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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman80731b92003-11-22 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 Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner3d482502003-10-02 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner020e1fc2004-05-23 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman80731b92003-11-22 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 Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner1a7e43c2004-04-01 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 Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattnere7525b52003-10-07 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattnere76e9ab2003-12-12 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerea309ff2004-05-04 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 Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]76bugs</a> as well.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]77
Misha Brukmanfa50a222004-05-12 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 Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]84</div>
85
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]86<!--=========================================================================-->
87<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]88<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]89</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]90
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]91<div class="doc_text">
92
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]93<ol>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]94<li>The LLVM <a href="LangRef.html#i_select"><tt>select</tt></a> instruction is
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]95now fully implemented and supported by all transformations, native code
96generators, and the interpreter.</li>
Misha Brukman017f2f32004-04-19 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 Gaekee307f8a72004-05-04 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 Lattner2ad48782004-05-02 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 Lattnereda4f472004-05-24 04:45:52 +0000[diff] [blame]108<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
109Garbage Collection</a>, enabling the use of aggressive copying and generational
110collectors.</li>
111<li>LLVM now includes an implementation of Andersen's interprocedural alias
112analysis algorithm.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]113</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]114
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]115</div>
116
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]117
118<!--=========================================================================-->
119<div class="doc_subsubsection">
120In this release, the following missing features were implemented:
121</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]122
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]123<div class="doc_text">
124
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]125<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]126<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
127more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]128<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
129non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]130<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
131with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]132<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
133uses of external fns by immediate constant exprs</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]134</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]135
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]136</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]137
138<!--=========================================================================-->
139<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]140<a name="qualityofimp">In this release, the following Quality of Implementation
141issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]142</div>
143
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]144<div class="doc_text">
145
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]146<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]147<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
148bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]149<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
150for structure typedefs</a></li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]151</ol>
152
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]153</div>
154
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]155<!--=========================================================================-->
156<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]157In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]158</div>
159
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]160<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]161<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]162<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
163-disable/enable-povray and -disable-spec</a></li>
164<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
165work if you change PATH</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]166</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]167</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]168
169<!--=========================================================================-->
170<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]171<a name="codequality">This release includes the following Code Quality
172improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]173</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]174
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]175<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]176<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]177<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
178due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]179
180<li>The X86 backend now generates substantially better code for 64-bit integer
181and floating point operations.</li>
182
183<li>The -inline pass no longer inlines mutually recursive functions until it
184hits the inlining threshold.</li>
185
186<li>The -inline pass no longer misses obvious inlining opportunities just
187because the callee eventually calls into an external function.</li>
188
189<li>The -simplifycfg pass can now "if convert" simple statements into the new
190<tt>select</tt> instruction.</li>
191
192<li>The -loopsimplify pass can now break <a
193href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
194into multiple nested loops. This enables a variety of subsequent
195optimizations.</li>
196
197<li>The -adce pass can now eliminate calls to functions that do not not write to
198memory.</li>
199
200<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]201exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]202
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]203<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
204"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
205operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
206&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
207
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]208<li>LLVM now has infrastructure for (simple and sparse conditional) constant
209propagation of function calls. It currently supports a few math library
210functions like sqrt/sin/cos/etc.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]211</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]212</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]213
214<!--=========================================================================-->
215<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]216<a name="bugfix">In this release, the following bugs in the previous release
217were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]218</div>
219
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]220<div class="doc_text">
221
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]222<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]223
224<ol>
John Criswell6956afa2004-05-06 22:23:24 +0000[diff] [blame]225<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
226asssertion</a></li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]227<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
228incorrectly updates dominator information</a></li>
229<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
230breaks SSA form</a></li>
231<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
232to floating point cast</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]233<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
234code that unwinds</a></li>
235<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
236of the same name, both having constant pools</a></li>
237<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
238physical register use of aliased definition</a></li>
Chris Lattner8f7cf272004-05-21 16:48:20 +0000[diff] [blame]239<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]240</ol>
241
