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Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 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
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]13 <li><a href="#intro">Introduction</a></li>
14 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]21 <li><a href="#core">Known problems with the LLVM Core</a>
22 <li><a href="#c-fe">Known problems with the C Front-end</a>
23 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
24 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]25 <li><a href="#sparcv9-be">Known problems with the SparcV9 Back-end</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]31<div class="doc_author">
32 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]41<div class="doc_text">
42
43<p>This document contains the release notes for the LLVM compiler
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]47href="http://llvm.cs.uiuc.edu/releases/1.3/">LLVM 1.3 web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]52current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
53web site</a>. If you have questions or comments, the <a
54href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]57<p>Note that if you are reading this file from CVS, this document applies
58to the <i>next</i> release, not the current one. To see the release notes for
59the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]73release primarily improves the <a href="#codequality">performance of the
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]74code</a> produced by all aspects of the LLVM compiler, adds many <a
75href="#newfeatures">new features</a>, <a href="#bugfix">fixes a few
Chris Lattnere58d3562004-08-05 21:53:13 +0000[diff] [blame]76bugs</a>, speeds up the compiler, and introduces a new (experimental)
77PowerPC code generator.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]78
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]79<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]80SPEC CPU95 &amp; 2000 benchmarks, the Olden benchmarks, and the Ptrdist
81benchmarks, and <b>many</b> other programs. LLVM now also works
82with a broad variety of C++ programs.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]84</div>
85
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]86<!--=========================================================================-->
87<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]88<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]89</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]90
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]91<div class="doc_text">
92
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]93<ol>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]94<li>The LLVM <a href="LangRef.html#i_select"><tt>select</tt></a> instruction is
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]95now fully implemented and supported by all transformations, native code
96generators, and the interpreter.</li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]97<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
98before it could only narrow them down to a function being miscompiled.</li>
Brian Gaeke43be3112004-05-04 21:22:57 +0000[diff] [blame]99<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]100modes of llc</a> and lli, by passing them command line flags (e.g.
101<tt>-regalloc=linearscan</tt>).</li>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]102<li>The Control Flow Graph in the native code generators is no longer
103constrained to be the same as the CFG for the LLVM input code.</li>
104<li>The LLVM induction variable analysis routines have been rewritten.</li>
105<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
106<li>The induction variable substitution pass performs linear function test
107replacement and exit value replacement optimizations.</li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]108<li>LLVM now has first-class support for <a
109href="GarbageCollection.html">Accurate Garbage Collection</a>, enabling the use
110of aggressive copying and generational collectors.</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]111<li>LLVM now includes a simple implementation of <a
112href="AliasAnalysis.html#anders-aa">Andersen's interprocedural alias
113analysis</a> algorithm.</li>
Chris Lattner14cd5392004-05-24 05:34:32 +0000[diff] [blame]114<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
115basic blocks</a> to track down reduce miscompilation testcases.</li>
Brian Gaeke5beb8ba2004-06-01 20:02:56 +0000[diff] [blame]116<li>LLVM and the C front-end now work under Win32 using the
117<a href="http://www.cygwin.com">Cygwin</a> runtime libraries.
