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gerrit-public.fairphone.software / toolchain / llvm-project / 6f9e65ef7a2f89552582312ee540e27dd5dbcd57 / . / 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
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]58<p>Note that if you are reading this file from CVS, this document applies
59to the <i>next</i> release, not the current one. To see the release notes for
60the current or previous releases, see the <a
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]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
Chris Lattnerba7bd472003-12-06 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 Lattnerd98fecb2003-12-06 20:24:46 +0000[diff] [blame]76includes a few new features, such as a simple profiler, support for Mac OS/X,
Chris Lattnerd25f26f2003-12-12 04:45:09 +0000[diff] [blame]77better interoperability with external source bases, a new example language
John Criswell604cd3c2003-12-12 19:54:20 +0000[diff] [blame]78front-end, and improvements in a few optimizations.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]79
Chris Lattner6f9e65e2003-12-12 21:33:08 +0000[diff] [blame^]80<p>At this time, LLVM is known to correctly compile and run all non-unwinding C
81&amp; C++ SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist
82benchmarks. It has also been used to compile <b>many</b> other programs. LLVM
83now also works with a broad variety of C++ programs, though it has still
84received much less testing than the C front-end.
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]85</p>
86
87<p>
Chris Lattner6f9e65e2003-12-12 21:33:08 +0000[diff] [blame^]88The LLVM native code generators are very stable, but do not currently support
89unwinding (exception throwing or <tt>longjmp</tt>ing), which prevent them from
90working with programs like the <tt>253.perlbmk</tt> in SPEC CPU2000. The C
91backend and the rest of LLVM does support these programs however, so you can
92still use LLVM with them. Support for unwinding will be added in a future
93release.
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]94</p>
95
96
97<!--=========================================================================-->
98<div class="doc_subsubsection">
99This release implements the following new features:
100</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]101
102<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]103<li><a
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]104href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000528.html">A new
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]105LLVM profiler, similar to gprof</a> is available</li>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]106
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]107<li>LLVM and the C/C++ front-end now compile on Mac OS/X! Mac OS/X users can
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]108now explore the LLVM optimizer with the C backend and interpreter. Note that
109LLVM requires GCC 3.3 on Mac OS/X.</li>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]110
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]111<li>LLVM has been <a
Chris Lattner74a22992003-11-11 23:46:35 +0000[diff] [blame]112href="http://mail.cs.uiuc.edu/pipermail/llvmdev/2003-November/000554.html">moved
113into an 'llvm' C++ namespace</a>, for easier integration with third-party
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]114code. Note that due to lack of namespace support in GDB 5.x, you will probably
115want to upgrade to GDB 6 or better to debug LLVM code.</li>
John Criswellf1387a52003-11-26 20:09:49 +0000[diff] [blame]116
117<li>
118The build system now copies Makefiles dynamically from the source tree to the
119object tree as subdirectories are built. This means that:
120 <ol>
121 <li>
122 New directories can be added to the source tree, and the build will
123 automatically pick them up (i.e. no need to re-run <tt>configure</tt>).
124 </li>
125
126 <li>
127 You will need to build LLVM from the top of the object tree once to ensure
128 that all of the Makefiles are copied into the object tree subdirectories.
129 </li>
130 </ol>
131</li>
132
Chris Lattnerd25f26f2003-12-12 04:45:09 +0000[diff] [blame]133<li>A front-end for "Stacker" (a simple Forth-like language) is now
134 <a href="http://llvm.cs.uiuc.edu/PR136">included in the main LLVM tree</a>.
135 Additionally, Reid Spencer, the author, contributed a document <a href="Stacker.html">describing his experiences writing Stacker, and the language itself</a>. This document is invaluable for others writing front-ends targetting LLVM.</li>
136
Chris Lattnere4151eb2003-12-11 23:31:21 +0000[diff] [blame]137<li>The <tt>configure</tt> script will now configure all projects placed in the
138<tt>llvm/projects</tt> directory.</li>
139
Chris Lattner88e24cf2003-12-12 04:51:00 +0000[diff] [blame]140<li>The <tt>-tailcallelim</tt> pass can now introduce "accumulator" variables
141 to transform functions in many common cases that it could not before.</li>
142
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]143<li>The <tt>-licm</tt> pass can now sink instructions out the bottom of loops
144in addition to being able to hoist them out the top.</li>
145
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]146<li>The <tt>-basicaa</tt> pass (the default alias analysis) has been upgraded
147to be <a href="http://llvm.cs.uiuc.edu/PR86">significantly more
148precise</a>.</li>
Chris Lattnere4151eb2003-12-11 23:31:21 +0000[diff] [blame]149
Chris Lattner4b34b352003-12-12 05:52:39 +0000[diff] [blame]150<li>LLVM 1.1 implements a simple size optimization for LLVM bytecode files.
