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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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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>
Brian Gaeke84c8bd02004-06-01 20:02:56 +0000[diff] [blame]117<li>LLVM and the C front-end now work under Win32 using the
118<a href="http://www.cygwin.com">Cygwin</a> runtime libraries.
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]119This includes the JIT compiler.</li>
Chris Lattnera7fac952004-06-04 00:40:11 +0000[diff] [blame^]120<li>The LLVM code generator is now being <a
121 href="CodeGenerator.html">documented</a>.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]122</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]123
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]124</div>
125
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]126
127<!--=========================================================================-->
128<div class="doc_subsubsection">
129In this release, the following missing features were implemented:
130</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]131
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]132<div class="doc_text">
133
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]134<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]135<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
136more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]137<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
138non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]139<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
140with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]141<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
142uses of external fns by immediate constant exprs</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]143</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]144
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]145</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]146
147<!--=========================================================================-->
148<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]149<a name="qualityofimp">In this release, the following Quality of Implementation
150issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]151</div>
152
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]153<div class="doc_text">
154
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]155<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]156<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
157bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
159for structure typedefs</a></li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame]160<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]161</ol>
162
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]163</div>
164
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]165<!--=========================================================================-->
166<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]167In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]168</div>
169
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]170<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]171<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]172<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
173-disable/enable-povray and -disable-spec</a></li>
174<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
175work if you change PATH</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]176</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]177</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]178
179<!--=========================================================================-->
180<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]181<a name="codequality">This release includes the following Code Quality
182improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]183</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]184
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]185<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]186<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]187<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
188due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]189
190<li>The X86 backend now generates substantially better code for 64-bit integer
191and floating point operations.</li>
192
193<li>The -inline pass no longer inlines mutually recursive functions until it
194hits the inlining threshold.</li>
195
196<li>The -inline pass no longer misses obvious inlining opportunities just
197because the callee eventually calls into an external function.</li>
198
199<li>The -simplifycfg pass can now "if convert" simple statements into the new
200<tt>select</tt> instruction.</li>
201
202<li>The -loopsimplify pass can now break <a
203href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
204into multiple nested loops. This enables a variety of subsequent
205optimizations.</li>
206
207<li>The -adce pass can now eliminate calls to functions that do not not write to
208memory.</li>
209
210<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]211exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]212
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]213<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
214"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
215operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
216&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
217
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]218<li>LLVM now has infrastructure for (simple and sparse conditional) constant
219propagation of function calls. It currently supports a few math library
220functions like sqrt/sin/cos/etc.</li>
Chris Lattner249b3552004-06-03 22:35:13 +0000[diff] [blame]221
222<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
223loops</a> in the code to help C compilers whose optimizers do not recognize
224loops formed from gotos (like GCC).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]225</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]226</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]227
228<!--=========================================================================-->
229<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]230<a name="bugfix">In this release, the following bugs in the previous release
231were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]232</div>
233
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]234<div class="doc_text">
235
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]236<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]237
238<ol>
John Criswell6956afa2004-05-06 22:23:24 +0000[diff] [blame]239<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
240asssertion</a></li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]241<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
242incorrectly updates dominator information</a></li>
243<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
244breaks SSA form</a></li>
245<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
246to floating point cast</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]247<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
248code that unwinds</a></li>
249<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
250of the same name, both having constant pools</a></li>
251<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
252physical register use of aliased definition</a></li>
Chris Lattner8f7cf272004-05-21 16:48:20 +0000[diff] [blame]253<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattner3edb94b2004-06-01 21:52:45 +0000[diff] [blame]254<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when missing external functions encountered</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]255</ol>
256
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]257<p>Bugs in the C/C++ front-end:</p>
258
259<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]260<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
261enum type</a></li>
262<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
263indexing miscompiled</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]264</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]265</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]266
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]267<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]268<div class="doc_section">
