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gerrit-public.fairphone.software / toolchain / llvm-project / 7ee7b40af58bf7f9e167e1963bae8287fffb2eaf / . / llvm / docs / ReleaseNotes.html
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6 <title>LLVM 1.1 Release Notes</title>
7</head>
8<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]9
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]10<div class="doc_title">
11 LLVM 1.1 Release Notes
12</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]13
14<ol>
Misha Brukman80731b92003-11-22 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 Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a>
20 <ul>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]21<!-- <li><a href="#portabilityprobs">Portability Problems</a> -->
Chris Lattner3d482502003-10-02 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]28 </ul></li>
29 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]30</ol>
31
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]32<div class="doc_text">
Misha Brukman80731b92003-11-22 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 Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]35
36<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]37<div class="doc_section">
38 <a name="intro">Introduction</a>
39</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]40<!-- *********************************************************************** -->
41
Misha Brukman80731b92003-11-22 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 Lattner7c4bd1d2003-10-27 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 Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]49not reading this on the LLVM web pages, you should probably go there, because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]50this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]51
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]52<p>For more information about LLVM, including information about potentially more
Chris Lattnere7525b52003-10-07 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]56list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]57
Misha Brukman80731b92003-11-22 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 Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]64
65<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]66<div class="doc_section">
67 <a name="whatsnew">What's New?</a>
68</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]69<!-- *********************************************************************** -->
70
Misha Brukman80731b92003-11-22 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
74release implements the following new features:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]75
76<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]77<li><a
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]78href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000528.html">A new
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]79LLVM profiler, similar to gprof</a> is available</li>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]80
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]81<li>LLVM and the C/C++ front-end now compile on Mac OSX! Mac OSX users can
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]82now explore the LLVM optimizer with the C backend (note that LLVM requires GCC
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]833.3 on Mac OSX).</li>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]84
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]85<li>LLVM has been <a
Chris Lattner74a22992003-11-11 23:46:35 +0000[diff] [blame]86href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000554.html">moved
87into an 'llvm' C++ namespace</a>, for easier integration with third-party
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]88code. Note that due to a bug in GDB 5.x, to debug namespacified LLVM code,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]89you will need to upgrade to GDB 6.</li>
John Criswellf1387a52003-11-26 20:09:49 +0000[diff] [blame]90
91<li>
92The build system now copies Makefiles dynamically from the source tree to the
93object tree as subdirectories are built. This means that:
94 <ol>
95 <li>
96 New directories can be added to the source tree, and the build will
97 automatically pick them up (i.e. no need to re-run <tt>configure</tt>).
98 </li>
99
100 <li>
101 You will need to build LLVM from the top of the object tree once to ensure
102 that all of the Makefiles are copied into the object tree subdirectories.
103 </li>
104 </ol>
105</li>
106
107<li>
108The <tt>configure</tt> script will now configure all projects placed in the
109<tt>llvm/projects</tt> directory.
