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4<head>
5 <link rel="stylesheet" href="llvm.css" type="text/css">
6 <title>LLVM 1.1 Release Notes</title>
7</head>
8<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]9
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]10<div class="doc_title">
11 LLVM 1.1 Release Notes
12</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]13
14<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]15 <li><a href="#intro">Introduction</a></li>
16 <li><a href="#whatsnew">What's New?</a></li>
17 <li><a href="#portability">Portability and Supported Platforms</a></li>
18 <li><a href="#install-instructions">Installation Instructions</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a>
20 <ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]21<!-- <li><a href="#portabilityprobs">Portability Problems</a> -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]22 <li><a href="#core">Known problems with the LLVM Core</a>
23 <li><a href="#c-fe">Known problems with the C Front-end</a>
24 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
25 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
26 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
27 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]28 </ul></li>
29 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]30</ol>
31
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]32<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]33 <p><b>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a></b><p>
34</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]35
36<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]37<div class="doc_section">
38 <a name="intro">Introduction</a>
39</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]40<!-- *********************************************************************** -->
41
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]42<div class="doc_text">
43
44<p>This document contains the release notes for the LLVM compiler
45infrastructure, release 1.1. Here we describe the status of LLVM, including any
46known problems, and bug fixes from the previous release. The most up-to-date
47version of this document can be found on the <a
Chris Lattner12d90632003-10-27 01:31:14 +0000[diff] [blame]48href="http://llvm.cs.uiuc.edu/releases/1.1/">LLVM 1.1 web site</a>. If you are
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]49not reading this on the LLVM web pages, you should probably go there, because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]50this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]51
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]52<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]53current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
54web site</a>. If you have questions or comments, the <a
55href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]56list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]57
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]58<p>Note that if you are reading this file from CVS, this document applies
59to the <i>next</i> release, not the current one. To see the release notes for
60the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]61href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
62
63</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]64
65<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]66<div class="doc_section">
67 <a name="whatsnew">What's New?</a>
68</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]69<!-- *********************************************************************** -->
70
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]71<div class="doc_text">
72
73<p>This is the second public release of the LLVM compiler infrastructure. This
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]74release is primarily a bugfix release, dramatically improving the C/C++
75front-end, and improving support for C++ in the LLVM core. This release also
Chris Lattner7fcfac02003-12-06 20:24:46 +0000[diff] [blame]76includes a few new features, such as a simple profiler, support for Mac OS/X,
Chris Lattner3b368c72003-12-12 04:45:09 +0000[diff] [blame]77better interoperability with external source bases, a new example language
78front-end, and improves a few optimizations.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]79
Chris Lattner2d9d4e72003-12-11 23:31:21 +0000[diff] [blame]80<p>At this time, LLVM is known to correctly compile the C &amp; C++ SPEC CPU2000
81benchmarks (X86 only), the Olden benchmarks, and the Ptrdist benchmarks along
82with <b>many</b> other programs. LLVM now also works with a broad variety of
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]83C++ programs, though it has still received much less testing than the C
84front-end.
85</p>
86
87<p>
88Note that the Sparc and X86 backends do not currently support exception throwing
89or long jumping (including 253.perlbmk in SPEC). For these programs, you must
90use the C backend. Support for unwinding will be added in a future release.
91</p>
92
93
94<!--=========================================================================-->
95<div class="doc_subsubsection">
96This release implements the following new features:
97</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]98
99<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]100<li><a
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]101href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000528.html">A new
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]102LLVM profiler, similar to gprof</a> is available</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]103
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]104<li>LLVM and the C/C++ front-end now compile on Mac OS/X! Mac OS/X users can
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]105now explore the LLVM optimizer with the C backend and interpreter. Note that
106LLVM requires GCC 3.3 on Mac OS/X.</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]107
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]108<li>LLVM has been <a
Chris Lattner2a77f2d2003-11-11 23:46:35 +0000[diff] [blame]109href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000554.html">moved
110into an 'llvm' C++ namespace</a>, for easier integration with third-party
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]111code. Note that due to lack of namespace support in GDB 5.x, you will probably
112want to upgrade to GDB 6 or better to debug LLVM code.</li>
John Criswellf2ec35b2003-11-26 20:09:49 +0000[diff] [blame]113
114<li>
115The build system now copies Makefiles dynamically from the source tree to the
116object tree as subdirectories are built. This means that:
117 <ol>
118 <li>
119 New directories can be added to the source tree, and the build will
120 automatically pick them up (i.e. no need to re-run <tt>configure</tt>).
