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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>
25 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
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>
126<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now being
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>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]182</ol>
183
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]184</div>
185
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]186<!--=========================================================================-->
187<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]188In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]189</div>
190
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]191<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]192<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]193<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
194-disable/enable-povray and -disable-spec</a></li>
195<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
196work if you change PATH</a></li>
Chris Lattner24738a72004-06-09 01:09:16 +0000[diff] [blame]197<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
198with gcc 3.4</a></li>
Chris Lattnerf82bba92004-06-18 17:57:29 +0000[diff] [blame]199<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
200obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]201</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]202</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]203
204<!--=========================================================================-->
205<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]206<a name="codequality">This release includes the following Code Quality
207improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]208</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]209
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]210<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]211<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]212<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
213due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]214
215<li>The X86 backend now generates substantially better code for 64-bit integer
216and floating point operations.</li>
217
218<li>The -inline pass no longer inlines mutually recursive functions until it
219hits the inlining threshold.</li>
220
221<li>The -inline pass no longer misses obvious inlining opportunities just
222because the callee eventually calls into an external function.</li>
223
224<li>The -simplifycfg pass can now "if convert" simple statements into the new
225<tt>select</tt> instruction.</li>
226
227<li>The -loopsimplify pass can now break <a
228href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
229into multiple nested loops. This enables a variety of subsequent
230optimizations.</li>
231
232<li>The -adce pass can now eliminate calls to functions that do not not write to
233memory.</li>
234
235<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]236exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]237
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]238<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
239"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
240operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
241&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
242
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]243<li>LLVM now has infrastructure for (simple and sparse conditional) constant
244propagation of function calls. It currently supports a few math library
245functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]246
247<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
248loops</a> in the code to help C compilers whose optimizers do not recognize
249loops formed from gotos (like GCC).</li>
Brian Gaeke11074e32004-06-11 02:15:39 +0000[diff] [blame]250
251<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR368">[sparcv9] null
252often spilled to constant pool</a>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]253</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]254</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]255
256<!--=========================================================================-->
257<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]258<a name="bugfix">In this release, the following bugs in the previous release
259were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]260</div>
261
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]262<div class="doc_text">
263
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]264<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]265
266<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]267<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
268incorrectly updates dominator information</a></li>
269<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
270breaks SSA form</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
272to floating point cast</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]273<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when
274missing external functions encountered</a></li>
275<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
276asssertion</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]277<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
278code that unwinds</a></li>
279<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
280of the same name, both having constant pools</a></li>
281<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
282physical register use of aliased definition</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]283<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch
284instruction</a></li>
285<li><a href="http://llvm.cs.uiuc.edu/PR365">[asmwriter] Asm writer aborts if
286an instruction is not embedded into a function</a></li>
287<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating
288point setcc X, X</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]289</ol>
290
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]291<p>Bugs in the C/C++ front-end:</p>
292
293<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]294<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
295indexing miscompiled</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]296<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
297enum type</a></li>
Chris Lattner19019602004-06-19 01:11:02 +0000[diff] [blame]298<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
299prototypes that take opaque structs by-value</a></li>
300<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
301length array of structures</a></li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame^]302<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]303initialized unsigned bitfields</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]304</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]305</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]306
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]307<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]308<div class="doc_section">
309 <a name="portability">Portability and Supported Platforms</a>
310</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]311<!-- *********************************************************************** -->
312
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]313<div class="doc_text">
314
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]315<p>LLVM is known to work in the following platforms:</p>
316
317<ul>
318<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
319 other unix-like systems).</li>
320<li>Sun UltraSPARC workstations running Solaris 8.</li>
321<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
322 interpreter only, no native codegen is available yet).</li>
323<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
324</ul>
325
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]326
327<p>The core LLVM infrastructure uses
328<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
329to the machine and operating system on which it is built. However, minor
330porting may be required to get LLVM to work on new platforms. We welcome your
331portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]332
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]333<p>Note that the LLVM build system does not currently support directories with
334spaces on them when running on Win32/cygwin. We strongly recommend running
335LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]336<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
337cygwin packages. By default, many important tools are not installed that
338are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]339
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]340</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]341
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]342<!--=========================================================================-->
343<div class="doc_subsection">
344In this release, the following portability problems were fixed:
345</div>
346
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]347<div class="doc_text">
348
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]349<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]350<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
351on Mac OS X</a></li>
352<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
353understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]354</ol>
355
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]356</div>
357
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]358<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]359<div class="doc_section">
360 <a name="knownproblems">Known Problems</a>
361</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]362<!-- *********************************************************************** -->
363
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]364<div class="doc_text">
365
366<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]367component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]368sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]369href="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]370there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +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
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]374<!-- ======================================================================= -->
375<div class="doc_subsection">
376 <a name="experimental">Experimental features included with this release</a>
377</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]378
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]379<div class="doc_text">
380
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]381<p>The following components of this LLVM release are either untested, known to
382be broken or unreliable, or are in early development. These components should
383not be relied on, and bugs should not be filed against them, but they may be
384useful to some people. In particular, if you would like to work on one of these
