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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
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 Lattnera5099962003-12-06 20:22:41 +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
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]192
193<!--=========================================================================-->
194<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]195<a name="bugfix">In this release, the following bugs in the previous release
196were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]197</div>
198
199<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]200
201<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]202<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
203asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]204<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
205incorrectly updates dominator information</a></li>
206<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
207breaks SSA form</a></li>
208<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
209to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]210<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
211code that unwinds</a></li>
212<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
213of the same name, both having constant pools</a></li>
214<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
215physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame^]216<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]217</ol>
218
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]219<p>Bugs in the C/C++ front-end:</p>
220
221<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]222<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
223enum type</a></li>
224<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
225indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]226</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]227
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]228</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]229
230<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]231<div class="doc_section">
232 <a name="portability">Portability and Supported Platforms</a>
233</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]234<!-- *********************************************************************** -->
235
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]236<div class="doc_text">
237
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]238<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
239Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
240workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
241above, but only with the C backend and interpreter; no native machine-code
242generator for the PowerPC is available yet.</p>
243
244<p>The core LLVM infrastructure uses
245<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
246to the machine and operating system on which it is built. However, minor
247porting may be required to get LLVM to work on new platforms. We welcome your
248portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]249
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]250</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]251
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]252<!--=========================================================================-->
253<div class="doc_subsection">
254In this release, the following portability problems were fixed:
255</div>
256
257<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]258<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
259on Mac OS X</a></li>
260<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
261understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]262</ol>
263
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]264<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]265<div class="doc_section">
266 <a name="knownproblems">Known Problems</a>
267</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]268<!-- *********************************************************************** -->
269
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]270<div class="doc_text">
271
272<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]273component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]274sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]275href="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]276there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]277
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]278</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]279
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]280<!-- ======================================================================= -->
281<div class="doc_subsection">
282 <a name="experimental">Experimental features included with this release</a>
283</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]284
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]285<div class="doc_text">
286
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]287<p>The following components of this LLVM release are either untested, known to
288be broken or unreliable, or are in early development. These components should
289not be relied on, and bugs should not be filed against them, but they may be
290useful to some people. In particular, if you would like to work on one of these
291components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]292
293<ul>
294<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
295 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
296
297<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
298 it should) and not thoroughly tested.</li>
299<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
300<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
301</ul>
302
303</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]304
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]305<!-- ======================================================================= -->
306<div class="doc_subsection">
307 <a name="core">Known problems with the LLVM Core</a>
308</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]309
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]310<div class="doc_text">
311
312<ul>
313
314<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
315work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]316
317<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]318such, execution of a threaded program could cause these data structures to be
319corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]320
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]321<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]322
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]323<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]324table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]325
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]326<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
327objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]328
329<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]330values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]331targets whose setjmp/longjmp libraries do not save and restore the entire
332register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]333</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]334</div>
335
336<!-- ======================================================================= -->
337<div class="doc_subsection">
338 <a name="c-fe">Known problems with the C front-end</a>
339</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]340
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]341<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]342<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]343
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]344<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]345<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]346<li>C99 Variable sized arrays do not release stack memory when they go out of
347 scope. Thus, the following program may run out of stack space:
348<pre>
349 for (i = 0; i != 1000000; ++i) {
350 int X[n];
351 foo(X);
352 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]353</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]354
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]355<li>Initialization of global union variables can only be done <a
356href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
357member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]358
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]359<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
360external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]361
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]362</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]363</div>
364
365<!-- _______________________________________________________________________ -->
366<div class="doc_subsubsection">
367 Notes
368</div>
369
370<div class="doc_text">
371
372<ul>
373
374<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]375
376<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]377support for floating point data types of any size other than 32 and 64
378bits.</li>
379
380<li>The following Unix system functionality has not been tested and may not
381work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]382 <ol>
383 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
384 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
385 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
386 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
387 - These functions have not been tested.