269 <a name="portability">Portability and Supported Platforms</a>
270</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]271<!-- *********************************************************************** -->
272
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]273<div class="doc_text">
274
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]275<p>LLVM is known to work in the following platforms:</p>
276
277<ul>
278<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
279 other unix-like systems).</li>
280<li>Sun UltraSPARC workstations running Solaris 8.</li>
281<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
282 interpreter only, no native codegen is available yet).</li>
283<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
284</ul>
285
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]286
287<p>The core LLVM infrastructure uses
288<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
289to the machine and operating system on which it is built. However, minor
290porting may be required to get LLVM to work on new platforms. We welcome your
291portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]292
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]293<p>Note that the LLVM build system does not currently support directories with
294spaces on them when running on Win32/cygwin. We strongly recommend running
295LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattnerce1a3842004-06-01 19:41:30 +0000[diff] [blame]296<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
297cygwin packages. By default, many important tools are not installed that
298are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]299
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]300</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]301
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]302<!--=========================================================================-->
303<div class="doc_subsection">
304In this release, the following portability problems were fixed:
305</div>
306
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]307<div class="doc_text">
308
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]309<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]310<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
311on Mac OS X</a></li>
312<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
313understand abbreviated names in headers</a></li>
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]314</ol>
315
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]316</div>
317
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]318<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]319<div class="doc_section">
320 <a name="knownproblems">Known Problems</a>
321</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]322<!-- *********************************************************************** -->
323
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]324<div class="doc_text">
325
326<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]327component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]328sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]329href="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]330there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]331
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]332</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]333
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]334<!-- ======================================================================= -->
335<div class="doc_subsection">
336 <a name="experimental">Experimental features included with this release</a>
337</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]338
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]339<div class="doc_text">
340
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]341<p>The following components of this LLVM release are either untested, known to
342be broken or unreliable, or are in early development. These components should
343not be relied on, and bugs should not be filed against them, but they may be
344useful to some people. In particular, if you would like to work on one of these
345components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]346
347<ul>
348<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
349 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
350
351<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
352 it should) and not thoroughly tested.</li>
353<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
354<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
355</ul>
356
357</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]358
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]359<!-- ======================================================================= -->
360<div class="doc_subsection">
361 <a name="core">Known problems with the LLVM Core</a>
362</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]363
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]364<div class="doc_text">
365
366<ul>
367
368<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
369work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]370
371<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]372such, execution of a threaded program could cause these data structures to be
373corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]374
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]375<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]376
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]377<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]378table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]379
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]380<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
381objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]382
383<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]384values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]385targets whose setjmp/longjmp libraries do not save and restore the entire
386register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]387</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]388</div>
389
390<!-- ======================================================================= -->
391<div class="doc_subsection">
392 <a name="c-fe">Known problems with the C front-end</a>
393</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]394
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]395<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]396<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]397
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]398<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]399<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]400<li>C99 Variable sized arrays do not release stack memory when they go out of
401 scope. Thus, the following program may run out of stack space:
402<pre>
403 for (i = 0; i != 1000000; ++i) {
404 int X[n];
405 foo(X);
406 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]407</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]408
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]409<li>Initialization of global union variables can only be done <a
410href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
411member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]412
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]413<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
414external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]415
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]416</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]417</div>
418
419<!-- _______________________________________________________________________ -->
420<div class="doc_subsubsection">
421 Notes
422</div>
423
424<div class="doc_text">
425
426<ul>
427
428<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]429
430<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]431support for floating point data types of any size other than 32 and 64
432bits.</li>
433
434<li>The following Unix system functionality has not been tested and may not
435work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]436 <ol>
437 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
438 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
439 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
440 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
441 - These functions have not been tested.