110</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]111</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]112
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]113<p>In this release, the following missing features were implemented:</p>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]114
115<ol>
116<li><a href="http://llvm.cs.uiuc.edu/PR88">The interpreter does not support
117invoke or unwind</a></li>
Misha Brukman133b35e2003-11-14 03:30:43 +0000[diff] [blame]118
119<li><a href="http://llvm.cs.uiuc.edu/PR99">Interpreter does not support the
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]120<tt>vaarg</tt> instruction</a></li>
Misha Brukman133b35e2003-11-14 03:30:43 +0000[diff] [blame]121
Brian Gaekec5961312003-11-16 23:49:26 +0000[diff] [blame]122<li><a href="http://llvm.cs.uiuc.edu/PR117">llvm-nm cannot read archive
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]123files</a></li>
Brian Gaekec5961312003-11-16 23:49:26 +0000[diff] [blame]124
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]125</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]126
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]127<p>In this release, the following Quality of Implementation issues were
128fixed:</p>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]129
130<ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]131
132<li><a href="http://llvm.cs.uiuc.edu/PR29">C++ front-end is not generating
133linkonce linkage type when it can</a></li>
134
135<li><a href="http://llvm.cs.uiuc.edu/PR84">C front-end doesn't emit
136getelementptr for address of array element</a></li>
137
Chris Lattnerb2e4d6d2003-11-16 20:25:24 +0000[diff] [blame]138<li><a href="http://llvm.cs.uiuc.edu/PR96">Bad path to the C/C++ frontend causes
139build problems</a></li>
140
141<li><a href="http://llvm.cs.uiuc.edu/PR114">LLVM header files should be -Wold-style-cast clean</a></li>
142
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]143<li>The LLVM bytecode reader has been <a
144href="http://llvm.cs.uiuc.edu/PR127">sped up a lot</a> (up to 4x in some
145cases).</li>
146
Chris Lattner3a9b2322003-11-22 01:14:58 +0000[diff] [blame]147<li>Methods and functions in anonymous namespaces <a href="http://llvm.cs.uiuc.edu/PR85">now get internal linkage</a>.</li>
148
Chris Lattner0548bc22003-11-26 08:20:34 +0000[diff] [blame]149<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>
150
Chris Lattner8139b782003-11-27 09:51:54 +0000[diff] [blame]151<li>Code for running C++ destructors is now properly shared when possible. Before, the C++ front-end
152<a href="http://llvm.cs.uiuc.edu/PR11">generated N^2 amounts of duplicated cleanup code</a> in some cases.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]153</ol>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]154
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]155<p>In this release, the following bugs in the previous release were fixed:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]156
157<ol>
Chris Lattner25fd5c12003-10-27 05:41:39 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR57">[inliner] Inlining invoke with PHI in unwind target is broken</a></li>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]159<li><a href="http://llvm.cs.uiuc.edu/PR58">[linker] linkonce globals should link successfully to external globals</a></li>
Chris Lattnerd16d9752003-10-27 17:58:57 +0000[diff] [blame]160<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
Chris Lattner36213c72003-10-28 23:13:03 +0000[diff] [blame]161<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
Chris Lattner56df0a52003-10-29 01:26:07 +0000[diff] [blame]162<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
Chris Lattnera1a090e2003-10-29 07:17:13 +0000[diff] [blame]163<li><a href="http://llvm.cs.uiuc.edu/PR64">[constmerge] Constant merging pass merges constants with external linkage</a></li>
164<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
Chris Lattner5b83b562003-10-29 18:49:14 +0000[diff] [blame]165<li><a href="http://llvm.cs.uiuc.edu/PR66">[scalarrepl] Scalar Replacement of aggregates is decimating structures it shouldn't be</a></li>