151 This means that the 1.1 files are smaller than 1.0, but that 1.0 won't
152 read 1.1 bytecode files.</li>
John Criswell604cd3c2003-12-12 19:54:20 +0000[diff] [blame]153
154<li><a href="http://llvm.cs.uiuc.edu/PR140">The gccld program produces a runner script that includes command-line options to load the necessary shared objects.</a></li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]155</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]156
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]157
158<!--=========================================================================-->
159<div class="doc_subsubsection">
160In this release, the following missing features were implemented:
161</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]162
163<ol>
164<li><a href="http://llvm.cs.uiuc.edu/PR88">The interpreter does not support
165invoke or unwind</a></li>
Misha Brukman133b35e2003-11-14 03:30:43 +0000[diff] [blame]166
167<li><a href="http://llvm.cs.uiuc.edu/PR99">Interpreter does not support the
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]168<tt>vaarg</tt> instruction</a></li>
Misha Brukman133b35e2003-11-14 03:30:43 +0000[diff] [blame]169
Brian Gaekec5961312003-11-16 23:49:26 +0000[diff] [blame]170<li><a href="http://llvm.cs.uiuc.edu/PR117">llvm-nm cannot read archive
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]171files</a></li>
Brian Gaekec5961312003-11-16 23:49:26 +0000[diff] [blame]172
Brian Gaeke4c563b82003-12-11 04:40:58 +0000[diff] [blame]173<li><a href="http://llvm.cs.uiuc.edu/PR146">Interpreter does not handle
174setne constant expression</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]175</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]176
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]177
178<!--=========================================================================-->
179<div class="doc_subsubsection">
180In this release, the following Quality of Implementation issues were
181fixed:
182</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]183
184<ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]185
Chris Lattnereb8b1842003-12-12 04:56:02 +0000[diff] [blame]186<li>The C++ front-end now compiles functions to
187 <a href="http://llvm.cs.uiuc.edu/PR29">use the linkonce linkage type</a>
188 more, giving the optimizer more freedom.</a></li>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]189
Chris Lattnereb8b1842003-12-12 04:56:02 +0000[diff] [blame]190<li>The C front-end now <a href="http://llvm.cs.uiuc.edu/PR84">generates
191 type-safe code</a> in several cases that it did not before, which prevented
192 some important optimizations.</li>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]193
Chris Lattnereb8b1842003-12-12 04:56:02 +0000[diff] [blame]194<li>The LLVM build system has been taught to catch some common configuration
195 problems that <a href="http://llvm.cs.uiuc.edu/PR96">caused it to get
196 horribly confused</a> before.</li>
Chris Lattnerb2e4d6d2003-11-16 20:25:24 +0000[diff] [blame]197
Chris Lattnereb8b1842003-12-12 04:56:02 +0000[diff] [blame]198<li>The LLVM header files are now
199 <a href="http://llvm.cs.uiuc.edu/PR114">-Wold-style-cast clean</a>.</li>
Chris Lattnerb2e4d6d2003-11-16 20:25:24 +0000[diff] [blame]200
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]201<li>The LLVM bytecode reader has been <a
202href="http://llvm.cs.uiuc.edu/PR127">sped up a lot</a> (up to 4x in some
203cases).</li>
204
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]205<li>In C++, methods and functions in anonymous namespaces <a href="http://llvm.cs.uiuc.edu/PR85">now get internal linkage</a>.</li>
Chris Lattner3a9b2322003-11-22 01:14:58 +0000[diff] [blame]206
