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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
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]58<p>Note that if you are reading this file from CVS, that this document applies
59to the <i>next</i> release, not the previous one. To see the release notes for
60the previous release, see the <a
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 Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]77and better interoperability with external source bases.</p>
78
79<p>At this time, LLVM is known to correctly compile the SPEC CPU2000 benchmarks
80(X86 only), the Olden benchmarks, and the Ptrdist benchmarks along with
81<b>many</b> other programs. LLVM now also works with a fairly broad variety of
82C++ programs, though it has still received much less testing than the C
83front-end.
84</p>
85
86<p>
87Note that the Sparc and X86 backends do not currently support exception throwing
88or long jumping (including 253.perlbmk in SPEC). For these programs, you must
89use the C backend. Support for unwinding will be added in a future release.
90</p>
91
92
93<!--=========================================================================-->
94<div class="doc_subsubsection">
95This release implements the following new features:
96</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]97
98<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]99<li><a
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]100href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000528.html">A new
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]101LLVM profiler, similar to gprof</a> is available</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]102
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]103<li>LLVM and the C/C++ front-end now compile on Mac OS/X! Mac OS/X users can
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]104now explore the LLVM optimizer with the C backend (note that LLVM requires GCC
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]1053.3 on Mac OS/X).</li>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]106
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]107<li>LLVM has been <a
Chris Lattner2a77f2d2003-11-11 23:46:35 +0000[diff] [blame]108href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000554.html">moved
109into an 'llvm' C++ namespace</a>, for easier integration with third-party
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]110code. Note that lack of namespace handling in GDB 5.x, you will probably want to
111upgrade to GDB 6 or better to debug LLVM code.</li>
John Criswellf2ec35b2003-11-26 20:09:49 +0000[diff] [blame]112
113<li>
114The build system now copies Makefiles dynamically from the source tree to the
115object tree as subdirectories are built. This means that:
116 <ol>
117 <li>
118 New directories can be added to the source tree, and the build will
119 automatically pick them up (i.e. no need to re-run <tt>configure</tt>).
120 </li>
121
122 <li>
123 You will need to build LLVM from the top of the object tree once to ensure
124 that all of the Makefiles are copied into the object tree subdirectories.
125 </li>
126 </ol>
127</li>
128
129<li>
130The <tt>configure</tt> script will now configure all projects placed in the
131<tt>llvm/projects</tt> directory.
132</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]133</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]134
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]135
136<!--=========================================================================-->
137<div class="doc_subsubsection">
138In this release, the following missing features were implemented:
139</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]140
141<ol>
142<li><a href="http://llvm.cs.uiuc.edu/PR88">The interpreter does not support
143invoke or unwind</a></li>
Misha Brukmanc99037d2003-11-14 03:30:43 +0000[diff] [blame]144
145<li><a href="http://llvm.cs.uiuc.edu/PR99">Interpreter does not support the
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]146<tt>vaarg</tt> instruction</a></li>
Misha Brukmanc99037d2003-11-14 03:30:43 +0000[diff] [blame]147
Brian Gaekeb7508ee2003-11-16 23:49:26 +0000[diff] [blame]148<li><a href="http://llvm.cs.uiuc.edu/PR117">llvm-nm cannot read archive
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]149files</a></li>
Brian Gaekeb7508ee2003-11-16 23:49:26 +0000[diff] [blame]150
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]151</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]152
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]153
154<!--=========================================================================-->
155<div class="doc_subsubsection">
156In this release, the following Quality of Implementation issues were
157fixed:
158</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]159
160<ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]161
162<li><a href="http://llvm.cs.uiuc.edu/PR29">C++ front-end is not generating
163linkonce linkage type when it can</a></li>
164
165<li><a href="http://llvm.cs.uiuc.edu/PR84">C front-end doesn't emit
166getelementptr for address of array element</a></li>
167
Chris Lattnerba46d552003-11-16 20:25:24 +0000[diff] [blame]168<li><a href="http://llvm.cs.uiuc.edu/PR96">Bad path to the C/C++ frontend causes
169build problems</a></li>
170
171<li><a href="http://llvm.cs.uiuc.edu/PR114">LLVM header files should be -Wold-style-cast clean</a></li>
172
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]173<li>The LLVM bytecode reader has been <a
174href="http://llvm.cs.uiuc.edu/PR127">sped up a lot</a> (up to 4x in some
175cases).</li>
176
Chris Lattner9f9d00a2003-11-22 01:14:58 +0000[diff] [blame]177<li>Methods and functions in anonymous namespaces <a href="http://llvm.cs.uiuc.edu/PR85">now get internal linkage</a>.</li>
178
Chris Lattnerf7330732003-11-26 08:20:34 +0000[diff] [blame]179<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>
180
Chris Lattner3074b342003-11-27 09:51:54 +0000[diff] [blame]181<li>Code for running C++ destructors is now properly shared when possible. Before, the C++ front-end
