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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 Lattner00f19b622004-06-04 00:40:11 +0000[diff] [blame]120<li>The LLVM code generator is now being <a
121 href="CodeGenerator.html">documented</a>.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]122</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]123
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]124</div>
125
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]126
127<!--=========================================================================-->
128<div class="doc_subsubsection">
129In this release, the following missing features were implemented:
130</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]131
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]132<div class="doc_text">
133
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]134<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]135<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
136more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]137<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
138non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]139<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
140with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]141<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
142uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]143</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]144
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]145</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]146
147<!--=========================================================================-->
148<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]149<a name="qualityofimp">In this release, the following Quality of Implementation
150issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]151</div>
152
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]153<div class="doc_text">
154
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]155<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]156<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
157bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
159for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]160<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerea955512004-06-08 07:19:29 +0000[diff] [blame^]161<li>The spurious "WARNING: Found global types that are not compatible" warning
162produced when linking C++ programs has been fixed.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]163</ol>
164
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]165</div>
166
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]167<!--=========================================================================-->
168<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]169In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]170</div>
171
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]172<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]173<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]174<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
175-disable/enable-povray and -disable-spec</a></li>
176<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
177work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]178</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]179</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]180
181<!--=========================================================================-->
182<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]183<a name="codequality">This release includes the following Code Quality
184improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]185</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]186
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]187<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]188<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]189<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
190due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]191
192<li>The X86 backend now generates substantially better code for 64-bit integer
193and floating point operations.</li>
194
195<li>The -inline pass no longer inlines mutually recursive functions until it
196hits the inlining threshold.</li>
197
198<li>The -inline pass no longer misses obvious inlining opportunities just
199because the callee eventually calls into an external function.</li>
200
201<li>The -simplifycfg pass can now "if convert" simple statements into the new
202<tt>select</tt> instruction.</li>
203
204<li>The -loopsimplify pass can now break <a
205href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
206into multiple nested loops. This enables a variety of subsequent
207optimizations.</li>
208
209<li>The -adce pass can now eliminate calls to functions that do not not write to
210memory.</li>
211
212<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]213exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]214
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]215<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
216"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
217operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
218&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
219
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]220<li>LLVM now has infrastructure for (simple and sparse conditional) constant
221propagation of function calls. It currently supports a few math library
222functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]223
224<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
225loops</a> in the code to help C compilers whose optimizers do not recognize
226loops formed from gotos (like GCC).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]227</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]228</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]229
230<!--=========================================================================-->
231<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]232<a name="bugfix">In this release, the following bugs in the previous release
233were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]234</div>
235
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]236<div class="doc_text">
237
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]238<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]239
240<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]241<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
242asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]243<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
244incorrectly updates dominator information</a></li>
245<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
246breaks SSA form</a></li>
247<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
248to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]249<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
250code that unwinds</a></li>
251<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
252of the same name, both having constant pools</a></li>
253<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
254physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]255<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]256<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]257</ol>
258
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]259<p>Bugs in the C/C++ front-end:</p>
260
261<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]262<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
263enum type</a></li>
264<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
265indexing miscompiled</a></li>
Chris Lattner11eaf532004-06-08 07:15:52 +0000[diff] [blame]266<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function prototypes that take opaque structs by-value</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]267</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]268</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]269
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]270<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]271<div class="doc_section">
272 <a name="portability">Portability and Supported Platforms</a>
273</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]274<!-- *********************************************************************** -->
275
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]276<div class="doc_text">
277
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]278<p>LLVM is known to work in the following platforms:</p>
279
280<ul>
281<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
282 other unix-like systems).</li>
283<li>Sun UltraSPARC workstations running Solaris 8.</li>
284<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
285 interpreter only, no native codegen is available yet).</li>
286<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
287</ul>
288
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]289
290<p>The core LLVM infrastructure uses
291<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
292to the machine and operating system on which it is built. However, minor
293porting may be required to get LLVM to work on new platforms. We welcome your
294portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]295
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]296<p>Note that the LLVM build system does not currently support directories with
297spaces on them when running on Win32/cygwin. We strongly recommend running
298LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]299<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
300cygwin packages. By default, many important tools are not installed that
301are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]302
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]303</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]304
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]305<!--=========================================================================-->
306<div class="doc_subsection">
307In this release, the following portability problems were fixed:
308</div>
309
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]310<div class="doc_text">
311
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]312<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]313<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
314on Mac OS X</a></li>
315<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
316understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]317</ol>
318
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]319</div>
320
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]321<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]322<div class="doc_section">
323 <a name="knownproblems">Known Problems</a>
324</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]325<!-- *********************************************************************** -->
326
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]327<div class="doc_text">
328
329<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]330component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]331sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]332href="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]333there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]334
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]335</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]336
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]337<!-- ======================================================================= -->
338<div class="doc_subsection">
339 <a name="experimental">Experimental features included with this release</a>
340</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]341
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]342<div class="doc_text">
343
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]344<p>The following components of this LLVM release are either untested, known to
345be broken or unreliable, or are in early development. These components should
346not be relied on, and bugs should not be filed against them, but they may be
347useful to some people. In particular, if you would like to work on one of these
348components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]349
350<ul>
351<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
352 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
353
354<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
355 it should) and not thoroughly tested.</li>
356<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
357<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
358</ul>
359
360</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]361
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]362<!-- ======================================================================= -->
363<div class="doc_subsection">
364 <a name="core">Known problems with the LLVM Core</a>
365</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]366
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]367<div class="doc_text">
368
369<ul>
370
371<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
372work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]373
374<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]375such, execution of a threaded program could cause these data structures to be
376corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]377
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]378<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]379
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]380<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]381table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]382
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]383<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
384objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]385
386<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]387values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]388targets whose setjmp/longjmp libraries do not save and restore the entire
389register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]390</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]391</div>
392
393<!-- ======================================================================= -->
394<div class="doc_subsection">
395 <a name="c-fe">Known problems with the C front-end</a>
396</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]397
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]398<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]399<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]400
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]401<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]402<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]403<li>C99 Variable sized arrays do not release stack memory when they go out of
404 scope. Thus, the following program may run out of stack space:
405<pre>
406 for (i = 0; i != 1000000; ++i) {
407 int X[n];
408 foo(X);
409 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]410</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]411
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]412<li>Initialization of global union variables can only be done <a
413href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
414member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]415
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]416<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
417external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]418
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]419</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]420</div>
421
422<!-- _______________________________________________________________________ -->
423<div class="doc_subsubsection">
424 Notes
425</div>
426
427<div class="doc_text">
428
429<ul>
430
431<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]432
433<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]434support for floating point data types of any size other than 32 and 64
435bits.</li>
436
437<li>The following Unix system functionality has not been tested and may not
438work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]439 <ol>
440 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
441 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
442 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
443 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
444 - These functions have not been tested.