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]242<p>Bugs in the C/C++ front-end:</p>
243
244<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]245<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
246enum type</a></li>
247<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
248indexing miscompiled</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]249</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]250</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]251
252<!--=========================================================================-->
253<div class="doc_subsubsection">
254<a name="misc">This release includes the following miscellaneous
255improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]256</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]257
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]258<div class="doc_text">
259
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]260<p>Documentation Improvements</p>
261<ol>
262<li><a href="BytecodeFormat.html">Documentation of the LLVM Bytecode file format
263was added.</a></li>
264<li>All documentation was brought up to HTML 4.01 (Strict) level.</li>
265</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]266</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]267
268
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]269<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]270<div class="doc_section">
271 <a name="portability">Portability and Supported Platforms</a>
272</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]273<!-- *********************************************************************** -->
274
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]275<div class="doc_text">
276
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]277<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
278Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
279workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
280above, but only with the C backend and interpreter; no native machine-code
281generator for the PowerPC is available yet.</p>
282
283<p>The core LLVM infrastructure uses
284<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
285to the machine and operating system on which it is built. However, minor
286porting may be required to get LLVM to work on new platforms. We welcome your
287portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]288
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]289</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]290
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]291<!--=========================================================================-->
292<div class="doc_subsection">
293In this release, the following portability problems were fixed:
294</div>
295
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]296<div class="doc_text">
297
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]298<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]299<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
300on Mac OS X</a></li>
301<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
302understand abbreviated names in headers</a></li>
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]303</ol>
304
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame^]305</div>
306
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]307<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]308<div class="doc_section">
309 <a name="knownproblems">Known Problems</a>
310</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]311<!-- *********************************************************************** -->
312
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]313<div class="doc_text">
314
315<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]316component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]317sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]318href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]319there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]320
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]321</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]322
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]323<!-- ======================================================================= -->
324<div class="doc_subsection">
325 <a name="experimental">Experimental features included with this release</a>
326</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]327
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]328<div class="doc_text">
329
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]330<p>The following components of this LLVM release are either untested, known to
331be broken or unreliable, or are in early development. These components should
332not be relied on, and bugs should not be filed against them, but they may be
333useful to some people. In particular, if you would like to work on one of these
334components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]335
336<ul>
337<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
338 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
339
340<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
341 it should) and not thoroughly tested.</li>
342<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
343<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
344</ul>
345
346</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]347
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]348<!-- ======================================================================= -->
349<div class="doc_subsection">
350 <a name="core">Known problems with the LLVM Core</a>
351</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]352
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]353<div class="doc_text">
354
355<ul>
356
357<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
358work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]359
360<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]361such, execution of a threaded program could cause these data structures to be
362corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]363
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]364<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]365
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]366<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]367table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]368
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]369<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
370objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]371
372<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswell5d6345a2004-03-12 21:29:42 +0000[diff] [blame]373values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]374targets whose setjmp/longjmp libraries do not save and restore the entire
375register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]376</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]377</div>
378
379<!-- ======================================================================= -->
380<div class="doc_subsection">
381 <a name="c-fe">Known problems with the C front-end</a>
382</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]383
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]384<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]385<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]386
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]387<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]388<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]389<li>C99 Variable sized arrays do not release stack memory when they go out of
390 scope. Thus, the following program may run out of stack space:
391<pre>
392 for (i = 0; i != 1000000; ++i) {
393 int X[n];
394 foo(X);
395 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]396</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]397
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]398<li>Initialization of global union variables can only be done <a
399href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
400member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]401
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]402<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
403external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]404
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]405</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]406</div>
407
408<!-- _______________________________________________________________________ -->
409<div class="doc_subsubsection">
410 Notes
411</div>
412
413<div class="doc_text">
414
415<ul>
416
417<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]418
419<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]420support for floating point data types of any size other than 32 and 64
421bits.</li>
422
423<li>The following Unix system functionality has not been tested and may not
424work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]425 <ol>
426 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
427 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
428 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
429 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
430 - These functions have not been tested.