121 </li>
122
123 <li>
124 You will need to build LLVM from the top of the object tree once to ensure
125 that all of the Makefiles are copied into the object tree subdirectories.
126 </li>
127 </ol>
128</li>
129
Chris Lattner3b368c72003-12-12 04:45:09 +0000[diff] [blame]130<li>A front-end for "Stacker" (a simple Forth-like language) is now
131 <a href="http://llvm.cs.uiuc.edu/PR136">included in the main LLVM tree</a>.
132 Additionally, Reid Spencer, the author, contributed a document <a href="Stacker.html">describing his experiences writing Stacker, and the language itself</a>. This document is invaluable for others writing front-ends targetting LLVM.</li>
133
Chris Lattner2d9d4e72003-12-11 23:31:21 +0000[diff] [blame]134<li>The <tt>configure</tt> script will now configure all projects placed in the
135<tt>llvm/projects</tt> directory.</li>
136
Chris Lattner287c9e62003-12-12 04:51:00 +0000[diff] [blame]137<li>The <tt>-tailcallelim</tt> pass can now introduce "accumulator" variables
138 to transform functions in many common cases that it could not before.</li>
139
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]140<li>The <tt>-licm</tt> pass can now sink instructions out the bottom of loops
141in addition to being able to hoist them out the top.</li>
142
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]143<li>The <tt>-basicaa</tt> pass (the default alias analysis) has been upgraded
144to be <a href="http://llvm.cs.uiuc.edu/PR86">significantly more
145precise</a>.</li>
Chris Lattner2d9d4e72003-12-11 23:31:21 +0000[diff] [blame]146
Chris Lattner8c1237e2003-12-12 05:52:39 +0000[diff] [blame]147<li>LLVM 1.1 implements a simple size optimization for LLVM bytecode files.
148 This means that the 1.1 files are smaller than 1.0, but that 1.0 won't
149 read 1.1 bytecode files.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]150</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]151
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]152
153<!--=========================================================================-->
154<div class="doc_subsubsection">
155In this release, the following missing features were implemented:
156</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]157
158<ol>
159<li><a href="http://llvm.cs.uiuc.edu/PR88">The interpreter does not support
160invoke or unwind</a></li>
Misha Brukmanc99037d2003-11-14 03:30:43 +0000[diff] [blame]161
162<li><a href="http://llvm.cs.uiuc.edu/PR99">Interpreter does not support the
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]163<tt>vaarg</tt> instruction</a></li>
Misha Brukmanc99037d2003-11-14 03:30:43 +0000[diff] [blame]164
Brian Gaekeb7508ee2003-11-16 23:49:26 +0000[diff] [blame]165<li><a href="http://llvm.cs.uiuc.edu/PR117">llvm-nm cannot read archive
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]166files</a></li>
Brian Gaekeb7508ee2003-11-16 23:49:26 +0000[diff] [blame]167
Brian Gaekea6ffa542003-12-11 04:40:58 +0000[diff] [blame]168<li><a href="http://llvm.cs.uiuc.edu/PR146">Interpreter does not handle
169setne constant expression</a></li>
170
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]171</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]172
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]173
174<!--=========================================================================-->
175<div class="doc_subsubsection">
176In this release, the following Quality of Implementation issues were
177fixed:
178</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]179
180<ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]181
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]182<li>The C++ front-end now compiles functions to
183 <a href="http://llvm.cs.uiuc.edu/PR29">use the linkonce linkage type</a>
184 more, giving the optimizer more freedom.</a></li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]185
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]186<li>The C front-end now <a href="http://llvm.cs.uiuc.edu/PR84">generates
