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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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4<head>
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Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman80731b92003-11-22 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 Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner3d482502003-10-02 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner020e1fc2004-05-23 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman80731b92003-11-22 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 Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner1a7e43c2004-04-01 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 Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattnere7525b52003-10-07 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattnere76e9ab2003-12-12 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerea309ff2004-05-04 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 Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]76bugs</a> as well.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]77
Misha Brukmanfa50a222004-05-12 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 Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]84</div>
85
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]86<!--=========================================================================-->
87<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]88<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]89</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]90
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]91<div class="doc_text">
92
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]93<ol>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]94<li>The LLVM <a href="LangRef.html#i_select"><tt>select</tt></a> instruction is
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]95now fully implemented and supported by all transformations, native code
96generators, and the interpreter.</li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]97<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
98before it could only narrow them down to a function being miscompiled.</li>
Brian Gaekee307f8a72004-05-04 21:22:57 +0000[diff] [blame]99<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
100modes of llc</a> and lli, by passing them command line flags (e.g.,
101<tt>-regalloc=linearscan</tt>, <tt>-enable-correct-eh-support</tt>, etc.) </li>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]102<li>The Control Flow Graph in the native code generators is no longer
103constrained to be the same as the CFG for the LLVM input code.</li>
104<li>The LLVM induction variable analysis routines have been rewritten.</li>
105<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
106<li>The induction variable substitution pass performs linear function test
107replacement and exit value replacement optimizations.</li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame^]108<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now
109 documented.</a></li>
Chris Lattnereda4f472004-05-24 04:45:52 +0000[diff] [blame]110<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
111Garbage Collection</a>, enabling the use of aggressive copying and generational
112collectors.</li>
113<li>LLVM now includes an implementation of Andersen's interprocedural alias
114analysis algorithm.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]115</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]116
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]117</div>
118
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]119
120<!--=========================================================================-->
121<div class="doc_subsubsection">
122In this release, the following missing features were implemented:
123</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]124
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]125<div class="doc_text">
126
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]127<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]128<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
129more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]130<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
131non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]132<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
133with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]134<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
135uses of external fns by immediate constant exprs</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]136</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]137
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]138</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]139
140<!--=========================================================================-->
141<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]142<a name="qualityofimp">In this release, the following Quality of Implementation
143issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]144</div>
145
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]146<div class="doc_text">
147
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]148<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]149<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
150bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]151<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
152for structure typedefs</a></li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame^]153<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]154</ol>
155
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]156</div>
157
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]158<!--=========================================================================-->
159<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]160In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]161</div>
162
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]163<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]164<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]165<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
166-disable/enable-povray and -disable-spec</a></li>
167<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
168work if you change PATH</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]169</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]170</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]171
172<!--=========================================================================-->
173<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]174<a name="codequality">This release includes the following Code Quality
175improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]176</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]177
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]178<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]179<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]180<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
181due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]182
183<li>The X86 backend now generates substantially better code for 64-bit integer
184and floating point operations.</li>
185
186<li>The -inline pass no longer inlines mutually recursive functions until it
187hits the inlining threshold.</li>
188
189<li>The -inline pass no longer misses obvious inlining opportunities just
190because the callee eventually calls into an external function.</li>
191
192<li>The -simplifycfg pass can now "if convert" simple statements into the new
193<tt>select</tt> instruction.</li>
194
195<li>The -loopsimplify pass can now break <a
196href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
197into multiple nested loops. This enables a variety of subsequent
198optimizations.</li>
199
200<li>The -adce pass can now eliminate calls to functions that do not not write to
201memory.</li>
202
203<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]204exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]205
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]206<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
207"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
208operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
209&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
210
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]211<li>LLVM now has infrastructure for (simple and sparse conditional) constant
212propagation of function calls. It currently supports a few math library
213functions like sqrt/sin/cos/etc.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]214</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]215</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]216
217<!--=========================================================================-->
218<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]219<a name="bugfix">In this release, the following bugs in the previous release
220were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]221</div>
222
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]223<div class="doc_text">
224
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]225<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]226
227<ol>
