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Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]6 <title>LLVM 1.2 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]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">
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]11 LLVM 1.2 Release Notes
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]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 Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]21 <li><a href="#experimental">Experimental features included with this release</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">
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]33 <p><b>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a></b><p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]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
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]45infrastructure, release 1.2. Here we describe the status of LLVM, including any
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]46known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]47version of this document can be found on the <a
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]48href="http://llvm.cs.uiuc.edu/releases/1.2/">LLVM 1.2 web site</a>. If you are
John Criswell86a3a482003-12-18 16:43:17 +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
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]73<p>
74This is the third public release of the LLVM compiler infrastructure. This
75release incorporates several <a href="#newfeatures">new features</a> (including
76exception handling support for the native code generators, the start of a
77source-level debugger, and profile guided optimizer components), many <a
78href="#qualityofimp">speedups</a> and <a href="#codequality">code quality</a>
79improvements, documentation improvements, and a small collection of important <a
80href="bugfix">bug fixes</a>. Overall, this is our highest quality release to
81date, and we encourage you to upgrade if you are using LLVM 1.0 or 1.1.
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]82</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]84<p><B> FIXME: UPDATE: </b>
85At this time, LLVM is known to correctly compile and run all C
Chris Lattner6f9e65e2003-12-12 21:33:08 +0000[diff] [blame]86&amp; C++ SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist
87benchmarks. It has also been used to compile <b>many</b> other programs. LLVM
88now also works with a broad variety of C++ programs, though it has still
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]89received less testing than the C front-end.
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]90</p>
91
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]92<!--=========================================================================-->
93<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]94<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]95</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]96
97<ol>
Chris Lattner35630ad2004-02-08 21:20:42 +0000[diff] [blame]98<li><a href="SourceLevelDebugging.html">A new LLVM source-level debugger has been started.</a></li>
Chris Lattnere0f79a62004-02-23 03:51:34 +0000[diff] [blame]99<li>LLVM 1.2 encodes bytecode files for large programs in 10-30% less space.</li>
Chris Lattnerd2d7ccd2004-03-11 00:50:54 +0000[diff] [blame]100<li>LLVM can now feed profile information back into optimizers for Profile Guided Optimization, includes a simple basic block reordering pass, and supports edge profiling as well as function and block-level profiling.</li>
Chris Lattnere0f79a62004-02-23 03:51:34 +0000[diff] [blame]101<li>The LLVM JIT lazily initializes global variables, reducing startup time for programs with lots of globals (like C++ programs).</li>
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]102
103<li>The build and installation infrastructure in this release is dramatically
104improved. There is now an <a
105href="http://llvm.cs.uiuc.edu/PR105"><tt>autoconf/AutoRegen.sh</tt> script</a>
106that you can run to rebuild the <tt>configure</tt> script and its associated
107files as well as beta support for "<a
108href="http://llvm.cs.uiuc.edu/PR208">make</a> <a
109href="http://llvm.cs.uiuc.edu/PR220">install</a>" and <a
110href="http://llvm.cs.uiuc.edu/PR203">RPM package generation</a>.</li>
111
Chris Lattnere0f79a62004-02-23 03:51:34 +0000[diff] [blame]112<li>The "tblgen" tool is <a href="TableGenFundamentals.html">now documented</a>.</li>
Chris Lattnerd2d7ccd2004-03-11 00:50:54 +0000[diff] [blame]113<li>The target-independent code generator got several improvements:
Alkis Evlogimenos6cf43732004-02-27 05:26:23 +0000[diff] [blame]114<ul>
Chris Lattnerd2d7ccd2004-03-11 00:50:54 +0000[diff] [blame]115 <li>It can now fold spill code into instructions (on targets that support it).</li>
116 <li>A generic machine code spiller/rewriter was added. It provides an API for
117 global register allocators to eliminate virtual registers and add the
118 appropriate spill code.</li>
119 <li>The represenation of machine code basic blocks is more efficient and has
120 an easier to use interface.</li>
Alkis Evlogimenos6cf43732004-02-27 05:26:23 +0000[diff] [blame]121</ul>
122</li>
Chris Lattner7479e1e2004-02-24 03:50:24 +0000[diff] [blame]123<li><a href="http://llvm.cs.uiuc.edu/PR253">LLVM now no longer depends on the boost library</a>.</li>
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]124<li>The X86 backend now generates <b>substantially</b> better native code, and is faster.</li>
125<li>The C backend has been turned moved from the "llvm-dis" tool to the "llc"
126tool. You can activate it with "<tt>llc -march=c foo.bc -o foo.c</tt>".</li>
Chris Lattner19cfc402004-02-26 08:02:57 +0000[diff] [blame]127<li>LLVM includes a new interprocedural optimization that marks global variables
128"constant" when they are provably never written to.</li>
Chris Lattnerd2d7ccd2004-03-11 00:50:54 +0000[diff] [blame]129<li>LLVM now includes a new interprocedural optimization that converts small "by reference" arguments to "by value" arguments, which is often improve the performance of C++ programs substantially.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]130</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]131
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]132
133<!--=========================================================================-->
134<div class="doc_subsubsection">
135In this release, the following missing features were implemented:
136</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]137
138<ol>
Chris Lattner50ceee12004-02-08 19:59:05 +0000[diff] [blame]139<li><a href="http://llvm.cs.uiuc.edu/PR16">Exception handling support in the X86
140&amp; Sparc native code generators</a></li>
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]141<li>The C/C++ front-end now support the GCC <tt>__builtin_return_address</tt> and <tt>__builtin_frame_address</tt> extensions.</li>
Chris Lattnerc6acc102004-02-23 03:36:36 +0000[diff] [blame]142<li><a href="http://llvm.cs.uiuc.edu/PR249">[X86] Missing cast from ULong -> Double, cast FP -> bool and support for -9223372036854775808</a></li>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame^]143<li>The C/C++ front-end <a href="http://llvm.cs.uiuc.edu/PR273">now supports</a>
144the "<a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">labels as values</a>" GCC extension, often used to build "threaded interpreters".</a></li>
145
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]146</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]147
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]148
149<!--=========================================================================-->
150<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]151<a name="qualityofimp">In this release, the following Quality of Implementation issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]152</div>
153
154<ol>
155
156<li><a href="http://llvm.cs.uiuc.edu/PR135">JIT should lazily initialize global variables</a></li>
Chris Lattner6448f892003-12-20 10:29:02 +0000[diff] [blame]157<li><a href="http://llvm.cs.uiuc.edu/PR192">[X86] X86 Backend never releases memory for machine code structures</a></li>
Chris Lattner4688edb2003-12-23 23:50:31 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR196">[vmcore] OpaqueType objects memory leak</a></li>
Chris Lattner74339162004-01-08 17:20:50 +0000[diff] [blame]159<li><a href="http://llvm.cs.uiuc.edu/PR182">[llvmgcc] C front-end does not compile "extern inline" into linkonce</a></li>
Chris Lattnera38ebcc2004-01-15 17:59:29 +0000[diff] [blame]160<li><a href="http://llvm.cs.uiuc.edu/PR73">Bytecode format inconsistent</a></li>
Chris Lattner66c16d12004-02-05 17:31:37 +0000[diff] [blame]161<li><a href="http://llvm.cs.uiuc.edu/PR209">[loadvn/inline/scalarrepl] Slow optimizations with extremely large basic blocks</a></li>
Chris Lattner805e5e72004-02-09 21:16:16 +0000[diff] [blame]162<li><a href="http://llvm.cs.uiuc.edu/PR224">[asmparser] Really slow parsing of types with complex upreferences</a></li>
Chris Lattnere9fbbc22004-02-15 05:47:37 +0000[diff] [blame]163<li><a href="http://llvm.cs.uiuc.edu/PR205">[llvmgcc] C front-end does not emit 'zeroinitializer' when possible</a></li>