445 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]446
447<li>Although many GCC extensions are supported, some are not. In particular,
448 the following extensions are known to <b>not be</b> supported:
449 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]450 <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]451 <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>
452 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
453 <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]454 <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]455 <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>
456 <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]457 <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>
458 <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>
459 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
460 <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]461 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]462
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]463 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]464 attribute means that the LLVM compiler ignores the presence of the attribute,
465 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]466 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]467 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]468
469 <ol>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
471 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]472 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]473
474 <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]475
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]476 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]477 return.<br>
478
479 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
480 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
481 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
482
483 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
484 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
485 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
486
487 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
488 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
489 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]490
491 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
492 Specifying attributes of variables.<br>
493 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
494 <tt>deprecated</tt>, <tt>transparent_union</tt>,
495 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]496
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]497 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
498 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
499 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]501
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]502 <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]503 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]504 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]505
506 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
507 all target specific attributes.</li>
508
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]509 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
510 Other built-in functions.<br>
511 We support all builtins which have a C language equivalent (e.g.,
512 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
513 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]514 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]515
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]516 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]517
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]518 <p>The following extensions <b>are</b> known to be supported:</p>
519
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]520 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]521 <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]522 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
523 <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>
524 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
525 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
526 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
528 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
529 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
530 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
531 <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>
532 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
533 <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]534 <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]535 <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]536 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
537or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]538 <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]539 <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]540 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
541 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
542 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
543 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
544 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
545 <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>
546 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
547 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
548 <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>
549 <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>
550 <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]551 <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]552 <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>
553 <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]554 </ol></li>
555
556</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]557
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]558<p>If you run into GCC extensions which have not been included in any of these
559lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]560
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]561</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]562
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]563<!-- ======================================================================= -->
564<div class="doc_subsection">
565 <a name="c++-fe">Known problems with the C++ front-end</a>
566</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]567
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]568<div class="doc_text">
569
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]570<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]571has not been tested as thoroughly as the C front-end. It has been tested and
572works for a number of non-trivial programs, but there may be lurking bugs.
573Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]574
575</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]576
577<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]578<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]579
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]580<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]581
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]582<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]583<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]584 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]585</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]586</div>
587
588<!-- _______________________________________________________________________ -->
589<div class="doc_subsubsection">
590 Notes
591</div>
592
593<div class="doc_text">
594
595<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]596
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]597<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
598parser is significantly more standards compliant (and picky) than prior GCC
599versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]600href="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]601
602<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]603 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]604 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]605 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]606 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]607
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]608<li>The LLVM C++ front-end follows the <a
609 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
610 This document, which is not Itanium specific, specifies a standard for name
611 mangling, class layout, v-table layout, RTTI formats, and other C++
612 representation issues. Because we use this API, code generated by the LLVM
613 compilers should be binary compatible with machine code generated by other
614 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
615 <i>However</i>, the exception handling mechanism used by LLVM is very
616 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]617 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]618
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]620
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]621</div>
622
623<!-- ======================================================================= -->
624<div class="doc_subsection">
625 <a name="x86-be">Known problems with the X86 back-end</a>
626</div>
627
628<div class="doc_text">
629
630<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]631<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]632</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]634</div>
635
636<!-- ======================================================================= -->
637<div class="doc_subsection">
638 <a name="sparc-be">Known problems with the Sparc back-end</a>
639</div>
640
641<div class="doc_text">
642
643<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]644<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]645</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]646
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647</div>
648
649<!-- ======================================================================= -->
650<div class="doc_subsection">
651 <a name="c-be">Known problems with the C back-end</a>
652</div>
653
654<div class="doc_text">
655
656<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]657
658<li>The C back-end produces code that violates the ANSI C Type-Based Alias
659Analysis rules. As such, special options may be necessary to compile the code
660(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]661problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]662
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]663<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]664cannot include special floating point numbers like Not-A-Number or
665Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]666
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]667<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]668supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]669frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]670
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]671</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]672
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]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_section">
677 <a name="additionalinfo">Additional Information</a>
678</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]679<!-- *********************************************************************** -->
680
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]681<div class="doc_text">
682
683<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]684including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]685implemented in LLVM. The web page also contains versions of the API
686documentation which is up-to-date with the CVS version of the source code. You
687can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]688the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]689
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]690<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]691us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
692lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]693
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]694</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]695
696<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]697
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]698<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]699<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]700 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]701 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
702 <a href="http://validator.w3.org/check/referer"><img
703 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
704
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]705 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]706 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]707</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]708
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]709</body>
710</html>