187 type-safe code</a> in several cases that it did not before, which prevented
188 some important optimizations.</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]189
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]190<li>The LLVM build system has been taught to catch some common configuration
191 problems that <a href="http://llvm.cs.uiuc.edu/PR96">caused it to get
192 horribly confused</a> before.</li>
Chris Lattnerba46d552003-11-16 20:25:24 +0000[diff] [blame]193
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]194<li>The LLVM header files are now
195 <a href="http://llvm.cs.uiuc.edu/PR114">-Wold-style-cast clean</a>.</li>
Chris Lattnerba46d552003-11-16 20:25:24 +0000[diff] [blame]196
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]197<li>The LLVM bytecode reader has been <a
198href="http://llvm.cs.uiuc.edu/PR127">sped up a lot</a> (up to 4x in some
199cases).</li>
200
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]201<li>In C++, methods and functions in anonymous namespaces <a href="http://llvm.cs.uiuc.edu/PR85">now get internal linkage</a>.</li>
Chris Lattner9f9d00a2003-11-22 01:14:58 +0000[diff] [blame]202
Chris Lattnerf7330732003-11-26 08:20:34 +0000[diff] [blame]203<li>Constant initializers now generate loops instead of potentially <a href="http://llvm.cs.uiuc.edu/PR75">huge amounts of straight-line code</a>.</li>
204
Chris Lattner3074b342003-11-27 09:51:54 +0000[diff] [blame]205<li>Code for running C++ destructors is now properly shared when possible. Before, the C++ front-end
206<a href="http://llvm.cs.uiuc.edu/PR11">generated N^2 amounts of duplicated cleanup code</a> in some cases.</li>
Chris Lattner8b644f92003-12-12 07:26:25 +0000[diff] [blame^]207
208<li>The JIT used to <a href="http://llvm.cs.uiuc.edu/PR177">generate code for
209 all functions pointed to by globals</a> immediately, before the program
210 started execution, but now it waits until the first time they are called to
211 compile them. This dramatically speeds up short runs of large C++ programs,
212 which often have large numbers of functions pointed to by vtables.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]213</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]214
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]215
216<!--=========================================================================-->
217<div class="doc_subsubsection">
218In this release, the following bugs in the previous release were fixed:
219</div>
220
221<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]222
223<ol>
Chris Lattnerf7100202003-10-27 05:41:39 +0000[diff] [blame]224<li><a href="http://llvm.cs.uiuc.edu/PR57">[inliner] Inlining invoke with PHI in unwind target is broken</a></li>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]225<li><a href="http://llvm.cs.uiuc.edu/PR58">[linker] linkonce globals should link successfully to external globals</a></li>
Chris Lattner32547fe2003-10-29 07:17:13 +0000[diff] [blame]226<li><a href="http://llvm.cs.uiuc.edu/PR64">[constmerge] Constant merging pass merges constants with external linkage</a></li>
Chris Lattner34790e52003-10-29 18:49:14 +0000[diff] [blame]227<li><a href="http://llvm.cs.uiuc.edu/PR66">[scalarrepl] Scalar Replacement of aggregates is decimating structures it shouldn't be</a></li>
Chris Lattner36bd5d12003-10-30 01:20:42 +0000[diff] [blame]228<li><a href="http://llvm.cs.uiuc.edu/PR70">[instcombine] Resolving invoke inserts cast after terminator</a></li>
Chris Lattnerf9e8a0f2003-10-30 01:43:33 +0000[diff] [blame]229<li><a href="http://llvm.cs.uiuc.edu/PR71">llvm-as crashes when labels are used in phi nodes</a></li>
Chris Lattner3dcc7b92003-10-30 16:20:15 +0000[diff] [blame]230<li><a href="http://llvm.cs.uiuc.edu/PR72">[build problem] Callgraph.cpp not pulled in from libipa.a</a></li>
Chris Lattner3af47222003-11-16 22:11:42 +0000[diff] [blame]231<li><a href="http://llvm.cs.uiuc.edu/PR77">Variables in scope of output setjmp