Chris Lattner0548bc22003-11-26 08:20:34 +0000[diff] [blame]207<li>Constant initializers now generate loops instead of potentially <a href="http://llvm.cs.uiuc.edu/PR75">huge amounts of straight-line code</a>.</li>
208
Chris Lattner8139b782003-11-27 09:51:54 +0000[diff] [blame]209<li>Code for running C++ destructors is now properly shared when possible. Before, the C++ front-end
210<a href="http://llvm.cs.uiuc.edu/PR11">generated N^2 amounts of duplicated cleanup code</a> in some cases.</li>
Chris Lattner542d24f2003-12-12 07:26:25 +0000[diff] [blame]211
212<li>The JIT used to <a href="http://llvm.cs.uiuc.edu/PR177">generate code for
213 all functions pointed to by globals</a> immediately, before the program
214 started execution, but now it waits until the first time they are called to
215 compile them. This dramatically speeds up short runs of large C++ programs,
216 which often have large numbers of functions pointed to by vtables.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]217</ol>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]218
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]219
220<!--=========================================================================-->
221<div class="doc_subsubsection">
222In this release, the following bugs in the previous release were fixed:
223</div>
224
225<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]226
227<ol>
Chris Lattner25fd5c12003-10-27 05:41:39 +0000[diff] [blame]228<li><a href="http://llvm.cs.uiuc.edu/PR57">[inliner] Inlining invoke with PHI in unwind target is broken</a></li>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]229<li><a href="http://llvm.cs.uiuc.edu/PR58">[linker] linkonce globals should link successfully to external globals</a></li>
Chris Lattnera1a090e2003-10-29 07:17:13 +0000[diff] [blame]230<li><a href="http://llvm.cs.uiuc.edu/PR64">[constmerge] Constant merging pass merges constants with external linkage</a></li>
Chris Lattner5b83b562003-10-29 18:49:14 +0000[diff] [blame]231<li><a href="http://llvm.cs.uiuc.edu/PR66">[scalarrepl] Scalar Replacement of aggregates is decimating structures it shouldn't be</a></li>
Chris Lattnera2bd4e02003-10-30 01:20:42 +0000[diff] [blame]232<li><a href="http://llvm.cs.uiuc.edu/PR70">[instcombine] Resolving invoke inserts cast after terminator</a></li>
Chris Lattnera306dd22003-10-30 01:43:33 +0000[diff] [blame]233<li><a href="http://llvm.cs.uiuc.edu/PR71">llvm-as crashes when labels are used in phi nodes</a></li>
Chris Lattnerb45e1f92003-10-30 16:20:15 +0000[diff] [blame]234<li><a href="http://llvm.cs.uiuc.edu/PR72">[build problem] Callgraph.cpp not pulled in from libipa.a</a></li>
Chris Lattner9dd6a822003-11-16 22:11:42 +0000[diff] [blame]235<li><a href="http://llvm.cs.uiuc.edu/PR77">Variables in scope of output setjmp
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]236calls should be volatile</a> (Note that this does not effect correctness on
237many platforms, such as X86).</li>
Chris Lattneref114d52003-11-03 20:08:08 +0000[diff] [blame]238<li><a href="http://llvm.cs.uiuc.edu/PR83">[X86] Emission of global bool initializers broken</a></li>
Chris Lattnerab77bc52003-11-05 06:30:04 +0000[diff] [blame]239<li><a href="http://llvm.cs.uiuc.edu/PR91">[gccld] The -r (relinking) option does not work correctly</a></li>
Chris Lattner34596d72003-11-07 04:46:56 +0000[diff] [blame]240<li><a href="http://llvm.cs.uiuc.edu/PR92">[bcreader] Cannot read shift constant expressions from bytecode file</a></li>
241<li><a href="http://llvm.cs.uiuc.edu/PR93">[lowersetjmp] Lowersetjmp pass breaks dominance properties!</a></li>
Chris Lattner881cb482003-11-09 19:44:07 +0000[diff] [blame]242<li><a href="http://llvm.cs.uiuc.edu/PR95">SymbolTable::getUniqueName is very inefficient</a></li>
