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Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]6 <title>LLVM 1.2 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]9
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]10<div class="doc_title">
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]11 LLVM 1.2 Release Notes
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]12</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]13
14<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]15 <li><a href="#intro">Introduction</a></li>
16 <li><a href="#whatsnew">What's New?</a></li>
17 <li><a href="#portability">Portability and Supported Platforms</a></li>
18 <li><a href="#install-instructions">Installation Instructions</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]19 <li><a href="#knownproblems">Known Problems</a>
20 <ul>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]21 <li><a href="#experimental">Experimental features included with this release</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]22 <li><a href="#core">Known problems with the LLVM Core</a>
23 <li><a href="#c-fe">Known problems with the C Front-end</a>
24 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
25 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
26 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
27 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]28 </ul></li>
29 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]30</ol>
31
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]32<div class="doc_text">
John Criswelld000e1d2003-12-18 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]34</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]35
36<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]37<div class="doc_section">
38 <a name="intro">Introduction</a>
39</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]40<!-- *********************************************************************** -->
41
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]42<div class="doc_text">
43
44<p>This document contains the release notes for the LLVM compiler
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]45infrastructure, release 1.2. Here we describe the status of LLVM, including any
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]46known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]47version of this document can be found on the <a
Chris Lattnerb40efb32003-12-14 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 Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]49not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]50this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]51
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]52<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]53current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
54web site</a>. If you have questions or comments, the <a
55href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]56list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]57
Chris Lattner9e848092003-12-12 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]61href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
62
63</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]64
65<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]66<div class="doc_section">
67 <a name="whatsnew">What's New?</a>
68</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]69<!-- *********************************************************************** -->
70
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]71<div class="doc_text">
72
Chris Lattnera39719f2004-02-25 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 Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]82</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattnera39719f2004-02-25 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 Lattner1124e2c2003-12-12 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 Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]89received less testing than the C front-end.
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]90</p>
91
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]92<!--=========================================================================-->
93<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]94<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]95</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]96
97<ol>
Chris Lattner95778a02004-02-08 21:20:42 +0000[diff] [blame]98<li><a href="SourceLevelDebugging.html">A new LLVM source-level debugger has been started.</a></li>
Chris Lattnera118ae12004-02-23 03:51:34 +0000[diff] [blame]99<li>LLVM 1.2 encodes bytecode files for large programs in 10-30% less space.</li>
Chris Lattner67195cf2004-03-11 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 Lattnera118ae12004-02-23 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 Lattnera39719f2004-02-25 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 Lattnera118ae12004-02-23 03:51:34 +0000[diff] [blame]112<li>The "tblgen" tool is <a href="TableGenFundamentals.html">now documented</a>.</li>
Chris Lattner67195cf2004-03-11 00:50:54 +0000[diff] [blame]113<li>The target-independent code generator got several improvements:
Alkis Evlogimenos4817e9c2004-02-27 05:26:23 +0000[diff] [blame]114<ul>
Chris Lattner67195cf2004-03-11 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 Evlogimenos4817e9c2004-02-27 05:26:23 +0000[diff] [blame]121</ul>
122</li>
Chris Lattner1e1a78a2004-02-24 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 Lattnera39719f2004-02-25 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 Lattnerfd343b02004-02-26 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 Lattner67195cf2004-03-11 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 Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]130</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]131
Chris Lattnera5099962003-12-06 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 Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]137
138<ol>
Chris Lattner127215e2004-02-08 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 Lattner3a51be12004-02-14 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 Lattner3fd82592004-02-23 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 Lattner7fe97dd2004-03-16 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]146</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]147
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]148
149<!--=========================================================================-->