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]118This includes the JIT compiler.</li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]119<li>The LLVM code generator is now being <a
120href="CodeGenerator.html">documented</a>.</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]121<li>LLVM includes a new tool, <a
122href="CommandGuide/html/llvm-bcanalyzer.html">llvm-bcanalyzer</a>, This tool
123can compute various statistics and dump information about LLVM bytecode
124encoding.</li>
125<li>The <a href="BytecodeFormat.html">LLVM bytecode file format</a> is now
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]126documented.</li>
127<li>LLVM now provides an <a
128href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic for efficient
129implementation of unordered floating point comparisons.</li>
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]130<li>The llvmgcc front-end now supports the GCC builtins for ISO C99 floating
131point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]132<li>We now generate <a href="CommandGuide/">HTML documentation and man pages</a>
133for the tools from a single source (perl-style POD files).</li>
Chris Lattnerc8cd7e92004-07-12 17:09:23 +0000[diff] [blame]134<li>The LLVM code generator can now dynamically load targets from shared
135objects.</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]136<li>LLVM now includes a "skeleton" target, which makes it easier to get
137started porting LLVM to new architectures.</li>
138<li>The linear scan register allocator is now enabled by default in the
139target-independent code generator.</li>
140<li>LLVM now includes a dead store elimination pass.</li>
141<li>Bugpoint can now debug miscompilations that lead to the program going
142into an infinite loop.</li>
143<li>LLVM now provides interfaces to support ML-style pattern matching on the
144LLVM IR.</li>
145<li>LLVM now includes a <a
146href="AliasAnalysis.html#globalsmodref">context-sensitive mod/ref analysis</a>
147for global variables, which is now enabled by default in gccld.</li>
148<li>LLVM can now autogenerate assembly printers for code generators from the
149tablegen description of the target (before they were hand coded).</li>
Reid Spencer17c2b922004-08-04 00:43:50 +0000[diff] [blame]150<li>All LLVM tools will now respond to the
151<a href="http://llvm.cs.uiuc.edu/PR413"><tt>--version</tt> option</a> which
152will tell you the version of LLVM on which the tool is based.</li>
Misha Brukman94118752004-08-05 21:04:03 +0000[diff] [blame]153<li>An experimental PowerPC backend has been added, capable of compiling several
154SPEC benchmarks.</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]155</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]156
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]157</div>
158
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]159
160<!--=========================================================================-->
161<div class="doc_subsubsection">
162In this release, the following missing features were implemented:
163</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]164
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]165<div class="doc_text">
166
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]167<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]168<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
169more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]170<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
171non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]172<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
173with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]174<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
175uses of external fns by immediate constant exprs</a></li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]176<li><a href="http://llvm.cs.uiuc.edu/PR407">Can't add function passes that
177depend on immutable passes to the FunctionPassManager</a>.</li>
178<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
179understand abbreviated names in headers</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]180</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]181
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]182</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]183
184<!--=========================================================================-->
185<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]186<a name="qualityofimp">In this release, the following Quality of Implementation
187issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]188</div>
189
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]190<div class="doc_text">
191
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]192<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]193<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
194bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]195<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
196for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]197<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerea955512004-06-08 07:19:29 +0000[diff] [blame]198<li>The spurious "WARNING: Found global types that are not compatible" warning
199produced when linking C++ programs has been fixed.</li>
Reid Spencer421991c2004-07-07 21:06:28 +0000[diff] [blame]200<li><a href="http://llvm.cs.uiuc.edu/PR391">lli Doesn't Handle Exceptions From
201Bytecode Reader</a></li>
Reid Spencerf8474322004-07-25 22:15:33 +0000[diff] [blame]202<li><a href="http://llvm.cs.uiuc.edu/PR392">Global Vars Have (Somewhat) Limited
203 Type Range</a></li>
Misha Brukman94118752004-08-05 21:04:03 +0000[diff] [blame]204<li><a href="http://llvm.cs.uiuc.edu/PR341">operator&lt;&lt; on a Value* now
205prints the address of the object instead of its contents.</a></li>
Reid Spencerf8474322004-07-25 22:15:33 +0000[diff] [blame]206<li><a href="http://llvm.cs.uiuc.edu/PR402">Bytecode Enhancements
Misha Brukman94118752004-08-05 21:04:03 +0000[diff] [blame]207Needed</a></li>
208<li><a href="http://llvm.cs.uiuc.edu/PR404">[loopsimplify] Loop simplify is
209really slow on 252.eon</a></li>
210<li><a href="Http://llvm.cs.uiuc.edu/PR122">[code-cleanup] SymbolTable class
211cleanup, Type should not derive from Value, eliminate ConstantPointerRef
212class</a>.</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]213<li>The memory footprint of the LLVM IR has been reduced substantially.</li>
Chris Lattnera834fe22004-08-04 08:00:45 +0000[diff] [blame]214<li>The LLVM linker and many core classes have been sped up substantially.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]215</ol>
216
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]217</div>
218
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]219<!--=========================================================================-->
220<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]221In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]222</div>
223
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]224<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]225<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]226<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
227-disable/enable-povray and -disable-spec</a></li>
228<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
