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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
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]31<div class="doc_text">
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]32 <p><b>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a></b><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
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]72<p>
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]73This is the fourth public release of the LLVM compiler infrastructure. This
74release primarily improves the <a href="#codequality">performance of the
75code</a> produced by all aspects of the LLVM compiler and adds some <a
76href="#newfeatures">new features</a>, though it does <a href="#bugfix">fix a few
77bugs</a> as well.
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]78</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]79
Chris Lattner835104c2004-03-17 03:54:41 +0000[diff] [blame]80<p>
81At this time, LLVM is known to correctly compile and run all C &amp; C++ SPEC
82CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It has
83also been used to compile <b>many</b> other programs. LLVM now also works with
84a broad variety of C++ programs, though it has still received less testing than
85the C front-end.
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]86</p>
87
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]88<!--=========================================================================-->
89<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]90<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]91</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]92
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 Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]108</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]109
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]110
111<!--=========================================================================-->
112<div class="doc_subsubsection">
113In this release, the following missing features were implemented:
114</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]115
116<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]117<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
118more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]119<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
120non-instruction entities, such as global constant initializer</a></li>
121<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
122uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]123</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]124
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]125
126<!--=========================================================================-->
127<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]128<a name="qualityofimp">In this release, the following Quality of Implementation
129issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]130</div>
131
132<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]133<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
134bytecode onto your terminal</a></li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]135</ol>
136
137<!--=========================================================================-->
138<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]139In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]140</div>
141
142<ol>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]143<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with -disable/enable-povray and -disable-spec</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]144</ol>
145
146<!--=========================================================================-->
147<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]148<a name="codequality">This release includes the following Code Quality
149improvements:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]150</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]151
152<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]153<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
154due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]155
156<li>The X86 backend now generates substantially better code for 64-bit integer
157and floating point operations.</li>
158
159<li>The -inline pass no longer inlines mutually recursive functions until it
160hits the inlining threshold.</li>
161
162<li>The -inline pass no longer misses obvious inlining opportunities just
163because the callee eventually calls into an external function.</li>
164
165<li>The -simplifycfg pass can now "if convert" simple statements into the new
166<tt>select</tt> instruction.</li>
167
168<li>The -loopsimplify pass can now break <a
169href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
170into multiple nested loops. This enables a variety of subsequent
171optimizations.</li>
172
173<li>The -adce pass can now eliminate calls to functions that do not not write to
174memory.</li>
175
176<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]177exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]178
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]179<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
180"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
181operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
182&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
183
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]184<li>LLVM now has infrastructure for (simple and sparse conditional) constant
185propagation of function calls. It currently supports a few math library
186functions like sqrt/sin/cos/etc.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]187</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]188
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]189
190<!--=========================================================================-->
191<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]192<a name="bugfix">In this release, the following bugs in the previous release
193were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]194</div>
195
196<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]197
198<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame^]199<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
200asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]201<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
202incorrectly updates dominator information</a></li>
203<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
204breaks SSA form</a></li>
205<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
206to floating point cast</a></li>
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]207<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable code that unwinds</a></li>
Brian Gaeke43be3112004-05-04 21:22:57 +0000[diff] [blame]208<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions of
209the same name, both having constant pools</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]210</ol>
211
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]212<p>Bugs in the C/C++ front-end:</p>
213
214<ol>
Chris Lattner6df29c62004-04-21 18:52:06 +0000[diff] [blame]215<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared enum type</a></li></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]216</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]217
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]218</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]219
220<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]221<div class="doc_section">
222 <a name="portability">Portability and Supported Platforms</a>
223</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]224<!-- *********************************************************************** -->
225
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]226<div class="doc_text">
227
228<p>LLVM has been extensively tested on Intel and AMD machines running Red
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]229Hat Linux and FreeBSD. It has also been tested on Sun UltraSPARC workstations
230running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and above, but
231only with the C backend or interpreter (no native backend for the PowerPC is
232available yet). The core LLVM infrastructure uses "autoconf" for portability,
233so hopefully we work on more platforms than that. However, it is likely that we
234missed something and that minor porting is required to get LLVM to work on new
235platforms. We welcome portability patches and error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]236
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]237</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]238
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]239<!--=========================================================================-->
240<div class="doc_subsection">
241In this release, the following portability problems were fixed:
242</div>
243
244<ol>
245<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler on Mac OS X</a></li>
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]246<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]247</ol>
248
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]249<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]250<div class="doc_section">
251 <a name="knownproblems">Known Problems</a>
252</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]253<!-- *********************************************************************** -->
254
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]255<div class="doc_text">
256
257<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]258component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]259sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]260href="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]261there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]262
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]263</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]264
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]265<!-- ======================================================================= -->
266<div class="doc_subsection">
267 <a name="experimental">Experimental features included with this release</a>
268</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]269
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]270<div class="doc_text">
271
272<p>
273The following components of this LLVM release are either untested, known to be
274broken or unreliable, or are in early development. These components should not
275be relied on, and bugs should not be filed against them, but they may be useful
276to some people. In particular, if you would like to work on one of these
277components, please contact us on the llvmdev list.