150<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]151<a name="qualityofimp">In this release, the following Quality of Implementation issues were fixed:</a>
Chris Lattnere29ac162003-12-20 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 Lattneref56a192003-12-20 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 Lattner71f0a822003-12-23 23:50:31 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR196">[vmcore] OpaqueType objects memory leak</a></li>
Chris Lattner1abc87e2004-01-08 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 Lattner23632f12004-01-15 17:59:29 +0000[diff] [blame]160<li><a href="http://llvm.cs.uiuc.edu/PR73">Bytecode format inconsistent</a></li>
Chris Lattner913a9342004-02-05 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 Lattnera50c4ba2004-02-09 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 Lattnerd6a185f2004-02-15 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 Lattnera39719f2004-02-25 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 Lattner9f3c7f72004-02-15 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 Lattner7c627282004-03-10 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 Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]167</ol>
168
169<!--=========================================================================-->
170<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]171In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 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 Criswell6b153402004-01-26 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 Lattner3e0bd312004-02-03 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 Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]178</ol>
179
180<!--=========================================================================-->
181<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]182<a name="codequality">In this release, the following Code Quality issues were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]183</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]184
185<ol>
Chris Lattner9e259062003-12-19 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 Lattner1fda3702004-02-15 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 Lattnera39719f2004-02-25 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]192</ol>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]193
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]194
195<!--=========================================================================-->
196<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]197<a name="bugfix">In this release, the following bugs in the previous release were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]198</div>
199
200<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]201
202<ol>
Misha Brukmanad643852003-12-15 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 Lattner5b7142a2003-12-18 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 Lattner5de946f2003-12-22 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 Lattner0cbdd972003-12-22 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 Lattnerae3664b2004-01-20 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 Lattner56e67052004-02-09 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 Lattnerc8a35812004-02-01 22:52:12 +0000[diff] [blame]213<li><a href="http://llvm.cs.uiuc.edu/PR218">VMCore mishandles double -0.0</a></li>
Chris Lattner02babb82004-02-02 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 Lattner741f6b42004-02-05 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 Lattner95778a02004-02-08 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 Lattner964b0d82004-02-10 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 Gaeke3a9ec192004-02-26 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 Lattnerbd8c4562004-02-13 16:40:24 +0000[diff] [blame]219<li><a href="http://llvm.cs.uiuc.edu/PR235">Tablegen aborts on errors</a></li>
Chris Lattner4b2b6842004-02-13 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 Lattner95026582004-02-17 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 Criswell412926e2004-02-26 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 Gaekebd1c2852004-03-09 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 Lattner7c627282004-03-10 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 Lattnerbc7c0b82004-03-16 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 Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]228</ol>
229
230
Chris Lattner56e67052004-02-09 21:22:51 +0000[diff] [blame]231
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]232<p>Bugs in the C/C++ front-end:</p>
233
234<ol>
Misha Brukmanad643852003-12-15 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 Lattner1abc87e2004-01-08 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 Lattnerc43f91f2004-01-12 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 Lattner55d14de2004-02-02 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 Lattneracc00bc2004-02-03 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 Lattner98328742004-02-20 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 Lattnereacf9272004-03-08 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 Lattner15f0a872004-03-09 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 Lattner0fe65a82004-03-09 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 Lattnerc62db6f2004-03-16 09:01:10 +0000[diff] [blame]245<li><a href="http://llvm.cs.uiuc.edu/PR291">[llvm-g++] Cleanups and gotos don't mix properly</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]246</ol>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]247
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]248</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]249
250<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]251<div class="doc_section">
252 <a name="portability">Portability and Supported Platforms</a>
253</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]254<!-- *********************************************************************** -->
255
Misha Brukman500bc302003-11-22 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 Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]259Hat Linux and FreeBSD. It has also been tested on Sun UltraSPARC workstations running Solaris 8.
John Criswellbb1bad52003-12-12 19:54:20 +0000[diff] [blame]260Additionally,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]261LLVM works on Mac OS X 10.3 and above, but only with the C backend or
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]262interpreter (no native backend for the PowerPC is available yet).
