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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 1124e2caef51ca440b796273999f8252ff9fbbec / . / 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 Lattner1124e2c2003-12-12 21:33:08 +0000[diff] [blame^]80<p>At this time, LLVM is known to correctly compile and run all non-unwinding C
81&amp; C++ SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist
82benchmarks. It has also been used to compile <b>many</b> other programs. LLVM
83now also works with a broad variety of C++ programs, though it has still
84received much less testing than the C front-end.
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]85</p>
86
87<p>
Chris Lattner1124e2c2003-12-12 21:33:08 +0000[diff] [blame^]88The LLVM native code generators are very stable, but do not currently support
89unwinding (exception throwing or <tt>longjmp</tt>ing), which prevent them from
90working with programs like the <tt>253.perlbmk</tt> in SPEC CPU2000. The C
91backend and the rest of LLVM does support these programs however, so you can
92still use LLVM with them. Support for unwinding will be added in a future
93release.
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]94</p>
95
96
97<!--=========================================================================-->
98<div class="doc_subsubsection">
99This release implements the following new features:
100</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]101
102<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]103<li><a
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]104href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000528.html">A new
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]105LLVM profiler, similar to gprof</a> is available</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]106
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]107<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]108now explore the LLVM optimizer with the C backend and interpreter. Note that
109LLVM requires GCC 3.3 on Mac OS/X.</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]110
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]111<li>LLVM has been <a
Chris Lattner2a77f2d2003-11-11 23:46:35 +0000[diff] [blame]112href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000554.html">moved
113into an 'llvm' C++ namespace</a>, for easier integration with third-party
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]114code. Note that due to lack of namespace support in GDB 5.x, you will probably
115want to upgrade to GDB 6 or better to debug LLVM code.</li>
John Criswellf2ec35b2003-11-26 20:09:49 +0000[diff] [blame]116
117<li>
118The build system now copies Makefiles dynamically from the source tree to the
119object tree as subdirectories are built. This means that:
120 <ol>
121 <li>
122 New directories can be added to the source tree, and the build will
123 automatically pick them up (i.e. no need to re-run <tt>configure</tt>).
124 </li>
125
126 <li>
127 You will need to build LLVM from the top of the object tree once to ensure
128 that all of the Makefiles are copied into the object tree subdirectories.
129 </li>
130 </ol>
131</li>
132
Chris Lattner3b368c72003-12-12 04:45:09 +0000[diff] [blame]133<li>A front-end for "Stacker" (a simple Forth-like language) is now
134 <a href="http://llvm.cs.uiuc.edu/PR136">included in the main LLVM tree</a>.
135 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>
136
Chris Lattner2d9d4e72003-12-11 23:31:21 +0000[diff] [blame]137<li>The <tt>configure</tt> script will now configure all projects placed in the
138<tt>llvm/projects</tt> directory.</li>
139
Chris Lattner287c9e62003-12-12 04:51:00 +0000[diff] [blame]140<li>The <tt>-tailcallelim</tt> pass can now introduce "accumulator" variables
141 to transform functions in many common cases that it could not before.</li>
142
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]143<li>The <tt>-licm</tt> pass can now sink instructions out the bottom of loops
144in addition to being able to hoist them out the top.</li>
145
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]146<li>The <tt>-basicaa</tt> pass (the default alias analysis) has been upgraded
147to be <a href="http://llvm.cs.uiuc.edu/PR86">significantly more
148precise</a>.</li>
Chris Lattner2d9d4e72003-12-11 23:31:21 +0000[diff] [blame]149
Chris Lattner8c1237e2003-12-12 05:52:39 +0000[diff] [blame]150<li>LLVM 1.1 implements a simple size optimization for LLVM bytecode files.