John Criswell6956afa2004-05-06 22:23:24 +0000[diff] [blame]228<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
229asssertion</a></li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]230<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
231incorrectly updates dominator information</a></li>
232<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
233breaks SSA form</a></li>
234<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
235to floating point cast</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]236<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
237code that unwinds</a></li>
238<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
239of the same name, both having constant pools</a></li>
240<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
241physical register use of aliased definition</a></li>
Chris Lattner8f7cf272004-05-21 16:48:20 +0000[diff] [blame]242<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]243</ol>
244
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]245<p>Bugs in the C/C++ front-end:</p>
246
247<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]248<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
249enum type</a></li>
250<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
251indexing miscompiled</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]252</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]253</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]254
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]255<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]256<div class="doc_section">
257 <a name="portability">Portability and Supported Platforms</a>
258</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]259<!-- *********************************************************************** -->
260
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]261<div class="doc_text">
262
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]263<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
264Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
265workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
266above, but only with the C backend and interpreter; no native machine-code
267generator for the PowerPC is available yet.</p>
268
269<p>The core LLVM infrastructure uses
270<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
271to the machine and operating system on which it is built. However, minor
272porting may be required to get LLVM to work on new platforms. We welcome your
273portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]274
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]275</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]276
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]277<!--=========================================================================-->
278<div class="doc_subsection">
279In this release, the following portability problems were fixed:
280</div>
281
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]282<div class="doc_text">
283
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]284<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]285<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
286on Mac OS X</a></li>
287<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
288understand abbreviated names in headers</a></li>
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]289</ol>
290
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]291</div>
292
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]293<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]294<div class="doc_section">
295 <a name="knownproblems">Known Problems</a>
296</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]297<!-- *********************************************************************** -->
298
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]299<div class="doc_text">
300
301<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]302component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]303sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]304href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]305there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]306
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]307</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]308
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]309<!-- ======================================================================= -->
310<div class="doc_subsection">
311 <a name="experimental">Experimental features included with this release</a>
312</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]313
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]314<div class="doc_text">
315
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]316<p>The following components of this LLVM release are either untested, known to
317be broken or unreliable, or are in early development. These components should
318not be relied on, and bugs should not be filed against them, but they may be
319useful to some people. In particular, if you would like to work on one of these
320components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]321
322<ul>
323<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
324 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
325
326<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
327 it should) and not thoroughly tested.</li>
328<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
329<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
330</ul>
331
332</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]333
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]334<!-- ======================================================================= -->
335<div class="doc_subsection">
336 <a name="core">Known problems with the LLVM Core</a>
337</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]338
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]339<div class="doc_text">
340
341<ul>
342
343<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
344work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]345
346<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]347such, execution of a threaded program could cause these data structures to be
348corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]349
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]350<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]351
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]352<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]353table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]354
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]355<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
356objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]357
358<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswell5d6345a2004-03-12 21:29:42 +0000[diff] [blame]359values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]360targets whose setjmp/longjmp libraries do not save and restore the entire
361register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]362</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]363</div>
364
365<!-- ======================================================================= -->
366<div class="doc_subsection">
367 <a name="c-fe">Known problems with the C front-end</a>
368</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]369
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]370<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]371<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]372
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]373<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]374<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]375<li>C99 Variable sized arrays do not release stack memory when they go out of
376 scope. Thus, the following program may run out of stack space:
377<pre>
378 for (i = 0; i != 1000000; ++i) {
379 int X[n];
380 foo(X);
381 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]382</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]383
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]384<li>Initialization of global union variables can only be done <a
385href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
386member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]387
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]388<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
389external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]390
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]391</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]392</div>
393
394<!-- _______________________________________________________________________ -->
395<div class="doc_subsubsection">
396 Notes
397</div>
398
399<div class="doc_text">
400
401<ul>
402
403<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]404
405<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]406support for floating point data types of any size other than 32 and 64
407bits.</li>
408
409<li>The following Unix system functionality has not been tested and may not
410work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]411 <ol>
412 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
413 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
414 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
415 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
416 - These functions have not been tested.