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]263The core LLVM infrastructure uses "autoconf" for portability, so hopefully we
Chris Lattner3e2959e2003-11-08 05:22:09 +0000[diff] [blame]264work on more platforms than that. However, it is likely that we
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]265missed something and that minor porting is required to get LLVM to work on
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]266new platforms. We welcome portability patches and error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]267
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]268</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]269
270<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]271<div class="doc_section">
272 <a name="knownproblems">Known Problems</a>
273</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]274<!-- *********************************************************************** -->
275
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]279component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]280sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]281href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]282there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]283
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]284</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]285
Chris Lattnerf5ee1702004-03-14 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]290
Chris Lattnerf5ee1702004-03-14 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]312
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]317
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]324
325<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]326such, execution of a threaded program could cause these data structures to be
327corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]328
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]330
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]331<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]332table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]333
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]334<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]335more than 256 elements</a>.</li>
336
Chris Lattner2e6fcaf2004-02-15 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 Criswelld46c6962004-03-12 21:29:42 +0000[diff] [blame]340values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]341targets whose setjmp/longjmp libraries do not save and restore the entire
342register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]343</ul>
Misha Brukman500bc302003-11-22 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 Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]350
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]351<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]352<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]353
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]354<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]355<ul>
Chris Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]363</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]364
John Criswelld000e1d2003-12-18 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 Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]370</ul>
Misha Brukman500bc302003-11-22 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 Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]383
384<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 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 Brukmane0c891c2003-11-22 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 Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 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 Brukman500bc302003-11-22 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 Criswelld000e1d2003-12-18 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 Brukman500bc302003-11-22 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 Brukman500bc302003-11-22 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 Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]412 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]413
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]414 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 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 Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]417 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]418 the program.</p>
Chris Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]423 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]426
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]427 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]447
Chris Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]451 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]452
Misha Brukmanc4b7bee2003-12-12 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]454 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]455 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]465 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]466
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]467 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]468
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]469 <p>The following extensions <b>are</b> known to be supported:</p>
470
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]471 <ol>
Chris Lattner7fe97dd2004-03-16 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 Brukman500bc302003-11-22 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 Brukmanc4b7bee2003-12-12 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 Brukman500bc302003-11-22 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 Criswelld000e1d2003-12-18 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 Brukman500bc302003-11-22 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 Brukmanc4b7bee2003-12-12 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 Brukman500bc302003-11-22 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 Lattner25795bc2004-02-14 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 Brukman500bc302003-11-22 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 Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]505 </ol></li>
506
507</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]508
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]511
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]512</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]513
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]518
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]519<div class="doc_text">
520
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]521<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattner9e848092003-12-12 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]525
526</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]527
528<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]529<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]531<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]534<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]535 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]536</ul>
Misha Brukman500bc302003-11-22 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 Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]547
Chris Lattner79c3fe12003-10-02 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 Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]551href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]552
553<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]554 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]555 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]556 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]557 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]558
Chris Lattner19092612003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]568 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]569
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]570</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]571
Misha Brukman500bc302003-11-22 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 Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]582<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]583</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]584
Misha Brukman500bc302003-11-22 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 Lattnerde4afdc2004-02-08 22:23:33 +0000[diff] [blame]595<li>None so far.
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]596</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]597
Misha Brukman500bc302003-11-22 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 Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]612problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]613
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]614<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]615cannot include special floating point numbers like Not-A-Number or
616Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]617
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]618<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]619supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]620frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]621
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]622</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]623
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]624</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]625
626<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]627<div class="doc_section">
628 <a name="additionalinfo">Additional Information</a>
629</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]630<!-- *********************************************************************** -->
631
Misha Brukman500bc302003-11-22 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 Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]635including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]639the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]640
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]641<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]642us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
643lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]644
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]645</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]646
647<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]648
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]649<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]650<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]651 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 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 Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]656 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]657 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]658</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]659
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]660</body>
661</html>