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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>
Chris Lattner39491a72004-05-24 04:45:52 +0000[diff] [blame]108<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
109Garbage Collection</a>, enabling the use of aggressive copying and generational
110collectors.</li>
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>
Chris Lattner00f19b622004-06-04 00:40:11 +0000[diff] [blame]118<li>The LLVM code generator is now being <a
119 href="CodeGenerator.html">documented</a>.</li>
Reid Spencer624c5432004-06-08 07:30:31 +0000[diff] [blame]120<li>There is a new tool, llvm-abcd, the Analysis of ByteCode Dumper (abcd).
121This tool can compute basic statistics and bytecode density statistics on a
122module or function basis and also dump out bytecode in a textual format that
123is lower level than assembly (values are not resolved from slot numbers).
124It should only be of interest to (a) those who are working to improve the
125bytecode format and (b) those who really want to understand or document the
126details of the bytecode format.</li>
127<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now
128 being documented.</li>
Chris Lattneree98bf52004-06-15 21:50:46 +0000[diff] [blame]129<li>LLVM now provides an <a href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic
Chris Lattner00cda7a2004-06-11 04:35:21 +0000[diff] [blame]130for efficient implementation 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>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]139</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]140
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]141</div>
142
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]143
144<!--=========================================================================-->
145<div class="doc_subsubsection">
146In this release, the following missing features were implemented:
147</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]148
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]149<div class="doc_text">
150
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]151<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]152<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
153more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]154<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
155non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]156<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
157with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]158<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
159uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]160</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]161
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]162</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]163
164<!--=========================================================================-->
165<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]166<a name="qualityofimp">In this release, the following Quality of Implementation
167issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]168</div>
169
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]170<div class="doc_text">
171
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]172<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]173<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
174bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]175<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
176for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]177<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerea955512004-06-08 07:19:29 +0000[diff] [blame]178<li>The spurious "WARNING: Found global types that are not compatible" warning
179produced when linking C++ programs has been fixed.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]180</ol>
181
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]182</div>
183
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]184<!--=========================================================================-->
185<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]186In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]187</div>
188
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]189<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]190<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]191<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
192-disable/enable-povray and -disable-spec</a></li>
193<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
194work if you change PATH</a></li>
Chris Lattner24738a72004-06-09 01:09:16 +0000[diff] [blame]195<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
196with gcc 3.4</a></li>
Chris Lattnerf82bba92004-06-18 17:57:29 +0000[diff] [blame]197<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
198obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]199</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]200</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]201
202<!--=========================================================================-->
203<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]204<a name="codequality">This release includes the following Code Quality
205improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]206</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]207
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]208<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]209<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]210<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
211due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]212
213<li>The X86 backend now generates substantially better code for 64-bit integer
214and floating point operations.</li>
215
216<li>The -inline pass no longer inlines mutually recursive functions until it
217hits the inlining threshold.</li>
218
219<li>The -inline pass no longer misses obvious inlining opportunities just
220because the callee eventually calls into an external function.</li>
221
222<li>The -simplifycfg pass can now "if convert" simple statements into the new
223<tt>select</tt> instruction.</li>
224
225<li>The -loopsimplify pass can now break <a
226href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
227into multiple nested loops. This enables a variety of subsequent
228optimizations.</li>
229
230<li>The -adce pass can now eliminate calls to functions that do not not write to
231memory.</li>
232
233<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]234exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]235
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]236<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
237"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
238operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
239&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
240
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]241<li>LLVM now has infrastructure for (simple and sparse conditional) constant
242propagation of function calls. It currently supports a few math library
243functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]244
245<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
246loops</a> in the code to help C compilers whose optimizers do not recognize
247loops formed from gotos (like GCC).</li>
Brian Gaeke11074e32004-06-11 02:15:39 +0000[diff] [blame]248
249<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR368">[sparcv9] null
250often spilled to constant pool</a>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]251</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]252</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]253
254<!--=========================================================================-->
255<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]256<a name="bugfix">In this release, the following bugs in the previous release
257were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]258</div>
259
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]260<div class="doc_text">
261
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]262<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]263
264<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]265<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
266asssertion</a></li>
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>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]273<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
274code that unwinds</a></li>
275<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
276of the same name, both having constant pools</a></li>
277<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
278physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]279<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattneraec5f262004-06-01 21:52:45 +0000[diff] [blame]280<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when missing external functions encountered</a></li>
Chris Lattner00cda7a2004-06-11 04:35:21 +0000[diff] [blame]281<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating point setcc X, X</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]282</ol>
283
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]284<p>Bugs in the C/C++ front-end:</p>
285
286<ol>
