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Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]13 <li><a href="#intro">Introduction</a></li>
14 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]21 <li><a href="#core">Known problems with the LLVM Core</a>
22 <li><a href="#c-fe">Known problems with the C Front-end</a>
23 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
24 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
25 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame^]31<div class="doc_author">
32 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]41<div class="doc_text">
42
43<p>This document contains the release notes for the LLVM compiler
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]47href="http://llvm.cs.uiuc.edu/releases/1.3/">LLVM 1.3 web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]52current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
53web site</a>. If you have questions or comments, the <a
54href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]57<p>Note that if you are reading this file from CVS, this document applies
58to the <i>next</i> release, not the current one. To see the release notes for
59the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]73release primarily improves the <a href="#codequality">performance of the
74code</a> produced by all aspects of the LLVM compiler and adds some <a
75href="#newfeatures">new features</a>, though it does <a href="#bugfix">fix a few
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]76bugs</a> as well.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]77
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]78<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
79SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It
80has also been used to compile <b>many</b> other programs. LLVM now also works
81with a broad variety of C++ programs, though it has still received less testing
82than the C front-end.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]84<!--=========================================================================-->
85<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]86<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]87</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]88
89<ol>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]90<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]91now fully implemented and supported by all transformations, native code
92generators, and the interpreter.</li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]93<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
94before it could only narrow them down to a function being miscompiled.</li>
Brian Gaeke43be3112004-05-04 21:22:57 +0000[diff] [blame]95<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
96modes of llc</a> and lli, by passing them command line flags (e.g.,
97<tt>-regalloc=linearscan</tt>, <tt>-enable-correct-eh-support</tt>, etc.) </li>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]98<li>The Control Flow Graph in the native code generators is no longer
99constrained to be the same as the CFG for the LLVM input code.</li>
100<li>The LLVM induction variable analysis routines have been rewritten.</li>
101<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
102<li>The induction variable substitution pass performs linear function test
103replacement and exit value replacement optimizations.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]104</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]105
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]106
107<!--=========================================================================-->
108<div class="doc_subsubsection">
109In this release, the following missing features were implemented:
110</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]111
112<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]113<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
114more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]115<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
116non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]117<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
118with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]119<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
120uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]121</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]122
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]123
124<!--=========================================================================-->
125<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]126<a name="qualityofimp">In this release, the following Quality of Implementation
127issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]128</div>
129
130<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]131<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
132bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]133<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
134for structure typedefs</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>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]143<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
144-disable/enable-povray and -disable-spec</a></li>
145<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
146work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]147</ol>
148
149<!--=========================================================================-->
150<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]151<a name="codequality">This release includes the following Code Quality
152improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]153</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]154
155<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]156<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
157due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]158
159<li>The X86 backend now generates substantially better code for 64-bit integer
160and floating point operations.</li>
161
162<li>The -inline pass no longer inlines mutually recursive functions until it
163hits the inlining threshold.</li>
164
165<li>The -inline pass no longer misses obvious inlining opportunities just
166because the callee eventually calls into an external function.</li>
167
168<li>The -simplifycfg pass can now "if convert" simple statements into the new
169<tt>select</tt> instruction.</li>
170
171<li>The -loopsimplify pass can now break <a
172href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
173into multiple nested loops. This enables a variety of subsequent
174optimizations.</li>
175
176<li>The -adce pass can now eliminate calls to functions that do not not write to
177memory.</li>
178
179<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]180exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]181
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]182<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
183"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
184operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
185&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
186
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]187<li>LLVM now has infrastructure for (simple and sparse conditional) constant
188propagation of function calls. It currently supports a few math library
189functions like sqrt/sin/cos/etc.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]190</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]191
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]192</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]193
194<!--=========================================================================-->
195<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]196<a name="bugfix">In this release, the following bugs in the previous release
197were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]198</div>
199
200<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]201
202<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]203<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
204asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]205<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
206incorrectly updates dominator information</a></li>
207<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
208breaks SSA form</a></li>
209<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
210to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]211<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
212code that unwinds</a></li>
213<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
214of the same name, both having constant pools</a></li>
215<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
216physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]217<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]218</ol>