Brian Gaeke4c563b82003-12-11 04:40:58 +0000[diff] [blame]243<li><a href="http://llvm.cs.uiuc.edu/PR97">bugpoint must not pass -R&lt;directory&gt; to Mach-O linker</a></li>
Chris Lattner34596d72003-11-07 04:46:56 +0000[diff] [blame]244<li><a href="http://llvm.cs.uiuc.edu/PR98">[buildscripts] Building into objdir with .o in it fails</a></li>
Chris Lattner699a58d2003-11-08 05:18:50 +0000[diff] [blame]245<li><a href="http://llvm.cs.uiuc.edu/PR101">[setjmp/longjmp] Linking C programs which use setjmp/longjmp sometimes fail with references to the C++ runtime library!</a></li>
Chris Lattnera7235372003-11-12 04:42:37 +0000[diff] [blame]246<li><a href="http://llvm.cs.uiuc.edu/PR107">AsmParser Misses Symbol Redefinition Error</a></li>
Brian Gaeke7aeb2b72003-11-11 21:52:34 +0000[diff] [blame]247<li><a href="http://llvm.cs.uiuc.edu/PR108">gccld -Lfoo -lfoo fails to find ./foo/libfoo.a</a></li>
Chris Lattner7c04a292003-11-14 06:42:01 +0000[diff] [blame]248<li><a href="http://llvm.cs.uiuc.edu/PR110">[bcreader] Incorrect cast causes misread forward constant references</a></li>
Chris Lattner2f486b82003-11-16 21:42:48 +0000[diff] [blame]249<li><a href="http://llvm.cs.uiuc.edu/PR116">[adce] ADCE considers blocks without postdominators to be unreachable</a></li>
Chris Lattnercf40b3f2003-11-18 23:04:02 +0000[diff] [blame]250<li><a href="http://llvm.cs.uiuc.edu/PR123">[X86] div and rem constant exprs invalidate iterators!</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]251<li><a href="http://llvm.cs.uiuc.edu/PR130">[vmcore] Symbol table doesn't rename colliding variables during type resolution</a></li>
Brian Gaeke4c563b82003-12-11 04:40:58 +0000[diff] [blame]252<li><a href="http://llvm.cs.uiuc.edu/PR138">Archive reader does not understand 4.4BSD/Mac OS X long filenames</a></li>
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]253<li><a href="http://llvm.cs.uiuc.edu/PR30">[llvm-ar] Command line arguments have funny syntax</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]254</ol>
255
256
257<p>Bugs in the C/C++ front-end:</p>
258
259<ol>
260<li><a href="http://llvm.cs.uiuc.edu/PR59">C++ frontend can crash when compiling virtual base classes</a></li>
261<li><a href="http://llvm.cs.uiuc.edu/PR62">C backend fails on constant cast expr to ptr-to-anonymous struct</a></li>
262<li><a href="http://llvm.cs.uiuc.edu/PR63">#ident is not recognized by C frontend</a></li>
263<li><a href="http://llvm.cs.uiuc.edu/PR65">C front-end miscompiles the builtin_expect intrinsic!</a></li>
264<li><a href="http://llvm.cs.uiuc.edu/PR67">1.0 precompiled libstdc++ does not include wchar_t support</a></li>
265<li><a href="http://llvm.cs.uiuc.edu/PR68">llvmgcc asserts when compiling functions renamed with asm's</a></li>
266<li><a href="http://llvm.cs.uiuc.edu/PR69">C frontend crashes on some programs with lots of types.</a></li>
267<li><a href="http://llvm.cs.uiuc.edu/PR79">llvm-gcc crashes compiling global union initializer</a></li>
268<li><a href="http://llvm.cs.uiuc.edu/PR80">C front-end crash on empty structure</a></li>
269<li><a href="http://llvm.cs.uiuc.edu/PR81">CFrontend crashes when compiling C99 compound expressions</a></li>
270<li><a href="http://llvm.cs.uiuc.edu/PR87">llvm-gcc infinite loops on "case MAXINT:"</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR89">[C++] Catch blocks make unparsable labels</a></li>
272<li><a href="http://llvm.cs.uiuc.edu/PR90">[C++] Initializing array with constructable objects fail</a></li>
273<li><a href="http://llvm.cs.uiuc.edu/PR94">llvm-gcc tries to add bools</a></li>
274<li><a href="http://llvm.cs.uiuc.edu/PR104">[c++] C++ Frontend lays out superclasses like anonymous bitfields!</a></li>