166<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
Chris Lattnerab8873d2003-10-29 20:59:45 +0000[diff] [blame]167<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
168<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
Chris Lattnera2bd4e02003-10-30 01:20:42 +0000[diff] [blame]169<li><a href="http://llvm.cs.uiuc.edu/PR70">[instcombine] Resolving invoke inserts cast after terminator</a></li>
Chris Lattnera306dd22003-10-30 01:43:33 +0000[diff] [blame]170<li><a href="http://llvm.cs.uiuc.edu/PR71">llvm-as crashes when labels are used in phi nodes</a></li>
Chris Lattnerb45e1f92003-10-30 16:20:15 +0000[diff] [blame]171<li><a href="http://llvm.cs.uiuc.edu/PR72">[build problem] Callgraph.cpp not pulled in from libipa.a</a></li>
Chris Lattner9dd6a822003-11-16 22:11:42 +0000[diff] [blame]172<li><a href="http://llvm.cs.uiuc.edu/PR77">Variables in scope of output setjmp
173calls should be volatile</a>. Note that this does not effect correctness on
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]174many platforms, such as X86.</li>
Chris Lattnerdd024a02003-11-02 02:15:11 +0000[diff] [blame]175<li><a href="http://llvm.cs.uiuc.edu/PR79">llvm-gcc crashes compiling global union initializer</a></li>
176<li><a href="http://llvm.cs.uiuc.edu/PR80">C front-end crash on empty structure</a></li>
177<li><a href="http://llvm.cs.uiuc.edu/PR81">CFrontend crashes when compiling C99 compound expressions</a></li>
Chris Lattneref114d52003-11-03 20:08:08 +0000[diff] [blame]178<li><a href="http://llvm.cs.uiuc.edu/PR83">[X86] Emission of global bool initializers broken</a></li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]179<li><a href="http://llvm.cs.uiuc.edu/PR87">llvm-gcc infinite loops on "case MAXINT:"</a></li>
Chris Lattnerab77bc52003-11-05 06:30:04 +0000[diff] [blame]180<li><a href="http://llvm.cs.uiuc.edu/PR89">[C++] Catch blocks make unparsable labels</a></li>
181<li><a href="http://llvm.cs.uiuc.edu/PR90">[C++] Initializing array with constructable objects fail</a></li>
182<li><a href="http://llvm.cs.uiuc.edu/PR91">[gccld] The -r (relinking) option does not work correctly</a></li>
Chris Lattner34596d72003-11-07 04:46:56 +0000[diff] [blame]183<li><a href="http://llvm.cs.uiuc.edu/PR92">[bcreader] Cannot read shift constant expressions from bytecode file</a></li>
184<li><a href="http://llvm.cs.uiuc.edu/PR93">[lowersetjmp] Lowersetjmp pass breaks dominance properties!</a></li>
185<li><a href="http://llvm.cs.uiuc.edu/PR94">llvm-gcc tries to add bools</a></li>
Chris Lattner881cb482003-11-09 19:44:07 +0000[diff] [blame]186<li><a href="http://llvm.cs.uiuc.edu/PR95">SymbolTable::getUniqueName is very inefficient</a></li>
Chris Lattner34596d72003-11-07 04:46:56 +0000[diff] [blame]187<li><a href="http://llvm.cs.uiuc.edu/PR98">[buildscripts] Building into objdir with .o in it fails</a></li>
Chris Lattner699a58d2003-11-08 05:18:50 +0000[diff] [blame]188<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 Lattner881cb482003-11-09 19:44:07 +0000[diff] [blame]189<li><a href="http://llvm.cs.uiuc.edu/PR104">[c++] C++ Frontend lays out superclasses like anonymous bitfields!</a></li>
Chris Lattnera7235372003-11-12 04:42:37 +0000[diff] [blame]190<li><a href="http://llvm.cs.uiuc.edu/PR107">AsmParser Misses Symbol Redefinition Error</a></li>
Brian Gaeke7aeb2b72003-11-11 21:52:34 +0000[diff] [blame]191<li><a href="http://llvm.cs.uiuc.edu/PR108">gccld -Lfoo -lfoo fails to find ./foo/libfoo.a</a></li>
Chris Lattner7c04a292003-11-14 06:42:01 +0000[diff] [blame]192<li><a href="http://llvm.cs.uiuc.edu/PR110">[bcreader] Incorrect cast causes misread forward constant references</a></li>
Brian Gaekeb8b238b2003-11-12 22:48:52 +0000[diff] [blame]193<li><a href="http://llvm.cs.uiuc.edu/PR112">Casting a string constant to void crashes llvm-gcc</a></li>
Chris Lattner2f486b82003-11-16 21:42:48 +0000[diff] [blame]194<li><a href="http://llvm.cs.uiuc.edu/PR116">[adce] ADCE considers blocks without postdominators to be unreachable</a></li>
Chris Lattner37d449d2003-11-18 06:25:05 +0000[diff] [blame]195<li><a href="http://llvm.cs.uiuc.edu/PR54">C front-end miscompiles unsigned enums whose LLVM types are signed</a></li>