219
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]220<p>Bugs in the C/C++ front-end:</p>
221
222<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]223<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
224enum type</a></li>
225<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
226indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]227</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]228
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]229
230<!--=========================================================================-->
231<div class="doc_subsubsection">
232<a name="misc">This release includes the following miscellaneous
233improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]234</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]235
236<p>Documentation Improvements</p>
237<ol>
238<li><a href="BytecodeFormat.html">Documentation of the LLVM Bytecode file format
239was added.</a></li>
240<li>All documentation was brought up to HTML 4.01 (Strict) level.</li>
241</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]242
243
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]244<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]245<div class="doc_section">
246 <a name="portability">Portability and Supported Platforms</a>
247</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]248<!-- *********************************************************************** -->
249
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]250<div class="doc_text">
251
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]252<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
253Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
254workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
255above, but only with the C backend and interpreter; no native machine-code
256generator for the PowerPC is available yet.</p>
257
258<p>The core LLVM infrastructure uses
259<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
260to the machine and operating system on which it is built. However, minor
261porting may be required to get LLVM to work on new platforms. We welcome your
262portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]263
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]264</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]265
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]266<!--=========================================================================-->
267<div class="doc_subsection">
268In this release, the following portability problems were fixed:
269</div>
270
271<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]272<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
273on Mac OS X</a></li>
274<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
275understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]276</ol>
277
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]278<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]279<div class="doc_section">
280 <a name="knownproblems">Known Problems</a>
281</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]282<!-- *********************************************************************** -->
283
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]284<div class="doc_text">
285
286<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]287component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]288sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]289href="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]290there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]291
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]292</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]293
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]294<!-- ======================================================================= -->
295<div class="doc_subsection">
296 <a name="experimental">Experimental features included with this release</a>
297</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]298
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]299<div class="doc_text">
300
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]301<p>The following components of this LLVM release are either untested, known to
302be broken or unreliable, or are in early development. These components should
303not be relied on, and bugs should not be filed against them, but they may be
304useful to some people. In particular, if you would like to work on one of these
305components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]306
307<ul>
308<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
309 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
310
311<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
312 it should) and not thoroughly tested.</li>
313<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
314<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
315</ul>
316
317</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]318
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]319<!-- ======================================================================= -->
320<div class="doc_subsection">
321 <a name="core">Known problems with the LLVM Core</a>
322</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]323
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]324<div class="doc_text">
325
326<ul>
327
328<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
329work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]330
331<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]332such, execution of a threaded program could cause these data structures to be
333corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]334
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]335<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]336
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]337<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]338table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]339
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]340<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
341objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]342
343<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]344values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]345targets whose setjmp/longjmp libraries do not save and restore the entire
346register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]347</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]348</div>
349
350<!-- ======================================================================= -->
351<div class="doc_subsection">
352 <a name="c-fe">Known problems with the C front-end</a>
353</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]354
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]355<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]356<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]357
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]358<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]359<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]360<li>C99 Variable sized arrays do not release stack memory when they go out of
361 scope. Thus, the following program may run out of stack space:
362<pre>
363 for (i = 0; i != 1000000; ++i) {
364 int X[n];
365 foo(X);
366 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]367</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]368
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]369<li>Initialization of global union variables can only be done <a
370href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
371member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]372
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]373<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
374external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]375
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]376</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]377</div>
378
379<!-- _______________________________________________________________________ -->
380<div class="doc_subsubsection">
381 Notes
382</div>
383
384<div class="doc_text">
385
386<ul>
387
388<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]389
390<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]391support for floating point data types of any size other than 32 and 64
392bits.</li>
393
394<li>The following Unix system functionality has not been tested and may not
395work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]396 <ol>
397 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
398 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
399 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
400 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
401 - These functions have not been tested.
