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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 5eccca4f20a1a8ddfa9b13b139fedb24e4708b8c / . / docs / ReleaseNotes.html
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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
John Criswellbb1bad52003-12-12 19:54:20 +0000[diff] [blame]78front-end, and improvements in 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
John Criswellbb1bad52003-12-12 19:54:20 +0000[diff] [blame]81benchmarks with the C backend (X86 only), the Olden benchmarks, and the Ptrdist
82benchmarks. It has also been used to compile
83<b>many</b> other programs. LLVM now also works with a broad variety of
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]84C++ programs, though it has still received much less testing than the C
85front-end.
86</p>
87
88<p>
89Note that the Sparc and X86 backends do not currently support exception throwing
90or long jumping (including 253.perlbmk in SPEC). For these programs, you must
91use the C backend. Support for unwinding will be added in a future release.
92</p>
93
94
95<!--=========================================================================-->
96<div class="doc_subsubsection">
97This release implements the following new features:
98</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]99
100<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]101<li><a
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]102href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000528.html">A new
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]103LLVM profiler, similar to gprof</a> is available</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]104
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]105<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]106now explore the LLVM optimizer with the C backend and interpreter. Note that
107LLVM requires GCC 3.3 on Mac OS/X.</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]108
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]109<li>LLVM has been <a
Chris Lattner2a77f2d2003-11-11 23:46:35 +0000[diff] [blame]110href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000554.html">moved
111into an 'llvm' C++ namespace</a>, for easier integration with third-party
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]112code. Note that due to lack of namespace support in GDB 5.x, you will probably
113want to upgrade to GDB 6 or better to debug LLVM code.</li>
John Criswellf2ec35b2003-11-26 20:09:49 +0000[diff] [blame]114
115<li>
116The build system now copies Makefiles dynamically from the source tree to the
117object tree as subdirectories are built. This means that:
118 <ol>
119 <li>
120 New directories can be added to the source tree, and the build will
121 automatically pick them up (i.e. no need to re-run <tt>configure</tt>).
122 </li>
123
124 <li>
125 You will need to build LLVM from the top of the object tree once to ensure
126 that all of the Makefiles are copied into the object tree subdirectories.
127 </li>
128 </ol>
129</li>
130
Chris Lattner3b368c72003-12-12 04:45:09 +0000[diff] [blame]131<li>A front-end for "Stacker" (a simple Forth-like language) is now
132 <a href="http://llvm.cs.uiuc.edu/PR136">included in the main LLVM tree</a>.
133 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>
134
Chris Lattner2d9d4e72003-12-11 23:31:21 +0000[diff] [blame]135<li>The <tt>configure</tt> script will now configure all projects placed in the
136<tt>llvm/projects</tt> directory.</li>
137
Chris Lattner287c9e62003-12-12 04:51:00 +0000[diff] [blame]138<li>The <tt>-tailcallelim</tt> pass can now introduce "accumulator" variables
139 to transform functions in many common cases that it could not before.</li>
140
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]141<li>The <tt>-licm</tt> pass can now sink instructions out the bottom of loops
142in addition to being able to hoist them out the top.</li>
143
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]144<li>The <tt>-basicaa</tt> pass (the default alias analysis) has been upgraded
145to be <a href="http://llvm.cs.uiuc.edu/PR86">significantly more
146precise</a>.</li>
Chris Lattner2d9d4e72003-12-11 23:31:21 +0000[diff] [blame]147
Chris Lattner8c1237e2003-12-12 05:52:39 +0000[diff] [blame]148<li>LLVM 1.1 implements a simple size optimization for LLVM bytecode files.
