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gerrit-public.fairphone.software / toolchain / llvm-project / 2c7b08766d651944418d449c9f41d9aa381e04ae / . / llvm / docs / ReleaseNotes.html
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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
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame^]109 documented.</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 Lattner57e7a4c2004-05-24 05:34:32 +0000[diff] [blame]115<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
116basic blocks</a> to track down reduce miscompilation testcases.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame^]117<li>LLVM and the C front-end now work under Win32 using the cygnus libraries.
118This includes the JIT compiler.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]119</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]120
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]121</div>
122
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]123
124<!--=========================================================================-->
125<div class="doc_subsubsection">
126In this release, the following missing features were implemented:
127</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]128
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]129<div class="doc_text">
130
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]131<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]132<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
133more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]134<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
135non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]136<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
137with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]138<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
139uses of external fns by immediate constant exprs</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]140</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]141
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]142</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]143
144<!--=========================================================================-->
145<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]146<a name="qualityofimp">In this release, the following Quality of Implementation
147issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]148</div>
149
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]150<div class="doc_text">
151
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]152<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]153<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
154bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]155<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
156for structure typedefs</a></li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame]157<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]158</ol>
159
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]160</div>
161
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]162<!--=========================================================================-->
163<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]164In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]165</div>
166
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]167<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]168<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]169<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
170-disable/enable-povray and -disable-spec</a></li>
171<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
172work if you change PATH</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]173</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]174</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]175
176<!--=========================================================================-->
177<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]178<a name="codequality">This release includes the following Code Quality
179improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]180</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]181
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]182<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]183<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]184<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
185due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]186
187<li>The X86 backend now generates substantially better code for 64-bit integer
188and floating point operations.</li>
189
190<li>The -inline pass no longer inlines mutually recursive functions until it
191hits the inlining threshold.</li>
192
193<li>The -inline pass no longer misses obvious inlining opportunities just
194because the callee eventually calls into an external function.</li>
195
196<li>The -simplifycfg pass can now "if convert" simple statements into the new
197<tt>select</tt> instruction.</li>
198
199<li>The -loopsimplify pass can now break <a
200href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
201into multiple nested loops. This enables a variety of subsequent
202optimizations.</li>
203
204<li>The -adce pass can now eliminate calls to functions that do not not write to
205memory.</li>
206
207<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]208exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]209
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]210<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
211"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
212operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
213&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
214
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]215<li>LLVM now has infrastructure for (simple and sparse conditional) constant
216propagation of function calls. It currently supports a few math library
217functions like sqrt/sin/cos/etc.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]218</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]219</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]220
221<!--=========================================================================-->
222<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]223<a name="bugfix">In this release, the following bugs in the previous release
224were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]225</div>
226
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]227<div class="doc_text">
228
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]229<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]230
231<ol>
John Criswell6956afa2004-05-06 22:23:24 +0000[diff] [blame]232<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
233asssertion</a></li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]234<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
235incorrectly updates dominator information</a></li>
236<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
237breaks SSA form</a></li>
238<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
239to floating point cast</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]240<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
241code that unwinds</a></li>
242<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
243of the same name, both having constant pools</a></li>
244<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
245physical register use of aliased definition</a></li>
Chris Lattner8f7cf272004-05-21 16:48:20 +0000[diff] [blame]246<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]247</ol>
248
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]249<p>Bugs in the C/C++ front-end:</p>
250
251<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]252<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
253enum type</a></li>
254<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
255indexing miscompiled</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]256</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]257</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]258
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]259<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]260<div class="doc_section">