229work if you change PATH</a></li>
Chris Lattner24738a72004-06-09 01:09:16 +0000[diff] [blame]230<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
231with gcc 3.4</a></li>
Chris Lattnerf82bba92004-06-18 17:57:29 +0000[diff] [blame]232<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
233obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]234</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]235</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]236
237<!--=========================================================================-->
238<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]239<a name="codequality">This release includes the following Code Quality
240improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]241</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]242
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]243<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]244<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]245<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
246due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]247
248<li>The X86 backend now generates substantially better code for 64-bit integer
249and floating point operations.</li>
250
251<li>The -inline pass no longer inlines mutually recursive functions until it
252hits the inlining threshold.</li>
253
254<li>The -inline pass no longer misses obvious inlining opportunities just
255because the callee eventually calls into an external function.</li>
256
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]257<li>The -simplifycfg pass can now "if convert" simple statements into the
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]258<tt>select</tt> instruction.</li>
259
260<li>The -loopsimplify pass can now break <a
261href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
262into multiple nested loops. This enables a variety of subsequent
263optimizations.</li>
264
265<li>The -adce pass can now eliminate calls to functions that do not not write to
266memory.</li>
267
268<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]269exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]270
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]271<li>The link-time optimizer now runs dead store elimination and uses a simple
272interprocedural alias analysis.</li>
273
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]274<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
275"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
276operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
277&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
278
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]279<li>LLVM now has infrastructure for (simple and sparse conditional) constant
280propagation of function calls. It currently supports a few math library
281functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]282
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]283<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">syntactic
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]284loops</a> in the code to help C compilers whose optimizers do not recognize
285loops formed from gotos (like GCC).</li>
Brian Gaeke11074e32004-06-11 02:15:39 +0000[diff] [blame]286
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]287<li>The SparcV9 backend no longers <a
288href="http://llvm.cs.uiuc.edu/PR368">spills the null constant to the constant
289pool</a>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]290</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]291</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]292
293<!--=========================================================================-->
294<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]295<a name="bugfix">In this release, the following bugs in the previous release
296were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]297</div>
298
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]299<div class="doc_text">
300
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]301<p>Bugs fixed in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]302
303<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]304<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
305incorrectly updates dominator information</a></li>
306<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
307breaks SSA form</a></li>
308<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
309to floating point cast</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]310<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
311asssertion</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]312<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
313code that unwinds</a></li>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]314<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparcv9] LLC can't emit 2 functions
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]315of the same name, both having constant pools</a></li>
316<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
317physical register use of aliased definition</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]318<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating
319point setcc X, X</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]320</ol>
321
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]322<p>Bugs in the C/C++ front-end:</p>
323
324<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]325<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
326indexing miscompiled</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]327<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
328enum type</a></li>
Chris Lattner19019602004-06-19 01:11:02 +0000[diff] [blame]329<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
330prototypes that take opaque structs by-value</a></li>
331<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
332length array of structures</a></li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]333<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]334initialized unsigned bitfields</a></li>
Chris Lattner5171eb52004-07-07 02:25:24 +0000[diff] [blame]335<li><a href="http://llvm.cs.uiuc.edu/PR396">[llvm-gcc] Crash casting function to void</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]336</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]337</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]338
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]339<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]340<div class="doc_section">
341 <a name="portability">Portability and Supported Platforms</a>
342</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]343<!-- *********************************************************************** -->
344
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]345<div class="doc_text">
346
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]347<p>LLVM is known to work in the following platforms:</p>
348
349<ul>
350<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
351 other unix-like systems).</li>
352<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]353<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
Chris Lattnere58d3562004-08-05 21:53:13 +0000[diff] [blame]354<li>PowerPC-based Mac OS X boxes, running 10.2 and above. Note that no JIT