388 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]389
390<li>Although many GCC extensions are supported, some are not. In particular,
391 the following extensions are known to <b>not be</b> supported:
392 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]393 <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]394 <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>
395 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
396 <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]397 <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]398 <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>
399 <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]400 <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>
401 <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>
402 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
403 <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]404 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]405
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]406 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]407 attribute means that the LLVM compiler ignores the presence of the attribute,
408 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]409 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]410 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]411
412 <ol>
413 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
414 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]415 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]416
417 <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]418
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]419 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]420 return.<br>
421
422 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
423 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
424 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
425
426 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
427 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
428 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
429
430 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
431 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
432 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]433
434 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
435 Specifying attributes of variables.<br>
436 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
437 <tt>deprecated</tt>, <tt>transparent_union</tt>,
438 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]439
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]440 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
441 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
442 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]443 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]444
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]445 <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]446 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]447 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]448
449 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
450 all target specific attributes.</li>
451
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]452 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
453 Other built-in functions.<br>
454 We support all builtins which have a C language equivalent (e.g.,
455 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
456 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]457 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]458
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]459 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]460
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]461 <p>The following extensions <b>are</b> known to be supported:</p>
462
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]463 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]464 <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]465 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
466 <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>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
468 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
469 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
471 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
472 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
474 <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>
475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
476 <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]477 <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]478 <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]479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
480or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]481 <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]482 <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]483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
484 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
487 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
488 <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>
489 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
490 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
491 <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>
492 <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>
493 <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]494 <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]495 <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>
496 <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]497 </ol></li>
498
499</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]500
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]501<p>If you run into GCC extensions which have not been included in any of these
502lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]503
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]504</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]505
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]506<!-- ======================================================================= -->
507<div class="doc_subsection">
508 <a name="c++-fe">Known problems with the C++ front-end</a>
509</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]510
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]511<div class="doc_text">
512
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]513<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]514has not been tested as thoroughly as the C front-end. It has been tested and
515works for a number of non-trivial programs, but there may be lurking bugs.
516Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]517
518</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]519
520<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]521<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]522
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]523<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]524
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]525<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]526<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]527 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]528</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]529</div>
530
531<!-- _______________________________________________________________________ -->
532<div class="doc_subsubsection">
533 Notes
534</div>
535
536<div class="doc_text">
537
538<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]539
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]540<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
541parser is significantly more standards compliant (and picky) than prior GCC
542versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]543href="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]544
545<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]546 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]548 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]549 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]550
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]551<li>The LLVM C++ front-end follows the <a
552 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
553 This document, which is not Itanium specific, specifies a standard for name
554 mangling, class layout, v-table layout, RTTI formats, and other C++
555 representation issues. Because we use this API, code generated by the LLVM
556 compilers should be binary compatible with machine code generated by other
557 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
558 <i>However</i>, the exception handling mechanism used by LLVM is very
559 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]560 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]561
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]562</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]563
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]564</div>
565
566<!-- ======================================================================= -->
567<div class="doc_subsection">
568 <a name="x86-be">Known problems with the X86 back-end</a>
569</div>
570
571<div class="doc_text">
572
573<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]574<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]575</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]576
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]577</div>
578
579<!-- ======================================================================= -->
580<div class="doc_subsection">
581 <a name="sparc-be">Known problems with the Sparc back-end</a>
582</div>
583
584<div class="doc_text">
585
586<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]587<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]588</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]589
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]590</div>
591
592<!-- ======================================================================= -->
593<div class="doc_subsection">
594 <a name="c-be">Known problems with the C back-end</a>
595</div>
596
597<div class="doc_text">
598
599<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]600
601<li>The C back-end produces code that violates the ANSI C Type-Based Alias
602Analysis rules. As such, special options may be necessary to compile the code
603(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]605
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]606<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]607cannot include special floating point numbers like Not-A-Number or
608Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]609
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]610<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]611supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]612frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]613
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]614</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]615
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]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_section">
620 <a name="additionalinfo">Additional Information</a>
621</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]622<!-- *********************************************************************** -->
623
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]624<div class="doc_text">
625
626<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]627including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]628implemented in LLVM. The web page also contains versions of the API
629documentation which is up-to-date with the CVS version of the source code. You
630can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]631the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]632
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]633<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]634us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
635lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]636
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]637</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]638
639<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]640
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]641<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]642<address>
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647
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]648 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]649 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]650</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]651
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]652</body>
653</html>