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gerrit-public.fairphone.software / platform / external / llvm / a6ffa54e1b1ff3da90fe0cd346fbaa307f683c5a / . / 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
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
Brian Gaekea6ffa542003-12-11 04:40:58 +0000[diff] [blame^]151<li><a href="http://llvm.cs.uiuc.edu/PR146">Interpreter does not handle
152setne constant expression</a></li>
153
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]154</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]155
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]156
157<!--=========================================================================-->
158<div class="doc_subsubsection">
159In this release, the following Quality of Implementation issues were
160fixed:
161</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]162
163<ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]164
165<li><a href="http://llvm.cs.uiuc.edu/PR29">C++ front-end is not generating
166linkonce linkage type when it can</a></li>
167
168<li><a href="http://llvm.cs.uiuc.edu/PR84">C front-end doesn't emit
169getelementptr for address of array element</a></li>
170
Chris Lattnerba46d552003-11-16 20:25:24 +0000[diff] [blame]171<li><a href="http://llvm.cs.uiuc.edu/PR96">Bad path to the C/C++ frontend causes
172build problems</a></li>
173
174<li><a href="http://llvm.cs.uiuc.edu/PR114">LLVM header files should be -Wold-style-cast clean</a></li>
175
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]176<li>The LLVM bytecode reader has been <a
177href="http://llvm.cs.uiuc.edu/PR127">sped up a lot</a> (up to 4x in some
178cases).</li>
179
Chris Lattner9f9d00a2003-11-22 01:14:58 +0000[diff] [blame]180<li>Methods and functions in anonymous namespaces <a href="http://llvm.cs.uiuc.edu/PR85">now get internal linkage</a>.</li>
181
Chris Lattnerf7330732003-11-26 08:20:34 +0000[diff] [blame]182<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>
183
Chris Lattner3074b342003-11-27 09:51:54 +0000[diff] [blame]184<li>Code for running C++ destructors is now properly shared when possible. Before, the C++ front-end
185<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]186</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]187
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]188
189<!--=========================================================================-->
190<div class="doc_subsubsection">
191In this release, the following bugs in the previous release were fixed:
192</div>
193
194<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]195
196<ol>
Chris Lattnerf7100202003-10-27 05:41:39 +0000[diff] [blame]197<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]198<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]199<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]200<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]201<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]202<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]203<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]204<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]205calls should be volatile</a> (Note that this does not effect correctness on
206many platforms, such as X86).</li>
Chris Lattner2fb1ef82003-11-03 20:08:08 +0000[diff] [blame]207<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]208<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]209<li><a href="http://llvm.cs.uiuc.edu/PR92">[bcreader] Cannot read shift constant expressions from bytecode file</a></li>
210<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]211<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^]212<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]213<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]214<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]215<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]216<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]217<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]218<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]219<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]220<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^]221<li><a href="http://llvm.cs.uiuc.edu/PR138">Archive reader does not understand 4.4BSD/Mac OS X long filenames</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]222<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>
223</ol>
224
225
226<p>Bugs in the C/C++ front-end:</p>
227
228<ol>
229<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
230<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
231<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
232<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
233<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
234<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
235<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
236<li><a href="http://llvm.cs.uiuc.edu/PR79">llvm-gcc crashes compiling global union initializer</a></li>
237<li><a href="http://llvm.cs.uiuc.edu/PR80">C front-end crash on empty structure</a></li>
238<li><a href="http://llvm.cs.uiuc.edu/PR81">CFrontend crashes when compiling C99 compound expressions</a></li>
239<li><a href="http://llvm.cs.uiuc.edu/PR87">llvm-gcc infinite loops on "case MAXINT:"</a></li>
240<li><a href="http://llvm.cs.uiuc.edu/PR89">[C++] Catch blocks make unparsable labels</a></li>
241<li><a href="http://llvm.cs.uiuc.edu/PR90">[C++] Initializing array with constructable objects fail</a></li>
242<li><a href="http://llvm.cs.uiuc.edu/PR94">llvm-gcc tries to add bools</a></li>
243<li><a href="http://llvm.cs.uiuc.edu/PR104">[c++] C++ Frontend lays out superclasses like anonymous bitfields!</a></li>
244<li><a href="http://llvm.cs.uiuc.edu/PR54">C front-end miscompiles unsigned enums whose LLVM types are signed</a></li>
245<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]246<li><a href="http://llvm.cs.uiuc.edu/PR125">[llvmg++] Enum types are incorrectly shrunk to smaller than 'int' size</a></li>
247<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]248<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]249<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]250<li><a href="http://llvm.cs.uiuc.edu/PR113">crash assigning into an array in a struct which contains a bitfield</a>.</li>
251<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]252<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]253<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]254<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]255<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]256<li><a href="http://llvm.cs.uiuc.edu/PR152">[llvmg++] Pointer to member initializers not supported in constructors</a></li>
257<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]258<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]259<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]260<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]261</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]262
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]263</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]264
265<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]266<div class="doc_section">
267 <a name="portability">Portability and Supported Platforms</a>
268</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]269<!-- *********************************************************************** -->
270
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]271<div class="doc_text">
272
273<p>LLVM has been extensively tested on Intel and AMD machines running Red
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]274Hat Linux, and Sun UltraSPARC workstations running Solaris 8. Additionally,
275LLVM works on Mac OS/X 10.3 and above, but only with the C back-end (no native
276backend for the PowerPC is available yet).