151 This means that the 1.1 files are smaller than 1.0, but that 1.0 won't
152 read 1.1 bytecode files.</li>
John Criswellbb1bad52003-12-12 19:54:20 +0000[diff] [blame]153
154<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]155</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]156
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]157
158<!--=========================================================================-->
159<div class="doc_subsubsection">
160In this release, the following missing features were implemented:
161</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]162
163<ol>
164<li><a href="http://llvm.cs.uiuc.edu/PR88">The interpreter does not support
165invoke or unwind</a></li>
Misha Brukmanc99037d2003-11-14 03:30:43 +0000[diff] [blame]166
167<li><a href="http://llvm.cs.uiuc.edu/PR99">Interpreter does not support the
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]168<tt>vaarg</tt> instruction</a></li>
Misha Brukmanc99037d2003-11-14 03:30:43 +0000[diff] [blame]169
Brian Gaekeb7508ee2003-11-16 23:49:26 +0000[diff] [blame]170<li><a href="http://llvm.cs.uiuc.edu/PR117">llvm-nm cannot read archive
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]171files</a></li>
Brian Gaekeb7508ee2003-11-16 23:49:26 +0000[diff] [blame]172
Brian Gaekea6ffa542003-12-11 04:40:58 +0000[diff] [blame]173<li><a href="http://llvm.cs.uiuc.edu/PR146">Interpreter does not handle
174setne constant expression</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]175</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]176
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]177
178<!--=========================================================================-->
179<div class="doc_subsubsection">
180In this release, the following Quality of Implementation issues were
181fixed:
182</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]183
184<ol>
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 compiles functions to
187 <a href="http://llvm.cs.uiuc.edu/PR29">use the linkonce linkage type</a>
188 more, giving the optimizer more freedom.</a></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 C front-end now <a href="http://llvm.cs.uiuc.edu/PR84">generates
191 type-safe code</a> in several cases that it did not before, which prevented
192 some important optimizations.</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]193
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]194<li>The LLVM build system has been taught to catch some common configuration
195 problems that <a href="http://llvm.cs.uiuc.edu/PR96">caused it to get
196 horribly confused</a> before.</li>
Chris Lattnerba46d552003-11-16 20:25:24 +0000[diff] [blame]197
Chris Lattner97e4acd2003-12-12 04:56:02 +0000[diff] [blame]198<li>The LLVM header files are now
199 <a href="http://llvm.cs.uiuc.edu/PR114">-Wold-style-cast clean</a>.</li>
Chris Lattnerba46d552003-11-16 20:25:24 +0000[diff] [blame]200
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]201<li>The LLVM bytecode reader has been <a
202href="http://llvm.cs.uiuc.edu/PR127">sped up a lot</a> (up to 4x in some
203cases).</li>
204
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]205<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]206
Chris Lattnerf7330732003-11-26 08:20:34 +0000[diff] [blame]207<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>
208
Chris Lattner3074b342003-11-27 09:51:54 +0000[diff] [blame]209<li>Code for running C++ destructors is now properly shared when possible. Before, the C++ front-end
210<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]211
212<li>The JIT used to <a href="http://llvm.cs.uiuc.edu/PR177">generate code for
213 all functions pointed to by globals</a> immediately, before the program
214 started execution, but now it waits until the first time they are called to
215 compile them. This dramatically speeds up short runs of large C++ programs,
216 which often have large numbers of functions pointed to by vtables.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]217</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]218
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]219
220<!--=========================================================================-->
221<div class="doc_subsubsection">
222In this release, the following bugs in the previous release were fixed:
223</div>
224
225<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]226
227<ol>
Chris Lattnerf7100202003-10-27 05:41:39 +0000[diff] [blame]228<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]229<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]230<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]231<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]232<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]233<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]234<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]235<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]236calls should be volatile</a> (Note that this does not effect correctness on
237many platforms, such as X86).</li>
Chris Lattner2fb1ef82003-11-03 20:08:08 +0000[diff] [blame]238<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]239<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]240<li><a href="http://llvm.cs.uiuc.edu/PR92">[bcreader] Cannot read shift constant expressions from bytecode file</a></li>
241<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]242<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]243<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]244<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]245<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]246<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]247<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]248<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]249<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]250<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]251<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]252<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]253<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]254</ol>
255
256
257<p>Bugs in the C/C++ front-end:</p>
258
259<ol>
260<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
261<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
262<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
263<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
264<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
265<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
266<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
267<li><a href="http://llvm.cs.uiuc.edu/PR79">llvm-gcc crashes compiling global union initializer</a></li>
268<li><a href="http://llvm.cs.uiuc.edu/PR80">C front-end crash on empty structure</a></li>
269<li><a href="http://llvm.cs.uiuc.edu/PR81">CFrontend crashes when compiling C99 compound expressions</a></li>
270<li><a href="http://llvm.cs.uiuc.edu/PR87">llvm-gcc infinite loops on "case MAXINT:"</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR89">[C++] Catch blocks make unparsable labels</a></li>
272<li><a href="http://llvm.cs.uiuc.edu/PR90">[C++] Initializing array with constructable objects fail</a></li>