417 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]418
419<li>Although many GCC extensions are supported, some are not. In particular,
420 the following extensions are known to <b>not be</b> supported:
421 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]422 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]423 <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>
424 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
425 <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 Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]426 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]427 <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>
428 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]429 <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>
430 <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>
431 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
432 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]433 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]434
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]435 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]436 attribute means that the LLVM compiler ignores the presence of the attribute,
437 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]438 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]439 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]440
441 <ol>
442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
443 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]444 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]445
446 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]447
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]448 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]449 return.<br>
450
451 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
452 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
453 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
454
455 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
456 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
457 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
458
459 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
460 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
461 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]462
463 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
464 Specifying attributes of variables.<br>
465 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
466 <tt>deprecated</tt>, <tt>transparent_union</tt>,
467 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]468
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]469 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
470 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
471 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]472 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]473
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]475 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]476 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]477
478 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
479 all target specific attributes.</li>
480
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
482 Other built-in functions.<br>
483 We support all builtins which have a C language equivalent (e.g.,
484 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
485 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]486 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]487
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]488 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]489
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]490 <p>The following extensions <b>are</b> known to be supported:</p>
491
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]492 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]493 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]494 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
495 <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>
496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
498 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
500 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
501 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
502 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
503 <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>
504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
505 <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 Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]506 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]508 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
509or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]510 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]511 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
517 <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>
518 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
520 <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>
521 <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>
522 <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 Lattner3646dad2004-02-14 04:08:29 +0000[diff] [blame]523 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]524 <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>
525 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]526 </ol></li>
527
528</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]529
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]530<p>If you run into GCC extensions which have not been included in any of these
531lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]533</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]534
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]535<!-- ======================================================================= -->
536<div class="doc_subsection">
537 <a name="c++-fe">Known problems with the C++ front-end</a>
538</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]539
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]540<div class="doc_text">
541
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]542<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]543has not been tested as thoroughly as the C front-end. It has been tested and
544works for a number of non-trivial programs, but there may be lurking bugs.
545Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]546
547</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]548
549<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]550<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]551
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]552<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]553
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]554<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]555<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]556 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]557</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]558</div>
559
560<!-- _______________________________________________________________________ -->
561<div class="doc_subsubsection">
562 Notes
563</div>
564
565<div class="doc_text">
566
567<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]568
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]569<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
570parser is significantly more standards compliant (and picky) than prior GCC
571versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]572href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]573
574<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]575 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]576 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]577 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]578 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]579
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]580<li>The LLVM C++ front-end follows the <a
581 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
582 This document, which is not Itanium specific, specifies a standard for name
583 mangling, class layout, v-table layout, RTTI formats, and other C++
584 representation issues. Because we use this API, code generated by the LLVM
585 compilers should be binary compatible with machine code generated by other
586 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
587 <i>However</i>, the exception handling mechanism used by LLVM is very
588 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]589 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]591</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]592
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]593</div>
594
595<!-- ======================================================================= -->
596<div class="doc_subsection">
597 <a name="x86-be">Known problems with the X86 back-end</a>
598</div>
599
600<div class="doc_text">
601
602<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]603<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]604</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]606</div>
607
608<!-- ======================================================================= -->
609<div class="doc_subsection">
610 <a name="sparc-be">Known problems with the Sparc back-end</a>
611</div>
612
613<div class="doc_text">
614
615<ul>
Chris Lattner9e0b81c2004-03-19 19:22:28 +0000[diff] [blame]616<li>There are several programs in the LLVM testsuite that the Sparc code generator is known to miscompile.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]617</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]618
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]619</div>
620
621<!-- ======================================================================= -->
622<div class="doc_subsection">
623 <a name="c-be">Known problems with the C back-end</a>
624</div>
625
626<div class="doc_text">
627
628<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]629
630<li>The C back-end produces code that violates the ANSI C Type-Based Alias
631Analysis rules. As such, special options may be necessary to compile the code
632(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]633problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]634
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]635<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]636cannot include special floating point numbers like Not-A-Number or
637Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]638
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]639<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]640supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]641frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]642
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]643</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]644
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]645</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]646
647<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]648<div class="doc_section">
649 <a name="additionalinfo">Additional Information</a>
650</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]651<!-- *********************************************************************** -->
652
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]653<div class="doc_text">
654
655<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]656including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]657implemented in LLVM. The web page also contains versions of the API
658documentation which is up-to-date with the CVS version of the source code. You
659can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]660the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]661
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]662<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]663us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
664lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]665
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]666</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]667
668<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]669
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]670<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]671<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]672 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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674 <a href="http://validator.w3.org/check/referer"><img
675 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
676
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]677 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]678 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]679</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]681</body>
682</html>