261 <a name="portability">Portability and Supported Platforms</a>
262</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]263<!-- *********************************************************************** -->
264
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]265<div class="doc_text">
266
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame^]267<p>LLVM is known to work in the following platforms:</p>
268
269<ul>
270<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
271 other unix-like systems).</li>
272<li>Sun UltraSPARC workstations running Solaris 8.</li>
273<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
274 interpreter only, no native codegen is available yet).</li>
275<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
276</ul>
277
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]278
279<p>The core LLVM infrastructure uses
280<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
281to the machine and operating system on which it is built. However, minor
282porting may be required to get LLVM to work on new platforms. We welcome your
283portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]284
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame^]285<p>Note that the LLVM build system does not currently support directories with
286spaces on them when running on Win32/cygwin. We strongly recommend running
287LLVM and the C frontend out of a top-level directory without spaces (e.g.,
288<tt>/cygdrive/c/llvm</tt>).</p>
289
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]290</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]291
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]292<!--=========================================================================-->
293<div class="doc_subsection">
294In this release, the following portability problems were fixed:
295</div>
296
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]297<div class="doc_text">
298
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]299<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]300<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
301on Mac OS X</a></li>
302<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
303understand abbreviated names in headers</a></li>
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]304</ol>
305
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]306</div>
307
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]308<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]309<div class="doc_section">
310 <a name="knownproblems">Known Problems</a>
311</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]312<!-- *********************************************************************** -->
313
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]314<div class="doc_text">
315
316<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]317component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]318sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]319href="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]320there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]321
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]322</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]323
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]324<!-- ======================================================================= -->
325<div class="doc_subsection">
326 <a name="experimental">Experimental features included with this release</a>
327</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]328
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]329<div class="doc_text">
330
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]331<p>The following components of this LLVM release are either untested, known to
332be broken or unreliable, or are in early development. These components should
333not be relied on, and bugs should not be filed against them, but they may be
334useful to some people. In particular, if you would like to work on one of these
335components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]336
337<ul>
338<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
339 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
340
341<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
342 it should) and not thoroughly tested.</li>
343<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
344<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
345</ul>
346
347</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]348
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]349<!-- ======================================================================= -->
350<div class="doc_subsection">
351 <a name="core">Known problems with the LLVM Core</a>
352</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]353
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]354<div class="doc_text">
355
356<ul>
357
358<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
359work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]360
361<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]362such, execution of a threaded program could cause these data structures to be
363corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]364
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]365<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]366
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]367<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]368table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]369
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]370<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
371objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]372
373<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]374values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]375targets whose setjmp/longjmp libraries do not save and restore the entire
376register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]377</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]378</div>
379
380<!-- ======================================================================= -->
381<div class="doc_subsection">
382 <a name="c-fe">Known problems with the C front-end</a>
383</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]384
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]385<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]386<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]387
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]388<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]389<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]390<li>C99 Variable sized arrays do not release stack memory when they go out of
391 scope. Thus, the following program may run out of stack space:
392<pre>
393 for (i = 0; i != 1000000; ++i) {
394 int X[n];
395 foo(X);
396 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]397</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]398
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]399<li>Initialization of global union variables can only be done <a
400href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
401member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]402
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]403<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
404external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]405
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]406</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]407</div>
408
409<!-- _______________________________________________________________________ -->
410<div class="doc_subsubsection">
411 Notes
412</div>
413
414<div class="doc_text">
415
416<ul>
417
418<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]419
420<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]421support for floating point data types of any size other than 32 and 64
422bits.</li>
423
424<li>The following Unix system functionality has not been tested and may not
425work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]426 <ol>
427 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
428 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
429 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
430 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
431 - These functions have not been tested.