149 This means that the 1.1 files are smaller than 1.0, but that 1.0 won't
150 read 1.1 bytecode files.</li>
John Criswellbb1bad52003-12-12 19:54:20 +0000[diff] [blame]151
152<li><a href="http://llvm.cs.uiuc.edu/PR140">The gccld program produces a runner script that includes command-line options to load the necessary shared objects.</a></li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]153</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]154
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]155
156<!--=========================================================================-->
157<div class="doc_subsubsection">
158In this release, the following missing features were implemented:
159</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]160
161<ol>
162<li><a href="http://llvm.cs.uiuc.edu/PR88">The interpreter does not support
163invoke or unwind</a></li>
Misha Brukmanc99037d2003-11-14 03:30:43 +0000[diff] [blame]164
165<li><a href="http://llvm.cs.uiuc.edu/PR99">Interpreter does not support the
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]166<tt>vaarg</tt> instruction</a></li>
Misha Brukmanc99037d2003-11-14 03:30:43 +0000[diff] [blame]167
Brian Gaekeb7508ee2003-11-16 23:49:26 +0000[diff] [blame]168<li><a href="http://llvm.cs.uiuc.edu/PR117">llvm-nm cannot read archive
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]169files</a></li>
Brian Gaekeb7508ee2003-11-16 23:49:26 +0000[diff] [blame]170
Brian Gaekea6ffa542003-12-11 04:40:58 +0000[diff] [blame]171<li><a href="http://llvm.cs.uiuc.edu/PR146">Interpreter does not handle
172setne constant expression</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]173</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]174
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]175
176<!--=========================================================================-->
177<div class="doc_subsubsection">
178In this release, the following Quality of Implementation issues were
179fixed:
180</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]181
182<ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]183
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]184<li>The C++ front-end now compiles functions to
185 <a href="http://llvm.cs.uiuc.edu/PR29">use the linkonce linkage type</a>
186 more, giving the optimizer more freedom.</a></li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]187
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]188<li>The C front-end now <a href="http://llvm.cs.uiuc.edu/PR84">generates
189 type-safe code</a> in several cases that it did not before, which prevented
190 some important optimizations.</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]191
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]192<li>The LLVM build system has been taught to catch some common configuration
193 problems that <a href="http://llvm.cs.uiuc.edu/PR96">caused it to get
194 horribly confused</a> before.</li>
Chris Lattnerba46d552003-11-16 20:25:24 +0000[diff] [blame]195
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]196<li>The LLVM header files are now
197 <a href="http://llvm.cs.uiuc.edu/PR114">-Wold-style-cast clean</a>.</li>
Chris Lattnerba46d552003-11-16 20:25:24 +0000[diff] [blame]198
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]199<li>The LLVM bytecode reader has been <a
200href="http://llvm.cs.uiuc.edu/PR127">sped up a lot</a> (up to 4x in some
201cases).</li>
202
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]203<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]204
Chris Lattnerf7330732003-11-26 08:20:34 +0000[diff] [blame]205<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>
206
Chris Lattner3074b342003-11-27 09:51:54 +0000[diff] [blame]207<li>Code for running C++ destructors is now properly shared when possible. Before, the C++ front-end
208<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]209
210<li>The JIT used to <a href="http://llvm.cs.uiuc.edu/PR177">generate code for
211 all functions pointed to by globals</a> immediately, before the program
212 started execution, but now it waits until the first time they are called to
213 compile them. This dramatically speeds up short runs of large C++ programs,
214 which often have large numbers of functions pointed to by vtables.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]215</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]216
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]217
218<!--=========================================================================-->
219<div class="doc_subsubsection">
220In this release, the following bugs in the previous release were fixed:
221</div>
222
223<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]224
225<ol>
Chris Lattnerf7100202003-10-27 05:41:39 +0000[diff] [blame]226<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]227<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]228<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]229<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]230<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]231<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]232<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]233<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]234calls should be volatile</a> (Note that this does not effect correctness on
235many platforms, such as X86).</li>
Chris Lattner2fb1ef82003-11-03 20:08:08 +0000[diff] [blame]236<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]237<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]238<li><a href="http://llvm.cs.uiuc.edu/PR92">[bcreader] Cannot read shift constant expressions from bytecode file</a></li>
239<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]240<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]241<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]242<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]243<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]244<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]245<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]246<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]247<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]248<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]249<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]250<li><a href="http://llvm.cs.uiuc.edu/PR138">Archive reader does not understand 4.4BSD/Mac OS X long filenames</a></li>
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame^]251<li><a href="http://llvm.cs.uiuc.edu/PR30">[llvm-ar] Command line arguments have funny syntax</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]252</ol>
253
254
255<p>Bugs in the C/C++ front-end:</p>
256
257<ol>
258<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
259<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
260<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
261<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
262<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
263<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
264<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
265<li><a href="http://llvm.cs.uiuc.edu/PR79">llvm-gcc crashes compiling global union initializer</a></li>
266<li><a href="http://llvm.cs.uiuc.edu/PR80">C front-end crash on empty structure</a></li>
267<li><a href="http://llvm.cs.uiuc.edu/PR81">CFrontend crashes when compiling C99 compound expressions</a></li>
268<li><a href="http://llvm.cs.uiuc.edu/PR87">llvm-gcc infinite loops on "case MAXINT:"</a></li>
