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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / adb1c39db9fcdfd8726f21532a789fed389e463c / . / docs / ReleaseNotes.html
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Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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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 Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]74code</a> produced by all aspects of the LLVM compiler and adds many <a
75href="#newfeatures">new features</a>, and <a href="#bugfix">fixes a few
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]76bugs</a> as well.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]77
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]78<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
79SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It
80has also been used to compile <b>many</b> other programs. LLVM now also works
81with a broad variety of C++ programs, though it has still received less testing
82than the C front-end.</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
100modes of llc</a> and lli, by passing them command line flags (e.g.,
101<tt>-regalloc=linearscan</tt>, <tt>-enable-correct-eh-support</tt>, etc.) </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 Lattner39491a72004-05-24 04:45:52 +0000[diff] [blame]111<li>LLVM now includes an implementation of Andersen's interprocedural alias
112analysis algorithm.</li>
Chris Lattner14cd5392004-05-24 05:34:32 +0000[diff] [blame]113<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
114basic blocks</a> to track down reduce miscompilation testcases.</li>
Brian Gaeke5beb8ba2004-06-01 20:02:56 +0000[diff] [blame]115<li>LLVM and the C front-end now work under Win32 using the
116<a href="http://www.cygwin.com">Cygwin</a> runtime libraries.
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]117This includes the JIT compiler.</li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]118<li>The LLVM code generator is now being <a
119href="CodeGenerator.html">documented</a>.</li>
120<li>There is a new tool, llvm-bcanalyzer. This tool can compute basic
121statistics and bytecode density statistics on a module or function basis and
122also dump out bytecode in a textual format that is lower level than assembly
123(values are not resolved from slot numbers). It should only be of interest to
124(a) those who are working to improve the bytecode format and (b) those who
125really want to understand or document the details of the bytecode format.</li>
Chris Lattner4f123992004-07-09 06:58:43 +0000[diff] [blame]126<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]127documented.</li>
128<li>LLVM now provides an <a
129href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic for efficient
130implementation of unordered floating point comparisons.</li>
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]131<li>The llvmgcc front-end now supports the GCC builtins for ISO C99 floating
132point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Reid Spencerb06e8482004-06-23 06:33:15 +0000[diff] [blame]133<li>Now that there are more source files than can fit on a 32Kbyte command
134line (Linux's limit), there's a new utility for searching the sources. The
135llvmgrep tool in the utils directory combines an egrep and a find without
136passing filenames through the command line. This improves performance
137slightly. Simply run llvmgrep like you might egrep but leave off the file
138names.</li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]139<li>We now generate HTML documentation and man pages for the tools from a single
140source (perl-style POD files).</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]141</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]142
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]143</div>
144
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]145
146<!--=========================================================================-->
147<div class="doc_subsubsection">
148In this release, the following missing features were implemented:
149</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]150
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]151<div class="doc_text">
152
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]153<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]154<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
155more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]156<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
157non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
159with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]160<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
161uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]162</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]163
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]164</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]165
166<!--=========================================================================-->
167<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]168<a name="qualityofimp">In this release, the following Quality of Implementation
169issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]170</div>
171
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]172<div class="doc_text">
173
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]174<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]175<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
176bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]177<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
178for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]179<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerea955512004-06-08 07:19:29 +0000[diff] [blame]180<li>The spurious "WARNING: Found global types that are not compatible" warning
181produced when linking C++ programs has been fixed.</li>
Reid Spencer421991c2004-07-07 21:06:28 +0000[diff] [blame]182<li><a href="http://llvm.cs.uiuc.edu/PR391">lli Doesn't Handle Exceptions From
183Bytecode Reader</a></li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]184</ol>
185
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]186</div>
187
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]188<!--=========================================================================-->
189<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]190In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]191</div>
192
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]193<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]194<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]195<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
196-disable/enable-povray and -disable-spec</a></li>
197<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
198work if you change PATH</a></li>
Chris Lattner24738a72004-06-09 01:09:16 +0000[diff] [blame]199<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
200with gcc 3.4</a></li>
Chris Lattnerf82bba92004-06-18 17:57:29 +0000[diff] [blame]201<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
202obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]203</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]204</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]205
206<!--=========================================================================-->
207<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]208<a name="codequality">This release includes the following Code Quality
209improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]210</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]211
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]212<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]213<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]214<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
215due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]216
217<li>The X86 backend now generates substantially better code for 64-bit integer
218and floating point operations.</li>
219
220<li>The -inline pass no longer inlines mutually recursive functions until it
221hits the inlining threshold.</li>
222
223<li>The -inline pass no longer misses obvious inlining opportunities just
224because the callee eventually calls into an external function.</li>
225
226<li>The -simplifycfg pass can now "if convert" simple statements into the new
227<tt>select</tt> instruction.</li>
228
229<li>The -loopsimplify pass can now break <a
230href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
231into multiple nested loops. This enables a variety of subsequent
232optimizations.</li>
233
234<li>The -adce pass can now eliminate calls to functions that do not not write to
235memory.</li>
236
237<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]238exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]239
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]240<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
241"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
242operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
243&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
244
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]245<li>LLVM now has infrastructure for (simple and sparse conditional) constant
246propagation of function calls. It currently supports a few math library
247functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]248
