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Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]13 <li><a href="#intro">Introduction</a></li>
14 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]21 <li><a href="#core">Known problems with the LLVM Core</a>
22 <li><a href="#c-fe">Known problems with the C Front-end</a>
23 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
24 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
25 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]31<div class="doc_text">
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]32 <p><b>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a></b><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]41<div class="doc_text">
42
43<p>This document contains the release notes for the LLVM compiler
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]47href="http://llvm.cs.uiuc.edu/releases/1.3/">LLVM 1.3 web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]52current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
53web site</a>. If you have questions or comments, the <a
54href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]57<p>Note that if you are reading this file from CVS, this document applies
58to the <i>next</i> release, not the current one. To see the release notes for
59the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]72<p>
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]73This is the fourth public release of the LLVM compiler infrastructure. This
74release primarily improves the <a href="#codequality">performance of the
75code</a> produced by all aspects of the LLVM compiler and adds some <a
76href="#newfeatures">new features</a>, though it does <a href="#bugfix">fix a few
77bugs</a> as well.
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]78</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]79
Chris Lattner835104c2004-03-17 03:54:41 +0000[diff] [blame]80<p>
81At this time, LLVM is known to correctly compile and run all C &amp; C++ SPEC
82CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It has
83also been used to compile <b>many</b> other programs. LLVM now also works with
84a broad variety of C++ programs, though it has still received less testing than
85the C front-end.
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]86</p>
87
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]88<!--=========================================================================-->
89<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]90<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]91</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]92
93<ol>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]94<li>The LLVM <a href="LangRef.html#i_select"><tt>select</tt></a> instruction is
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]95now fully implemented and supported by all transformations, native code
96generators, and the interpreter.</li>
Misha Brukmana7aadf12004-04-19 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 Gaeke43be3112004-05-04 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 Lattner6e1ef192004-05-02 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 Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]108</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]109
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]110
111<!--=========================================================================-->
112<div class="doc_subsubsection">
113In this release, the following missing features were implemented:
114</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]115
116<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]117<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
118more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]119<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
120non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame^]121<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
122with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]123<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
124uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]125</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]126
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]127
128<!--=========================================================================-->
129<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]130<a name="qualityofimp">In this release, the following Quality of Implementation
131issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]132</div>
133
134<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]135<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
136bytecode onto your terminal</a></li>
Chris Lattneradd68af2004-05-07 19:23:05 +0000[diff] [blame]137<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted for structure typedefs</a></li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]138</ol>
139
140<!--=========================================================================-->
141<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]142In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]143</div>
144
145<ol>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]146<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with -disable/enable-povray and -disable-spec</a></li>
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]147<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't work if you change PATH</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]148</ol>
149
150<!--=========================================================================-->
151<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]152<a name="codequality">This release includes the following Code Quality
153improvements:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]154</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]155
156<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]157<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
158due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]159
160<li>The X86 backend now generates substantially better code for 64-bit integer
161and floating point operations.</li>
162
163<li>The -inline pass no longer inlines mutually recursive functions until it
164hits the inlining threshold.</li>
165
166<li>The -inline pass no longer misses obvious inlining opportunities just
167because the callee eventually calls into an external function.</li>
168
169<li>The -simplifycfg pass can now "if convert" simple statements into the new
170<tt>select</tt> instruction.</li>
171
172<li>The -loopsimplify pass can now break <a
173href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
174into multiple nested loops. This enables a variety of subsequent
175optimizations.</li>
176
177<li>The -adce pass can now eliminate calls to functions that do not not write to
178memory.</li>
179
180<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]181exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]182
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]183<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
184"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
185operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
186&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
187
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]188<li>LLVM now has infrastructure for (simple and sparse conditional) constant
189propagation of function calls. It currently supports a few math library
190functions like sqrt/sin/cos/etc.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]191</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]192
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]193
194<!--=========================================================================-->
195<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]196<a name="bugfix">In this release, the following bugs in the previous release
197were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]198</div>
199
200<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]201
202<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]203<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
204asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]205<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
206incorrectly updates dominator information</a></li>
207<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
208breaks SSA form</a></li>
209<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
210to floating point cast</a></li>