Chris Lattner3cf519a2004-06-20 19:08:50 +0000[diff] [blame]287<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly initialized unsigned bitfields</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]288<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
289enum type</a></li>
290<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
291indexing miscompiled</a></li>
Chris Lattner19019602004-06-19 01:11:02 +0000[diff] [blame]292<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
293prototypes that take opaque structs by-value</a></li>
294<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
295length array of structures</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]296</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]297</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]298
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]299<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]300<div class="doc_section">
301 <a name="portability">Portability and Supported Platforms</a>
302</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]303<!-- *********************************************************************** -->
304
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]305<div class="doc_text">
306
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]307<p>LLVM is known to work in the following platforms:</p>
308
309<ul>
310<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
311 other unix-like systems).</li>
312<li>Sun UltraSPARC workstations running Solaris 8.</li>
313<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
314 interpreter only, no native codegen is available yet).</li>
315<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
316</ul>
317
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]318
319<p>The core LLVM infrastructure uses
320<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
321to the machine and operating system on which it is built. However, minor
322porting may be required to get LLVM to work on new platforms. We welcome your
323portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]324
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]325<p>Note that the LLVM build system does not currently support directories with
326spaces on them when running on Win32/cygwin. We strongly recommend running
327LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]328<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
329cygwin packages. By default, many important tools are not installed that
330are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]331
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]332</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]333
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]334<!--=========================================================================-->
335<div class="doc_subsection">
336In this release, the following portability problems were fixed:
337</div>
338
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]339<div class="doc_text">
340
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]341<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]342<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
343on Mac OS X</a></li>
344<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
345understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]346</ol>
347
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]348</div>
349
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]350<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]351<div class="doc_section">
352 <a name="knownproblems">Known Problems</a>
353</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]354<!-- *********************************************************************** -->
355
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]356<div class="doc_text">
357
358<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]359component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]360sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]361href="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]362there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]363
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]364</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]365
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]366<!-- ======================================================================= -->
367<div class="doc_subsection">
368 <a name="experimental">Experimental features included with this release</a>
369</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]370
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]371<div class="doc_text">
372
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]373<p>The following components of this LLVM release are either untested, known to
374be broken or unreliable, or are in early development. These components should
375not be relied on, and bugs should not be filed against them, but they may be
376useful to some people. In particular, if you would like to work on one of these
377components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]378
379<ul>
380<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
381 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
382
383<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
384 it should) and not thoroughly tested.</li>
385<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
386<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
387</ul>
388
389</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]390
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]391<!-- ======================================================================= -->
392<div class="doc_subsection">
393 <a name="core">Known problems with the LLVM Core</a>
394</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]395
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]396<div class="doc_text">
397
398<ul>
399
400<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
401work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]402
403<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]404such, execution of a threaded program could cause these data structures to be
405corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]406
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]407<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]408
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]409<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]410table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]411
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]412<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
413objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]414
415<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]416values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]417targets whose setjmp/longjmp libraries do not save and restore the entire
418register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]419</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]420</div>
421
422<!-- ======================================================================= -->
423<div class="doc_subsection">
424 <a name="c-fe">Known problems with the C front-end</a>
425</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]426
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]427<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]428<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]429
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]430<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]431<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]432<li>C99 Variable sized arrays do not release stack memory when they go out of
433 scope. Thus, the following program may run out of stack space:
434<pre>
435 for (i = 0; i != 1000000; ++i) {
436 int X[n];
437 foo(X);
438 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]439</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]440
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]441<li>Initialization of global union variables can only be done <a
442href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
443member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]444
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]445<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
446external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]447
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]448</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]449</div>
450
451<!-- _______________________________________________________________________ -->
452<div class="doc_subsubsection">
453 Notes
454</div>
455
456<div class="doc_text">
457
458<ul>
459
460<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]461
462<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]463support for floating point data types of any size other than 32 and 64
464bits.</li>
465
466<li>The following Unix system functionality has not been tested and may not
467work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]468 <ol>
469 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
470 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
471 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
472 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
473 - These functions have not been tested.