432 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]433
434<li>Although many GCC extensions are supported, some are not. In particular,
435 the following extensions are known to <b>not be</b> supported:
436 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]437 <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]438 <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>
439 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
440 <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]441 <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]442 <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>
443 <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]444 <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>
445 <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>
446 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
447 <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]448 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]449
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]450 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]451 attribute means that the LLVM compiler ignores the presence of the attribute,
452 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]453 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]454 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]455
456 <ol>
457 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
458 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]459 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]460
461 <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]462
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]463 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]464 return.<br>
465
466 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
467 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
468 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
469
470 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
471 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
472 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
473
474 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
475 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
476 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]477
478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
479 Specifying attributes of variables.<br>
480 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
481 <tt>deprecated</tt>, <tt>transparent_union</tt>,
482 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]483
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]484 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
485 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
486 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]487 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]488
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]489 <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]490 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]491 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]492
493 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
494 all target specific attributes.</li>
495
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
497 Other built-in functions.<br>
498 We support all builtins which have a C language equivalent (e.g.,
499 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
500 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]501 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]502
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]503 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]504
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]505 <p>The following extensions <b>are</b> known to be supported:</p>
506
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]507 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]508 <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]509 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
510 <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>
511 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
518 <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>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
520 <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]521 <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]522 <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]523 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
524or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]525 <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]526 <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]527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
528 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
529 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
530 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
532 <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>
533 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
534 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
535 <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>
536 <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>
537 <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]538 <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]539 <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>
540 <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]541 </ol></li>
542
543</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]544
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]545<p>If you run into GCC extensions which have not been included in any of these
546lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]547
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]548</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]549
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]550<!-- ======================================================================= -->
551<div class="doc_subsection">
552 <a name="c++-fe">Known problems with the C++ front-end</a>
553</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]554
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]555<div class="doc_text">
556
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]557<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]558has not been tested as thoroughly as the C front-end. It has been tested and
559works for a number of non-trivial programs, but there may be lurking bugs.
560Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]561
562</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]563
564<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]565<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]566
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]567<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]568
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]569<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]570<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]571 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]572</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]573</div>
574
575<!-- _______________________________________________________________________ -->
576<div class="doc_subsubsection">
577 Notes
578</div>
579
580<div class="doc_text">
581
582<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]583
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]584<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
585parser is significantly more standards compliant (and picky) than prior GCC
586versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]587href="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]588
589<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]590 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]591 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]592 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]593 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]594
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]595<li>The LLVM C++ front-end follows the <a
596 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
597 This document, which is not Itanium specific, specifies a standard for name
598 mangling, class layout, v-table layout, RTTI formats, and other C++
599 representation issues. Because we use this API, code generated by the LLVM
600 compilers should be binary compatible with machine code generated by other
601 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
602 <i>However</i>, the exception handling mechanism used by LLVM is very
603 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]604 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]606</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]607
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]608</div>
609
610<!-- ======================================================================= -->
611<div class="doc_subsection">
612 <a name="x86-be">Known problems with the X86 back-end</a>
613</div>
614
615<div class="doc_text">
616
617<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]618<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]619</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]620
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]621</div>
622
623<!-- ======================================================================= -->
624<div class="doc_subsection">
625 <a name="sparc-be">Known problems with the Sparc back-end</a>
626</div>
627
628<div class="doc_text">
629
630<ul>
Chris Lattner9e0b81c2004-03-19 19:22:28 +0000[diff] [blame]631<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]632</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]634</div>
635
636<!-- ======================================================================= -->
637<div class="doc_subsection">
638 <a name="c-be">Known problems with the C back-end</a>
639</div>
640
641<div class="doc_text">
642
643<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]644
645<li>The C back-end produces code that violates the ANSI C Type-Based Alias
646Analysis rules. As such, special options may be necessary to compile the code
647(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]648problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]649
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]650<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]651cannot include special floating point numbers like Not-A-Number or
652Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]653
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]654<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]655supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]656frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]657
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]658</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]659
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]660</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]661
662<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]663<div class="doc_section">
664 <a name="additionalinfo">Additional Information</a>
665</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]666<!-- *********************************************************************** -->
667
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]668<div class="doc_text">
669
670<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]671including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]672implemented in LLVM. The web page also contains versions of the API
673documentation which is up-to-date with the CVS version of the source code. You
674can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]675the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]676
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]677<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]678us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
679lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]681</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]682
683<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]684
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]685<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]686<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]687 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]688 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
689 <a href="http://validator.w3.org/check/referer"><img
690 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
691
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]692 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]693 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]694</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]695
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]696</body>
697</html>