273<li><a href="http://llvm.cs.uiuc.edu/PR94">llvm-gcc tries to add bools</a></li>
274<li><a href="http://llvm.cs.uiuc.edu/PR104">[c++] C++ Frontend lays out superclasses like anonymous bitfields!</a></li>
275<li><a href="http://llvm.cs.uiuc.edu/PR54">C front-end miscompiles unsigned enums whose LLVM types are signed</a></li>
276<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]277<li><a href="http://llvm.cs.uiuc.edu/PR125">[llvmg++] Enum types are incorrectly shrunk to smaller than 'int' size</a></li>
278<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]279<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]280<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]281<li><a href="http://llvm.cs.uiuc.edu/PR113">crash assigning into an array in a struct which contains a bitfield</a>.</li>
282<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]283<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]284<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]285<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]286<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]287<li><a href="http://llvm.cs.uiuc.edu/PR152">[llvmg++] Pointer to member initializers not supported in constructors</a></li>
288<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]289<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]290<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]291<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]292</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]293
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]294</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]295
296<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]297<div class="doc_section">
298 <a name="portability">Portability and Supported Platforms</a>
299</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]300<!-- *********************************************************************** -->
301
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]302<div class="doc_text">
303
304<p>LLVM has been extensively tested on Intel and AMD machines running Red
John Criswellbb1bad52003-12-12 19:54:20 +0000[diff] [blame]305Hat Linux and has been tested on Sun UltraSPARC workstations running Solaris 8.
306Additionally,
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]307LLVM works on Mac OS/X 10.3 and above, but only with the C backend or
308interpreter (no native backend for the PowerPC is available yet).
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]309The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]310work on more platforms than that. However, it is likely that we
311missed something, and that minor porting is required to get LLVM to work on
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]312new platforms. We welcome portability patches and error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]313
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]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_section">
318 <a name="knownproblems">Known Problems</a>
319</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]320<!-- *********************************************************************** -->
321
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]322<div class="doc_text">
323
324<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]325component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]326sections. If you run into a problem, please check the <a
327href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a>, and submit a bug if
328there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]329
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]330</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]331
332<!-- _______________________________________________________________________ -->
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]333<!--
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]334</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]335-->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]336
337
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]338<!-- ======================================================================= -->
339<div class="doc_subsection">
340 <a name="core">Known problems with the LLVM Core</a>
341</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]342
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]343<div class="doc_text">
344
345<ul>
346
347<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
348work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]349
350<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]351such, execution of a threaded program could cause these data structures to be
352corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]353
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]354<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]355
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]356<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]357table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]358
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]359<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]360more than 256 elements</a>.</li>
361
362</ul>
363
364</div>
365
366<!-- ======================================================================= -->
367<div class="doc_subsection">
368 <a name="c-fe">Known problems with the C front-end</a>
369</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]370
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]371<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]372<div class="doc_subsubsection">
373 Bugs
374</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]375
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]376<div class="doc_text">
377
378<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]379
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]380<li>C99 Variable sized arrays do not release stack memory when they go out of
381 scope. Thus, the following program may run out of stack space:
382<pre>
383 for (i = 0; i != 1000000; ++i) {
384 int X[n];
385 foo(X);
386 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]387</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]388
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]389</ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]390
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]391</div>
392
393<!-- _______________________________________________________________________ -->
394<div class="doc_subsubsection">
395 Notes
396</div>
397
398<div class="doc_text">
399
400<ul>
401
402<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]403
404<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]405support for floating point data types of any size other than 32 and 64
406bits.</li>
407
408<li>The following Unix system functionality has not been tested and may not
409work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]410 <ol>
411 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
412 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
413 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
414 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
415 - These functions have not been tested.