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]164<li><a href="http://llvm.cs.uiuc.edu/PR233">[llvmgcc] Structure copies result in a LOT of code</a></li>
Chris Lattner8579a6f2004-02-15 06:00:04 +0000[diff] [blame]165<li><a href="http://llvm.cs.uiuc.edu/PR239">LLVM is now much more memory efficient when handling large zero initialized arrays</a></li>
Chris Lattnerd68b5892004-03-10 21:43:47 +0000[diff] [blame]166<li><a href="http://llvm.cs.uiuc.edu/PR275">[llvmgcc] Local array initializers are expanded into large amounts of code</a></li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]167</ol>
168
169<!--=========================================================================-->
170<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]171In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]172</div>
173
174<ol>
175<li><a href="http://llvm.cs.uiuc.edu/PR210">[build] Makefiles break if C frontend target string has unexpected value</a></li>
John Criswell47b48bf92004-01-26 21:03:54 +0000[diff] [blame]176<li><a href="http://llvm.cs.uiuc.edu/PR214">[build] hard-wired assumption that shared-library extension is ".so"</a></li>
Chris Lattner3d96eb62004-02-03 22:59:56 +0000[diff] [blame]177<li><A href="http://llvm.cs.uiuc.edu/PR222">make tools-only doesn't make lib/Support</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]178</ol>
179
180<!--=========================================================================-->
181<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]182<a name="codequality">In this release, the following Code Quality issues were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]183</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]184
185<ol>
Chris Lattner3d35e872003-12-19 06:31:56 +0000[diff] [blame]186<li><a href="http://llvm.cs.uiuc.edu/PR187">[loopsimplify] Many pointless phi nodes are created</a></li>
Chris Lattnerd5eec5e2004-02-15 00:23:15 +0000[diff] [blame]187<li><a href="http://llvm.cs.uiuc.edu/PR237">[x86] wierd stack/frame pointer manipulation</a></li>
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]188
189<li>The X86 backend now generate <tt>fchs</tt> to negate floating point numbers,
190compiles memcpy() into the <tt>rep movs</tt> instruction, and makes much better
191use of powerful addressing modes and instructions.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]192</ol>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]193
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]194
195<!--=========================================================================-->
196<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]197<a name="bugfix">In this release, the following bugs in the previous release were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]198</div>
199
200<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]201
202<ol>
Misha Brukman34cba912003-12-15 22:48:12 +0000[diff] [blame]203<li><a href="http://llvm.cs.uiuc.edu/PR179">[licm] LICM promotes volatile memory
204locations to registers</a></li>
Chris Lattnerb3fdf832003-12-18 08:16:25 +0000[diff] [blame]205<li><a href="http://llvm.cs.uiuc.edu/PR191">[licm] Memory read after free causes
206infrequent crash</a></li>
Chris Lattner8e570bab2003-12-22 04:06:24 +0000[diff] [blame]207<li><a href="http://llvm.cs.uiuc.edu/PR194">[indvars] Induction variable
208canonicalization always makes 32-bit indvars</a></li>
Chris Lattner0b428c12003-12-22 23:56:37 +0000[diff] [blame]209<li><a href="http://llvm.cs.uiuc.edu/PR193">[constantmerge] Merging globals can
210cause use of invalid pointers!</a></li>
Chris Lattner1d199372004-01-20 19:16:50 +0000[diff] [blame]211<li><a href="http://llvm.cs.uiuc.edu/PR212">[bcreader] Bytecode reader misreads 'long -9223372036854775808'!</a></li>
Chris Lattner24fa5662004-02-09 21:22:51 +0000[diff] [blame]212<li><a href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=174">Tail duplication does not update SSA form correctly.</a></li>
Chris Lattnere2d61892004-02-01 22:52:12 +0000[diff] [blame]213<li><a href="http://llvm.cs.uiuc.edu/PR218">VMCore mishandles double -0.0</a></li>
Chris Lattnerd932cbf2004-02-02 19:40:06 +0000[diff] [blame]214<li><a href="http://llvm.cs.uiuc.edu/PR219">[X86] X86 backend code generates -0.0 as +0.0</a></li>
Chris Lattneraaaaec42004-02-05 21:16:42 +0000[diff] [blame]215<li><a href="http://llvm.cs.uiuc.edu/PR223">[loopsimplify] Loopsimplify incorrectly updates dominator information</a></li>
Chris Lattner35630ad2004-02-08 21:20:42 +0000[diff] [blame]216<li><a href="http://llvm.cs.uiuc.edu/PR225">[pruneeh] -pruneeh pass removes invoke instructions it shouldn't</a></li>