182<a href="http://llvm.cs.uiuc.edu/PR11">generated N^2 amounts of duplicated cleanup code</a> in some cases.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]183</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]184
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]185
186<!--=========================================================================-->
187<div class="doc_subsubsection">
188In this release, the following bugs in the previous release were fixed:
189</div>
190
191<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]192
193<ol>
Chris Lattnerf7100202003-10-27 05:41:39 +0000[diff] [blame]194<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]195<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]196<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]197<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]198<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]199<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]200<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]201<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]202calls should be volatile</a> (Note that this does not effect correctness on
203many platforms, such as X86).</li>
Chris Lattner2fb1ef82003-11-03 20:08:08 +0000[diff] [blame]204<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]205<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]206<li><a href="http://llvm.cs.uiuc.edu/PR92">[bcreader] Cannot read shift constant expressions from bytecode file</a></li>
207<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]208<li><a href="http://llvm.cs.uiuc.edu/PR95">SymbolTable::getUniqueName is very inefficient</a></li>
Chris Lattner5b3fb032003-11-07 04:46:56 +0000[diff] [blame]209<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]210<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]211<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]212<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]213<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]214<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]215<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]216<li><a href="http://llvm.cs.uiuc.edu/PR130">[vmcore] Symbol table doesn't rename colliding variables during type resolution</a></li>
217<li><a href="http://llvm.cs.uiuc.edu/PR97">bugpoint must not pass -R&lt;directory&gt; to Mach-O linker</a></li>
218<li><a href="http://llvm.cs.uiuc.edu/PR140">gccld produces a runner script that includes command-line options to load the necessary shared objects</a></li>
219</ol>
220
221
222<p>Bugs in the C/C++ front-end:</p>
223
224<ol>
225<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
226<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
227<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
228<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
229<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
230<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
231<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
232<li><a href="http://llvm.cs.uiuc.edu/PR79">llvm-gcc crashes compiling global union initializer</a></li>
233<li><a href="http://llvm.cs.uiuc.edu/PR80">C front-end crash on empty structure</a></li>
234<li><a href="http://llvm.cs.uiuc.edu/PR81">CFrontend crashes when compiling C99 compound expressions</a></li>
235<li><a href="http://llvm.cs.uiuc.edu/PR87">llvm-gcc infinite loops on "case MAXINT:"</a></li>
236<li><a href="http://llvm.cs.uiuc.edu/PR89">[C++] Catch blocks make unparsable labels</a></li>
237<li><a href="http://llvm.cs.uiuc.edu/PR90">[C++] Initializing array with constructable objects fail</a></li>
238<li><a href="http://llvm.cs.uiuc.edu/PR94">llvm-gcc tries to add bools</a></li>
239<li><a href="http://llvm.cs.uiuc.edu/PR104">[c++] C++ Frontend lays out superclasses like anonymous bitfields!</a></li>
240<li><a href="http://llvm.cs.uiuc.edu/PR54">C front-end miscompiles unsigned enums whose LLVM types are signed</a></li>
241<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]242<li><a href="http://llvm.cs.uiuc.edu/PR125">[llvmg++] Enum types are incorrectly shrunk to smaller than 'int' size</a></li>
243<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]244<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]245<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]246<li><a href="http://llvm.cs.uiuc.edu/PR113">crash assigning into an array in a struct which contains a bitfield</a>.</li>
247<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]248<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]249<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]250<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]251<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]252<li><a href="http://llvm.cs.uiuc.edu/PR152">[llvmg++] Pointer to member initializers not supported in constructors</a></li>
253<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]254<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]255<li><a href="http://llvm.cs.uiuc.edu/PR157">[llvm-gcc] Pointer & constant results in invalid shift</a></li>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]256
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]257</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]258
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]259</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]260
261<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]262<div class="doc_section">
263 <a name="portability">Portability and Supported Platforms</a>
264</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]265<!-- *********************************************************************** -->
266
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]267<div class="doc_text">
268
269<p>LLVM has been extensively tested on Intel and AMD machines running Red
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]270Hat Linux, and Sun UltraSPARC workstations running Solaris 8. Additionally,
271LLVM works on Mac OS/X 10.3 and above, but only with the C back-end (no native
272backend for the PowerPC is available yet).