275<li><a href="http://llvm.cs.uiuc.edu/PR54">C front-end miscompiles unsigned enums whose LLVM types are signed</a></li>
276<li><a href="http://llvm.cs.uiuc.edu/PR112">Casting a string constant to void crashes llvm-gcc</a></li>
Chris Lattnercf40b3f2003-11-18 23:04:02 +0000[diff] [blame]277<li><a href="http://llvm.cs.uiuc.edu/PR125">[llvmg++] Enum types are incorrectly shrunk to smaller than 'int' size</a></li>
278<li><a href="http://llvm.cs.uiuc.edu/PR128">[llvmg++] Cannot use pointer to member to initialize global</a></li>
Chris Lattner983c6672003-11-19 01:08:24 +0000[diff] [blame]279<li><a href="http://llvm.cs.uiuc.edu/PR131">[llvm-gcc] ?: operator as lvalue not implemented</a></li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]280<li><a href="http://llvm.cs.uiuc.edu/PR133">[C/C++] Bogus warning about taking the address of 'register' variable</a></li>
Chris Lattnerc4fe9722003-11-20 01:07:41 +0000[diff] [blame]281<li><a href="http://llvm.cs.uiuc.edu/PR113">crash assigning into an array in a struct which contains a bitfield</a>.</li>
282<li><a href="http://llvm.cs.uiuc.edu/PR6">Oversized integer bitfields cause crash</a></li>
Chris Lattner0548bc22003-11-26 08:20:34 +0000[diff] [blame]283<li><a href="http://llvm.cs.uiuc.edu/PR141">[llvm-gcc] Bitfields &amp; large array don't mix well</a></li>
Chris Lattner16bbed22003-11-20 19:30:17 +0000[diff] [blame]284<li><a href="http://llvm.cs.uiuc.edu/PR132">[llvm-gcc] Complex division is not supported</a></li>
Chris Lattner5eac2d62003-11-20 20:59:57 +0000[diff] [blame]285<li><a href="http://llvm.cs.uiuc.edu/PR143">[llvm-gcc] Illegal union field reference</a></li>
Chris Lattner83f43a02003-11-25 08:49:12 +0000[diff] [blame]286<li><a href="http://llvm.cs.uiuc.edu/PR148">[llvmg++] Front-end attempts to return structure by value</a></li>
Chris Lattner86d5c1c2003-11-26 01:18:49 +0000[diff] [blame]287<li><a href="http://llvm.cs.uiuc.edu/PR152">[llvmg++] Pointer to member initializers not supported in constructors</a></li>
288<li><a href="http://llvm.cs.uiuc.edu/PR155">[llvm-gcc] crash on union initialization</a></li>
Chris Lattnerb27353c2003-11-26 02:48:00 +0000[diff] [blame]289<li><a href="http://llvm.cs.uiuc.edu/PR124">[llvm-g++] ?: expressions do not run correct number of destructors!</a></li>
Chris Lattner0548bc22003-11-26 08:20:34 +0000[diff] [blame]290<li><a href="http://llvm.cs.uiuc.edu/PR157">[llvm-gcc] Pointer & constant results in invalid shift</a></li>
Chris Lattnerd2a55f302003-12-08 06:33:19 +0000[diff] [blame]291<li><a href="http://llvm.cs.uiuc.edu/PR165">[llvmg++] call through array of pointers to member functions causes assertion</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]292</ol>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]293
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]294</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]295
296<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]297<div class="doc_section">
298 <a name="portability">Portability and Supported Platforms</a>
299</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]300<!-- *********************************************************************** -->
301
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]302<div class="doc_text">
303
304<p>LLVM has been extensively tested on Intel and AMD machines running Red
John Criswell604cd3c2003-12-12 19:54:20 +0000[diff] [blame]305Hat Linux and has been tested on Sun UltraSPARC workstations running Solaris 8.
306Additionally,
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]307LLVM works on Mac OS/X 10.3 and above, but only with the C backend or
308interpreter (no native backend for the PowerPC is available yet).