Chris Lattner6b3dea22004-02-10 05:19:54 +0000[diff] [blame]217<li><a href="http://llvm.cs.uiuc.edu/PR228">[sparc] Boolean constants are emitted as true and false</a></li>
Brian Gaeke11331e52004-02-26 00:08:25 +0000[diff] [blame]218<li><a href="http://llvm.cs.uiuc.edu/PR234">[interpreter] va_list values silently corrupted by function calls</a></li>
Chris Lattnerc68c6a62004-02-13 16:40:24 +0000[diff] [blame]219<li><a href="http://llvm.cs.uiuc.edu/PR235">Tablegen aborts on errors</a></li>
Chris Lattner963f2732004-02-13 17:03:01 +0000[diff] [blame]220<li><a href="http://llvm.cs.uiuc.edu/PR236">[inliner] Error inlining intrinsic calls into invoke instructions</a></li>
Chris Lattnerbe1c3002004-02-17 22:00:39 +0000[diff] [blame]221<li><a href="http://llvm.cs.uiuc.edu/PR245">Linking weak and strong global variables is dependent on link order</a></li>
John Criswellbbde7d62004-02-26 23:13:34 +0000[diff] [blame]222<li><a href="http://llvm.cs.uiuc.edu/PR258">Variables used to define non-printable FP constants are externally visible</a></li>
223<li><a href="http://llvm.cs.uiuc.edu/PR259">CBE gives linkonce functions wrong linkage semantics</a></li>
Brian Gaeke75a2efd2004-03-09 05:43:59 +0000[diff] [blame]224<li><a href="http://llvm.cs.uiuc.edu/PR274">[JIT] Programs cannot resolve the fstat function</a></li>
Chris Lattnerd68b5892004-03-10 21:43:47 +0000[diff] [blame]225<li><a href="http://llvm.cs.uiuc.edu/PR284">[indvars] Induction variable analysis violates LLVM invariants</a></li>
Chris Lattnere1f51612004-03-16 08:40:35 +0000[diff] [blame]226<li><a href="http://llvm.cs.uiuc.edu/PR296">[execution engines] Unhandled cast constant expression</a></li>
227
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]228</ol>
229
230
Chris Lattner24fa5662004-02-09 21:22:51 +0000[diff] [blame]231
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]232<p>Bugs in the C/C++ front-end:</p>
233
234<ol>
Misha Brukman34cba912003-12-15 22:48:12 +0000[diff] [blame]235<li><a href="http://llvm.cs.uiuc.edu/PR186">Need weak linkage on memory
236management functions in libc runtime to allow them to be overriden</a></li>
Chris Lattner74339162004-01-08 17:20:50 +0000[diff] [blame]237<li><a href="http://llvm.cs.uiuc.edu/PR202">[llvm-gcc] asserts when an extern inline function is redefined</a></li>
Chris Lattner69fba002004-01-12 05:15:04 +0000[diff] [blame]238<li><a href="http://llvm.cs.uiuc.edu/PR204">[llvmg++] Dynamically initialized constants cannot be marked 'constant'</a></li>
Chris Lattner7bae4ce2004-02-02 17:48:56 +0000[diff] [blame]239<li><a href="http://llvm.cs.uiuc.edu/PR216">[llvmgcc] floating-point unary minus is incorrect for +0.0</a></li>
Chris Lattner8a630012004-02-03 08:03:41 +0000[diff] [blame]240<li><a href="http://llvm.cs.uiuc.edu/PR221">[llvm-gcc] miscompilation of 'X = Y = Z' with aggregate values</a></li>
Chris Lattnerbd086412004-02-20 17:41:35 +0000[diff] [blame]241<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] miscompilation when a function is re-declared as static</a></li>
Chris Lattnerf0cbbab2004-03-08 04:55:45 +0000[diff] [blame]242<li><a href="http://llvm.cs.uiuc.edu/PR272">[llvmgcc] Invalid code created for complex division operation</a></li>
Chris Lattner0536f8d2004-03-09 00:40:49 +0000[diff] [blame]243<li><a href="http://llvm.cs.uiuc.edu/PR268">[llvmgcc] Incorrect code generation for pointer subtraction</a></li>
Chris Lattnerc567f402004-03-09 00:59:15 +0000[diff] [blame]244<li><a href="http://llvm.cs.uiuc.edu/PR261">[llvmg++] Crash assigning pointers-to-members with casted types</a></li>
Chris Lattner0128c9a2004-03-16 05:28:35 +0000[diff] [blame]245<li><a href="http://llvm.cs.uiuc.edu/PR291">[llvm-g++] Cleanups and exception handlers don't mix properly</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]246</ol>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]247
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]248</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]249
250<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]251<div class="doc_section">
252 <a name="portability">Portability and Supported Platforms</a>
253</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]254<!-- *********************************************************************** -->
255
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]256<div class="doc_text">
257
258<p>LLVM has been extensively tested on Intel and AMD machines running Red
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]259Hat Linux and FreeBSD. It has also been tested on Sun UltraSPARC workstations running Solaris 8.
