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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / b965669d558e42220f011f5885a15f9a28522fe8 / . / 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 Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]115</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]116
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]117</div>
118
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]119
120<!--=========================================================================-->
121<div class="doc_subsubsection">
122In this release, the following missing features were implemented:
123</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]124
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]125<div class="doc_text">
126
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]127<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]128<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
129more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]130<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
131non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]132<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
133with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]134<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
135uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]136</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]137
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]138</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]139
140<!--=========================================================================-->
141<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]142<a name="qualityofimp">In this release, the following Quality of Implementation
143issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]144</div>
145
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]146<div class="doc_text">
147
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]148<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]149<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
150bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]151<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
152for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame^]153<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]154</ol>
155
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]156</div>
157
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]158<!--=========================================================================-->
159<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]160In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]161</div>
162
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]163<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]164<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]165<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
166-disable/enable-povray and -disable-spec</a></li>
167<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
168work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]169</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]170</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]171
172<!--=========================================================================-->
173<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]174<a name="codequality">This release includes the following Code Quality
175improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]176</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]177
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]178<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]179<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]180<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
181due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]182
183<li>The X86 backend now generates substantially better code for 64-bit integer
184and floating point operations.</li>
185
186<li>The -inline pass no longer inlines mutually recursive functions until it
187hits the inlining threshold.</li>
188
189<li>The -inline pass no longer misses obvious inlining opportunities just
190because the callee eventually calls into an external function.</li>
191
192<li>The -simplifycfg pass can now "if convert" simple statements into the new
193<tt>select</tt> instruction.</li>
194
195<li>The -loopsimplify pass can now break <a
196href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
197into multiple nested loops. This enables a variety of subsequent
198optimizations.</li>
199
200<li>The -adce pass can now eliminate calls to functions that do not not write to
201memory.</li>
202
203<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]204exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]205
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]206<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
207"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
208operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
209&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
210
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]211<li>LLVM now has infrastructure for (simple and sparse conditional) constant
212propagation of function calls. It currently supports a few math library
213functions like sqrt/sin/cos/etc.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]214</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]215</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]216
217<!--=========================================================================-->
218<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]219<a name="bugfix">In this release, the following bugs in the previous release
220were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]221</div>
222
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]223<div class="doc_text">
224
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]225<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]226
227<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]228<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
229asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]230<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
231incorrectly updates dominator information</a></li>
232<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
233breaks SSA form</a></li>
234<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
235to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]236<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
237code that unwinds</a></li>
238<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
239of the same name, both having constant pools</a></li>
240<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
241physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]242<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]243</ol>
244
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]245<p>Bugs in the C/C++ front-end:</p>
246
247<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]248<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
249enum type</a></li>
250<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
251indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]252</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]253</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]254
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]255<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]256<div class="doc_section">
257 <a name="portability">Portability and Supported Platforms</a>
258</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]259<!-- *********************************************************************** -->
260
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]261<div class="doc_text">
262
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]263<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
264Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
265workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
266above, but only with the C backend and interpreter; no native machine-code
267generator for the PowerPC is available yet.</p>
268
269<p>The core LLVM infrastructure uses
270<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
271to the machine and operating system on which it is built. However, minor
272porting may be required to get LLVM to work on new platforms. We welcome your
273portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]274
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]275</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]276
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]277<!--=========================================================================-->
278<div class="doc_subsection">
279In this release, the following portability problems were fixed:
280</div>
281
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]282<div class="doc_text">
283
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]284<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]285<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
286on Mac OS X</a></li>
287<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
288understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]289</ol>
290
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]291</div>
292
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]293<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]294<div class="doc_section">
295 <a name="knownproblems">Known Problems</a>
296</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]297<!-- *********************************************************************** -->
298
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]299<div class="doc_text">
300
301<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]302component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]303sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]304href="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]305there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]306
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]307</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]308
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]309<!-- ======================================================================= -->
310<div class="doc_subsection">
311 <a name="experimental">Experimental features included with this release</a>
312</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]313
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]314<div class="doc_text">
315
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]316<p>The following components of this LLVM release are either untested, known to
317be broken or unreliable, or are in early development. These components should
318not be relied on, and bugs should not be filed against them, but they may be
319useful to some people. In particular, if you would like to work on one of these
320components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]321
322<ul>
323<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
324 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
325
326<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
327 it should) and not thoroughly tested.</li>
328<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
329<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
330</ul>
331
332</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]333
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]334<!-- ======================================================================= -->
335<div class="doc_subsection">
336 <a name="core">Known problems with the LLVM Core</a>
337</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]338
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]339<div class="doc_text">
340
341<ul>
342
343<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
344work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]345
346<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]347such, execution of a threaded program could cause these data structures to be
348corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]349
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]350<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]351
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]352<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]353table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]354
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]355<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
356objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]357
358<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]359values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]360targets whose setjmp/longjmp libraries do not save and restore the entire
361register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]362</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]363</div>
364
365<!-- ======================================================================= -->
366<div class="doc_subsection">
367 <a name="c-fe">Known problems with the C front-end</a>
368</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]369
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]370<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]371<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]372
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]373<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]374<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]375<li>C99 Variable sized arrays do not release stack memory when they go out of
376 scope. Thus, the following program may run out of stack space:
377<pre>
378 for (i = 0; i != 1000000; ++i) {
379 int X[n];
380 foo(X);
381 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]382</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]383
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]384<li>Initialization of global union variables can only be done <a
385href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
386member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]387
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]388<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
389external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]390
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]391</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]392</div>
393
394<!-- _______________________________________________________________________ -->
395<div class="doc_subsubsection">
396 Notes
397</div>
398
399<div class="doc_text">
400
401<ul>
402
403<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]404
405<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]406support for floating point data types of any size other than 32 and 64
407bits.</li>
408
409<li>The following Unix system functionality has not been tested and may not
410work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]411 <ol>
412 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
413 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
414 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
415 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
416 - These functions have not been tested.