249<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
250loops</a> in the code to help C compilers whose optimizers do not recognize
251loops formed from gotos (like GCC).</li>
Brian Gaeke11074e32004-06-11 02:15:39 +0000[diff] [blame]252
253<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR368">[sparcv9] null
254often spilled to constant pool</a>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]255</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]256</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]257
258<!--=========================================================================-->
259<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]260<a name="bugfix">In this release, the following bugs in the previous release
261were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]262</div>
263
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]264<div class="doc_text">
265
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]266<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]267
268<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]269<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
270incorrectly updates dominator information</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
272breaks SSA form</a></li>
273<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
274to floating point cast</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]275<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when
276missing external functions encountered</a></li>
277<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
278asssertion</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]279<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
280code that unwinds</a></li>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame^]281<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]282of the same name, both having constant pools</a></li>
283<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
284physical register use of aliased definition</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]285<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch
286instruction</a></li>
287<li><a href="http://llvm.cs.uiuc.edu/PR365">[asmwriter] Asm writer aborts if
288an instruction is not embedded into a function</a></li>
289<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating
290point setcc X, X</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]291</ol>
292
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]293<p>Bugs in the C/C++ front-end:</p>
294
295<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]296<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
297indexing miscompiled</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]298<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
299enum type</a></li>
Chris Lattner19019602004-06-19 01:11:02 +0000[diff] [blame]300<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
301prototypes that take opaque structs by-value</a></li>
302<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
303length array of structures</a></li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]304<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]305initialized unsigned bitfields</a></li>
Chris Lattner5171eb52004-07-07 02:25:24 +0000[diff] [blame]306<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]307</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]308</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]309
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]310<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]311<div class="doc_section">
312 <a name="portability">Portability and Supported Platforms</a>
313</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]314<!-- *********************************************************************** -->
315
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]316<div class="doc_text">
317
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]318<p>LLVM is known to work in the following platforms:</p>
319
320<ul>
321<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
322 other unix-like systems).</li>
323<li>Sun UltraSPARC workstations running Solaris 8.</li>
324<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
325 interpreter only, no native codegen is available yet).</li>
326<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
327</ul>
328
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]329
330<p>The core LLVM infrastructure uses
331<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
332to the machine and operating system on which it is built. However, minor
333porting may be required to get LLVM to work on new platforms. We welcome your
334portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]335
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]336<p>Note that the LLVM build system does not currently support directories with
337spaces on them when running on Win32/cygwin. We strongly recommend running
338LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]339<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
340cygwin packages. By default, many important tools are not installed that
341are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]342
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]343</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]344
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]345<!--=========================================================================-->
346<div class="doc_subsection">
347In this release, the following portability problems were fixed:
348</div>
349
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]350<div class="doc_text">
351
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]352<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]353<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
354on Mac OS X</a></li>
355<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
356understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]357</ol>
358
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]359</div>
360
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]361<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]362<div class="doc_section">
363 <a name="knownproblems">Known Problems</a>
364</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]365<!-- *********************************************************************** -->
366
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]367<div class="doc_text">
368
369<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]370component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]371sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]372href="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]373there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]374
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]375</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]376
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]377<!-- ======================================================================= -->
378<div class="doc_subsection">
379 <a name="experimental">Experimental features included with this release</a>
380</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]381
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]382<div class="doc_text">
383
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]384<p>The following components of this LLVM release are either untested, known to
385be broken or unreliable, or are in early development. These components should
386not be relied on, and bugs should not be filed against them, but they may be
387useful to some people. In particular, if you would like to work on one of these
388components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]389
390<ul>
391<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattnercbabe702004-06-28 00:44:45 +0000[diff] [blame]392 -ipmodref, -cee</tt></li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]393
394<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
395 it should) and not thoroughly tested.</li>
396<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
397<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
398</ul>
399
400</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]401
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]402<!-- ======================================================================= -->
403<div class="doc_subsection">
404 <a name="core">Known problems with the LLVM Core</a>
405</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]406
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]407<div class="doc_text">
408
409<ul>
410
411<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
412work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]413
414<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]415such, execution of a threaded program could cause these data structures to be
416corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]417
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]418<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]419
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]420<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]421table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]422
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]423<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
424objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]425