355support is available yet, and LLC support is beta. The C backend can be used
356to produce stable code for this platform.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]357</ul>
358
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]359<p>The core LLVM infrastructure uses
360<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
361to the machine and operating system on which it is built. However, minor
362porting may be required to get LLVM to work on new platforms. We welcome your
363portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]364
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]365<p>Note that the LLVM build system does not currently support directories with
366spaces on them when running on Win32/cygwin. We strongly recommend running
367LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]368<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
369cygwin packages. By default, many important tools are not installed that
370are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]371
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]372</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]373
374<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]375<div class="doc_section">
376 <a name="knownproblems">Known Problems</a>
377</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]378<!-- *********************************************************************** -->
379
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]380<div class="doc_text">
381
382<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]383component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]384sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]385href="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]386there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]387
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]388</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]389
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]390<!-- ======================================================================= -->
391<div class="doc_subsection">
392 <a name="experimental">Experimental features included with this release</a>
393</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]394
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]395<div class="doc_text">
396
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]397<p>The following components of this LLVM release are either untested, known to
398be broken or unreliable, or are in early development. These components should
399not be relied on, and bugs should not be filed against them, but they may be
400useful to some people. In particular, if you would like to work on one of these
401components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]402
403<ul>
Misha Brukman94118752004-08-05 21:04:03 +0000[diff] [blame]404<li>The PowerPC backend is incomplete and is known to miscompile several SPEC
405benchmarks. The file <tt>llvm/lib/Target/PowerPC/README.txt</tt> has
406details.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]407<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattnercbabe702004-06-28 00:44:45 +0000[diff] [blame]408 -ipmodref, -cee</tt></li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]409<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
410 it should) and not thoroughly tested.</li>
411<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
412<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
413</ul>
414
415</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]416
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]417<!-- ======================================================================= -->
418<div class="doc_subsection">
419 <a name="core">Known problems with the LLVM Core</a>
420</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]421
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]422<div class="doc_text">
423
424<ul>
425
426<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
427work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]428
429<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]430such, execution of a threaded program could cause these data structures to be
431corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]432
Chris Lattnereb673962004-08-08 03:33:07 +0000[diff] [blame^]433<li>Linking in static archive files (.a files) is slow (there is no symbol
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]434table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]435
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]436<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
437objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]438
439<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]440values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]441targets whose setjmp/longjmp libraries do not save and restore the entire
442register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]443</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]444</div>
445
446<!-- ======================================================================= -->
447<div class="doc_subsection">
448 <a name="c-fe">Known problems with the C front-end</a>
449</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]450
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]451<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]452<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]453
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]454<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]455<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]456<li>C99 Variable sized arrays do not release stack memory when they go out of
457 scope. Thus, the following program may run out of stack space:
458<pre>
459 for (i = 0; i != 1000000; ++i) {
460 int X[n];
461 foo(X);
462 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]463</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]464
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]465<li>Initialization of global union variables can only be done <a
466href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
467member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]468
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]469<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
470external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]471
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]472</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]473</div>
474
475<!-- _______________________________________________________________________ -->
476<div class="doc_subsubsection">
477 Notes
478</div>
479
480<div class="doc_text">
481
482<ul>
483
484<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]485
486<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]487support for floating point data types of any size other than 32 and 64
488bits.</li>
489
490<li>The following Unix system functionality has not been tested and may not
491work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]492 <ol>
493 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
494 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
495 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
496 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
497 - These functions have not been tested.