Chris Lattnercf40b3f2003-11-18 23:04:02 +0000[diff] [blame]196<li><a href="http://llvm.cs.uiuc.edu/PR123">[X86] div and rem constant exprs invalidate iterators!</a></li>
197<li><a href="http://llvm.cs.uiuc.edu/PR125">[llvmg++] Enum types are incorrectly shrunk to smaller than 'int' size</a></li>
198<li><a href="http://llvm.cs.uiuc.edu/PR128">[llvmg++] Cannot use pointer to member to initialize global</a></li>
Chris Lattner983c6672003-11-19 01:08:24 +0000[diff] [blame]199<li><a href="http://llvm.cs.uiuc.edu/PR130">[vmcore] Symbol table doesn't rename colliding variables during type resolution</a></li>
200<li><a href="http://llvm.cs.uiuc.edu/PR131">[llvm-gcc] ?: operator as lvalue not implemented</a></li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]201<li><a href="http://llvm.cs.uiuc.edu/PR133">[C/C++] Bogus warning about taking the address of 'register' variable</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]202<li><a href="http://llvm.cs.uiuc.edu/PR97">bugpoint must not pass -R&lt;directory&gt; to Mach-O linker</a></li>
Chris Lattnerc4fe9722003-11-20 01:07:41 +0000[diff] [blame]203<li><a href="http://llvm.cs.uiuc.edu/PR113">crash assigning into an array in a struct which contains a bitfield</a>.</li>
204<li><a href="http://llvm.cs.uiuc.edu/PR6">Oversized integer bitfields cause crash</a></li>
Misha Brukmanffec0b72003-11-21 22:11:12 +0000[diff] [blame]205<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>
Chris Lattner0548bc22003-11-26 08:20:34 +0000[diff] [blame]206<li><a href="http://llvm.cs.uiuc.edu/PR141">[llvm-gcc] Bitfields &amp; large array don't mix well</a></li>
Chris Lattner16bbed22003-11-20 19:30:17 +0000[diff] [blame]207<li><a href="http://llvm.cs.uiuc.edu/PR132">[llvm-gcc] Complex division is not supported</a></li>
Chris Lattner5eac2d62003-11-20 20:59:57 +0000[diff] [blame]208<li><a href="http://llvm.cs.uiuc.edu/PR143">[llvm-gcc] Illegal union field reference</a></li>
Chris Lattner83f43a02003-11-25 08:49:12 +0000[diff] [blame]209<li><a href="http://llvm.cs.uiuc.edu/PR148">[llvmg++] Front-end attempts to return structure by value</a></li>
Chris Lattner86d5c1c2003-11-26 01:18:49 +0000[diff] [blame]210<li><a href="http://llvm.cs.uiuc.edu/PR152">[llvmg++] Pointer to member initializers not supported in constructors</a></li>
211<li><a href="http://llvm.cs.uiuc.edu/PR155">[llvm-gcc] crash on union initialization</a></li>
Chris Lattnerb27353c2003-11-26 02:48:00 +0000[diff] [blame]212<li><a href="http://llvm.cs.uiuc.edu/PR124">[llvm-g++] ?: expressions do not run correct number of destructors!</a></li>
Chris Lattner0548bc22003-11-26 08:20:34 +0000[diff] [blame]213<li><a href="http://llvm.cs.uiuc.edu/PR157">[llvm-gcc] Pointer & constant results in invalid shift</a></li>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]214</ol><p>
215
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]216<p>At this time, LLVM is known to work properly with SPEC CPU 2000 (X86 only),
217the Olden benchmarks, and the Ptrdist benchmarks among many other programs.
218Note however that the Sparc and X86 backends do not currently support exception
219throwing or long jumping (including 253.perlbmk in SPEC). For these programs,
220you must use the C backend.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]221
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]222</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]223
224<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]225<div class="doc_section">
226 <a name="portability">Portability and Supported Platforms</a>
227</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]228<!-- *********************************************************************** -->
229
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]230<div class="doc_text">
231
232<p>LLVM has been extensively tested on Intel and AMD machines running Red
Chris Lattner14b5d5a2003-11-08 05:22:09 +0000[diff] [blame]233Hat Linux, and Sun UltraSPARC workstations running Solaris 8. Additionally,
234LLVM works on Mac OS/X 10.3 and above, but only with the C back-end (no native
235backend for the PowerPC is available yet).