416 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]417
418<li>Although many GCC extensions are supported, some are not. In particular,
419 the following extensions are known to <b>not be</b> supported:
420 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]421 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
422 <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>
423 <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>
424 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
425 <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>
426 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
427 <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>
428 <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>
429 <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>
430 <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>
431 <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>
432 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
433 <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]434 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]435
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]436 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]437 attribute means that the LLVM compiler ignores the presence of the attribute,
438 but the code should still work. An unsupported attribute is one which is
439 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]440 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]441
442 <ol>
443 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
444 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]445 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]446
447 <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]448
449 Declaring that functions have no side effects, or that they can never
450 return.<br>
451
452 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
453 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
454 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
455
456 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
457 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
458 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
459
460 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
461 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
462 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]463
464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
465 Specifying attributes of variables.<br>
466 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
467 <tt>deprecated</tt>, <tt>transparent_union</tt>,
468 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]469
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]470 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
471 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
472 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]473 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]474
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]475 <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]476 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]477 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]478
479 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
480 all target specific attributes.</li>
481
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
483 Other built-in functions.<br>
484 We support all builtins which have a C language equivalent (e.g.,
485 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
486 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]487 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]488
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]489 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]490
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]491 <p>The following extensions <b>are</b> known to be supported:</p>
492
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]493 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]494 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
495 <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>
496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
498 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
500 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
501 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
502 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
503 <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>
504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
505 <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]506 <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]507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
508 <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>
509 <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]510 <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]511 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
516 <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>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
518 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
519 <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>
520 <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>
521 <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>
522 <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>
523 <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]524 </ol></li>
525
526</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]527
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]528<p>If you run into GCC extensions which have not been included in any of these
529lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]531</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533<!-- ======================================================================= -->
534<div class="doc_subsection">
535 <a name="c++-fe">Known problems with the C++ front-end</a>
536</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]537
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]538<div class="doc_text">
539
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]540<p>For this release, the C++ front-end is considered to be fully functional, but
541has not been tested as thoroughly as the C front-end. It has been tested and
542works for a number of non-trivial programs, but there may be lurking bugs.
543Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]544
545</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]546
547<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]548<div class="doc_subsubsection">
549 Bugs
550</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]551
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]552<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]553
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]554<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]555<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]556 front-end</a></li>
557</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]558
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]559</div>
560
561<!-- _______________________________________________________________________ -->
562<div class="doc_subsubsection">
563 Notes
564</div>
565
566<div class="doc_text">
567
568<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]569
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]570<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
571parser is significantly more standards compliant (and picky) than prior GCC
572versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]573href="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]574
575<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]576 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]577 function and in the <tt>setjmp</tt> receiver function may not be run.
578 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]579 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]580
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]581<li>The LLVM C++ front-end follows the <a
582 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
583 This document, which is not Itanium specific, specifies a standard for name
584 mangling, class layout, v-table layout, RTTI formats, and other C++
585 representation issues. Because we use this API, code generated by the LLVM
586 compilers should be binary compatible with machine code generated by other
587 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
588 <i>However</i>, the exception handling mechanism used by LLVM is very
589 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]590 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]591
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]592</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]593
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]594</div>
595
596<!-- ======================================================================= -->
597<div class="doc_subsection">
598 <a name="x86-be">Known problems with the X86 back-end</a>
599</div>
600
601<div class="doc_text">
602
603<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]604
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]605<li>The X86 code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]606href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]607support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]608or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]609
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]610</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]611
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]612</div>
613
614<!-- ======================================================================= -->
615<div class="doc_subsection">
616 <a name="sparc-be">Known problems with the Sparc back-end</a>
617</div>
618
619<div class="doc_text">
620
621<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]622
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]623<li>The Sparc code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]624href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]625support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]626or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]627
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]628</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]629
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]630</div>
631
632<!-- ======================================================================= -->
633<div class="doc_subsection">
634 <a name="c-be">Known problems with the C back-end</a>
635</div>
636
637<div class="doc_text">
638
639<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]640
641<li>The C back-end produces code that violates the ANSI C Type-Based Alias
642Analysis rules. As such, special options may be necessary to compile the code
643(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]644problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]645
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]646<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647cannot include special floating point numbers like Not-A-Number or
648Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]649
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]650<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]651supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]652frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]653
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]654</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]655
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]656</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]657
658<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]659<div class="doc_section">
660 <a name="additionalinfo">Additional Information</a>
661</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]662<!-- *********************************************************************** -->
663
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]664<div class="doc_text">
665
666<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]667including mailing lists publications describing algorithms and components
668implemented in LLVM. The web page also contains versions of the API
669documentation which is up-to-date with the CVS version of the source code. You
670can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]671the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]672
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]673<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]674us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
675lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]676
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]677</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]678
679<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]681<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]682<address>
683 <a href="http://jigsaw.w3.org/css-validator/"><img
684 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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687
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]688 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]689 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]690</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]691
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]692</body>
693</html>