John Criswell604cd3c2003-12-12 19:54:20 +0000[diff] [blame]260Additionally,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]261LLVM works on Mac OS X 10.3 and above, but only with the C backend or
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]262interpreter (no native backend for the PowerPC is available yet).
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]263The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner14b5d5a2003-11-08 05:22:09 +0000[diff] [blame]264work on more platforms than that. However, it is likely that we
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]265missed something and that minor porting is required to get LLVM to work on
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]266new platforms. We welcome portability patches and error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]267
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]268</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]269
270<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]271<div class="doc_section">
272 <a name="knownproblems">Known Problems</a>
273</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]274<!-- *********************************************************************** -->
275
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]276<div class="doc_text">
277
278<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]279component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]280sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]281href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]282there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]283
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]284</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]285
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]286<!-- ======================================================================= -->
287<div class="doc_subsection">
288 <a name="experimental">Experimental features included with this release</a>
289</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]290
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]291<div class="doc_text">
292
293<p>
294The following components of this LLVM release are either untested, known to be
295broken or unreliable, or are in early development. These components should not
296be relied on, and bugs should not be filed against them, but they may be useful
297to some people. In particular, if you would like to work on one of these
298components, please contact us on the llvmdev list.
299</p>
300
301<ul>
302<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
303 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
304
305<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
306 it should) and not thoroughly tested.</li>
307<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
308<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
309</ul>
310
311</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]312
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]313<!-- ======================================================================= -->
314<div class="doc_subsection">
315 <a name="core">Known problems with the LLVM Core</a>
316</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]317
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]318<div class="doc_text">
319
320<ul>
321
322<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
323work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]324
325<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]326such, execution of a threaded program could cause these data structures to be
327corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]328
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]329<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]330
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]331<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]332table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]333
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]334<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]335more than 256 elements</a>.</li>
336
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]337<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link objects/archives in the order specified on the command line.</a></li>
338
339<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswell5d6345a2004-03-12 21:29:42 +0000[diff] [blame]340values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]341targets whose setjmp/longjmp libraries do not save and restore the entire
342register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]343</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]344</div>
345
346<!-- ======================================================================= -->
347<div class="doc_subsection">
348 <a name="c-fe">Known problems with the C front-end</a>
349</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]350
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]351<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]352<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]353
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]354<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]355<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]356<li>C99 Variable sized arrays do not release stack memory when they go out of
357 scope. Thus, the following program may run out of stack space:
358<pre>
359 for (i = 0; i != 1000000; ++i) {
360 int X[n];
361 foo(X);
362 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]363</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]364
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]365<li>
366Initialization of global union variables can only be done
367<a href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest
368union member</a>.
369</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]370</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]371</div>
372
373<!-- _______________________________________________________________________ -->
374<div class="doc_subsubsection">
375 Notes
376</div>
377
378<div class="doc_text">
379
380<ul>
381
382<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]383
384<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]385support for floating point data types of any size other than 32 and 64
386bits.</li>
387
388<li>The following Unix system functionality has not been tested and may not
389work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]390 <ol>
391 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
392 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
393 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
394 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
395 - These functions have not been tested.