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]236The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner14b5d5a2003-11-08 05:22:09 +0000[diff] [blame]237work on more platforms than that. However, it is likely that we
238missed something, and that minor porting is required to get LLVM to work on
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]239new platforms. We welcome portability patches and error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]240
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]241</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]242
243<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]244<div class="doc_section">
245 <a name="knownproblems">Known Problems</a>
246</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]247<!-- *********************************************************************** -->
248
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]249<div class="doc_text">
250
251<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]252component. As new problems are discovered, they will be added to these
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]253sections.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]254
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]255</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]256
257<!-- _______________________________________________________________________ -->
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]258<!--
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]259</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]260-->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]261
262
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]263<!-- ======================================================================= -->
264<div class="doc_subsection">
265 <a name="core">Known problems with the LLVM Core</a>
266</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]267
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]268<div class="doc_text">
269
270<ul>
271
272<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
273work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]274
275<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]276such, execution of a threaded program could cause these data structures to be
277corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]278
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]279<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]280
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]281<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]282table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]283
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]284<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]285more than 256 elements</a>.</li>
286
287</ul>
288
289</div>
290
291<!-- ======================================================================= -->
292<div class="doc_subsection">
293 <a name="c-fe">Known problems with the C front-end</a>
294</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]295
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]296<!-- _______________________________________________________________________ -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]297<div class="doc_subsubsection">
298 Bugs
299</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]300
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]301<div class="doc_text">
302
303<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]304
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]305<li>C99 Variable sized arrays do not release stack memory when they go out of
306 scope. Thus, the following program may run out of stack space:
307<pre>
308 for (i = 0; i != 1000000; ++i) {
309 int X[n];
310 foo(X);
311 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]312</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]313
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]314</ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]315
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]316</div>
317
318<!-- _______________________________________________________________________ -->
319<div class="doc_subsubsection">
320 Notes
321</div>
322
323<div class="doc_text">
324
325<ul>
326
327<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]328
329<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]330support for floating point data types of any size other than 32 and 64
331bits.</li>
332
333<li>The following Unix system functionality has not been tested and may not
334work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]335 <ol>
336 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
337 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
338 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
339 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
340 - These functions have not been tested.
341 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]342
343<li>Although many GCC extensions are supported, some are not. In particular,
344 the following extensions are known to <b>not be</b> supported:
345 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]346 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
347 <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>
348 <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>
349 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
350 <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>
351 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
352 <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>
353 <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>
354 <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>
355 <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>
356 <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>
357 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
358 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]359 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]360
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]361 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]362 attribute means that the LLVM compiler ignores the presence of the attribute,
363 but the code should still work. An unsupported attribute is one which is
364 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]365 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]366
367 <ol>
368 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
369 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]370 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]371
372 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]373
374 Declaring that functions have no side effects, or that they can never
375 return.<br>
376
377 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
378 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
379 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
380
381 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
382 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
383 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
384
385 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
386 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
387 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]388
389 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
390 Specifying attributes of variables.<br>
391 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
392 <tt>deprecated</tt>, <tt>transparent_union</tt>,
393 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]394
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]395 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
396 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
397 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]398 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]399
400 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.
