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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
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]109 documented.</li>
Chris Lattner39491a72004-05-24 04:45:52 +0000[diff] [blame]110<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
111Garbage Collection</a>, enabling the use of aggressive copying and generational
112collectors.</li>
113<li>LLVM now includes an implementation of Andersen's interprocedural alias
114analysis algorithm.</li>
Chris Lattner14cd5392004-05-24 05:34:32 +0000[diff] [blame]115<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
116basic blocks</a> to track down reduce miscompilation testcases.</li>
Brian Gaeke5beb8ba2004-06-01 20:02:56 +0000[diff] [blame]117<li>LLVM and the C front-end now work under Win32 using the
118<a href="http://www.cygwin.com">Cygwin</a> runtime libraries.
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]119This includes the JIT compiler.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]120</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]121
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]122</div>
123
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]124
125<!--=========================================================================-->
126<div class="doc_subsubsection">
127In this release, the following missing features were implemented:
128</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]129
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]130<div class="doc_text">
131
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]132<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]133<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
134more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]135<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
136non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]137<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
138with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]139<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
140uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]141</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]142
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]143</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]144
145<!--=========================================================================-->
146<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]147<a name="qualityofimp">In this release, the following Quality of Implementation
148issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]149</div>
150
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]151<div class="doc_text">
152
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]153<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]154<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
155bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]156<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
157for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]158<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]159</ol>
160
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]161</div>
162
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]163<!--=========================================================================-->
164<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]165In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]166</div>
167
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]168<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]169<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]170<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
171-disable/enable-povray and -disable-spec</a></li>
172<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
173work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]174</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]175</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]176
177<!--=========================================================================-->
178<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]179<a name="codequality">This release includes the following Code Quality
180improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]181</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]182
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]183<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]184<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]185<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
186due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]187
188<li>The X86 backend now generates substantially better code for 64-bit integer
189and floating point operations.</li>
190
191<li>The -inline pass no longer inlines mutually recursive functions until it
192hits the inlining threshold.</li>
193
194<li>The -inline pass no longer misses obvious inlining opportunities just
195because the callee eventually calls into an external function.</li>
196
197<li>The -simplifycfg pass can now "if convert" simple statements into the new
198<tt>select</tt> instruction.</li>
199
200<li>The -loopsimplify pass can now break <a
201href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
202into multiple nested loops. This enables a variety of subsequent
203optimizations.</li>
204
205<li>The -adce pass can now eliminate calls to functions that do not not write to
206memory.</li>
207
208<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]209exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]210
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]211<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
212"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
213operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
214&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
215
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]216<li>LLVM now has infrastructure for (simple and sparse conditional) constant
217propagation of function calls. It currently supports a few math library
218functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame^]219
220<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
221loops</a> in the code to help C compilers whose optimizers do not recognize
222loops formed from gotos (like GCC).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]223</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]224</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]225
226<!--=========================================================================-->
227<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]228<a name="bugfix">In this release, the following bugs in the previous release
229were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]230</div>
231
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]232<div class="doc_text">
233
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]234<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]235
236<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]237<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
238asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]239<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
240incorrectly updates dominator information</a></li>
241<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
242breaks SSA form</a></li>
243<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
244to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]245<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
246code that unwinds</a></li>
247<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
248of the same name, both having constant pools</a></li>
249<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
250physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]251<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattneraec5f262004-06-01 21:52:45 +0000[diff] [blame]252<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when missing external functions encountered</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]253</ol>
254
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]255<p>Bugs in the C/C++ front-end:</p>
256
257<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]258<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
259enum type</a></li>
260<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
261indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]262</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]263</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]264
