
288<tt>/cygdrive/c/llvm</tt>).</p>
289
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]290</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]291
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]292<!--=========================================================================-->
293<div class="doc_subsection">
294In this release, the following portability problems were fixed:
295</div>
296
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]297<div class="doc_text">
298
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]299<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]300<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
301on Mac OS X</a></li>
302<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
303understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]304</ol>
305
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]306</div>
307
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]308<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]309<div class="doc_section">
310 <a name="knownproblems">Known Problems</a>
311</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]312<!-- *********************************************************************** -->
313
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]314<div class="doc_text">
315
316<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]317component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]318sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]319href="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]320there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]321
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]322</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]323
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]324<!-- ======================================================================= -->
325<div class="doc_subsection">
326 <a name="experimental">Experimental features included with this release</a>
327</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]328
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]329<div class="doc_text">
330
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]331<p>The following components of this LLVM release are either untested, known to
332be broken or unreliable, or are in early development. These components should
333not be relied on, and bugs should not be filed against them, but they may be
334useful to some people. In particular, if you would like to work on one of these
335components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]336
337<ul>
338<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
339 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
340
341<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
342 it should) and not thoroughly tested.</li>
343<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
344<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
345</ul>
346
347</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]348
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]349<!-- ======================================================================= -->
350<div class="doc_subsection">
351 <a name="core">Known problems with the LLVM Core</a>
352</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]353
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]354<div class="doc_text">
355
356<ul>
357
358<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
359work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]360
361<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]362such, execution of a threaded program could cause these data structures to be
363corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]364
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]365<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]366
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]367<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]368table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]369
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]370<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
371objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]372
373<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]374values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]375targets whose setjmp/longjmp libraries do not save and restore the entire
376register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]377</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]378</div>
379
380<!-- ======================================================================= -->
381<div class="doc_subsection">
382 <a name="c-fe">Known problems with the C front-end</a>
383</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]384
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]385<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]386<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]387
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]388<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]389<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]390<li>C99 Variable sized arrays do not release stack memory when they go out of
391 scope. Thus, the following program may run out of stack space:
392<pre>
393 for (i = 0; i != 1000000; ++i) {
394 int X[n];
395 foo(X);
396 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]397</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]398
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]399<li>Initialization of global union variables can only be done <a
400href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
401member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]402
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]403<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
404external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]405
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]406</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]407</div>
408
409<!-- _______________________________________________________________________ -->
410<div class="doc_subsubsection">
411 Notes
412</div>
413
414<div class="doc_text">
415
416<ul>
417
418<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]419
420<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]421support for floating point data types of any size other than 32 and 64
422bits.</li>
423
424<li>The following Unix system functionality has not been tested and may not
425work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]426 <ol>
427 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
428 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
429 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
430 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
431 - These functions have not been tested.
432 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]433
434<li>Although many GCC extensions are supported, some are not. In particular,
435 the following extensions are known to <b>not be</b> supported:
436 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]437 <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]438 <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>
439 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
440 <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]441 <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]442 <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>
443 <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]444 <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>
445 <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>
446 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
447 <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]448 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]449
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]450 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]451 attribute means that the LLVM compiler ignores the presence of the attribute,
452 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]453 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]454 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]455
456 <ol>
457 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
458 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]459 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]460
461 <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]462
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]463 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]464 return.<br>
465
466 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
467 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
468 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
469
470 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
471 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
472 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
473
474 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
475 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
476 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]477
478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
479 Specifying attributes of variables.<br>
480 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
481 <tt>deprecated</tt>, <tt>transparent_union</tt>,
482 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]483
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]484 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
485 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
486 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]487 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]488
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]489 <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]490 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]491 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]492
493 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
494 all target specific attributes.</li>
495
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
497 Other built-in functions.<br>
498 We support all builtins which have a C language equivalent (e.g.,
499 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
500 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]501 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]502
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]503 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]504
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]505 <p>The following extensions <b>are</b> known to be supported:</p>
506
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]507 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]508 <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]509 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
510 <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>
511 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
518 <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>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
520 <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]521 <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]522 <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]523 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
524or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]525 <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]526 <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]527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
528 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
529 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
530 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
532 <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>
533 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
534 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
535 <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>
536 <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>
537 <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]538 <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]539 <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>
540 <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]541 </ol></li>
542
543</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]544
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]545<p>If you run into GCC extensions which have not been included in any of these
546lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]548</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]549
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]550<!-- ======================================================================= -->
551<div class="doc_subsection">
552 <a name="c++-fe">Known problems with the C++ front-end</a>
553</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]554
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]555<div class="doc_text">
556
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]557<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]558has not been tested as thoroughly as the C front-end. It has been tested and
559works for a number of non-trivial programs, but there may be lurking bugs.
560Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]561
562</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]563
564<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]565<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]566
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]567<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]568
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]569<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]570<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]571 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]572</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]573</div>
574
575<!-- _______________________________________________________________________ -->
576<div class="doc_subsubsection">
577 Notes
578</div>
579
580<div class="doc_text">
581
582<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]583
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]584<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
585parser is significantly more standards compliant (and picky) than prior GCC
586versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]587href="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]588
589<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]590 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]591 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]592 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]593 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]594
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]595<li>The LLVM C++ front-end follows the <a
596 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
597 This document, which is not Itanium specific, specifies a standard for name
598 mangling, class layout, v-table layout, RTTI formats, and other C++
599 representation issues. Because we use this API, code generated by the LLVM
600 compilers should be binary compatible with machine code generated by other
601 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
602 <i>However</i>, the exception handling mechanism used by LLVM is very
603 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]606</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]607
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]608</div>
609
610<!-- ======================================================================= -->
611<div class="doc_subsection">
612 <a name="x86-be">Known problems with the X86 back-end</a>
613</div>
614
615<div class="doc_text">
616
617<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]618<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]620
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]621</div>
622
623<!-- ======================================================================= -->
624<div class="doc_subsection">
625 <a name="sparc-be">Known problems with the Sparc back-end</a>
626</div>
627
628<div class="doc_text">
629
630<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]631<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]632</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]634</div>
635
636<!-- ======================================================================= -->
637<div class="doc_subsection">
638 <a name="c-be">Known problems with the C back-end</a>
639</div>
640
641<div class="doc_text">
642
643<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]644
645<li>The C back-end produces code that violates the ANSI C Type-Based Alias
646Analysis rules. As such, special options may be necessary to compile the code
647(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]648problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]649
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]650<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]651cannot include special floating point numbers like Not-A-Number or
652Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]653
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]654<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]655supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]656frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]657
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]658</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]659
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]660</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]661
662<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]663<div class="doc_section">
664 <a name="additionalinfo">Additional Information</a>
665</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]666<!-- *********************************************************************** -->
667
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]668<div class="doc_text">
669
670<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]671including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]672implemented in LLVM. The web page also contains versions of the API
673documentation which is up-to-date with the CVS version of the source code. You
674can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]675the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]676
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]677<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]678us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
679lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]681</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]682
683<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]684
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]685<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]686<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]687 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]688 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
689 <a href="http://validator.w3.org/check/referer"><img
690 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
691
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]692 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]693 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]694</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]695
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]696</body>
697</html>