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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 5c7af72c08604dc2cd00d00864ab81395acd76b4 / . / docs / ReleaseNotes.html
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Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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4<head>
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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 Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]108<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now
109 documented.</a></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 Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]117</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]118
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]119</div>
120
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]121
122<!--=========================================================================-->
123<div class="doc_subsubsection">
124In this release, the following missing features were implemented:
125</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]126
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]127<div class="doc_text">
128
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]129<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]130<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
131more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]132<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
133non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]134<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
135with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]136<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
137uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]138</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]139
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]140</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]141
142<!--=========================================================================-->
143<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]144<a name="qualityofimp">In this release, the following Quality of Implementation
145issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]146</div>
147
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]148<div class="doc_text">
149
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]150<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]151<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
152bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]153<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
154for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]155<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]156</ol>
157
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]158</div>
159
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]160<!--=========================================================================-->
161<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]162In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]163</div>
164
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]165<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]166<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]167<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
168-disable/enable-povray and -disable-spec</a></li>
169<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
170work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]171</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]172</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]173
174<!--=========================================================================-->
175<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]176<a name="codequality">This release includes the following Code Quality
177improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]178</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]179
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]180<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]181<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]182<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
183due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]184
185<li>The X86 backend now generates substantially better code for 64-bit integer
186and floating point operations.</li>
187
188<li>The -inline pass no longer inlines mutually recursive functions until it
189hits the inlining threshold.</li>
190
191<li>The -inline pass no longer misses obvious inlining opportunities just
192because the callee eventually calls into an external function.</li>
193
194<li>The -simplifycfg pass can now "if convert" simple statements into the new
195<tt>select</tt> instruction.</li>
196
197<li>The -loopsimplify pass can now break <a
198href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
199into multiple nested loops. This enables a variety of subsequent
200optimizations.</li>
201
202<li>The -adce pass can now eliminate calls to functions that do not not write to
203memory.</li>
204
205<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]206exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]207
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]208<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
209"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
210operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
211&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
212
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]213<li>LLVM now has infrastructure for (simple and sparse conditional) constant
214propagation of function calls. It currently supports a few math library
215functions like sqrt/sin/cos/etc.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]216</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]217</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]218
219<!--=========================================================================-->
220<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]221<a name="bugfix">In this release, the following bugs in the previous release
222were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]223</div>
224
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]225<div class="doc_text">
226
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]227<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]228
229<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]230<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
231asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]232<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
233incorrectly updates dominator information</a></li>
234<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
235breaks SSA form</a></li>
236<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
237to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]238<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
239code that unwinds</a></li>
240<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
241of the same name, both having constant pools</a></li>
242<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
243physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]244<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]245</ol>
246
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]247<p>Bugs in the C/C++ front-end:</p>
248
249<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]250<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
251enum type</a></li>
252<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
253indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]254</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]255</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]256
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]257<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]258<div class="doc_section">
259 <a name="portability">Portability and Supported Platforms</a>
260</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]261<!-- *********************************************************************** -->
262
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]263<div class="doc_text">
264
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]265<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
266Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
267workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
268above, but only with the C backend and interpreter; no native machine-code
269generator for the PowerPC is available yet.</p>
270
271<p>The core LLVM infrastructure uses
272<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
273to the machine and operating system on which it is built. However, minor
274porting may be required to get LLVM to work on new platforms. We welcome your
275portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]276
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]277</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]278
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]279<!--=========================================================================-->
280<div class="doc_subsection">
281In this release, the following portability problems were fixed:
282</div>
283
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]284<div class="doc_text">
285
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]286<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]287<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
288on Mac OS X</a></li>
289<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
290understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]291</ol>
292
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]293</div>
294
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]295<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]296<div class="doc_section">
297 <a name="knownproblems">Known Problems</a>
298</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]299<!-- *********************************************************************** -->
300
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]301<div class="doc_text">
302
303<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]304component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]305sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]306href="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]307there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]308
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]309</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]310
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]311<!-- ======================================================================= -->
312<div class="doc_subsection">
313 <a name="experimental">Experimental features included with this release</a>
314</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]315
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]316<div class="doc_text">
317
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]318<p>The following components of this LLVM release are either untested, known to
319be broken or unreliable, or are in early development. These components should
320not be relied on, and bugs should not be filed against them, but they may be
321useful to some people. In particular, if you would like to work on one of these
322components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]323
324<ul>
325<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
326 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
327
328<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
329 it should) and not thoroughly tested.</li>
330<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
331<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
332</ul>
333
334</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]335
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]336<!-- ======================================================================= -->
337<div class="doc_subsection">
338 <a name="core">Known problems with the LLVM Core</a>
339</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]340
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]341<div class="doc_text">
342
343<ul>
344
345<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
346work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]347
348<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]349such, execution of a threaded program could cause these data structures to be
350corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]351
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]352<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]353
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]354<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]355table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]356
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]357<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
358objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]359
360<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]361values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]362targets whose setjmp/longjmp libraries do not save and restore the entire
363register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]364</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]365</div>
366
367<!-- ======================================================================= -->
368<div class="doc_subsection">
369 <a name="c-fe">Known problems with the C front-end</a>
370</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]371
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]372<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]373<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]374
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]375<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]376<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]377<li>C99 Variable sized arrays do not release stack memory when they go out of
378 scope. Thus, the following program may run out of stack space:
379<pre>
380 for (i = 0; i != 1000000; ++i) {
381 int X[n];
382 foo(X);
383 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]384</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]385
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]386<li>Initialization of global union variables can only be done <a
387href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
388member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]389
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]390<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
391external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]392
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]393</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]394</div>
395
396<!-- _______________________________________________________________________ -->
397<div class="doc_subsubsection">
398 Notes
399</div>
400
401<div class="doc_text">
402
403<ul>
404
405<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]406
407<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]408support for floating point data types of any size other than 32 and 64
409bits.</li>
410
411<li>The following Unix system functionality has not been tested and may not
412work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]413 <ol>
414 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
415 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
416 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
417 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
418 - These functions have not been tested.