442 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]443
444<li>Although many GCC extensions are supported, some are not. In particular,
445 the following extensions are known to <b>not be</b> supported:
446 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]447 <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]448 <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>
449 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
450 <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]451 <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]452 <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>
453 <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]454 <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>
455 <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>
456 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
457 <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]458 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]459
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]460 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]461 attribute means that the LLVM compiler ignores the presence of the attribute,
462 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]463 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]464 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]465
466 <ol>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
468 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]469 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]470
471 <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]472
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]473 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]474 return.<br>
475
476 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
477 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
478 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
479
480 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
481 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
482 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
483
484 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
485 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
486 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]487
488 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
489 Specifying attributes of variables.<br>
490 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
491 <tt>deprecated</tt>, <tt>transparent_union</tt>,
492 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]493
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]494 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
495 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
496 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]497 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]498
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]499 <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]500 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]501 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]502
503 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
504 all target specific attributes.</li>
505
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]506 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
507 Other built-in functions.<br>
508 We support all builtins which have a C language equivalent (e.g.,
509 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
510 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]511 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]512
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]513 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]514
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]515 <p>The following extensions <b>are</b> known to be supported:</p>
516
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]517 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]518 <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]519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
520 <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>
521 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
522 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
523 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
524 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
525 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
526 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
528 <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>
529 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
530 <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]531 <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]532 <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]533 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
534or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]535 <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]536 <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]537 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
538 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
539 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
540 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
541 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
542 <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>
543 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
544 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
545 <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>
546 <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>
547 <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]548 <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]549 <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>
550 <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]551 </ol></li>
552
553</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]554
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]555<p>If you run into GCC extensions which have not been included in any of these
556lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]557
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]558</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]559
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]560<!-- ======================================================================= -->
561<div class="doc_subsection">
562 <a name="c++-fe">Known problems with the C++ front-end</a>
563</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]564
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]565<div class="doc_text">
566
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]567<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]568has not been tested as thoroughly as the C front-end. It has been tested and
569works for a number of non-trivial programs, but there may be lurking bugs.
570Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]571
572</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]573
574<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]575<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]576
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]577<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]578
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]579<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]580<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]581 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]582</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]583</div>
584
585<!-- _______________________________________________________________________ -->
586<div class="doc_subsubsection">
587 Notes
588</div>
589
590<div class="doc_text">
591
592<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]593
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]594<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
595parser is significantly more standards compliant (and picky) than prior GCC
596versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]597href="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]598
599<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]600 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]601 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]602 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]603 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]604
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]605<li>The LLVM C++ front-end follows the <a
606 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
607 This document, which is not Itanium specific, specifies a standard for name
608 mangling, class layout, v-table layout, RTTI formats, and other C++
609 representation issues. Because we use this API, code generated by the LLVM
610 compilers should be binary compatible with machine code generated by other
611 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
612 <i>However</i>, the exception handling mechanism used by LLVM is very
613 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]614 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]615
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]616</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]617
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]618</div>
619
620<!-- ======================================================================= -->
621<div class="doc_subsection">
622 <a name="x86-be">Known problems with the X86 back-end</a>
623</div>
624
625<div class="doc_text">
626
627<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]628<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]629</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]630
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]631</div>
632
633<!-- ======================================================================= -->
634<div class="doc_subsection">
635 <a name="sparc-be">Known problems with the Sparc back-end</a>
636</div>
637
638<div class="doc_text">
639
640<ul>
Chris Lattner9e0b81c2004-03-19 19:22:28 +0000[diff] [blame]641<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]642</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]643
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]644</div>
645
646<!-- ======================================================================= -->
647<div class="doc_subsection">
648 <a name="c-be">Known problems with the C back-end</a>
649</div>
650
651<div class="doc_text">
652
653<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]654
655<li>The C back-end produces code that violates the ANSI C Type-Based Alias
656Analysis rules. As such, special options may be necessary to compile the code
657(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]658problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]659
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]660<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]661cannot include special floating point numbers like Not-A-Number or
662Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]663
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]664<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]665supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]666frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]667
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]668</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]669
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]670</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]671
672<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]673<div class="doc_section">
674 <a name="additionalinfo">Additional Information</a>
675</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]676<!-- *********************************************************************** -->
677
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]678<div class="doc_text">
679
680<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]681including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]682implemented in LLVM. The web page also contains versions of the API
683documentation which is up-to-date with the CVS version of the source code. You
684can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]685the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]686
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]687<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]688us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
689lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]690
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]691</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]692
693<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]694
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]695<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]696<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]697 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]698 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
699 <a href="http://validator.w3.org/check/referer"><img
700 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
701
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]702 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]703 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]704</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]705
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]706</body>
707</html>