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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>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]133</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]134
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]135</div>
136
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]137
138<!--=========================================================================-->
139<div class="doc_subsubsection">
140In this release, the following missing features were implemented:
141</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]142
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]143<div class="doc_text">
144
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]145<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]146<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
147more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]148<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
149non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]150<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
151with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]152<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
153uses of external fns by immediate constant exprs</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]154</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]155
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]156</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]157
158<!--=========================================================================-->
159<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]160<a name="qualityofimp">In this release, the following Quality of Implementation
161issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]162</div>
163
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]164<div class="doc_text">
165
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]166<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]167<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
168bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]169<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
170for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]171<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerea955512004-06-08 07:19:29 +0000[diff] [blame]172<li>The spurious "WARNING: Found global types that are not compatible" warning
173produced when linking C++ programs has been fixed.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]174</ol>
175
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]176</div>
177
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]178<!--=========================================================================-->
179<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]180In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]181</div>
182
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]183<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]184<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]185<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
186-disable/enable-povray and -disable-spec</a></li>
187<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
188work if you change PATH</a></li>
Chris Lattner24738a72004-06-09 01:09:16 +0000[diff] [blame]189<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
190with gcc 3.4</a></li>
Chris Lattnerf82bba92004-06-18 17:57:29 +0000[diff] [blame]191<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
192obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]193</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]194</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]195
196<!--=========================================================================-->
197<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]198<a name="codequality">This release includes the following Code Quality
199improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]200</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]201
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]202<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]203<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]204<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
205due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]206
207<li>The X86 backend now generates substantially better code for 64-bit integer
208and floating point operations.</li>
209
210<li>The -inline pass no longer inlines mutually recursive functions until it
211hits the inlining threshold.</li>
212
213<li>The -inline pass no longer misses obvious inlining opportunities just
214because the callee eventually calls into an external function.</li>
215
216<li>The -simplifycfg pass can now "if convert" simple statements into the new
217<tt>select</tt> instruction.</li>
218
219<li>The -loopsimplify pass can now break <a
220href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
221into multiple nested loops. This enables a variety of subsequent
222optimizations.</li>
223
224<li>The -adce pass can now eliminate calls to functions that do not not write to
225memory.</li>
226
227<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]228exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]229
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]230<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
231"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
232operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
233&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
234
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]235<li>LLVM now has infrastructure for (simple and sparse conditional) constant
236propagation of function calls. It currently supports a few math library
237functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]238
239<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
240loops</a> in the code to help C compilers whose optimizers do not recognize
241loops formed from gotos (like GCC).</li>
Brian Gaeke11074e32004-06-11 02:15:39 +0000[diff] [blame]242
243<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR368">[sparcv9] null
244often spilled to constant pool</a>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]245</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]246</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]247
248<!--=========================================================================-->
249<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]250<a name="bugfix">In this release, the following bugs in the previous release
251were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]252</div>
253
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]254<div class="doc_text">
255
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]256<p>Bugs in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]257
258<ol>
John Criswell4d8d49f2004-05-06 22:23:24 +0000[diff] [blame]259<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
260asssertion</a></li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]261<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
262incorrectly updates dominator information</a></li>
263<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
264breaks SSA form</a></li>
265<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
266to floating point cast</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]267<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
268code that unwinds</a></li>
269<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
270of the same name, both having constant pools</a></li>
271<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
272physical register use of aliased definition</a></li>
Chris Lattnere5ad10a2004-05-21 16:48:20 +0000[diff] [blame]273<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]274<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]275<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]276</ol>
277
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]278<p>Bugs in the C/C++ front-end:</p>
279
280<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]281<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
282enum type</a></li>
283<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
284indexing miscompiled</a></li>
Chris Lattner19019602004-06-19 01:11:02 +0000[diff] [blame]285<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
286prototypes that take opaque structs by-value</a></li>
287<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
288length array of structures</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]289</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]290</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]291
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]292<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]293<div class="doc_section">
294 <a name="portability">Portability and Supported Platforms</a>
295</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]296<!-- *********************************************************************** -->
297
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]298<div class="doc_text">
299
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]300<p>LLVM is known to work in the following platforms:</p>
301
302<ul>
303<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
304 other unix-like systems).</li>
305<li>Sun UltraSPARC workstations running Solaris 8.</li>
306<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
307 interpreter only, no native codegen is available yet).</li>
308<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
309</ul>
310
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]311
312<p>The core LLVM infrastructure uses
313<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
314to the machine and operating system on which it is built. However, minor
315porting may be required to get LLVM to work on new platforms. We welcome your
316portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]317
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]318<p>Note that the LLVM build system does not currently support directories with
319spaces on them when running on Win32/cygwin. We strongly recommend running
320LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]321<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
322cygwin packages. By default, many important tools are not installed that
323are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]324
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]325</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]326
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]327<!--=========================================================================-->
328<div class="doc_subsection">
329In this release, the following portability problems were fixed:
330</div>
331
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]332<div class="doc_text">
333
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]334<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]335<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
336on Mac OS X</a></li>
337<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
338understand abbreviated names in headers</a></li>
Brian Gaeke21a710a2004-04-20 18:18:46 +0000[diff] [blame]339</ol>
340
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]341</div>
342
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]343<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]344<div class="doc_section">
345 <a name="knownproblems">Known Problems</a>
346</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]347<!-- *********************************************************************** -->
348
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]349<div class="doc_text">
350
351<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]352component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]353sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]354href="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]355there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]356