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]277The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]278work on more platforms than that. However, it is likely that we
279missed something, and that minor porting is required to get LLVM to work on
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]280new platforms. We welcome portability patches and error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]281
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]282</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]283
284<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]285<div class="doc_section">
286 <a name="knownproblems">Known Problems</a>
287</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]288<!-- *********************************************************************** -->
289
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]290<div class="doc_text">
291
292<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]293component. As new problems are discovered, they will be added to these
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]294sections.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]295
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]296</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]297
298<!-- _______________________________________________________________________ -->
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]299<!--
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]300</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]301-->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]302
303
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]304<!-- ======================================================================= -->
305<div class="doc_subsection">
306 <a name="core">Known problems with the LLVM Core</a>
307</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]308
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]309<div class="doc_text">
310
311<ul>
312
313<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
314work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]315
316<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]317such, execution of a threaded program could cause these data structures to be
318corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]319
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]320<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]321
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]322<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]323table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]324
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]325<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]326more than 256 elements</a>.</li>
327
328</ul>
329
330</div>
331
332<!-- ======================================================================= -->
333<div class="doc_subsection">
334 <a name="c-fe">Known problems with the C front-end</a>
335</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]336
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_subsubsection">
339 Bugs
340</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]341
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]342<div class="doc_text">
343
344<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]345
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]346<li>C99 Variable sized arrays do not release stack memory when they go out of
347 scope. Thus, the following program may run out of stack space:
348<pre>
349 for (i = 0; i != 1000000; ++i) {
350 int X[n];
351 foo(X);
352 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]353</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]354
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]355</ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]356
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]357</div>
358
359<!-- _______________________________________________________________________ -->
360<div class="doc_subsubsection">
361 Notes
362</div>
363
364<div class="doc_text">
365
366<ul>
367
368<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]369
370<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]371support for floating point data types of any size other than 32 and 64
372bits.</li>
373
374<li>The following Unix system functionality has not been tested and may not
375work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]376 <ol>
377 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
378 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
379 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
380 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
381 - These functions have not been tested.
382 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]383
384<li>Although many GCC extensions are supported, some are not. In particular,
385 the following extensions are known to <b>not be</b> supported:
386 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]387 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
388 <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>
389 <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>
390 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
391 <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>
392 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
393 <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>
394 <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>
395 <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>
396 <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>
397 <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>
398 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
399 <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]400 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]401
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]402 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]403 attribute means that the LLVM compiler ignores the presence of the attribute,
404 but the code should still work. An unsupported attribute is one which is
405 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]406 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]407
408 <ol>
409 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
410 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]411 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]412
413 <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]414
415 Declaring that functions have no side effects, or that they can never
416 return.<br>
417
418 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
419 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
420 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
421
422 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
423 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
424 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
425
426 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
427 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
428 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]429
430 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
431 Specifying attributes of variables.<br>
432 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
433 <tt>deprecated</tt>, <tt>transparent_union</tt>,
434 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]435
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]436 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
437 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
438 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]439 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]440
441 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.