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]211<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable code that unwinds</a></li>
Brian Gaeke43be3112004-05-04 21:22:57 +0000[diff] [blame]212<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions of
213the same name, both having constant pools</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]214</ol>
215
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]216<p>Bugs in the C/C++ front-end:</p>
217
218<ol>
Chris Lattner581dc802004-05-07 18:40:38 +0000[diff] [blame]219<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared enum type</a></li>
220<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array indexing miscompiled</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]221</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]222
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]223</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]224
225<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]226<div class="doc_section">
227 <a name="portability">Portability and Supported Platforms</a>
228</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]229<!-- *********************************************************************** -->
230
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]231<div class="doc_text">
232
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]233<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
234Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
235workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
236above, but only with the C backend and interpreter; no native machine-code
237generator for the PowerPC is available yet.</p>
238
239<p>The core LLVM infrastructure uses
240<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
241to the machine and operating system on which it is built. However, minor
242porting may be required to get LLVM to work on new platforms. We welcome your
243portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]244
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]245</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]246
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]247<!--=========================================================================-->
248<div class="doc_subsection">
249In this release, the following portability problems were fixed:
250</div>
251
252<ol>
253<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler on Mac OS X</a></li>
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]254<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]255</ol>
256
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]257<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]258<div class="doc_section">
259 <a name="knownproblems">Known Problems</a>
260</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]261<!-- *********************************************************************** -->
262
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]263<div class="doc_text">
264
265<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]266component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]267sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]268href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]269there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]270
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]271</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]272
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]273<!-- ======================================================================= -->
274<div class="doc_subsection">
275 <a name="experimental">Experimental features included with this release</a>
276</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]277
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]278<div class="doc_text">
279
280<p>
281The following components of this LLVM release are either untested, known to be
282broken or unreliable, or are in early development. These components should not
283be relied on, and bugs should not be filed against them, but they may be useful
284to some people. In particular, if you would like to work on one of these
285components, please contact us on the llvmdev list.
286</p>
287
288<ul>
289<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
290 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
291
292<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
293 it should) and not thoroughly tested.</li>
294<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
295<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
296</ul>
297
298</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]299
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]300<!-- ======================================================================= -->
301<div class="doc_subsection">
302 <a name="core">Known problems with the LLVM Core</a>
303</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]304
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]305<div class="doc_text">
306
307<ul>
308
309<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
310work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]311
312<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]313such, execution of a threaded program could cause these data structures to be
314corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]315
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]316<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]317
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]318<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]319table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]320
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]321<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
322objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]323
324<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswelld46c6962004-03-12 21:29:42 +0000[diff] [blame]325values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]326targets whose setjmp/longjmp libraries do not save and restore the entire
327register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]328</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]329</div>
330
331<!-- ======================================================================= -->
332<div class="doc_subsection">
333 <a name="c-fe">Known problems with the C front-end</a>
334</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]335
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]336<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]337<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]338
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]339<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]340<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]341<li>C99 Variable sized arrays do not release stack memory when they go out of
342 scope. Thus, the following program may run out of stack space:
343<pre>
344 for (i = 0; i != 1000000; ++i) {
345 int X[n];
346 foo(X);
347 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]348</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]349
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]350<li>
351Initialization of global union variables can only be done
352<a href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest
353union member</a>.
354</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]355
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]356<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
357external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]358
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]359</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]360</div>
361
362<!-- _______________________________________________________________________ -->
363<div class="doc_subsubsection">
364 Notes
365</div>
366
367<div class="doc_text">
368
369<ul>
370
371<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]372
373<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]374support for floating point data types of any size other than 32 and 64
375bits.</li>
376
377<li>The following Unix system functionality has not been tested and may not
378work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]379 <ol>
380 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
381 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
382 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
383 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
384 - These functions have not been tested.