401 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
402 <tt>deprecated</tt>, <tt>may_alias</tt>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]403
404 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
405 all target specific attributes.</li>
406
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]407 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
408 Other built-in functions.<br>
409 We support all builtins which have a C language equivalent (e.g.,
410 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
411 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]412 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]413
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]414 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]415
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]416 <p>The following extensions <b>are</b> known to be supported:</p>
417
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]418 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]419 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
420 <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>
421 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
422 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
423 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
424 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
425 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
426 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
427 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
428 <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>
429 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
430 <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>
431 <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>
432 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
433 <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>
434 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
435 <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>
436 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
437 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
438 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
439 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
440 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
441 <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>
442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
443 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
444 <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>
445 <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>
446 <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>
447 <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>
448 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]449 </ol></li>
450
451</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]452
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]453<p>If you run into GCC extensions which have not been included in any of these
454lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]455
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]456</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]457
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]458<!-- ======================================================================= -->
459<div class="doc_subsection">
460 <a name="c++-fe">Known problems with the C++ front-end</a>
461</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]462
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]463<div class="doc_text">
464
465<p>For this release, the C++ front-end is considered to be fully functional but
466of <b>beta</b> quality. It has been tested and works for a number of simple
467programs that collectively exercise most of the language. Nevertheless, it has
468not been in use as long as the C front-end. Please report any bugs or
469problems.</p>
470
471</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]472
473<!-- _______________________________________________________________________ -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]474<div class="doc_subsubsection">
475 Bugs
476</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]477
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]478<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]479
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]480<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]481<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]482 front-end</a></li>
483</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]484
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]485</div>
486
487<!-- _______________________________________________________________________ -->
488<div class="doc_subsubsection">
489 Notes
490</div>
491
492<div class="doc_text">
493
494<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]495
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]496<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
497parser is significantly more standards compliant (and picky) than prior GCC
498versions. For more information, see the C++ section of the <a
499href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.<p>
500
501<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]502 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]503 function and in the <tt>setjmp</tt> receiver function may not be run.
504 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]505 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]506
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]507<li>The LLVM C++ front-end follows the <a
508 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
509 This document, which is not Itanium specific, specifies a standard for name
510 mangling, class layout, v-table layout, RTTI formats, and other C++
511 representation issues. Because we use this API, code generated by the LLVM
512 compilers should be binary compatible with machine code generated by other
513 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
514 <i>However</i>, the exception handling mechanism used by LLVM is very
515 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]516 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]517
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]518</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]519
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]520</div>
521
522<!-- ======================================================================= -->
523<div class="doc_subsection">
524 <a name="x86-be">Known problems with the X86 back-end</a>
525</div>
526
527<div class="doc_text">
528
529<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]530
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]531<li>The X86 code generator <a
Chris Lattnerc4788bb2003-10-08 06:01:38 +0000[diff] [blame]532href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]533support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]534or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]535
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]536</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]537
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]538</div>
539
540<!-- ======================================================================= -->
541<div class="doc_subsection">
542 <a name="sparc-be">Known problems with the Sparc back-end</a>
543</div>
544
545<div class="doc_text">
546
547<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]548
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]549<li>The Sparc code generator <a
Chris Lattnerc4788bb2003-10-08 06:01:38 +0000[diff] [blame]550href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]551support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]552or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]553
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]554</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]555
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]556</div>
557
558<!-- ======================================================================= -->
559<div class="doc_subsection">
560 <a name="c-be">Known problems with the C back-end</a>
561</div>
562
563<div class="doc_text">
564
565<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]566
567<li>The C back-end produces code that violates the ANSI C Type-Based Alias
568Analysis rules. As such, special options may be necessary to compile the code
569(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]570problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]571
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]572<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]573cannot include special floating point numbers like Not-A-Number or
574Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]575
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]576<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]577supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]578frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]579
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]580<li>The code produces by the C back-end has only been tested with the Sun CC,
581GCC, and Intel compilers. It is possible that it will have to be adjusted to
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]582support other C compilers.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]583
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]584</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]585
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]586</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]587
588<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]589<div class="doc_section">
590 <a name="additionalinfo">Additional Information</a>
591</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]592<!-- *********************************************************************** -->
593
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]594<div class="doc_text">
595
596<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]597including mailing lists publications describing algorithms and components
598implemented in LLVM. The web page also contains versions of the API
599documentation which is up-to-date with the CVS version of the source code. You
600can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]601the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]602
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]603<p>If you have any questions or comments about LLVM, please feel free to contact
604us via the mailing lists.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]606</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]607
608<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]609
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]610<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]611<address>
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Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]617 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]621</body>
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