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]265<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]266<div class="doc_section">
267 <a name="portability">Portability and Supported Platforms</a>
268</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]269<!-- *********************************************************************** -->
270
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]271<div class="doc_text">
272
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]273<p>LLVM is known to work in the following platforms:</p>
274
275<ul>
276<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
277 other unix-like systems).</li>
278<li>Sun UltraSPARC workstations running Solaris 8.</li>
279<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
280 interpreter only, no native codegen is available yet).</li>
281<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
282</ul>
283
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]284
285<p>The core LLVM infrastructure uses
286<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
287to the machine and operating system on which it is built. However, minor
288porting may be required to get LLVM to work on new platforms. We welcome your
289portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]290
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]291<p>Note that the LLVM build system does not currently support directories with
292spaces on them when running on Win32/cygwin. We strongly recommend running
293LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]294<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
295cygwin packages. By default, many important tools are not installed that
296are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]297
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]298</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]299
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]300<!--=========================================================================-->
301<div class="doc_subsection">
302In this release, the following portability problems were fixed:
303</div>
304
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]305<div class="doc_text">
306
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]307<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]308<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
309on Mac OS X</a></li>
310<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
311understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]312</ol>
313
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]314</div>
315
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]316<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]317<div class="doc_section">
318 <a name="knownproblems">Known Problems</a>
319</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]320<!-- *********************************************************************** -->
321
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]322<div class="doc_text">
323
324<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]325component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]326sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]327href="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]328there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]329
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]330</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]331
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]332<!-- ======================================================================= -->
333<div class="doc_subsection">
334 <a name="experimental">Experimental features included with this release</a>
335</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]336
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]337<div class="doc_text">
338
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]339<p>The following components of this LLVM release are either untested, known to
340be broken or unreliable, or are in early development. These components should
341not be relied on, and bugs should not be filed against them, but they may be
342useful to some people. In particular, if you would like to work on one of these
343components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]344
345<ul>
346<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
347 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
348
349<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
350 it should) and not thoroughly tested.</li>
351<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
352<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
353</ul>
354
355</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]356
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]357<!-- ======================================================================= -->
358<div class="doc_subsection">
359 <a name="core">Known problems with the LLVM Core</a>
360</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]361
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]362<div class="doc_text">
363
364<ul>
365
366<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
367work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]368
369<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]370such, execution of a threaded program could cause these data structures to be
371corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]372
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]373<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]374
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]375<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]376table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]377
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]378<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
379objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]380
381<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]382values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]383targets whose setjmp/longjmp libraries do not save and restore the entire
384register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]385</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]386</div>
387
388<!-- ======================================================================= -->
389<div class="doc_subsection">
390 <a name="c-fe">Known problems with the C front-end</a>
391</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]392
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]393<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]394<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]395
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]396<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]397<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]398<li>C99 Variable sized arrays do not release stack memory when they go out of
399 scope. Thus, the following program may run out of stack space:
400<pre>
401 for (i = 0; i != 1000000; ++i) {
402 int X[n];
403 foo(X);
404 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]405</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]406
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]407<li>Initialization of global union variables can only be done <a
408href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
409member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]410
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]411<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
412external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]413
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]414</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]415</div>
416
417<!-- _______________________________________________________________________ -->
418<div class="doc_subsubsection">
419 Notes
420</div>
421
422<div class="doc_text">
423
424<ul>
425
426<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]427
428<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]429support for floating point data types of any size other than 32 and 64
430bits.</li>
431
432<li>The following Unix system functionality has not been tested and may not
433work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]434 <ol>
435 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
436 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
437 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
438 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
439 - These functions have not been tested.