402 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]403
404<li>Although many GCC extensions are supported, some are not. In particular,
405 the following extensions are known to <b>not be</b> supported:
406 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]407 <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]408 <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>
409 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
410 <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]411 <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]412 <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>
413 <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]414 <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>
415 <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>
416 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
417 <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]418 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]419
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]420 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]421 attribute means that the LLVM compiler ignores the presence of the attribute,
422 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]423 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]424 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]425
426 <ol>
427 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
428 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]429 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]430
431 <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]432
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]433 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]434 return.<br>
435
436 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
437 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
438 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
439
440 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
441 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
442 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
443
444 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
445 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
446 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]447
448 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
449 Specifying attributes of variables.<br>
450 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
451 <tt>deprecated</tt>, <tt>transparent_union</tt>,
452 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]453
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]454 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
455 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
456 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]457 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]458
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]459 <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]460 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]461 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]462
463 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
464 all target specific attributes.</li>
465
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
467 Other built-in functions.<br>
468 We support all builtins which have a C language equivalent (e.g.,
469 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
470 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]471 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]472
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]473 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]474
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]475 <p>The following extensions <b>are</b> known to be supported:</p>
476
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]477 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]478 <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]479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
480 <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>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
484 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
487 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
488 <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>
489 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
490 <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]491 <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]492 <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]493 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
494or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]495 <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]496 <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]497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
498 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
500 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
501 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
502 <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>
503 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
505 <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>
506 <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>
507 <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]508 <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]509 <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>
510 <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]511 </ol></li>
512
513</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]514
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]515<p>If you run into GCC extensions which have not been included in any of these
516lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]517
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]518</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]519
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]520<!-- ======================================================================= -->
521<div class="doc_subsection">
522 <a name="c++-fe">Known problems with the C++ front-end</a>
523</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]524
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]525<div class="doc_text">
526
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]527<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]528has not been tested as thoroughly as the C front-end. It has been tested and
529works for a number of non-trivial programs, but there may be lurking bugs.
530Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]531
532</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]533
534<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]535<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]536
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]537<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]538
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]539<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]540<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]541 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]542</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]543</div>
544
545<!-- _______________________________________________________________________ -->
546<div class="doc_subsubsection">
547 Notes
548</div>
549
550<div class="doc_text">
551
552<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]553
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]554<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
555parser is significantly more standards compliant (and picky) than prior GCC
556versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]557href="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]558
559<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]560 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]561 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]562 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]563 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]564
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]565<li>The LLVM C++ front-end follows the <a
566 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
567 This document, which is not Itanium specific, specifies a standard for name
568 mangling, class layout, v-table layout, RTTI formats, and other C++
569 representation issues. Because we use this API, code generated by the LLVM
570 compilers should be binary compatible with machine code generated by other
571 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
572 <i>However</i>, the exception handling mechanism used by LLVM is very
573 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]574 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]575
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]576</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]577
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]578</div>
579
580<!-- ======================================================================= -->
581<div class="doc_subsection">
582 <a name="x86-be">Known problems with the X86 back-end</a>
583</div>
584
585<div class="doc_text">
586
587<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]588<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]589</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]591</div>
592
593<!-- ======================================================================= -->
594<div class="doc_subsection">
595 <a name="sparc-be">Known problems with the Sparc back-end</a>
596</div>
597
598<div class="doc_text">
599
600<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]601<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]602</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]603
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604</div>
605
606<!-- ======================================================================= -->
607<div class="doc_subsection">
608 <a name="c-be">Known problems with the C back-end</a>
609</div>
610
611<div class="doc_text">
612
613<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]614
615<li>The C back-end produces code that violates the ANSI C Type-Based Alias
616Analysis rules. As such, special options may be necessary to compile the code
617(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]618problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]619
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]620<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]621cannot include special floating point numbers like Not-A-Number or
622Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]623
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]624<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]625supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]626frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]627
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]628</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]629
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]630</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]631
632<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]633<div class="doc_section">
634 <a name="additionalinfo">Additional Information</a>
635</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]636<!-- *********************************************************************** -->
637
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]638<div class="doc_text">
639
640<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]641including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]642implemented in LLVM. The web page also contains versions of the API
643documentation which is up-to-date with the CVS version of the source code. You
644can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]645the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]646
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647<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]648us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
649lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]650
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]651</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]652
653<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]654
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]655<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]656<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]657 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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659 <a href="http://validator.w3.org/check/referer"><img
660 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
661
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]662 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]663 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]664</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]665
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]666</body>
667</html>