426<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]427values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]428targets whose setjmp/longjmp libraries do not save and restore the entire
429register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]430</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]431</div>
432
433<!-- ======================================================================= -->
434<div class="doc_subsection">
435 <a name="c-fe">Known problems with the C front-end</a>
436</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]437
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]438<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]439<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]440
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]441<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]442<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]443<li>C99 Variable sized arrays do not release stack memory when they go out of
444 scope. Thus, the following program may run out of stack space:
445<pre>
446 for (i = 0; i != 1000000; ++i) {
447 int X[n];
448 foo(X);
449 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]450</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]451
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]452<li>Initialization of global union variables can only be done <a
453href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
454member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]455
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]456<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
457external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]458
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]459</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]460</div>
461
462<!-- _______________________________________________________________________ -->
463<div class="doc_subsubsection">
464 Notes
465</div>
466
467<div class="doc_text">
468
469<ul>
470
471<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]472
473<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]474support for floating point data types of any size other than 32 and 64
475bits.</li>
476
477<li>The following Unix system functionality has not been tested and may not
478work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]479 <ol>
480 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
481 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
482 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
483 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
484 - These functions have not been tested.
485 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]486
487<li>Although many GCC extensions are supported, some are not. In particular,
488 the following extensions are known to <b>not be</b> supported:
489 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]490 <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]491 <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>
492 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
493 <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]494 <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]495 <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>
496 <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]497 <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>
498 <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>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
500 <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]501 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]502
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]503 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]504 attribute means that the LLVM compiler ignores the presence of the attribute,
505 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]506 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]507 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]508
509 <ol>
510 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
511 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]512 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]513
514 <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]515
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]516 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]517 return.<br>
518
519 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
520 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
521 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
522
523 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
524 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
525 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
526
527 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
528 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
529 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]530
531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
532 Specifying attributes of variables.<br>
533 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
534 <tt>deprecated</tt>, <tt>transparent_union</tt>,
535 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]536
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]537 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
538 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
539 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]540 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]541
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]542 <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]543 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]544 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]545
546 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
547 all target specific attributes.</li>
548
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]549 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
550 Other built-in functions.<br>
551 We support all builtins which have a C language equivalent (e.g.,
552 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
553 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]554 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
555 (currently ignored). We also support builtins for ISO C99 floating
556 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]557 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]558
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]559 <p>The following extensions <b>are</b> known to be supported:</p>
560
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]561 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]562 <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]563 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
564 <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]565 <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]566 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
567 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
568 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
569 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
570 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
571 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
572 <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>
573 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
574 <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]575 <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]576 <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]577 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
578or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]579 <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]580 <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]581 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
582 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
583 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
584 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
585 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
586 <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>
587 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
588 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
589 <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>
590 <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>
591 <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]592 <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]593 <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>
594 <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]595 </ol></li>
596
597</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]598
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]599<p>If you run into GCC extensions which have not been included in any of these
600lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]601
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]602</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]603
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604<!-- ======================================================================= -->
605<div class="doc_subsection">
606 <a name="c++-fe">Known problems with the C++ front-end</a>
607</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]608
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]609<div class="doc_text">
610
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]611<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]612has not been tested as thoroughly as the C front-end. It has been tested and
613works for a number of non-trivial programs, but there may be lurking bugs.
614Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]615
616</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]617
618<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]619<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]620
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]621<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]622
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]623<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]624<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]625 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]626</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]627</div>
628
629<!-- _______________________________________________________________________ -->
630<div class="doc_subsubsection">
631 Notes
632</div>
633
634<div class="doc_text">
635
636<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]637
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]638<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
639parser is significantly more standards compliant (and picky) than prior GCC
640versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]641href="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]642
643<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]644 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]645 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]646 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]648
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]649<li>The LLVM C++ front-end follows the <a
650 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
651 This document, which is not Itanium specific, specifies a standard for name
652 mangling, class layout, v-table layout, RTTI formats, and other C++
653 representation issues. Because we use this API, code generated by the LLVM
654 compilers should be binary compatible with machine code generated by other
655 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
656 <i>However</i>, the exception handling mechanism used by LLVM is very
657 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]658 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]659
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]660</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]661
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]662</div>
663
664<!-- ======================================================================= -->
665<div class="doc_subsection">
666 <a name="x86-be">Known problems with the X86 back-end</a>
667</div>
668
669<div class="doc_text">
670
671<ul>
Reid Spencerc08bc9a2004-06-19 18:24:05 +0000[diff] [blame]672 <li>Optimized (Release) versions of LLVM built with GCC 3.3.2 or 3.3.3 will
673 produce an llc tool that always enters an infinite loop due to what
674 appears to be an optimization bug (-O2 and -O3) in those versions of GCC.
675 This problem does not happen in GCC 3.3.1 nor GCC 3.4.0 nor does it happen if
676 you build a Debug version of LLVM. You are cautioned not to use GCC 3.3.2 or
677 GCC 3.3.3 to build Optimized versions of LLVM. It is unclear whether this problem
678 affects other backends but it is unlikely.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]679</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]681</div>
682
683<!-- ======================================================================= -->
684<div class="doc_subsection">
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame^]685 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]686</div>
687
688<div class="doc_text">
689
690<ul>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame^]691<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
692several programs in the LLVM test suite</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]693</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]694
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]695</div>
696
697<!-- ======================================================================= -->
698<div class="doc_subsection">
699 <a name="c-be">Known problems with the C back-end</a>
700</div>
701
702<div class="doc_text">
703
704<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]705
706<li>The C back-end produces code that violates the ANSI C Type-Based Alias
707Analysis rules. As such, special options may be necessary to compile the code
708(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]709problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]710
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]711<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]712cannot include special floating point numbers like Not-A-Number or
713Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]714
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]715<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]716supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]717frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]718
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]719</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]720
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]721</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]722
723<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]724<div class="doc_section">
725 <a name="additionalinfo">Additional Information</a>
726</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]727<!-- *********************************************************************** -->
728
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]729<div class="doc_text">
730
731<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]732including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]733implemented in LLVM. The web page also contains versions of the API
734documentation which is up-to-date with the CVS version of the source code. You
735can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]736the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]737
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]738<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]739us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
740lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]741
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]742</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]743
744<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]745
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]746<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]747<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]748 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]749 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
750 <a href="http://validator.w3.org/check/referer"><img
751 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
752
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]753 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]754 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]755</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]756
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]757</body>
758</html>