385components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]386
387<ul>
388<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattnercbabe702004-06-28 00:44:45 +0000[diff] [blame]389 -ipmodref, -cee</tt></li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]390
391<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
392 it should) and not thoroughly tested.</li>
393<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
394<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
395</ul>
396
397</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]398
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]399<!-- ======================================================================= -->
400<div class="doc_subsection">
401 <a name="core">Known problems with the LLVM Core</a>
402</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]403
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]404<div class="doc_text">
405
406<ul>
407
408<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
409work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]410
411<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]412such, execution of a threaded program could cause these data structures to be
413corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]414
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]415<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]416
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]417<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]418table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]419
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]420<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
421objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]422
423<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]424values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]425targets whose setjmp/longjmp libraries do not save and restore the entire
426register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]427</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]428</div>
429
430<!-- ======================================================================= -->
431<div class="doc_subsection">
432 <a name="c-fe">Known problems with the C front-end</a>
433</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]434
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]435<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]436<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]437
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]438<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]439<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]440<li>C99 Variable sized arrays do not release stack memory when they go out of
441 scope. Thus, the following program may run out of stack space:
442<pre>
443 for (i = 0; i != 1000000; ++i) {
444 int X[n];
445 foo(X);
446 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]447</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]448
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]449<li>Initialization of global union variables can only be done <a
450href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
451member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]452
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]453<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
454external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]455
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]456</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]457</div>
458
459<!-- _______________________________________________________________________ -->
460<div class="doc_subsubsection">
461 Notes
462</div>
463
464<div class="doc_text">
465
466<ul>
467
468<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]469
470<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]471support for floating point data types of any size other than 32 and 64
472bits.</li>
473
474<li>The following Unix system functionality has not been tested and may not
475work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]476 <ol>
477 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
478 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
479 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
480 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
481 - These functions have not been tested.
482 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]483
484<li>Although many GCC extensions are supported, some are not. In particular,
485 the following extensions are known to <b>not be</b> supported:
486 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]487 <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]488 <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>
489 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
490 <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]491 <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]492 <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>
493 <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]494 <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>
495 <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>
496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
497 <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]498 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]499
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]501 attribute means that the LLVM compiler ignores the presence of the attribute,
502 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]503 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]504 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]505
506 <ol>
507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
508 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]509 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]510
511 <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]512
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]513 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]514 return.<br>
515
516 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
517 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
518 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
519
520 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
521 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
522 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
523
524 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
525 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
526 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]527
528 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
529 Specifying attributes of variables.<br>
530 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
531 <tt>deprecated</tt>, <tt>transparent_union</tt>,
532 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]534 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
535 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
536 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]537 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]538
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]539 <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]540 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]541 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]542
543 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
544 all target specific attributes.</li>
545
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]546 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
547 Other built-in functions.<br>
548 We support all builtins which have a C language equivalent (e.g.,
549 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
550 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]551 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
552 (currently ignored). We also support builtins for ISO C99 floating
553 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]554 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]555
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]556 <p>The following extensions <b>are</b> known to be supported:</p>
557
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]558 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]559 <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]560 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
561 <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]562 <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]563 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
564 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
565 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
566 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
567 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
568 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
569 <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>
570 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
571 <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]572 <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]573 <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]574 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
575or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]576 <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]577 <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]578 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
579 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
580 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
581 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
582 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
583 <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>
584 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
585 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
586 <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>
587 <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>
588 <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]589 <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]590 <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>
591 <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]592 </ol></li>
593
594</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]595
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]596<p>If you run into GCC extensions which have not been included in any of these
597lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]598
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]599</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]600
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]601<!-- ======================================================================= -->
602<div class="doc_subsection">
603 <a name="c++-fe">Known problems with the C++ front-end</a>
604</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]606<div class="doc_text">
607
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]608<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]609has not been tested as thoroughly as the C front-end. It has been tested and
610works for a number of non-trivial programs, but there may be lurking bugs.
611Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]612
613</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]614
615<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]616<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]617
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]618<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]619
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]620<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]621<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]622 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]623</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]624</div>
625
626<!-- _______________________________________________________________________ -->
627<div class="doc_subsubsection">
628 Notes
629</div>
630
631<div class="doc_text">
632
633<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]634
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]635<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
636parser is significantly more standards compliant (and picky) than prior GCC
637versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]638href="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]639
640<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]641 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]642 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]643 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]644 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]645
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]646<li>The LLVM C++ front-end follows the <a
647 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
648 This document, which is not Itanium specific, specifies a standard for name
649 mangling, class layout, v-table layout, RTTI formats, and other C++
650 representation issues. Because we use this API, code generated by the LLVM
651 compilers should be binary compatible with machine code generated by other
652 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
653 <i>However</i>, the exception handling mechanism used by LLVM is very
654 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]655 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]656
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]657</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]658
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]659</div>
660
661<!-- ======================================================================= -->
662<div class="doc_subsection">
663 <a name="x86-be">Known problems with the X86 back-end</a>
664</div>
665
666<div class="doc_text">
667
668<ul>
Reid Spencerc08bc9a2004-06-19 18:24:05 +0000[diff] [blame]669 <li>Optimized (Release) versions of LLVM built with GCC 3.3.2 or 3.3.3 will
670 produce an llc tool that always enters an infinite loop due to what
671 appears to be an optimization bug (-O2 and -O3) in those versions of GCC.
672 This problem does not happen in GCC 3.3.1 nor GCC 3.4.0 nor does it happen if
673 you build a Debug version of LLVM. You are cautioned not to use GCC 3.3.2 or
674 GCC 3.3.3 to build Optimized versions of LLVM. It is unclear whether this problem
675 affects other backends but it is unlikely.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]676</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]677
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]678</div>
679
680<!-- ======================================================================= -->
681<div class="doc_subsection">
682 <a name="sparc-be">Known problems with the Sparc back-end</a>
683</div>
684
685<div class="doc_text">
686
687<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]688<li>There are several programs in the LLVM testsuite that the Sparc code generator is known to miscompile.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]689</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]690
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]691</div>
692
693<!-- ======================================================================= -->
694<div class="doc_subsection">
695 <a name="c-be">Known problems with the C back-end</a>
696</div>
697
698<div class="doc_text">
699
700<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]701
702<li>The C back-end produces code that violates the ANSI C Type-Based Alias
703Analysis rules. As such, special options may be necessary to compile the code
704(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]705problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]706
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]707<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]708cannot include special floating point numbers like Not-A-Number or
709Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]710
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]711<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]712supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]713frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]714
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]715</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]716
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]717</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]718
719<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]720<div class="doc_section">
721 <a name="additionalinfo">Additional Information</a>
722</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]723<!-- *********************************************************************** -->
724
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]725<div class="doc_text">
726
727<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]728including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]729implemented in LLVM. The web page also contains versions of the API
730documentation which is up-to-date with the CVS version of the source code. You
731can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]732the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]733
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]734<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]735us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
736lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]737
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]738</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]739
740<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]741
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]742<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]743<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]744 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]745 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
746 <a href="http://validator.w3.org/check/referer"><img
747 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
748
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]749 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]750 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]751</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]752
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]753</body>
754</html>