385 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]386
387<li>Although many GCC extensions are supported, some are not. In particular,
388 the following extensions are known to <b>not be</b> supported:
389 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]390 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]391 <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>
392 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
393 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]394 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]395 <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>
396 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]397 <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>
398 <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>
399 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
400 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]401 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]402
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]403 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]404 attribute means that the LLVM compiler ignores the presence of the attribute,
405 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]406 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]407 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]408
409 <ol>
410 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
411 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]412 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]413
414 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]415
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]416 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]417 return.<br>
418
419 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
420 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
421 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
422
423 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
424 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
425 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
426
427 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
428 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
429 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]430
431 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
432 Specifying attributes of variables.<br>
433 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
434 <tt>deprecated</tt>, <tt>transparent_union</tt>,
435 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]436
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]437 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
438 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
439 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]440 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]441
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]443 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]444 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]445
446 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
447 all target specific attributes.</li>
448
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]449 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
450 Other built-in functions.<br>
451 We support all builtins which have a C language equivalent (e.g.,
452 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
453 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]454 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]455
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]456 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]457
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]458 <p>The following extensions <b>are</b> known to be supported:</p>
459
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]460 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]461 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]462 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
463 <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>
464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
465 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
468 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
469 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
471 <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>
472 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]476 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
477or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]480 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
484 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
485 <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>
486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
487 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
488 <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>
489 <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>
490 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner25795bc2004-02-14 04:08:29 +0000[diff] [blame]491 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]492 <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>
493 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]494 </ol></li>
495
496</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]497
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]498<p>If you run into GCC extensions which have not been included in any of these
499lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]500
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]501</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]502
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]503<!-- ======================================================================= -->
504<div class="doc_subsection">
505 <a name="c++-fe">Known problems with the C++ front-end</a>
506</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]507
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]508<div class="doc_text">
509
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]510<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]511has not been tested as thoroughly as the C front-end. It has been tested and
512works for a number of non-trivial programs, but there may be lurking bugs.
513Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]514
515</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]516
517<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]518<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]519
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]520<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]521
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]522<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]523<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]524 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]525</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]526</div>
527
528<!-- _______________________________________________________________________ -->
529<div class="doc_subsubsection">
530 Notes
531</div>
532
533<div class="doc_text">
534
535<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]536
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]537<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
538parser is significantly more standards compliant (and picky) than prior GCC
539versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]540href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]541
542<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]543 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]544 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]545 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]546 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]548<li>The LLVM C++ front-end follows the <a
549 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
550 This document, which is not Itanium specific, specifies a standard for name
551 mangling, class layout, v-table layout, RTTI formats, and other C++
552 representation issues. Because we use this API, code generated by the LLVM
553 compilers should be binary compatible with machine code generated by other
554 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
555 <i>However</i>, the exception handling mechanism used by LLVM is very
556 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]557 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]558
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]559</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]560
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]561</div>
562
563<!-- ======================================================================= -->
564<div class="doc_subsection">
565 <a name="x86-be">Known problems with the X86 back-end</a>
566</div>
567
568<div class="doc_text">
569
570<ul>
Chris Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]571<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]572</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]573
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]574</div>
575
576<!-- ======================================================================= -->
577<div class="doc_subsection">
578 <a name="sparc-be">Known problems with the Sparc back-end</a>
579</div>
580
581<div class="doc_text">
582
583<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]584<li>There are several programs in the LLVM testsuite that the Sparc code generator is known to miscompile.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]585</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]586
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]587</div>
588
589<!-- ======================================================================= -->
590<div class="doc_subsection">
591 <a name="c-be">Known problems with the C back-end</a>
592</div>
593
594<div class="doc_text">
595
596<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]597
598<li>The C back-end produces code that violates the ANSI C Type-Based Alias
599Analysis rules. As such, special options may be necessary to compile the code
600(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]601problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]602
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]603<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604cannot include special floating point numbers like Not-A-Number or
605Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]606
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]607<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]608supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]609frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]610
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]611</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]612
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]613</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]614
615<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]616<div class="doc_section">
617 <a name="additionalinfo">Additional Information</a>
618</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]619<!-- *********************************************************************** -->
620
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]621<div class="doc_text">
622
623<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]624including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]625implemented in LLVM. The web page also contains versions of the API
626documentation which is up-to-date with the CVS version of the source code. You
627can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]628the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]629
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]630<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]631us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
632lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]634</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]635
636<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]637
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]638<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]639<address>
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644
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]645 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]646 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]647</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]648
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]649</body>
650</html>