417 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]418
419<li>Although many GCC extensions are supported, some are not. In particular,
420 the following extensions are known to <b>not be</b> supported:
421 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]422 <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]423 <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>
424 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
425 <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]426 <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]427 <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>
428 <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]429 <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>
430 <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>
431 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
432 <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]433 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]434
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]435 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]436 attribute means that the LLVM compiler ignores the presence of the attribute,
437 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]438 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]439 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]440
441 <ol>
442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
443 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]444 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]445
446 <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]447
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]448 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]449 return.<br>
450
451 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
452 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
453 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
454
455 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
456 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
457 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
458
459 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
460 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
461 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]462
463 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
464 Specifying attributes of variables.<br>
465 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
466 <tt>deprecated</tt>, <tt>transparent_union</tt>,
467 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]468
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]469 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
470 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
471 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]472 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]473
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]474 <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]475 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]476 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]477
478 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
479 all target specific attributes.</li>
480
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
482 Other built-in functions.<br>
483 We support all builtins which have a C language equivalent (e.g.,
484 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
485 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]486 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]487
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]488 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]489
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]490 <p>The following extensions <b>are</b> known to be supported:</p>
491
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]492 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]493 <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]494 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
495 <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>
496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
498 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
500 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
501 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
502 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
503 <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>
504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
505 <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]506 <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]507 <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]508 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
509or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]510 <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]511 <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]512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
517 <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>
518 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
520 <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>
521 <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>
522 <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]523 <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]524 <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>
525 <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]526 </ol></li>
527
528</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]529
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]530<p>If you run into GCC extensions which have not been included in any of these
531lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]534
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]535<!-- ======================================================================= -->
536<div class="doc_subsection">
537 <a name="c++-fe">Known problems with the C++ front-end</a>
538</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]539
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]540<div class="doc_text">
541
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]542<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]543has not been tested as thoroughly as the C front-end. It has been tested and
544works for a number of non-trivial programs, but there may be lurking bugs.
545Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]546
547</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]548
549<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]550<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]551
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]552<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]553
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]554<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]555<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]556 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]557</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]558</div>
559
560<!-- _______________________________________________________________________ -->
561<div class="doc_subsubsection">
562 Notes
563</div>
564
565<div class="doc_text">
566
567<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]568
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]569<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
570parser is significantly more standards compliant (and picky) than prior GCC
571versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]572href="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]573
574<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]575 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]576 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]577 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]578 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]579
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]580<li>The LLVM C++ front-end follows the <a
581 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
582 This document, which is not Itanium specific, specifies a standard for name
583 mangling, class layout, v-table layout, RTTI formats, and other C++
584 representation issues. Because we use this API, code generated by the LLVM
585 compilers should be binary compatible with machine code generated by other
586 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
587 <i>However</i>, the exception handling mechanism used by LLVM is very
588 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]589 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]591</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]592
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]593</div>
594
595<!-- ======================================================================= -->
596<div class="doc_subsection">
597 <a name="x86-be">Known problems with the X86 back-end</a>
598</div>
599
600<div class="doc_text">
601
602<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]603<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]606</div>
607
608<!-- ======================================================================= -->
609<div class="doc_subsection">
610 <a name="sparc-be">Known problems with the Sparc back-end</a>
611</div>
612
613<div class="doc_text">
614
615<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]616<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]617</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]618
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619</div>
620
621<!-- ======================================================================= -->
622<div class="doc_subsection">
623 <a name="c-be">Known problems with the C back-end</a>
624</div>
625
626<div class="doc_text">
627
628<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]629
630<li>The C back-end produces code that violates the ANSI C Type-Based Alias
631Analysis rules. As such, special options may be necessary to compile the code
632(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]633problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]634
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]635<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]636cannot include special floating point numbers like Not-A-Number or
637Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]638
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]639<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]640supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]641frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]642
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]643</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]644
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]645</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]646
647<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]648<div class="doc_section">
649 <a name="additionalinfo">Additional Information</a>
650</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]651<!-- *********************************************************************** -->
652
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]653<div class="doc_text">
654
655<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]656including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]657implemented in LLVM. The web page also contains versions of the API
658documentation which is up-to-date with the CVS version of the source code. You
659can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]660the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]661
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]662<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]663us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
664lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]665
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]666</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]667
668<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]669
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]670<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]671<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]672 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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676
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]677 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]678 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]679</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]681</body>
682</html>