396 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]397
398<li>Although many GCC extensions are supported, some are not. In particular,
399 the following extensions are known to <b>not be</b> supported:
400 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]401 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]402 <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>
403 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
404 <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>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]405 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]406 <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>
407 <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>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]408 <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>
409 <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>
410 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
411 <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]412 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]413
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]414 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]415 attribute means that the LLVM compiler ignores the presence of the attribute,
416 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]417 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]418 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]419
420 <ol>
421 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
422 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]423 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]424
425 <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]426
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]427 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]428 return.<br>
429
430 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
431 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
432 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
433
434 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
435 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
436 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
437
438 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
439 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
440 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]441
442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
443 Specifying attributes of variables.<br>
444 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
445 <tt>deprecated</tt>, <tt>transparent_union</tt>,
446 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]447
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]448 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
449 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
450 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]451 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]452
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]453 <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]454 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]455 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]456
457 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
458 all target specific attributes.</li>
459
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
461 Other built-in functions.<br>
462 We support all builtins which have a C language equivalent (e.g.,
463 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
464 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]465 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]466
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]467 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]468
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]469 <p>The following extensions <b>are</b> known to be supported:</p>
470
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]471 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame^]472 <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>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
474 <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>
475 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
476 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
477 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
479 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
480 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
482 <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>
483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
484 <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]485 <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]486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]487 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
488or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]489 <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]490 <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]491 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
492 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
493 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
494 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
495 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
496 <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>
497 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
498 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
499 <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>
500 <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>
501 <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>
Chris Lattner3646dad2004-02-14 04:08:29 +0000[diff] [blame]502 <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>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]503 <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>
504 <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]505 </ol></li>
506
507</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]508
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]509<p>If you run into GCC extensions which have not been included in any of these
510lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]511
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]512</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]513
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]514<!-- ======================================================================= -->
515<div class="doc_subsection">
516 <a name="c++-fe">Known problems with the C++ front-end</a>
517</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]518
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]519<div class="doc_text">
520
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]521<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]522has not been tested as thoroughly as the C front-end. It has been tested and
523works for a number of non-trivial programs, but there may be lurking bugs.
524Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]525
526</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]527
528<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]529<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]531<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]533<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]534<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]535 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]536</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]537</div>
538
539<!-- _______________________________________________________________________ -->
540<div class="doc_subsubsection">
541 Notes
542</div>
543
544<div class="doc_text">
545
546<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]547
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]548<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
549parser is significantly more standards compliant (and picky) than prior GCC
550versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]551href="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]552
553<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]554 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]555 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]556 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]557 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]558
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]559<li>The LLVM C++ front-end follows the <a
560 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
561 This document, which is not Itanium specific, specifies a standard for name
562 mangling, class layout, v-table layout, RTTI formats, and other C++
563 representation issues. Because we use this API, code generated by the LLVM
564 compilers should be binary compatible with machine code generated by other
565 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
566 <i>However</i>, the exception handling mechanism used by LLVM is very
567 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]568 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]569
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]570</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]571
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]572</div>
573
574<!-- ======================================================================= -->
575<div class="doc_subsection">
576 <a name="x86-be">Known problems with the X86 back-end</a>
577</div>
578
579<div class="doc_text">
580
581<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]582<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]583</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]584
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]585</div>
586
587<!-- ======================================================================= -->
588<div class="doc_subsection">
589 <a name="sparc-be">Known problems with the Sparc back-end</a>
590</div>
591
592<div class="doc_text">
593
594<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]595<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]596</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]597
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]598</div>
599
600<!-- ======================================================================= -->
601<div class="doc_subsection">
602 <a name="c-be">Known problems with the C back-end</a>
603</div>
604
605<div class="doc_text">
606
607<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]608
609<li>The C back-end produces code that violates the ANSI C Type-Based Alias
610Analysis rules. As such, special options may be necessary to compile the code
611(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]612problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]613
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]614<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]615cannot include special floating point numbers like Not-A-Number or
616Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]617
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]618<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]619supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]620frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]621
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]622</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]623
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]624</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]625
626<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]627<div class="doc_section">
628 <a name="additionalinfo">Additional Information</a>
629</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]630<!-- *********************************************************************** -->
631
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]632<div class="doc_text">
633
634<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]635including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]636implemented in LLVM. The web page also contains versions of the API
637documentation which is up-to-date with the CVS version of the source code. You
638can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]639the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]640
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]641<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]642us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
643lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]644
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]645</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]646
647<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]648
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]649<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]650<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]651 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]652 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
653 <a href="http://validator.w3.org/check/referer"><img
654 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
655
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]656 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]657 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]658</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]659
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]660</body>
661</html>