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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 Lattneradd68af2004-05-07 19:23:05 +0000[diff] [blame]135<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted for structure typedefs</a></li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]136</ol>
137
138<!--=========================================================================-->
139<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]140In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]141</div>
142
143<ol>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]144<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with -disable/enable-povray and -disable-spec</a></li>
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame^]145<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]146</ol>
147
148<!--=========================================================================-->
149<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]150<a name="codequality">This release includes the following Code Quality
151improvements:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]152</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]153
154<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]155<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
156due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]157
158<li>The X86 backend now generates substantially better code for 64-bit integer
159and floating point operations.</li>
160
161<li>The -inline pass no longer inlines mutually recursive functions until it
162hits the inlining threshold.</li>
163
164<li>The -inline pass no longer misses obvious inlining opportunities just
165because the callee eventually calls into an external function.</li>
166
167<li>The -simplifycfg pass can now "if convert" simple statements into the new
168<tt>select</tt> instruction.</li>
169
170<li>The -loopsimplify pass can now break <a
171href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
172into multiple nested loops. This enables a variety of subsequent
173optimizations.</li>
174
175<li>The -adce pass can now eliminate calls to functions that do not not write to
176memory.</li>
177
178<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]179exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]180
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]181<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
182"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
183operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
184&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
185
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]186<li>LLVM now has infrastructure for (simple and sparse conditional) constant
187propagation of function calls. It currently supports a few math library
188functions like sqrt/sin/cos/etc.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]189</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]190
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]191
192<!--=========================================================================-->
193<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]194<a name="bugfix">In this release, the following bugs in the previous release
195were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]196</div>
197
198<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]199
200<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]201<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
202asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]203<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
204incorrectly updates dominator information</a></li>
205<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
206breaks SSA form</a></li>
207<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
208to floating point cast</a></li>
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]209<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]210<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions of
211the same name, both having constant pools</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]212</ol>
213
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]214<p>Bugs in the C/C++ front-end:</p>
215
216<ol>
Chris Lattner581dc802004-05-07 18:40:38 +0000[diff] [blame]217<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared enum type</a></li>
218<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]219</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]220
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]221</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]222
223<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]224<div class="doc_section">
225 <a name="portability">Portability and Supported Platforms</a>
226</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]227<!-- *********************************************************************** -->
228
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]229<div class="doc_text">
230
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame^]231<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
232Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
233workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
234above, but only with the C backend and interpreter; no native machine-code
235generator for the PowerPC is available yet.</p>
236
237<p>The core LLVM infrastructure uses
238<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
239to the machine and operating system on which it is built. However, minor
240porting may be required to get LLVM to work on new platforms. We welcome your
241portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]242
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]243</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]244
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]245<!--=========================================================================-->
246<div class="doc_subsection">
247In this release, the following portability problems were fixed:
248</div>
249
250<ol>
251<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]252<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]253</ol>
254
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]255<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]256<div class="doc_section">
257 <a name="knownproblems">Known Problems</a>
258</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]259<!-- *********************************************************************** -->
260
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]261<div class="doc_text">
262
263<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]264component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]265sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]266href="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]267there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]268
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]269</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]270
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]271<!-- ======================================================================= -->
272<div class="doc_subsection">
273 <a name="experimental">Experimental features included with this release</a>
274</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]275
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]276<div class="doc_text">
277
278<p>
279The following components of this LLVM release are either untested, known to be
280broken or unreliable, or are in early development. These components should not
281be relied on, and bugs should not be filed against them, but they may be useful
282to some people. In particular, if you would like to work on one of these
283components, please contact us on the llvmdev list.
284</p>
285
286<ul>
287<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
288 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
289
290<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
291 it should) and not thoroughly tested.</li>
292<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
293<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
294</ul>
295
296</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]297
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]298<!-- ======================================================================= -->
299<div class="doc_subsection">
300 <a name="core">Known problems with the LLVM Core</a>
301</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]302
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]303<div class="doc_text">
304
305<ul>
306
307<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
308work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]309
310<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]311such, execution of a threaded program could cause these data structures to be
312corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]313
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]314<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]315
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]316<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]317table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]318
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]319<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
320objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]321
322<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]323values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]324targets whose setjmp/longjmp libraries do not save and restore the entire
325register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]326</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]327</div>
328
329<!-- ======================================================================= -->
330<div class="doc_subsection">
331 <a name="c-fe">Known problems with the C front-end</a>
332</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]333
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]334<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]335<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]336
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]337<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]338<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]339<li>C99 Variable sized arrays do not release stack memory when they go out of
340 scope. Thus, the following program may run out of stack space:
341<pre>
342 for (i = 0; i != 1000000; ++i) {
343 int X[n];
344 foo(X);
345 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]346</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]347
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]348<li>
349Initialization of global union variables can only be done
350<a href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest
351union member</a>.