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]232calls should be volatile</a> (Note that this does not effect correctness on
233many platforms, such as X86).</li>
Chris Lattner2fb1ef82003-11-03 20:08:08 +0000[diff] [blame]234<li><a href="http://llvm.cs.uiuc.edu/PR83">[X86] Emission of global bool initializers broken</a></li>
Chris Lattnerde3bb572003-11-05 06:30:04 +0000[diff] [blame]235<li><a href="http://llvm.cs.uiuc.edu/PR91">[gccld] The -r (relinking) option does not work correctly</a></li>
Chris Lattner5b3fb032003-11-07 04:46:56 +0000[diff] [blame]236<li><a href="http://llvm.cs.uiuc.edu/PR92">[bcreader] Cannot read shift constant expressions from bytecode file</a></li>
237<li><a href="http://llvm.cs.uiuc.edu/PR93">[lowersetjmp] Lowersetjmp pass breaks dominance properties!</a></li>
Chris Lattner11dde852003-11-09 19:44:07 +0000[diff] [blame]238<li><a href="http://llvm.cs.uiuc.edu/PR95">SymbolTable::getUniqueName is very inefficient</a></li>
Brian Gaekea6ffa542003-12-11 04:40:58 +0000[diff] [blame]239<li><a href="http://llvm.cs.uiuc.edu/PR97">bugpoint must not pass -R&lt;directory&gt; to Mach-O linker</a></li>
Chris Lattner5b3fb032003-11-07 04:46:56 +0000[diff] [blame]240<li><a href="http://llvm.cs.uiuc.edu/PR98">[buildscripts] Building into objdir with .o in it fails</a></li>
Chris Lattner7af4d5e2003-11-08 05:18:50 +0000[diff] [blame]241<li><a href="http://llvm.cs.uiuc.edu/PR101">[setjmp/longjmp] Linking C programs which use setjmp/longjmp sometimes fail with references to the C++ runtime library!</a></li>
Chris Lattner9b29bde2003-11-12 04:42:37 +0000[diff] [blame]242<li><a href="http://llvm.cs.uiuc.edu/PR107">AsmParser Misses Symbol Redefinition Error</a></li>
Brian Gaeke78792062003-11-11 21:52:34 +0000[diff] [blame]243<li><a href="http://llvm.cs.uiuc.edu/PR108">gccld -Lfoo -lfoo fails to find ./foo/libfoo.a</a></li>
Chris Lattner6e4046f2003-11-14 06:42:01 +0000[diff] [blame]244<li><a href="http://llvm.cs.uiuc.edu/PR110">[bcreader] Incorrect cast causes misread forward constant references</a></li>
Chris Lattner5edc1bb2003-11-16 21:42:48 +0000[diff] [blame]245<li><a href="http://llvm.cs.uiuc.edu/PR116">[adce] ADCE considers blocks without postdominators to be unreachable</a></li>
Chris Lattner43a54cc2003-11-18 23:04:02 +0000[diff] [blame]246<li><a href="http://llvm.cs.uiuc.edu/PR123">[X86] div and rem constant exprs invalidate iterators!</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]247<li><a href="http://llvm.cs.uiuc.edu/PR130">[vmcore] Symbol table doesn't rename colliding variables during type resolution</a></li>
Brian Gaekea6ffa542003-12-11 04:40:58 +0000[diff] [blame]248<li><a href="http://llvm.cs.uiuc.edu/PR138">Archive reader does not understand 4.4BSD/Mac OS X long filenames</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]249<li><a href="http://llvm.cs.uiuc.edu/PR140">gccld produces a runner script that includes command-line options to load the necessary shared objects</a></li>
250</ol>
251
252
253<p>Bugs in the C/C++ front-end:</p>
254
255<ol>
256<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
257<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
258<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
259<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
260<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
261<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
262<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
263<li><a href="http://llvm.cs.uiuc.edu/PR79">llvm-gcc crashes compiling global union initializer</a></li>
264<li><a href="http://llvm.cs.uiuc.edu/PR80">C front-end crash on empty structure</a></li>
265<li><a href="http://llvm.cs.uiuc.edu/PR81">CFrontend crashes when compiling C99 compound expressions</a></li>
266<li><a href="http://llvm.cs.uiuc.edu/PR87">llvm-gcc infinite loops on "case MAXINT:"</a></li>
267<li><a href="http://llvm.cs.uiuc.edu/PR89">[C++] Catch blocks make unparsable labels</a></li>