474 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]475
476<li>Although many GCC extensions are supported, some are not. In particular,
477 the following extensions are known to <b>not be</b> supported:
478 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]479 <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]480 <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>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
482 <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]483 <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]484 <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>
485 <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]486 <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>
487 <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>
488 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
489 <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]490 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]491
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]492 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]493 attribute means that the LLVM compiler ignores the presence of the attribute,
494 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]495 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]496 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]497
498 <ol>
499 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
500 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]501 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]502
503 <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]504
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]505 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]506 return.<br>
507
508 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
509 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
510 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
511
512 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
513 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
514 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
515
516 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
517 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
518 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]519
520 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
521 Specifying attributes of variables.<br>
522 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
523 <tt>deprecated</tt>, <tt>transparent_union</tt>,
524 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]525
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]526 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
527 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
528 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]529 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]531 <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]532 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]533 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]534
535 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
536 all target specific attributes.</li>
537
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]538 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
539 Other built-in functions.<br>
540 We support all builtins which have a C language equivalent (e.g.,
541 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
542 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]543 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
544 (currently ignored). We also support builtins for ISO C99 floating
545 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]546 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]548 <p>The following extensions <b>are</b> known to be supported:</p>
549
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]550 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]551 <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]552 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
553 <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]554 <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]555 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
556 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
557 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
558 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
559 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
560 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
561 <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>
562 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
563 <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]564 <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]565 <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]566 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
567or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]568 <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]569 <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]570 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
571 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
572 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
573 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
574 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
575 <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>
576 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
577 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
578 <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>
579 <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>
580 <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]581 <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]582 <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>
583 <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]584 </ol></li>
585
586</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]587
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]588<p>If you run into GCC extensions which have not been included in any of these
589lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]591</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]592
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]593<!-- ======================================================================= -->
594<div class="doc_subsection">
595 <a name="c++-fe">Known problems with the C++ front-end</a>
596</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]597
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]598<div class="doc_text">
599
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]600<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]601has not been tested as thoroughly as the C front-end. It has been tested and
602works for a number of non-trivial programs, but there may be lurking bugs.
603Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]604
605</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]606
607<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]608<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]609
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]610<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]611
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]612<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]613<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]614 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]615</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]616</div>
617
618<!-- _______________________________________________________________________ -->
619<div class="doc_subsubsection">
620 Notes
621</div>
622
623<div class="doc_text">
624
625<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]626
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]627<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
628parser is significantly more standards compliant (and picky) than prior GCC
629versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]630href="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]631
632<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]633 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]634 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]635 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]636 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]637
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]638<li>The LLVM C++ front-end follows the <a
639 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
640 This document, which is not Itanium specific, specifies a standard for name
641 mangling, class layout, v-table layout, RTTI formats, and other C++
642 representation issues. Because we use this API, code generated by the LLVM
643 compilers should be binary compatible with machine code generated by other
644 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
645 <i>However</i>, the exception handling mechanism used by LLVM is very
646 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]647 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]648
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]649</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]650
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]651</div>
652
653<!-- ======================================================================= -->
654<div class="doc_subsection">
655 <a name="x86-be">Known problems with the X86 back-end</a>
656</div>
657
658<div class="doc_text">
659
660<ul>
Reid Spencerc08bc9a2004-06-19 18:24:05 +0000[diff] [blame]661 <li>Optimized (Release) versions of LLVM built with GCC 3.3.2 or 3.3.3 will
662 produce an llc tool that always enters an infinite loop due to what
663 appears to be an optimization bug (-O2 and -O3) in those versions of GCC.
664 This problem does not happen in GCC 3.3.1 nor GCC 3.4.0 nor does it happen if
665 you build a Debug version of LLVM. You are cautioned not to use GCC 3.3.2 or
666 GCC 3.3.3 to build Optimized versions of LLVM. It is unclear whether this problem
667 affects other backends but it is unlikely.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]668</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]669
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]670</div>
671
672<!-- ======================================================================= -->
673<div class="doc_subsection">
674 <a name="sparc-be">Known problems with the Sparc back-end</a>
675</div>
676
677<div class="doc_text">
678
679<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]680<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]681</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]682
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]683</div>
684
685<!-- ======================================================================= -->
686<div class="doc_subsection">
687 <a name="c-be">Known problems with the C back-end</a>
688</div>
689
690<div class="doc_text">
691
692<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]693
694<li>The C back-end produces code that violates the ANSI C Type-Based Alias
695Analysis rules. As such, special options may be necessary to compile the code
696(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]697problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]698
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]699<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]700cannot include special floating point numbers like Not-A-Number or
701Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]702
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]703<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]704supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]705frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]706
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]707</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]708
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]709</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]710
711<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]712<div class="doc_section">
713 <a name="additionalinfo">Additional Information</a>
714</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]715<!-- *********************************************************************** -->
716
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]717<div class="doc_text">
718
719<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]720including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]721implemented in LLVM. The web page also contains versions of the API
722documentation which is up-to-date with the CVS version of the source code. You
723can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]724the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]725
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]726<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]727us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
728lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]729
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]730</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]731
732<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]733
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]734<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]735<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]736 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]737 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
738 <a href="http://validator.w3.org/check/referer"><img
739 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
740
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]741 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]742 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]743</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]744
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]745</body>
746</html>