278</p>
279
280<ul>
281<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
282 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
283
284<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
285 it should) and not thoroughly tested.</li>
286<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
287<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
288</ul>
289
290</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]291
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]292<!-- ======================================================================= -->
293<div class="doc_subsection">
294 <a name="core">Known problems with the LLVM Core</a>
295</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]296
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]297<div class="doc_text">
298
299<ul>
300
301<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
302work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]303
304<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]305such, execution of a threaded program could cause these data structures to be
306corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]307
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]308<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]309
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]310<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]311table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]312
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]313<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
314objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]315
316<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]317values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]318targets whose setjmp/longjmp libraries do not save and restore the entire
319register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]320</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]321</div>
322
323<!-- ======================================================================= -->
324<div class="doc_subsection">
325 <a name="c-fe">Known problems with the C front-end</a>
326</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]327
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]328<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]329<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]330
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]331<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]332<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]333<li>C99 Variable sized arrays do not release stack memory when they go out of
334 scope. Thus, the following program may run out of stack space:
335<pre>
336 for (i = 0; i != 1000000; ++i) {
337 int X[n];
338 foo(X);
339 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]340</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]341
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]342<li>
343Initialization of global union variables can only be done
344<a href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest
345union member</a>.
346</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]347
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]348<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
349external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]350
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]351</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]352</div>
353
354<!-- _______________________________________________________________________ -->
355<div class="doc_subsubsection">
356 Notes
357</div>
358
359<div class="doc_text">
360
361<ul>
362
363<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]364
365<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]366support for floating point data types of any size other than 32 and 64
367bits.</li>
368
369<li>The following Unix system functionality has not been tested and may not
370work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]371 <ol>
372 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
373 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
374 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
375 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
376 - These functions have not been tested.
377 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]378
379<li>Although many GCC extensions are supported, some are not. In particular,
380 the following extensions are known to <b>not be</b> supported:
381 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]382 <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]383 <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>
384 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
385 <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]386 <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]387 <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>
388 <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]389 <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>
390 <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>
391 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
392 <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]393 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]394
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]395 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]396 attribute means that the LLVM compiler ignores the presence of the attribute,
397 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]398 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]399 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]400
401 <ol>
402 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
403 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]404 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]405
406 <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]407
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]408 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]409 return.<br>
410
411 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
412 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
413 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
414
415 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
416 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
417 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
418
419 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
420 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
421 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]422
423 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
424 Specifying attributes of variables.<br>
425 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
426 <tt>deprecated</tt>, <tt>transparent_union</tt>,
427 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]428
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]429 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
430 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
431 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]432 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]433
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]434 <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]435 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]436 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]437
438 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
439 all target specific attributes.</li>
440
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]441 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
442 Other built-in functions.<br>
443 We support all builtins which have a C language equivalent (e.g.,
444 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
445 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]446 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]447
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]448 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]449
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]450 <p>The following extensions <b>are</b> known to be supported:</p>
451
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]452 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]453 <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]454 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
455 <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>
456 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
457 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
458 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
459 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
461 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
462 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
463 <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>
464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
465 <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]466 <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]467 <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]468 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
469or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]470 <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]471 <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]472 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
476 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
477 <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>
478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
480 <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>
481 <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>
482 <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]483 <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]484 <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>
485 <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]486 </ol></li>
487
488</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]489
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]490<p>If you run into GCC extensions which have not been included in any of these
491lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]492
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]493</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]494
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]495<!-- ======================================================================= -->
496<div class="doc_subsection">
497 <a name="c++-fe">Known problems with the C++ front-end</a>
498</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]499
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500<div class="doc_text">
501
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]502<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]503has not been tested as thoroughly as the C front-end. It has been tested and
504works for a number of non-trivial programs, but there may be lurking bugs.
505Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]506
507</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]508
509<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]510<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]511
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]512<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]513
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]514<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]515<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]516 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]517</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]518</div>
519
520<!-- _______________________________________________________________________ -->
521<div class="doc_subsubsection">
522 Notes
523</div>
524
525<div class="doc_text">
526
527<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]528
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]529<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
530parser is significantly more standards compliant (and picky) than prior GCC
531versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]532href="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]533
534<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]535 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]536 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]537 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]538 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]539
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]540<li>The LLVM C++ front-end follows the <a
541 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
542 This document, which is not Itanium specific, specifies a standard for name
543 mangling, class layout, v-table layout, RTTI formats, and other C++
544 representation issues. Because we use this API, code generated by the LLVM
545 compilers should be binary compatible with machine code generated by other
546 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
547 <i>However</i>, the exception handling mechanism used by LLVM is very
548 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]549 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]550
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]551</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]552
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]553</div>
554
555<!-- ======================================================================= -->
556<div class="doc_subsection">
557 <a name="x86-be">Known problems with the X86 back-end</a>
558</div>
559
560<div class="doc_text">
561
562<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]563<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]564</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]565
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]566</div>
567
568<!-- ======================================================================= -->
569<div class="doc_subsection">
570 <a name="sparc-be">Known problems with the Sparc back-end</a>
571</div>
572
573<div class="doc_text">
574
575<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]576<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]577</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]578
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]579</div>
580
581<!-- ======================================================================= -->
582<div class="doc_subsection">
583 <a name="c-be">Known problems with the C back-end</a>
584</div>
585
586<div class="doc_text">
587
588<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]589
590<li>The C back-end produces code that violates the ANSI C Type-Based Alias
591Analysis rules. As such, special options may be necessary to compile the code
592(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]593problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]594
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]595<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]596cannot include special floating point numbers like Not-A-Number or
597Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]598
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]599<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]600supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]601frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]602
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]603</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]604
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]605</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]606
607<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]608<div class="doc_section">
609 <a name="additionalinfo">Additional Information</a>
610</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]611<!-- *********************************************************************** -->
612
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]613<div class="doc_text">
614
615<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]616including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]617implemented in LLVM. The web page also contains versions of the API
618documentation which is up-to-date with the CVS version of the source code. You
619can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]620the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]621
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]622<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]623us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
624lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]625
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]626</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]627
628<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]629
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]630<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]631<address>
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636
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]637 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]638 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]639</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]640
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]641</body>
642</html>