419 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]420
421<li>Although many GCC extensions are supported, some are not. In particular,
422 the following extensions are known to <b>not be</b> supported:
423 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]424 <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]425 <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>
426 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
427 <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]428 <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]429 <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>
430 <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]431 <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>
432 <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>
433 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
434 <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]435 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]436
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]437 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]438 attribute means that the LLVM compiler ignores the presence of the attribute,
439 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]440 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]441 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]442
443 <ol>
444 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
445 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]446 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]447
448 <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]449
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]450 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]451 return.<br>
452
453 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
454 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
455 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
456
457 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
458 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
459 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
460
461 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
462 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
463 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]464
465 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
466 Specifying attributes of variables.<br>
467 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
468 <tt>deprecated</tt>, <tt>transparent_union</tt>,
469 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]470
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]471 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
472 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
473 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]474 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]475
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]476 <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]477 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]478 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]479
480 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
481 all target specific attributes.</li>
482
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
484 Other built-in functions.<br>
485 We support all builtins which have a C language equivalent (e.g.,
486 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
487 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]488 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]489
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]490 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]491
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]492 <p>The following extensions <b>are</b> known to be supported:</p>
493
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]494 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]495 <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]496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
497 <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>
498 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
500 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
501 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
502 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
503 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
505 <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>
506 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
507 <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]508 <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]509 <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]510 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
511or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]512 <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]513 <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]514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
518 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
519 <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>
520 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
521 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
522 <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>
523 <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>
524 <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]525 <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]526 <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>
527 <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]528 </ol></li>
529
530</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]531
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]532<p>If you run into GCC extensions which have not been included in any of these
533lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]534
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]535</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]536
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]537<!-- ======================================================================= -->
538<div class="doc_subsection">
539 <a name="c++-fe">Known problems with the C++ front-end</a>
540</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]541
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]542<div class="doc_text">
543
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]544<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]545has not been tested as thoroughly as the C front-end. It has been tested and
546works for a number of non-trivial programs, but there may be lurking bugs.
547Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]548
549</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]550
551<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]552<div class="doc_subsubsection">Bugs</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">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]555
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]556<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]557<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]558 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]559</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]560</div>
561
562<!-- _______________________________________________________________________ -->
563<div class="doc_subsubsection">
564 Notes
565</div>
566
567<div class="doc_text">
568
569<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]570
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]571<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
572parser is significantly more standards compliant (and picky) than prior GCC
573versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]574href="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]575
576<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]577 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]578 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]579 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]580 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]581
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]582<li>The LLVM C++ front-end follows the <a
583 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
584 This document, which is not Itanium specific, specifies a standard for name
585 mangling, class layout, v-table layout, RTTI formats, and other C++
586 representation issues. Because we use this API, code generated by the LLVM
587 compilers should be binary compatible with machine code generated by other
588 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
589 <i>However</i>, the exception handling mechanism used by LLVM is very
590 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]591 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]592
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]593</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]594
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]595</div>
596
597<!-- ======================================================================= -->
598<div class="doc_subsection">
599 <a name="x86-be">Known problems with the X86 back-end</a>
600</div>
601
602<div class="doc_text">
603
604<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]605<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]606</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +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="sparc-be">Known problems with the Sparc back-end</a>
613</div>
614
615<div class="doc_text">
616
617<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]618<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]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="c-be">Known problems with the C back-end</a>
626</div>
627
628<div class="doc_text">
629
630<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]631
632<li>The C back-end produces code that violates the ANSI C Type-Based Alias
633Analysis rules. As such, special options may be necessary to compile the code
634(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]635problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]636
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]637<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]638cannot include special floating point numbers like Not-A-Number or
639Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]640
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]641<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]642supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]643frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]644
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]645</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]646
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]648
649<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]650<div class="doc_section">
651 <a name="additionalinfo">Additional Information</a>
652</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]653<!-- *********************************************************************** -->
654
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]655<div class="doc_text">
656
657<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]658including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]659implemented in LLVM. The web page also contains versions of the API
660documentation which is up-to-date with the CVS version of the source code. You
661can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]662the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]663
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]664<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]665us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
666lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]667
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]668</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]669
670<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]671
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]672<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]673<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]674 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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678
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]679 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]680 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]681</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]682
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]683</body>
684</html>