442 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
443 <tt>deprecated</tt>, <tt>may_alias</tt>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]444
445 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
446 all target specific attributes.</li>
447
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]448 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
449 Other built-in functions.<br>
450 We support all builtins which have a C language equivalent (e.g.,
451 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
452 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]453 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]454
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]455 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]456
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]457 <p>The following extensions <b>are</b> known to be supported:</p>
458
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]459 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
461 <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>
462 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
463 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
465 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
468 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
469 <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>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
471 <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>
472 <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>
473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
474 <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>
475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
476 <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>
477 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
480 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
482 <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>
483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
484 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
485 <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>
486 <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>
487 <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>
488 <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>
489 <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]490 </ol></li>
491
492</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]493
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]494<p>If you run into GCC extensions which have not been included in any of these
495lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]496
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]497</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]498
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]499<!-- ======================================================================= -->
500<div class="doc_subsection">
501 <a name="c++-fe">Known problems with the C++ front-end</a>
502</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]503
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]504<div class="doc_text">
505
506<p>For this release, the C++ front-end is considered to be fully functional but
507of <b>beta</b> quality. It has been tested and works for a number of simple
508programs that collectively exercise most of the language. Nevertheless, it has
509not been in use as long as the C front-end. Please report any bugs or
510problems.</p>
511
512</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]513
514<!-- _______________________________________________________________________ -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]515<div class="doc_subsubsection">
516 Bugs
517</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]518
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]519<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]520
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]521<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]522<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]523 front-end</a></li>
524</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]525
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]526</div>
527
528<!-- _______________________________________________________________________ -->
529<div class="doc_subsubsection">
530 Notes
531</div>
532
533<div class="doc_text">
534
535<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]536
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]537<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
538parser is significantly more standards compliant (and picky) than prior GCC
539versions. For more information, see the C++ section of the <a
540href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.<p>
541
542<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]543 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]544 function and in the <tt>setjmp</tt> receiver function may not be run.
545 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]546 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]548<li>The LLVM C++ front-end follows the <a
549 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
550 This document, which is not Itanium specific, specifies a standard for name
551 mangling, class layout, v-table layout, RTTI formats, and other C++
552 representation issues. Because we use this API, code generated by the LLVM
553 compilers should be binary compatible with machine code generated by other
554 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
555 <i>However</i>, the exception handling mechanism used by LLVM is very
556 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]557 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]558
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]559</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]560
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]561</div>
562
563<!-- ======================================================================= -->
564<div class="doc_subsection">
565 <a name="x86-be">Known problems with the X86 back-end</a>
566</div>
567
568<div class="doc_text">
569
570<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]571
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]572<li>The X86 code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]573href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]574support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]575or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]576
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]577</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]578
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]579</div>
580
581<!-- ======================================================================= -->
582<div class="doc_subsection">
583 <a name="sparc-be">Known problems with the Sparc back-end</a>
584</div>
585
586<div class="doc_text">
587
588<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]589
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]590<li>The Sparc code generator <a
Chris Lattner0d4379a2003-10-08 06:01:38 +0000[diff] [blame]591href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]592support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]593or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]594
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]595</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]596
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]597</div>
598
599<!-- ======================================================================= -->
600<div class="doc_subsection">
601 <a name="c-be">Known problems with the C back-end</a>
602</div>
603
604<div class="doc_text">
605
606<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]607
608<li>The C back-end produces code that violates the ANSI C Type-Based Alias
609Analysis rules. As such, special options may be necessary to compile the code
610(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]611problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]612
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]613<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]614cannot include special floating point numbers like Not-A-Number or
615Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]616
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]617<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]618supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]620
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]621</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]622
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]623</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]624
625<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]626<div class="doc_section">
627 <a name="additionalinfo">Additional Information</a>
628</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]629<!-- *********************************************************************** -->
630
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]631<div class="doc_text">
632
633<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]634including mailing lists publications describing algorithms and components
635implemented in LLVM. The web page also contains versions of the API
636documentation which is up-to-date with the CVS version of the source code. You
637can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]638the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]639
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]640<p>If you have any questions or comments about LLVM, please feel free to contact
641us via the mailing lists.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]642
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]643</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]644
645<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]646
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]648<address>
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653
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]654 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
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