431 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]432
433<li>Although many GCC extensions are supported, some are not. In particular,
434 the following extensions are known to <b>not be</b> supported:
435 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]436 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]437 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>: As in Algol and Pascal, lexical scoping of functions.</li>
438 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
439 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]440 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]441 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Asm-Labels.html#Asm%20Labels">Asm Labels</a>: Specifying the assembler name to use for a C symbol.</li>
442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]443 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html#Vector%20Extensions">Vector Extensions</a>: Using vector instructions through built-in functions.</li>
444 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Target-Builtins.html#Target%20Builtins">Target Builtins</a>: Built-in functions specific to particular targets.</li>
445 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
446 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]447 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]448
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]449 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]450 attribute means that the LLVM compiler ignores the presence of the attribute,
451 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]452 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]453 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]454
455 <ol>
456 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
457 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]458 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]459
460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]461
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]462 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]463 return.<br>
464
465 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
466 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
467 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
468
469 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
470 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
471 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
472
473 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
474 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
475 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]476
477 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
478 Specifying attributes of variables.<br>
479 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
480 <tt>deprecated</tt>, <tt>transparent_union</tt>,
481 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]482
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]483 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
484 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
485 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]486 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]487
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]488 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]489 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]490 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]491
492 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
493 all target specific attributes.</li>
494
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]495 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
496 Other built-in functions.<br>
497 We support all builtins which have a C language equivalent (e.g.,
498 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
499 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]500 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]501
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]502 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]503
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]504 <p>The following extensions <b>are</b> known to be supported:</p>
505
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]506 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]508 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
509 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
510 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
511 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variadic-Macros.html#Variadic%20Macros">Variadic Macros</a>: Macros with a variable number of arguments.</li>
518 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]520 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]521 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]522 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
523or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]524 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]525 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]526 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
528 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
529 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
530 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Character-Escapes.html#Character%20Escapes">Character Escapes</a>: <code>\e</code> stands for the character &lt;ESC&gt;.</li>
532 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
533 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
534 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html#Alternate%20Keywords">Alternate Keywords</a>:<code>__const__</code>, <code>__asm__</code>, etc., for header files.</li>
535 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Incomplete-Enums.html#Incomplete%20Enums">Incomplete Enums</a>: <code>enum foo;</code>, with details to follow.</li>
536 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner3646dad2004-02-14 04:08:29 +0000[diff] [blame]537 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]538 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed%20Fields">Unnamed Fields</a>: Unnamed struct/union fields within structs/unions.</li>
539 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]540 </ol></li>
541
542</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]543
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]544<p>If you run into GCC extensions which have not been included in any of these
545lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]546
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]547</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]548
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]549<!-- ======================================================================= -->
550<div class="doc_subsection">
551 <a name="c++-fe">Known problems with the C++ front-end</a>
552</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]553
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]554<div class="doc_text">
555
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]556<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]557has not been tested as thoroughly as the C front-end. It has been tested and
558works for a number of non-trivial programs, but there may be lurking bugs.
559Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]560
561</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]562
563<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]564<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]565
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]566<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]567
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]568<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]569<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]570 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]571</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]572</div>
573
574<!-- _______________________________________________________________________ -->
575<div class="doc_subsubsection">
576 Notes
577</div>
578
579<div class="doc_text">
580
581<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]582
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]583<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
584parser is significantly more standards compliant (and picky) than prior GCC
585versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]586href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]587
588<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]589 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]590 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]591 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]592 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]593
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]594<li>The LLVM C++ front-end follows the <a
595 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
596 This document, which is not Itanium specific, specifies a standard for name
597 mangling, class layout, v-table layout, RTTI formats, and other C++
598 representation issues. Because we use this API, code generated by the LLVM
599 compilers should be binary compatible with machine code generated by other
600 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
601 <i>However</i>, the exception handling mechanism used by LLVM is very
602 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]603 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]604
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]605</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]606
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]607</div>
608
609<!-- ======================================================================= -->
610<div class="doc_subsection">
611 <a name="x86-be">Known problems with the X86 back-end</a>
612</div>
613
614<div class="doc_text">
615
616<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]617<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]618</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]619
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]620</div>
621
622<!-- ======================================================================= -->
623<div class="doc_subsection">
624 <a name="sparc-be">Known problems with the Sparc back-end</a>
625</div>
626
627<div class="doc_text">
628
629<ul>
Chris Lattner9e0b81c2004-03-19 19:22:28 +0000[diff] [blame]630<li>There are several programs in the LLVM testsuite that the Sparc code generator is known to miscompile.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]631</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]632
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]633</div>
634
635<!-- ======================================================================= -->
636<div class="doc_subsection">
637 <a name="c-be">Known problems with the C back-end</a>
638</div>
639
640<div class="doc_text">
641
642<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]643
644<li>The C back-end produces code that violates the ANSI C Type-Based Alias
645Analysis rules. As such, special options may be necessary to compile the code
646(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]647problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]648
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]649<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]650cannot include special floating point numbers like Not-A-Number or
651Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]652
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]653<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]654supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]655frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]656
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]657</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]658
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]659</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]660
661<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]662<div class="doc_section">
663 <a name="additionalinfo">Additional Information</a>
664</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]665<!-- *********************************************************************** -->
666
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]667<div class="doc_text">
668
669<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]670including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]671implemented in LLVM. The web page also contains versions of the API
672documentation which is up-to-date with the CVS version of the source code. You
673can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]674the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]675
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]676<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]677us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
678lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]679
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]680</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]681
682<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]683
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]684<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]685<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]686 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]687 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
688 <a href="http://validator.w3.org/check/referer"><img
689 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
690
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]691 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]692 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]693</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]694
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]695</body>
696</html>