498 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]499
500<li>Although many GCC extensions are supported, some are not. In particular,
501 the following extensions are known to <b>not be</b> supported:
502 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]503 <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]504 <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>
505 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
506 <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]507 <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]508 <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>
509 <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]510 <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>
511 <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>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
513 <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]514 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]515
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]516 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]517 attribute means that the LLVM compiler ignores the presence of the attribute,
518 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]519 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]520 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]521
522 <ol>
523 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
524 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]525 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]526
527 <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]528
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]529 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]530 return.<br>
531
532 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
533 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
534 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
535
536 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
537 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
538 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
539
540 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
541 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
542 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]543
544 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
545 Specifying attributes of variables.<br>
546 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
547 <tt>deprecated</tt>, <tt>transparent_union</tt>,
548 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]549
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]550 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
551 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
552 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]553 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]554
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]555 <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]556 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]557 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]558
559 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
560 all target specific attributes.</li>
561
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]562 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
563 Other built-in functions.<br>
564 We support all builtins which have a C language equivalent (e.g.,
565 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
566 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]567 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
568 (currently ignored). We also support builtins for ISO C99 floating
569 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]570 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]571
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]572 <p>The following extensions <b>are</b> known to be supported:</p>
573
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]574 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]575 <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]576 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
577 <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>
Tanya Lattnerca26c3e2004-06-22 03:48:17 +0000[diff] [blame]578 <li><a href="http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]579 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
580 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
581 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
582 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
583 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
584 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
585 <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>
586 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
587 <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]588 <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]589 <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]590 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
591or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]592 <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]593 <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]594 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
595 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
596 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
597 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
598 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
599 <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>
600 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
601 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
602 <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>
603 <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>
604 <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]605 <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]606 <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>
607 <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]608 </ol></li>
609
610</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]611
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]612<p>If you run into GCC extensions which have not been included in any of these
613lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]614
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]615</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]616
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]617<!-- ======================================================================= -->
618<div class="doc_subsection">
619 <a name="c++-fe">Known problems with the C++ front-end</a>
620</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]621
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]622<div class="doc_text">
623
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]624<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]625has not been tested as thoroughly as the C front-end. It has been tested and
626works for a number of non-trivial programs, but there may be lurking bugs.
627Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]628
629</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]630
631<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]632<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]634<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]635
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]636<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]637<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]638 front-end</a>.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]639
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]640<li><b>IA-64 specific</b>: The C++ front-end does not use <a
641href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]642In particular, it just stores function pointers instead of function
643descriptors in the vtable. This bug prevents mixing C++ code compiled with
Chris Lattner04db8082004-08-02 20:29:51 +0000[diff] [blame]644LLVM with C++ objects compiled by other C++ compilers.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]645
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]646</ul>
647
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]648</div>
649
650<!-- _______________________________________________________________________ -->
651<div class="doc_subsubsection">
652 Notes
653</div>
654
655<div class="doc_text">
656
657<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]658
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]659<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
660parser is significantly more standards compliant (and picky) than prior GCC
661versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]662href="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]663
664<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]665 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]666 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]667 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]668 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]669
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]670<li>The LLVM C++ front-end follows the <a
671 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
672 This document, which is not Itanium specific, specifies a standard for name
673 mangling, class layout, v-table layout, RTTI formats, and other C++
674 representation issues. Because we use this API, code generated by the LLVM
675 compilers should be binary compatible with machine code generated by other
676 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
677 <i>However</i>, the exception handling mechanism used by LLVM is very
678 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]679 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]681</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]682
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]683</div>
684
685<!-- ======================================================================= -->
686<div class="doc_subsection">
687 <a name="x86-be">Known problems with the X86 back-end</a>
688</div>
689
690<div class="doc_text">
691
692<ul>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]693 <li>none yet</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]694</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]695
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]696</div>
697
698<!-- ======================================================================= -->
699<div class="doc_subsection">
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]700 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]701</div>
702
703<div class="doc_text">
704
705<ul>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]706<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
707several programs in the LLVM test suite</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]708</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]709
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]710</div>
711
712<!-- ======================================================================= -->
713<div class="doc_subsection">
714 <a name="c-be">Known problems with the C back-end</a>
715</div>
716
717<div class="doc_text">
718
719<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]720
721<li>The C back-end produces code that violates the ANSI C Type-Based Alias
722Analysis rules. As such, special options may be necessary to compile the code
723(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]724problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]725
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]726<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]727cannot include special floating point numbers like Not-A-Number or
728Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]729
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]730<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]731supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]732frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]733
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]734</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]735
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]736</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]737
738<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]739<div class="doc_section">
740 <a name="additionalinfo">Additional Information</a>
741</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]742<!-- *********************************************************************** -->
743
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]744<div class="doc_text">
745
746<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]747including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]748implemented in LLVM. The web page also contains versions of the API
749documentation which is up-to-date with the CVS version of the source code. You
750can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]751the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]752
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]753<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]754us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
755lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]756
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]757</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]758
759<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]760
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]761<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]762<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]763 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]764 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
765 <a href="http://validator.w3.org/check/referer"><img
766 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
767
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]768 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]769 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]770</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]771
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]772</body>
773</html>