269<li><a href="http://llvm.cs.uiuc.edu/PR89">[C++] Catch blocks make unparsable labels</a></li>
270<li><a href="http://llvm.cs.uiuc.edu/PR90">[C++] Initializing array with constructable objects fail</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR94">llvm-gcc tries to add bools</a></li>
272<li><a href="http://llvm.cs.uiuc.edu/PR104">[c++] C++ Frontend lays out superclasses like anonymous bitfields!</a></li>
273<li><a href="http://llvm.cs.uiuc.edu/PR54">C front-end miscompiles unsigned enums whose LLVM types are signed</a></li>
274<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]275<li><a href="http://llvm.cs.uiuc.edu/PR125">[llvmg++] Enum types are incorrectly shrunk to smaller than 'int' size</a></li>
276<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]277<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]278<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]279<li><a href="http://llvm.cs.uiuc.edu/PR113">crash assigning into an array in a struct which contains a bitfield</a>.</li>
280<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]281<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]282<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]283<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]284<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]285<li><a href="http://llvm.cs.uiuc.edu/PR152">[llvmg++] Pointer to member initializers not supported in constructors</a></li>
286<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]287<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]288<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]289<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]290</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]291
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]292</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]293
294<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]295<div class="doc_section">
296 <a name="portability">Portability and Supported Platforms</a>
297</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]298<!-- *********************************************************************** -->
299
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]300<div class="doc_text">
301
302<p>LLVM has been extensively tested on Intel and AMD machines running Red
John Criswellbb1bad52003-12-12 19:54:20 +0000[diff] [blame]303Hat Linux and has been tested on Sun UltraSPARC workstations running Solaris 8.
304Additionally,
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]305LLVM works on Mac OS/X 10.3 and above, but only with the C backend or
306interpreter (no native backend for the PowerPC is available yet).
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]307The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]308work on more platforms than that. However, it is likely that we
309missed something, and that minor porting is required to get LLVM to work on
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]310new platforms. We welcome portability patches and error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]311
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]312</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]313
314<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]315<div class="doc_section">
316 <a name="knownproblems">Known Problems</a>
317</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]318<!-- *********************************************************************** -->
319
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]320<div class="doc_text">
321
322<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]323component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame^]324sections. If you run into a problem, please check the <a
325href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a>, and submit a bug if
326there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]327
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]328</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]329
330<!-- _______________________________________________________________________ -->
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]331<!--
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]332</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]333-->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]334
335
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]336<!-- ======================================================================= -->
337<div class="doc_subsection">
338 <a name="core">Known problems with the LLVM Core</a>
339</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]340
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]341<div class="doc_text">
342
343<ul>
344
345<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
346work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]347
348<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]349such, execution of a threaded program could cause these data structures to be
350corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]351
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]352<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]353
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]354<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]355table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]356
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]357<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]358more than 256 elements</a>.</li>
359
360</ul>
361
362</div>
363
364<!-- ======================================================================= -->
365<div class="doc_subsection">
366 <a name="c-fe">Known problems with the C front-end</a>
367</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]368
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]369<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]370<div class="doc_subsubsection">
371 Bugs
372</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]373
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]374<div class="doc_text">
375
376<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]377
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]378<li>C99 Variable sized arrays do not release stack memory when they go out of
379 scope. Thus, the following program may run out of stack space:
380<pre>
381 for (i = 0; i != 1000000; ++i) {
382 int X[n];
383 foo(X);
384 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]385</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]386
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]387</ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]388
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]389</div>
390
391<!-- _______________________________________________________________________ -->
392<div class="doc_subsubsection">
393 Notes
394</div>
395
396<div class="doc_text">
397
398<ul>
399
400<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]401
402<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]403support for floating point data types of any size other than 32 and 64
404bits.</li>
405
406<li>The following Unix system functionality has not been tested and may not
407work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]408 <ol>
409 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
410 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
411 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
412 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
413 - These functions have not been tested.