352</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]353
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]354<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
355external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]356
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]357</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]358</div>
359
360<!-- _______________________________________________________________________ -->
361<div class="doc_subsubsection">
362 Notes
363</div>
364
365<div class="doc_text">
366
367<ul>
368
369<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]370
371<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]372support for floating point data types of any size other than 32 and 64
373bits.</li>
374
375<li>The following Unix system functionality has not been tested and may not
376work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]377 <ol>
378 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
379 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
380 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
381 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
382 - These functions have not been tested.
383 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]384
385<li>Although many GCC extensions are supported, some are not. In particular,
386 the following extensions are known to <b>not be</b> supported:
387 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]388 <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]389 <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>
390 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
391 <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]392 <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]393 <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>
394 <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]395 <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>
396 <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>
397 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
398 <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]399 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]400
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]401 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]402 attribute means that the LLVM compiler ignores the presence of the attribute,
403 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]404 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]405 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]406
407 <ol>
408 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
409 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]410 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]411
412 <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]413
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]414 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]415 return.<br>
416
417 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
418 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
419 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
420
421 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
422 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
423 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
424
425 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
426 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
427 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]428
429 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
430 Specifying attributes of variables.<br>
431 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
432 <tt>deprecated</tt>, <tt>transparent_union</tt>,
433 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]434
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]435 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
436 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
437 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]438 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]439
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]440 <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]441 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]442 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]443
444 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
445 all target specific attributes.</li>
446
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]447 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
448 Other built-in functions.<br>
449 We support all builtins which have a C language equivalent (e.g.,
450 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
451 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]452 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]453
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]454 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]455
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]456 <p>The following extensions <b>are</b> known to be supported:</p>
457
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]458 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]459 <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]460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
461 <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>
462 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
463 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
465 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
468 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
469 <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>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
471 <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]472 <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]473 <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]474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
475or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]476 <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]477 <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]478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
480 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
483 <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>
484 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
486 <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>
487 <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>
488 <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]489 <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]490 <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>
491 <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]492 </ol></li>
493
494</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]495
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]496<p>If you run into GCC extensions which have not been included in any of these
497lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]498
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]499</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]500
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]501<!-- ======================================================================= -->
502<div class="doc_subsection">
503 <a name="c++-fe">Known problems with the C++ front-end</a>
504</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]505
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]506<div class="doc_text">
507
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]508<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]509has not been tested as thoroughly as the C front-end. It has been tested and
510works for a number of non-trivial programs, but there may be lurking bugs.
511Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]512
513</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]514
515<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]516<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]517
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]518<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]519
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]520<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]521<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]522 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]523</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]524</div>
525
526<!-- _______________________________________________________________________ -->
527<div class="doc_subsubsection">
528 Notes
529</div>
530
531<div class="doc_text">
532
533<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]534
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]535<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
536parser is significantly more standards compliant (and picky) than prior GCC
537versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]538href="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]539
540<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]541 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]542 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]543 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]544 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]545
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]546<li>The LLVM C++ front-end follows the <a
547 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
548 This document, which is not Itanium specific, specifies a standard for name
549 mangling, class layout, v-table layout, RTTI formats, and other C++
550 representation issues. Because we use this API, code generated by the LLVM
551 compilers should be binary compatible with machine code generated by other
552 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
553 <i>However</i>, the exception handling mechanism used by LLVM is very
554 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]555 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]556
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]557</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]558
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]559</div>
560
561<!-- ======================================================================= -->
562<div class="doc_subsection">
563 <a name="x86-be">Known problems with the X86 back-end</a>
564</div>
565
566<div class="doc_text">
567
568<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]569<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]570</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]571
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]572</div>
573
574<!-- ======================================================================= -->
575<div class="doc_subsection">
576 <a name="sparc-be">Known problems with the Sparc back-end</a>
577</div>
578
579<div class="doc_text">
580
581<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]582<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]583</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]584
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]585</div>
586
587<!-- ======================================================================= -->
588<div class="doc_subsection">
589 <a name="c-be">Known problems with the C back-end</a>
590</div>
591
592<div class="doc_text">
593
594<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]595
596<li>The C back-end produces code that violates the ANSI C Type-Based Alias
597Analysis rules. As such, special options may be necessary to compile the code
598(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]599problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]600
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]601<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]602cannot include special floating point numbers like Not-A-Number or
603Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]604
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]605<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]606supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]607frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]608
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]609</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]610
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]611</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]612
613<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]614<div class="doc_section">
615 <a name="additionalinfo">Additional Information</a>
616</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]617<!-- *********************************************************************** -->
618
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619<div class="doc_text">
620
621<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]622including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]623implemented in LLVM. The web page also contains versions of the API
624documentation which is up-to-date with the CVS version of the source code. You
625can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]626the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]627
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]628<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]629us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
630lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]631
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]632</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]633
634<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]635
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]636<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]637<address>
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642
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]643 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]644 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]645</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]646
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647</body>
648</html>