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]309The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner14b5d5a2003-11-08 05:22:09 +0000[diff] [blame]310work on more platforms than that. However, it is likely that we
311missed something, and that minor porting is required to get LLVM to work on
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]312new platforms. We welcome portability patches and error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]313
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]314</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]315
316<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]317<div class="doc_section">
318 <a name="knownproblems">Known Problems</a>
319</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]320<!-- *********************************************************************** -->
321
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]322<div class="doc_text">
323
324<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]325component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]326sections. If you run into a problem, please check the <a
327href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a>, and submit a bug if
328there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]329
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]330</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]331
332<!-- _______________________________________________________________________ -->
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]333<!--
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]334</ul><h4><a name="portability"><hr size=0>Portability Problems</h4><ul>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]335-->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]336
337
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]338<!-- ======================================================================= -->
339<div class="doc_subsection">
340 <a name="core">Known problems with the LLVM Core</a>
341</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]342
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]343<div class="doc_text">
344
345<ul>
346
347<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
348work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]349
350<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]351such, execution of a threaded program could cause these data structures to be
352corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]353
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]354<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]355
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]356<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]357table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]358
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]359<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]360more than 256 elements</a>.</li>
361
362</ul>
363
364</div>
365
366<!-- ======================================================================= -->
367<div class="doc_subsection">
368 <a name="c-fe">Known problems with the C front-end</a>
369</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]370
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]371<!-- _______________________________________________________________________ -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]372<div class="doc_subsubsection">
373 Bugs
374</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]375
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]376<div class="doc_text">
377
378<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]379
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]380<li>C99 Variable sized arrays do not release stack memory when they go out of
381 scope. Thus, the following program may run out of stack space:
382<pre>
383 for (i = 0; i != 1000000; ++i) {
384 int X[n];
385 foo(X);
386 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]387</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]388
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]389</ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]390
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]391</div>
392
393<!-- _______________________________________________________________________ -->
394<div class="doc_subsubsection">
395 Notes
396</div>
397
398<div class="doc_text">
399
400<ul>
401
402<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]403
404<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]405support for floating point data types of any size other than 32 and 64
406bits.</li>
407
408<li>The following Unix system functionality has not been tested and may not
409work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]410 <ol>
411 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
412 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
413 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
414 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
415 - These functions have not been tested.
416 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]417
418<li>Although many GCC extensions are supported, some are not. In particular,
419 the following extensions are known to <b>not be</b> supported:
420 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]421 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
422 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels, and computed gotos.</li>
423 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>: As in Algol and Pascal, lexical scoping of functions.</li>
424 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
425 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
426 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands</li>
427 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Asm-Labels.html#Asm%20Labels">Asm Labels</a>: Specifying the assembler name to use for a C symbol.</li>
428 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
429 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
430 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html#Vector%20Extensions">Vector Extensions</a>: Using vector instructions through built-in functions.</li>
431 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Target-Builtins.html#Target%20Builtins">Target Builtins</a>: Built-in functions specific to particular targets.</li>
432 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
433 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]434 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]435
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]436 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]437 attribute means that the LLVM compiler ignores the presence of the attribute,
438 but the code should still work. An unsupported attribute is one which is
439 ignored by the LLVM compiler, which will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]440 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]441
442 <ol>
443 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
444 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]445 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]446
447 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]448
449 Declaring that functions have no side effects, or that they can never
450 return.<br>
451
452 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
453 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
454 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
455
456 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
457 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
458 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
459
460 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
461 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
462 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]463
464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
465 Specifying attributes of variables.<br>
466 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
467 <tt>deprecated</tt>, <tt>transparent_union</tt>,
468 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]469
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]470 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
471 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
472 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]473 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]474
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]476 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]477 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]478
479 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
480 all target specific attributes.</li>
481
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
483 Other built-in functions.<br>
484 We support all builtins which have a C language equivalent (e.g.,
485 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
486 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]487 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]488
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]489 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]490
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]491 <p>The following extensions <b>are</b> known to be supported:</p>
492
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]493 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]494 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
495 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
498 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
500 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
501 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
502 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
503 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variadic-Macros.html#Variadic%20Macros">Variadic Macros</a>: Macros with a variable number of arguments.</li>
504 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
505 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]506 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
508 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions or arrays as values.</li>
509 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]510 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]511 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
515 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
516 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Character-Escapes.html#Character%20Escapes">Character Escapes</a>: <code>\e</code> stands for the character &lt;ESC&gt;.</li>
517 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
518 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
519 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html#Alternate%20Keywords">Alternate Keywords</a>:<code>__const__</code>, <code>__asm__</code>, etc., for header files.</li>
520 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Incomplete-Enums.html#Incomplete%20Enums">Incomplete Enums</a>: <code>enum foo;</code>, with details to follow.</li>
521 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
522 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed%20Fields">Unnamed Fields</a>: Unnamed struct/union fields within structs/unions.</li>
523 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]524 </ol></li>
525
526</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]527
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]528<p>If you run into GCC extensions which have not been included in any of these
529lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]531</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]533<!-- ======================================================================= -->
534<div class="doc_subsection">
535 <a name="c++-fe">Known problems with the C++ front-end</a>
536</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]537
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]538<div class="doc_text">
539
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]540<p>For this release, the C++ front-end is considered to be fully functional, but
541has not been tested as thoroughly as the C front-end. It has been tested and
542works for a number of non-trivial programs, but there may be lurking bugs.
543Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]544
545</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]546
547<!-- _______________________________________________________________________ -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]548<div class="doc_subsubsection">
549 Bugs
550</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]551
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]552<div class="doc_text">
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<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]556 front-end</a></li>
557</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]558
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]559</div>
560
561<!-- _______________________________________________________________________ -->
562<div class="doc_subsubsection">
563 Notes
564</div>
565
566<div class="doc_text">
567
568<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]569
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]570<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
571parser is significantly more standards compliant (and picky) than prior GCC
572versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]573href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]574
575<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]576 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]577 function and in the <tt>setjmp</tt> receiver function may not be run.
578 Objects in intervening stack frames will be destroyed however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]579 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]580
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]581<li>The LLVM C++ front-end follows the <a
582 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
583 This document, which is not Itanium specific, specifies a standard for name
584 mangling, class layout, v-table layout, RTTI formats, and other C++
585 representation issues. Because we use this API, code generated by the LLVM
586 compilers should be binary compatible with machine code generated by other
587 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
588 <i>However</i>, the exception handling mechanism used by LLVM is very
589 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]590 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]591
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]592</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]593
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]594</div>
595
596<!-- ======================================================================= -->
597<div class="doc_subsection">
598 <a name="x86-be">Known problems with the X86 back-end</a>
599</div>
600
601<div class="doc_text">
602
603<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]604
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]605<li>The X86 code generator <a
Chris Lattnerc4788bb2003-10-08 06:01:38 +0000[diff] [blame]606href="http://llvm.cs.uiuc.edu/PR16">does not currently
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]607support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]608or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]609
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]610</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]611
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]612</div>
613
614<!-- ======================================================================= -->
615<div class="doc_subsection">
616 <a name="sparc-be">Known problems with the Sparc back-end</a>
617</div>
618
619<div class="doc_text">
620
621<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]622
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]623<li>The Sparc code generator <a
Chris Lattnerc4788bb2003-10-08 06:01:38 +0000[diff] [blame]624href="http://llvm.cs.uiuc.edu/PR15">does not currently
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]625support the <tt>unwind</tt> instruction</a>, so code that throws a C++ exception
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]626or calls the C <tt>longjmp</tt> function will abort.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]627
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]628</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]629
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]630</div>
631
632<!-- ======================================================================= -->
633<div class="doc_subsection">
634 <a name="c-be">Known problems with the C back-end</a>
635</div>
636
637<div class="doc_text">
638
639<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]640
641<li>The C back-end produces code that violates the ANSI C Type-Based Alias
642Analysis rules. As such, special options may be necessary to compile the code
643(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]644problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]645
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]646<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]647cannot include special floating point numbers like Not-A-Number or
648Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]649
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]650<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]651supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]652frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]653
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]654</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]655
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]656</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]657
658<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]659<div class="doc_section">
660 <a name="additionalinfo">Additional Information</a>
661</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]662<!-- *********************************************************************** -->
663
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]664<div class="doc_text">
665
666<p>A wide variety of additional information is available on the LLVM web page,
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]667including mailing lists publications describing algorithms and components
668implemented in LLVM. The web page also contains versions of the API
669documentation which is up-to-date with the CVS version of the source code. You
670can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]671the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]672
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]673<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]674us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
675lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]676
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]677</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]678
679<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]681<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]682<address>
683 <a href="http://jigsaw.w3.org/css-validator/"><img
684 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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687
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]688 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]689 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]690</address>
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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]692</body>
693</html>