414 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]415
416<li>Although many GCC extensions are supported, some are not. In particular,
417 the following extensions are known to <b>not be</b> supported:
418 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]419 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
420 <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>
421 <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>
422 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
423 <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>
424 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
425 <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>
426 <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>
427 <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>
428 <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>
429 <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>
430 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
431 <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]432 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]433
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]434 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]435 attribute means that the LLVM compiler ignores the presence of the attribute,
436 but the code should still work. An unsupported attribute is one which is
437 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]438 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]439
440 <ol>
441 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
442 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]443 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]444
445 <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]446
447 Declaring that functions have no side effects, or that they can never
448 return.<br>
449
450 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
451 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
452 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
453
454 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
455 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
456 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
457
458 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
459 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
460 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]461
462 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
463 Specifying attributes of variables.<br>
464 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
465 <tt>deprecated</tt>, <tt>transparent_union</tt>,
466 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]467
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]468 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
469 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
470 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]471 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]472
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]473 <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]474 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]475 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]476
477 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
478 all target specific attributes.</li>
479
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]480 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
481 Other built-in functions.<br>
482 We support all builtins which have a C language equivalent (e.g.,
483 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
484 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]485 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]486
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]487 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]488
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]489 <p>The following extensions <b>are</b> known to be supported:</p>
490
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]491 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]492 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
493 <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>
494 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
495 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
498 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
500 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
501 <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>
502 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
503 <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]504 <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]505 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
506 <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>
507 <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]508 <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]509 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
510 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
511 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
514 <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>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
517 <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>
518 <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>
519 <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>
520 <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>
521 <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]522 </ol></li>
523
524</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]525
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]526<p>If you run into GCC extensions which have not been included in any of these
527lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]528
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]529</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]531<!-- ======================================================================= -->
532<div class="doc_subsection">
533 <a name="c++-fe">Known problems with the C++ front-end</a>
534</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]535
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]536<div class="doc_text">
537
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]538<p>For this release, the C++ front-end is considered to be fully functional, but
539has not been tested as thoroughly as the C front-end. It has been tested and
540works for a number of non-trivial programs, but there may be lurking bugs.
541Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]542
543</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]544
545<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]546<div class="doc_subsubsection">
547 Bugs
548</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]549
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]550<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]551
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]552<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]553<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]554 front-end</a></li>
555</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]556
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]557</div>
558
559<!-- _______________________________________________________________________ -->
560<div class="doc_subsubsection">
561 Notes
562</div>
563
564<div class="doc_text">
565
566<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]567
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]568<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
569parser is significantly more standards compliant (and picky) than prior GCC
570versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]571href="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]572
573<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]574 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]575 function and in the <tt>setjmp</tt> receiver function may not be run.
576 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]577 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]578
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]579<li>The LLVM C++ front-end follows the <a
580 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
581 This document, which is not Itanium specific, specifies a standard for name
582 mangling, class layout, v-table layout, RTTI formats, and other C++
583 representation issues. Because we use this API, code generated by the LLVM
584 compilers should be binary compatible with machine code generated by other
585 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
586 <i>However</i>, the exception handling mechanism used by LLVM is very
587 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]588 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]589
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]590</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]591
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]592</div>
593
594<!-- ======================================================================= -->
595<div class="doc_subsection">
596 <a name="x86-be">Known problems with the X86 back-end</a>
597</div>
598
599<div class="doc_text">
600
601<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]602
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]603<li>The X86 code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]604href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]605support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]606or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]607
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]608</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]609
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]610</div>
611
612<!-- ======================================================================= -->
613<div class="doc_subsection">
614 <a name="sparc-be">Known problems with the Sparc back-end</a>
615</div>
616
617<div class="doc_text">
618
619<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]620
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]621<li>The Sparc code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]622href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]623support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]624or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]625
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]626</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]627
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]628</div>
629
630<!-- ======================================================================= -->
631<div class="doc_subsection">
632 <a name="c-be">Known problems with the C back-end</a>
633</div>
634
635<div class="doc_text">
636
637<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]638
639<li>The C back-end produces code that violates the ANSI C Type-Based Alias
640Analysis rules. As such, special options may be necessary to compile the code
641(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]642problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]643
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]644<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]645cannot include special floating point numbers like Not-A-Number or
646Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]647
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]648<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]649supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]650frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]651
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]652</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]653
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]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_section">
658 <a name="additionalinfo">Additional Information</a>
659</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]660<!-- *********************************************************************** -->
661
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]662<div class="doc_text">
663
664<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]665including mailing lists publications describing algorithms and components
666implemented in LLVM. The web page also contains versions of the API
667documentation which is up-to-date with the CVS version of the source code. You
668can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]669the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]670
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]671<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^]672us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
673lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]674
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]675</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]676
677<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]678
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]679<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]680<address>
681 <a href="http://jigsaw.w3.org/css-validator/"><img
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685
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]686 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]687 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]688</address>
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Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]690</body>
691</html>