268<li><a href="http://llvm.cs.uiuc.edu/PR90">[C++] Initializing array with constructable objects fail</a></li>
269<li><a href="http://llvm.cs.uiuc.edu/PR94">llvm-gcc tries to add bools</a></li>
270<li><a href="http://llvm.cs.uiuc.edu/PR104">[c++] C++ Frontend lays out superclasses like anonymous bitfields!</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR54">C front-end miscompiles unsigned enums whose LLVM types are signed</a></li>
272<li><a href="http://llvm.cs.uiuc.edu/PR112">Casting a string constant to void crashes llvm-gcc</a></li>
Chris Lattner43a54cc2003-11-18 23:04:02 +0000[diff] [blame]273<li><a href="http://llvm.cs.uiuc.edu/PR125">[llvmg++] Enum types are incorrectly shrunk to smaller than 'int' size</a></li>
274<li><a href="http://llvm.cs.uiuc.edu/PR128">[llvmg++] Cannot use pointer to member to initialize global</a></li>
Chris Lattner6ff1a922003-11-19 01:08:24 +0000[diff] [blame]275<li><a href="http://llvm.cs.uiuc.edu/PR131">[llvm-gcc] ?: operator as lvalue not implemented</a></li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]276<li><a href="http://llvm.cs.uiuc.edu/PR133">[C/C++] Bogus warning about taking the address of 'register' variable</a></li>
Chris Lattner18c4d852003-11-20 01:07:41 +0000[diff] [blame]277<li><a href="http://llvm.cs.uiuc.edu/PR113">crash assigning into an array in a struct which contains a bitfield</a>.</li>
278<li><a href="http://llvm.cs.uiuc.edu/PR6">Oversized integer bitfields cause crash</a></li>
Chris Lattnerf7330732003-11-26 08:20:34 +0000[diff] [blame]279<li><a href="http://llvm.cs.uiuc.edu/PR141">[llvm-gcc] Bitfields &amp; large array don't mix well</a></li>
Chris Lattner6c024c4b2003-11-20 19:30:17 +0000[diff] [blame]280<li><a href="http://llvm.cs.uiuc.edu/PR132">[llvm-gcc] Complex division is not supported</a></li>
Chris Lattner5f36ebe2003-11-20 20:59:57 +0000[diff] [blame]281<li><a href="http://llvm.cs.uiuc.edu/PR143">[llvm-gcc] Illegal union field reference</a></li>
Chris Lattner38eeb152003-11-25 08:49:12 +0000[diff] [blame]282<li><a href="http://llvm.cs.uiuc.edu/PR148">[llvmg++] Front-end attempts to return structure by value</a></li>
Chris Lattner676c2552003-11-26 01:18:49 +0000[diff] [blame]283<li><a href="http://llvm.cs.uiuc.edu/PR152">[llvmg++] Pointer to member initializers not supported in constructors</a></li>
284<li><a href="http://llvm.cs.uiuc.edu/PR155">[llvm-gcc] crash on union initialization</a></li>
Chris Lattner5b266582003-11-26 02:48:00 +0000[diff] [blame]285<li><a href="http://llvm.cs.uiuc.edu/PR124">[llvm-g++] ?: expressions do not run correct number of destructors!</a></li>
Chris Lattnerf7330732003-11-26 08:20:34 +0000[diff] [blame]286<li><a href="http://llvm.cs.uiuc.edu/PR157">[llvm-gcc] Pointer & constant results in invalid shift</a></li>
Chris Lattner296b2e62003-12-08 06:33:19 +0000[diff] [blame]287<li><a href="http://llvm.cs.uiuc.edu/PR165">[llvmg++] call through array of pointers to member functions causes assertion</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]288</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]289
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]290</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]291
292<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]293<div class="doc_section">
294 <a name="portability">Portability and Supported Platforms</a>
295</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]296<!-- *********************************************************************** -->
297
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]298<div class="doc_text">
299
300<p>LLVM has been extensively tested on Intel and AMD machines running Red
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]301Hat Linux, and Sun UltraSPARC workstations running Solaris 8. Additionally,
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]302LLVM works on Mac OS/X 10.3 and above, but only with the C backend or
303interpreter (no native backend for the PowerPC is available yet).