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]273The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]274work on more platforms than that. However, it is likely that we
275missed something, and that minor porting is required to get LLVM to work on
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]276new platforms. We welcome portability patches and error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]277
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]278</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]279
280<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]281<div class="doc_section">
282 <a name="knownproblems">Known Problems</a>
283</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]284<!-- *********************************************************************** -->
285
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]286<div class="doc_text">
287
288<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]289component. As new problems are discovered, they will be added to these
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]290sections.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]291
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]292</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]293
294<!-- _______________________________________________________________________ -->
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]295<!--
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]296</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]297-->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]298
299
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]300<!-- ======================================================================= -->
301<div class="doc_subsection">
302 <a name="core">Known problems with the LLVM Core</a>
303</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]304
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]305<div class="doc_text">
306
307<ul>
308
309<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
310work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]311
312<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]313such, execution of a threaded program could cause these data structures to be
314corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]315
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]316<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]317
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]318<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]319table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]320
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]321<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]322more than 256 elements</a>.</li>
323
324</ul>
325
326</div>
327
328<!-- ======================================================================= -->
329<div class="doc_subsection">
330 <a name="c-fe">Known problems with the C front-end</a>
331</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]332
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]333<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]334<div class="doc_subsubsection">
335 Bugs
336</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]337
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]338<div class="doc_text">
339
340<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]341
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]342<li>C99 Variable sized arrays do not release stack memory when they go out of
343 scope. Thus, the following program may run out of stack space:
344<pre>
345 for (i = 0; i != 1000000; ++i) {
346 int X[n];
347 foo(X);
348 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]349</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]350
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]351</ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]352
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]353</div>
354
355<!-- _______________________________________________________________________ -->
356<div class="doc_subsubsection">
357 Notes
358</div>
359
360<div class="doc_text">
361
362<ul>
363
364<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]365
366<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]367support for floating point data types of any size other than 32 and 64
368bits.</li>
369
370<li>The following Unix system functionality has not been tested and may not
371work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]372 <ol>
373 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
374 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
375 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
376 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
377 - These functions have not been tested.
378 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]379
380<li>Although many GCC extensions are supported, some are not. In particular,
381 the following extensions are known to <b>not be</b> supported:
382 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]383 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
384 <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>
385 <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>
386 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
387 <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>
388 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
389 <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>
390 <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>
391 <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>
392 <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>
393 <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>
394 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
395 <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]396 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]397
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]398 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]399 attribute means that the LLVM compiler ignores the presence of the attribute,
400 but the code should still work. An unsupported attribute is one which is
401 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]402 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]403
404 <ol>
405 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
406 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]407 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]408
409 <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]410
411 Declaring that functions have no side effects, or that they can never
412 return.<br>
413
414 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
415 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
416 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
417
418 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
419 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
420 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
421
422 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
423 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
424 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]425
426 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
427 Specifying attributes of variables.<br>
428 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
429 <tt>deprecated</tt>, <tt>transparent_union</tt>,
430 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]431
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]432 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
433 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
434 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]435 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]436
437 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.