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]357</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]358
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]359<!-- ======================================================================= -->
360<div class="doc_subsection">
361 <a name="experimental">Experimental features included with this release</a>
362</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]363
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]364<div class="doc_text">
365
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]366<p>The following components of this LLVM release are either untested, known to
367be broken or unreliable, or are in early development. These components should
368not be relied on, and bugs should not be filed against them, but they may be
369useful to some people. In particular, if you would like to work on one of these
370components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]371
372<ul>
373<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
374 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
375
376<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
377 it should) and not thoroughly tested.</li>
378<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
379<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
380</ul>
381
382</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]383
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]384<!-- ======================================================================= -->
385<div class="doc_subsection">
386 <a name="core">Known problems with the LLVM Core</a>
387</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]388
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]389<div class="doc_text">
390
391<ul>
392
393<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
394work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]395
396<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]397such, execution of a threaded program could cause these data structures to be
398corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]399
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]400<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]401
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]402<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]403table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]404
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]405<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
406objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]407
408<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]409values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]410targets whose setjmp/longjmp libraries do not save and restore the entire
411register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]412</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]413</div>
414
415<!-- ======================================================================= -->
416<div class="doc_subsection">
417 <a name="c-fe">Known problems with the C front-end</a>
418</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]419
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]420<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]421<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]422
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]423<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]424<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]425<li>C99 Variable sized arrays do not release stack memory when they go out of
426 scope. Thus, the following program may run out of stack space:
427<pre>
428 for (i = 0; i != 1000000; ++i) {
429 int X[n];
430 foo(X);
431 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]432</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]433
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]434<li>Initialization of global union variables can only be done <a
435href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
436member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]437
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]438<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
439external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]440
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]441</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]442</div>
443
444<!-- _______________________________________________________________________ -->
445<div class="doc_subsubsection">
446 Notes
447</div>
448
449<div class="doc_text">
450
451<ul>
452
453<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]454
455<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]456support for floating point data types of any size other than 32 and 64
457bits.</li>
458
459<li>The following Unix system functionality has not been tested and may not
460work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]461 <ol>
462 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
463 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
464 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
465 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
466 - These functions have not been tested.
467 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]468
469<li>Although many GCC extensions are supported, some are not. In particular,
470 the following extensions are known to <b>not be</b> supported:
471 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]472 <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]473 <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>
474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
475 <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]476 <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]477 <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>
478 <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]479 <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>
480 <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>
481 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
482 <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]483 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]484
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]485 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]486 attribute means that the LLVM compiler ignores the presence of the attribute,
487 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]488 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]489 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]490
491 <ol>
492 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
493 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]494 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]495
496 <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]497
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]498 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]499 return.<br>
500
501 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
502 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
503 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
504
505 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
506 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
507 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
508
509 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
510 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
511 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]512
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
514 Specifying attributes of variables.<br>
515 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
516 <tt>deprecated</tt>, <tt>transparent_union</tt>,
517 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]518
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]519 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
520 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
521 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]522 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]523
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]524 <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]525 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]526 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]527
528 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
529 all target specific attributes.</li>
530
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]531 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
532 Other built-in functions.<br>
533 We support all builtins which have a C language equivalent (e.g.,
534 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
535 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]536 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
537 (currently ignored). We also support builtins for ISO C99 floating
538 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]539 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]540
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]541 <p>The following extensions <b>are</b> known to be supported:</p>
542
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]543 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]544 <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]545 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
546 <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>
547 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
548 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
549 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
550 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
551 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
552 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
553 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
554 <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>
555 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
556 <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]557 <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]558 <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]559 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
560or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]561 <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]562 <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]563 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
564 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
565 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
566 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
567 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
568 <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>
569 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
570 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
571 <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>
572 <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>
573 <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]574 <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]575 <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>
576 <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]577 </ol></li>
578
579</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]580
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]581<p>If you run into GCC extensions which have not been included in any of these
582lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]583
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]584</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]585
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]586<!-- ======================================================================= -->
587<div class="doc_subsection">
588 <a name="c++-fe">Known problems with the C++ front-end</a>
589</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]591<div class="doc_text">
592
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]593<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]594has not been tested as thoroughly as the C front-end. It has been tested and
595works for a number of non-trivial programs, but there may be lurking bugs.
596Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]597
598</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]599
600<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]601<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]602
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]603<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]604
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]605<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]606<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]607 front-end</a>.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]608</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]609</div>
610
611<!-- _______________________________________________________________________ -->
612<div class="doc_subsubsection">
613 Notes
614</div>
615
616<div class="doc_text">
617
618<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]619
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]620<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
621parser is significantly more standards compliant (and picky) than prior GCC
622versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]623href="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]624
625<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]626 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]627 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]628 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]629 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]630
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]631<li>The LLVM C++ front-end follows the <a
632 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
633 This document, which is not Itanium specific, specifies a standard for name
634 mangling, class layout, v-table layout, RTTI formats, and other C++
635 representation issues. Because we use this API, code generated by the LLVM
636 compilers should be binary compatible with machine code generated by other
637 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
638 <i>However</i>, the exception handling mechanism used by LLVM is very
639 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]640 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]641
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]642</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]643
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]644</div>
645
646<!-- ======================================================================= -->
647<div class="doc_subsection">
648 <a name="x86-be">Known problems with the X86 back-end</a>
649</div>
650
651<div class="doc_text">
652
653<ul>
Reid Spencerc08bc9a2004-06-19 18:24:05 +0000[diff] [blame]654 <li>Optimized (Release) versions of LLVM built with GCC 3.3.2 or 3.3.3 will
655 produce an llc tool that always enters an infinite loop due to what
656 appears to be an optimization bug (-O2 and -O3) in those versions of GCC.
657 This problem does not happen in GCC 3.3.1 nor GCC 3.4.0 nor does it happen if
658 you build a Debug version of LLVM. You are cautioned not to use GCC 3.3.2 or
659 GCC 3.3.3 to build Optimized versions of LLVM. It is unclear whether this problem
660 affects other backends but it is unlikely.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]661</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]662
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]663</div>
664
665<!-- ======================================================================= -->
666<div class="doc_subsection">
667 <a name="sparc-be">Known problems with the Sparc back-end</a>
668</div>
669
670<div class="doc_text">
671
672<ul>
Chris Lattner6a39aa52004-03-19 19:22:28 +0000[diff] [blame]673<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]674</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]675
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]676</div>
677
678<!-- ======================================================================= -->
679<div class="doc_subsection">
680 <a name="c-be">Known problems with the C back-end</a>
681</div>
682
683<div class="doc_text">
684
685<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]686
687<li>The C back-end produces code that violates the ANSI C Type-Based Alias
688Analysis rules. As such, special options may be necessary to compile the code
689(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]690problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]691
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]692<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]693cannot include special floating point numbers like Not-A-Number or
694Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]695
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]696<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]697supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]698frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]699
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]700</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]701
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]702</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]703
704<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]705<div class="doc_section">
706 <a name="additionalinfo">Additional Information</a>
707</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]708<!-- *********************************************************************** -->
709
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]710<div class="doc_text">
711
712<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]713including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]714implemented in LLVM. The web page also contains versions of the API
715documentation which is up-to-date with the CVS version of the source code. You
716can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]717the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]718
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]719<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]720us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
721lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]722
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]723</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]724
725<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]726
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]727<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]728<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]729 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]730 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
731 <a href="http://validator.w3.org/check/referer"><img
732 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
733
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]734 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]735 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]736</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]737
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]738</body>
739</html>