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]304The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]305work on more platforms than that. However, it is likely that we
306missed something, and that minor porting is required to get LLVM to work on
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]307new platforms. We welcome portability patches and error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]308
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]309</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]310
311<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]312<div class="doc_section">
313 <a name="knownproblems">Known Problems</a>
314</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]315<!-- *********************************************************************** -->
316
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]317<div class="doc_text">
318
319<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]320component. As new problems are discovered, they will be added to these
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]321sections.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]322
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]323</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]324
325<!-- _______________________________________________________________________ -->
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]326<!--
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]327</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]328-->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]329
330
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]331<!-- ======================================================================= -->
332<div class="doc_subsection">
333 <a name="core">Known problems with the LLVM Core</a>
334</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]335
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]336<div class="doc_text">
337
338<ul>
339
340<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
341work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]342
343<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]344such, execution of a threaded program could cause these data structures to be
345corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]346
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]347<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]348
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]349<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]350table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]351
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]352<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]353more than 256 elements</a>.</li>
354
355</ul>
356
357</div>
358
359<!-- ======================================================================= -->
360<div class="doc_subsection">
361 <a name="c-fe">Known problems with the C front-end</a>
362</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]363
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]364<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]365<div class="doc_subsubsection">
366 Bugs
367</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]368
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]369<div class="doc_text">
370
371<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]372
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]373<li>C99 Variable sized arrays do not release stack memory when they go out of
374 scope. Thus, the following program may run out of stack space:
375<pre>
376 for (i = 0; i != 1000000; ++i) {
377 int X[n];
378 foo(X);
379 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]380</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]381
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]382</ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]383
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]384</div>
385
386<!-- _______________________________________________________________________ -->
387<div class="doc_subsubsection">
388 Notes
389</div>
390
391<div class="doc_text">
392
393<ul>
394
395<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]396
397<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]398support for floating point data types of any size other than 32 and 64
399bits.</li>
400
401<li>The following Unix system functionality has not been tested and may not
402work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]403 <ol>
404 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
405 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
406 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
407 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
408 - These functions have not been tested.