438 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
439 <tt>deprecated</tt>, <tt>may_alias</tt>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]440
441 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
442 all target specific attributes.</li>
443
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]444 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
445 Other built-in functions.<br>
446 We support all builtins which have a C language equivalent (e.g.,
447 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
448 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]449 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]450
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]451 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]452
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]453 <p>The following extensions <b>are</b> known to be supported:</p>
454
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]455 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]456 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
457 <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>
458 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
459 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
461 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
462 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
463 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
465 <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>
466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
467 <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>
468 <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>
469 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
470 <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>
471 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
472 <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>
473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
476 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
477 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
478 <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>
479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
480 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
481 <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>
482 <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>
483 <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>
484 <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>
485 <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]486 </ol></li>
487
488</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]489
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]490<p>If you run into GCC extensions which have not been included in any of these
491lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]492
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]493</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]494
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]495<!-- ======================================================================= -->
496<div class="doc_subsection">
497 <a name="c++-fe">Known problems with the C++ front-end</a>
498</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]499
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500<div class="doc_text">
501
502<p>For this release, the C++ front-end is considered to be fully functional but
503of <b>beta</b> quality. It has been tested and works for a number of simple
504programs that collectively exercise most of the language. Nevertheless, it has
505not been in use as long as the C front-end. Please report any bugs or
506problems.</p>
507
508</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]509
510<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]511<div class="doc_subsubsection">
512 Bugs
513</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]514
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]515<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]516
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]517<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]518<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]519 front-end</a></li>
520</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]521
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]522</div>
523
524<!-- _______________________________________________________________________ -->
525<div class="doc_subsubsection">
526 Notes
527</div>
528
529<div class="doc_text">
530
531<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]532
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]533<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
534parser is significantly more standards compliant (and picky) than prior GCC
535versions. For more information, see the C++ section of the <a
536href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.<p>
537
538<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]539 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]540 function and in the <tt>setjmp</tt> receiver function may not be run.
541 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]542 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]543
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]544<li>The LLVM C++ front-end follows the <a
545 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
546 This document, which is not Itanium specific, specifies a standard for name
547 mangling, class layout, v-table layout, RTTI formats, and other C++
548 representation issues. Because we use this API, code generated by the LLVM
549 compilers should be binary compatible with machine code generated by other
550 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
551 <i>However</i>, the exception handling mechanism used by LLVM is very
552 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]553 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]554
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]555</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]556
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]557</div>
558
559<!-- ======================================================================= -->
560<div class="doc_subsection">
561 <a name="x86-be">Known problems with the X86 back-end</a>
562</div>
563
564<div class="doc_text">
565
566<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]567
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]568<li>The X86 code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]569href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]570support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]571or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]572
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]573</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]574
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]575</div>
576
577<!-- ======================================================================= -->
578<div class="doc_subsection">
579 <a name="sparc-be">Known problems with the Sparc back-end</a>
580</div>
581
582<div class="doc_text">
583
584<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]585
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]586<li>The Sparc code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]587href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]588support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]589or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]591</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]592
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]593</div>
594
595<!-- ======================================================================= -->
596<div class="doc_subsection">
597 <a name="c-be">Known problems with the C back-end</a>
598</div>
599
600<div class="doc_text">
601
602<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]603
604<li>The C back-end produces code that violates the ANSI C Type-Based Alias
605Analysis rules. As such, special options may be necessary to compile the code
606(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]607problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]608
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]609<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]610cannot include special floating point numbers like Not-A-Number or
611Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]612
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]613<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]614supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]615frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]616
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]617</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]618
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]620
621<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]622<div class="doc_section">
623 <a name="additionalinfo">Additional Information</a>
624</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]625<!-- *********************************************************************** -->
626
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]627<div class="doc_text">
628
629<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]630including mailing lists publications describing algorithms and components
631implemented in LLVM. The web page also contains versions of the API
632documentation which is up-to-date with the CVS version of the source code. You
633can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]634the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]635
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]636<p>If you have any questions or comments about LLVM, please feel free to contact
637us via the mailing lists.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]638
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]639</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]640
641<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]642
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]643<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]644<address>
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649
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]650 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]651 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]652</address>
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Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]654</body>
655</html>