440 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]441
442<li>Although many GCC extensions are supported, some are not. In particular,
443 the following extensions are known to <b>not be</b> supported:
444 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]445 <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]446 <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>
447 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
448 <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]449 <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]450 <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>
451 <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]452 <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>
453 <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>
454 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
455 <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]456 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]457
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]458 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]459 attribute means that the LLVM compiler ignores the presence of the attribute,
460 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]461 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]462 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]463
464 <ol>
465 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
466 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]467 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]468
469 <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]470
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]471 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]472 return.<br>
473
474 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
475 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
476 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
477
478 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
479 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
480 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
481
482 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
483 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
484 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]485
486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
487 Specifying attributes of variables.<br>
488 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
489 <tt>deprecated</tt>, <tt>transparent_union</tt>,
490 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]491
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]492 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
493 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
494 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]495 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]496
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]497 <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]498 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]499 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500
501 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
502 all target specific attributes.</li>
503
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
505 Other built-in functions.<br>
506 We support all builtins which have a C language equivalent (e.g.,
507 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
508 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]509 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]510
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]511 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]512
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]513 <p>The following extensions <b>are</b> known to be supported:</p>
514
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]515 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]516 <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]517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
518 <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>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
520 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
521 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
522 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
523 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
524 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
525 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
526 <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>
527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
528 <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]529 <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]530 <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]531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
532or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533 <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]534 <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]535 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
536 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
537 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
538 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
539 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
540 <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>
541 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
542 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
543 <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>
544 <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>
545 <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]546 <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]547 <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>
548 <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]549 </ol></li>
550
551</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]552
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]553<p>If you run into GCC extensions which have not been included in any of these
554lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]555
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]556</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]557
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]558<!-- ======================================================================= -->
559<div class="doc_subsection">
560 <a name="c++-fe">Known problems with the C++ front-end</a>
561</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]562
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]563<div class="doc_text">
564
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]565<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]566has not been tested as thoroughly as the C front-end. It has been tested and
567works for a number of non-trivial programs, but there may be lurking bugs.
568Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]569
570</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]571
572<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]573<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]574
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]575<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]576
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]577<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]578<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]579 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]580</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]581</div>
582
583<!-- _______________________________________________________________________ -->
584<div class="doc_subsubsection">
585 Notes
586</div>
587
588<div class="doc_text">
589
590<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]591
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]592<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
593parser is significantly more standards compliant (and picky) than prior GCC
594versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]595href="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]596
597<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]598 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]599 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]600 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]601 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]602
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]603<li>The LLVM C++ front-end follows the <a
604 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
605 This document, which is not Itanium specific, specifies a standard for name
606 mangling, class layout, v-table layout, RTTI formats, and other C++
607 representation issues. Because we use this API, code generated by the LLVM
608 compilers should be binary compatible with machine code generated by other
609 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
610 <i>However</i>, the exception handling mechanism used by LLVM is very
611 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]612 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]613
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]614</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]615
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]616</div>
617
618<!-- ======================================================================= -->
619<div class="doc_subsection">
620 <a name="x86-be">Known problems with the X86 back-end</a>
621</div>
622
623<div class="doc_text">
624
625<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]626<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]627</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]628
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]629</div>
630
631<!-- ======================================================================= -->
632<div class="doc_subsection">
633 <a name="sparc-be">Known problems with the Sparc back-end</a>
634</div>
635
636<div class="doc_text">
637
638<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]639<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]640</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]641
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]642</div>
643
644<!-- ======================================================================= -->
645<div class="doc_subsection">
646 <a name="c-be">Known problems with the C back-end</a>
647</div>
648
649<div class="doc_text">
650
651<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]652
653<li>The C back-end produces code that violates the ANSI C Type-Based Alias
654Analysis rules. As such, special options may be necessary to compile the code
655(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]656problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]657
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]658<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]659cannot include special floating point numbers like Not-A-Number or
660Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]661
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]662<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]663supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]664frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]665
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]666</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]667
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]668</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]669
670<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]671<div class="doc_section">
672 <a name="additionalinfo">Additional Information</a>
673</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]674<!-- *********************************************************************** -->
675
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]676<div class="doc_text">
677
678<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]679including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]680implemented in LLVM. The web page also contains versions of the API
681documentation which is up-to-date with the CVS version of the source code. You
682can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]683the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]684
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]685<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]686us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
687lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]688
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]689</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]690
691<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]692
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]693<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]694<address>
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699
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]700 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]701 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]702</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]703
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]704</body>
705</html>