409 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]410
411<li>Although many GCC extensions are supported, some are not. In particular,
412 the following extensions are known to <b>not be</b> supported:
413 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]414 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
415 <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>
416 <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>
417 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
418 <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>
419 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
420 <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>
421 <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>
422 <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>
423 <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>
424 <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>
425 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
426 <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]427 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]428
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]429 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]430 attribute means that the LLVM compiler ignores the presence of the attribute,
431 but the code should still work. An unsupported attribute is one which is
432 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]433 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]434
435 <ol>
436 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
437 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]438 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]439
440 <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]441
442 Declaring that functions have no side effects, or that they can never
443 return.<br>
444
445 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
446 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
447 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
448
449 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
450 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
451 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
452
453 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
454 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
455 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]456
457 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
458 Specifying attributes of variables.<br>
459 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
460 <tt>deprecated</tt>, <tt>transparent_union</tt>,
461 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]462
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]463 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
464 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
465 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]466 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]467
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]468 <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]469 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]470 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]471
472 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
473 all target specific attributes.</li>
474
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
476 Other built-in functions.<br>
477 We support all builtins which have a C language equivalent (e.g.,
478 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
479 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]480 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]481
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]482 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]483
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]484 <p>The following extensions <b>are</b> known to be supported:</p>
485
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]486 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]487 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
488 <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>
489 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
490 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
491 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
492 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
493 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
494 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
495 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
496 <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>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
498 <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]499 <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]500 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
501 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions or arrays as values.</li>
502 <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]503 <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]504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
505 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
506 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
508 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
509 <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>
510 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
511 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
512 <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>
513 <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>
514 <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>
515 <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>
516 <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]517 </ol></li>
518
519</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]520
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]521<p>If you run into GCC extensions which have not been included in any of these
522lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]523
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]524</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]525
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]526<!-- ======================================================================= -->
527<div class="doc_subsection">
528 <a name="c++-fe">Known problems with the C++ front-end</a>
529</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]531<div class="doc_text">
532
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]533<p>For this release, the C++ front-end is considered to be fully functional, but
534has not been tested as thoroughly as the C front-end. It has been tested and
535works for a number of non-trivial programs, but there may be lurking bugs.
536Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]537
538</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]539
540<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]541<div class="doc_subsubsection">
542 Bugs
543</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]544
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]545<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]546
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]547<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]548<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]549 front-end</a></li>
550</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]551
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]552</div>
553
554<!-- _______________________________________________________________________ -->
555<div class="doc_subsubsection">
556 Notes
557</div>
558
559<div class="doc_text">
560
561<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]562
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]563<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
564parser is significantly more standards compliant (and picky) than prior GCC
565versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]566href="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]567
568<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]569 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]570 function and in the <tt>setjmp</tt> receiver function may not be run.
571 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]572 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]573
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]574<li>The LLVM C++ front-end follows the <a
575 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
576 This document, which is not Itanium specific, specifies a standard for name
577 mangling, class layout, v-table layout, RTTI formats, and other C++
578 representation issues. Because we use this API, code generated by the LLVM
579 compilers should be binary compatible with machine code generated by other
580 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
581 <i>However</i>, the exception handling mechanism used by LLVM is very
582 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]583 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]584
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]585</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +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="x86-be">Known problems with the X86 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
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]598<li>The X86 code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]599href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]600support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]601or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]602
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]603</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]604
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]605</div>
606
607<!-- ======================================================================= -->
608<div class="doc_subsection">
609 <a name="sparc-be">Known problems with the Sparc back-end</a>
610</div>
611
612<div class="doc_text">
613
614<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]615
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]616<li>The Sparc code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]617href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]618support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]620
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]621</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]622
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]623</div>
624
625<!-- ======================================================================= -->
626<div class="doc_subsection">
627 <a name="c-be">Known problems with the C back-end</a>
628</div>
629
630<div class="doc_text">
631
632<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]633
634<li>The C back-end produces code that violates the ANSI C Type-Based Alias
635Analysis rules. As such, special options may be necessary to compile the code
636(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]637problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]638
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]639<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]640cannot include special floating point numbers like Not-A-Number or
641Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]642
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]643<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]644supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]645frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]646
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]648
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]649</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]650
651<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]652<div class="doc_section">
653 <a name="additionalinfo">Additional Information</a>
654</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]655<!-- *********************************************************************** -->
656
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]657<div class="doc_text">
658
659<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]660including mailing lists publications describing algorithms and components
661implemented in LLVM. The web page also contains versions of the API
662documentation which is up-to-date with the CVS version of the source code. You
663can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]664the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]665
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]666<p>If you have any questions or comments about LLVM, please feel free to contact
667us via the mailing lists.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]668
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]669</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]670
671<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]672
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]673<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]674<address>
675 <a href="http://jigsaw.w3.org/css-validator/"><img
676 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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679
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]680 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]681 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]682</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]683
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]684</body>
685</html>