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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / d5713885dc92cf7275e4f768daee2de7123904b4 / . / docs / ReleaseNotes.html
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Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]13 <li><a href="#intro">Introduction</a></li>
14 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]21 <li><a href="#core">Known problems with the LLVM Core</a>
22 <li><a href="#c-fe">Known problems with the C Front-end</a>
23 <li><a href="#c++-fe">Known problems with the C++ Front-end</a>
24 <li><a href="#x86-be">Known problems with the X86 Back-end</a>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]25 <li><a href="#sparcv9-be">Known problems with the SparcV9 Back-end</a>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]31<div class="doc_author">
32 <p>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]41<div class="doc_text">
42
43<p>This document contains the release notes for the LLVM compiler
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]47href="http://llvm.cs.uiuc.edu/releases/1.3/">LLVM 1.3 web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]52current releases, please check out the <a href="http://llvm.cs.uiuc.edu">main
53web site</a>. If you have questions or comments, the <a
54href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]57<p>Note that if you are reading this file from CVS, this document applies
58to the <i>next</i> release, not the current one. To see the release notes for
59the current or previous releases, see the <a
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]73release primarily improves the <a href="#codequality">performance of the
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]74code</a> produced by all aspects of the LLVM compiler, adds many <a
75href="#newfeatures">new features</a>, <a href="#bugfix">fixes a few
76bugs</a>, and speeds up the compiler.</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++
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]79SPEC CPU95 &amp; 2000 benchmarks, the Olden benchmarks, and the Ptrdist
80benchmarks, and <b>many</b> other programs. LLVM now also works
81with a broad variety of C++ programs.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]82
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]83</div>
84
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]85<!--=========================================================================-->
86<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]87<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]88</div>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]89
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]90<div class="doc_text">
91
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]92<ol>
Chris Lattner2974b5b2004-04-01 00:41:31 +0000[diff] [blame]93<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]94now fully implemented and supported by all transformations, native code
95generators, and the interpreter.</li>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]96<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
97before it could only narrow them down to a function being miscompiled.</li>
Brian Gaeke43be3112004-05-04 21:22:57 +0000[diff] [blame]98<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]99modes of llc</a> and lli, by passing them command line flags (e.g.
100<tt>-regalloc=linearscan</tt>).</li>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]101<li>The Control Flow Graph in the native code generators is no longer
102constrained to be the same as the CFG for the LLVM input code.</li>
103<li>The LLVM induction variable analysis routines have been rewritten.</li>
104<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
105<li>The induction variable substitution pass performs linear function test
106replacement and exit value replacement optimizations.</li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]107<li>LLVM now has first-class support for <a
108href="GarbageCollection.html">Accurate Garbage Collection</a>, enabling the use
109of aggressive copying and generational collectors.</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]110<li>LLVM now includes a simple implementation of <a
111href="AliasAnalysis.html#anders-aa">Andersen's interprocedural alias
112analysis</a> algorithm.</li>
Chris Lattner14cd5392004-05-24 05:34:32 +0000[diff] [blame]113<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
114basic blocks</a> to track down reduce miscompilation testcases.</li>
Brian Gaeke5beb8ba2004-06-01 20:02:56 +0000[diff] [blame]115<li>LLVM and the C front-end now work under Win32 using the
116<a href="http://www.cygwin.com">Cygwin</a> runtime libraries.
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]117This includes the JIT compiler.</li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]118<li>The LLVM code generator is now being <a
119href="CodeGenerator.html">documented</a>.</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]120<li>LLVM includes a new tool, <a
121href="CommandGuide/html/llvm-bcanalyzer.html">llvm-bcanalyzer</a>, This tool
122can compute various statistics and dump information about LLVM bytecode
123encoding.</li>
124<li>The <a href="BytecodeFormat.html">LLVM bytecode file format</a> is now
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]125documented.</li>
126<li>LLVM now provides an <a
127href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic for efficient
128implementation of unordered floating point comparisons.</li>
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]129<li>The llvmgcc front-end now supports the GCC builtins for ISO C99 floating
130point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]131<li>We now generate <a href="CommandGuide/">HTML documentation and man pages</a>
132for the tools from a single source (perl-style POD files).</li>
Chris Lattnerc8cd7e92004-07-12 17:09:23 +0000[diff] [blame]133<li>The LLVM code generator can now dynamically load targets from shared
134objects.</li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]135<li>LLVM now includes a "skeleton" target, which makes it easier to get
136started porting LLVM to new architectures.</li>
137<li>The linear scan register allocator is now enabled by default in the
138target-independent code generator.</li>
139<li>LLVM now includes a dead store elimination pass.</li>
140<li>Bugpoint can now debug miscompilations that lead to the program going
141into an infinite loop.</li>
142<li>LLVM now provides interfaces to support ML-style pattern matching on the
143LLVM IR.</li>
144<li>LLVM now includes a <a
145href="AliasAnalysis.html#globalsmodref">context-sensitive mod/ref analysis</a>
146for global variables, which is now enabled by default in gccld.</li>
147<li>LLVM can now autogenerate assembly printers for code generators from the
148tablegen description of the target (before they were hand coded).</li>
Chris Lattner55ee0312003-11-19 22:05:38 +0000[diff] [blame]149</ol>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]150
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]151</div>
152
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]153
154<!--=========================================================================-->
155<div class="doc_subsubsection">
156In this release, the following missing features were implemented:
157</div>
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]158
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]159<div class="doc_text">
160
Chris Lattner0ef19062003-11-08 04:28:55 +0000[diff] [blame]161<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]162<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
163more than 256 elements</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]164<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
165non-instruction entities, such as global constant initializer</a></li>
Reid Spencer44ff57a2004-05-09 23:32:39 +0000[diff] [blame]166<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
167with 64-bit pointers.</a></li>
Misha Brukmancb003362004-04-19 03:01:01 +0000[diff] [blame]168<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
169uses of external fns by immediate constant exprs</a></li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]170<li><a href="http://llvm.cs.uiuc.edu/PR407">Can't add function passes that
171depend on immutable passes to the FunctionPassManager</a>.</li>
172<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
173understand abbreviated names in headers</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]174</ol>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]175
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]176</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]177
178<!--=========================================================================-->
179<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]180<a name="qualityofimp">In this release, the following Quality of Implementation
181issues were fixed:</a>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]182</div>
183
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]184<div class="doc_text">
185
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]186<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]187<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
188bytecode onto your terminal</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]189<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
190for structure typedefs</a></li>
Chris Lattnerb9656692004-05-24 04:53:32 +0000[diff] [blame]191<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerea955512004-06-08 07:19:29 +0000[diff] [blame]192<li>The spurious "WARNING: Found global types that are not compatible" warning
193produced when linking C++ programs has been fixed.</li>
Reid Spencer421991c2004-07-07 21:06:28 +0000[diff] [blame]194<li><a href="http://llvm.cs.uiuc.edu/PR391">lli Doesn't Handle Exceptions From
195Bytecode Reader</a></li>
Reid Spencerf8474322004-07-25 22:15:33 +0000[diff] [blame]196<li><a href="http://llvm.cs.uiuc.edu/PR392">Global Vars Have (Somewhat) Limited
197 Type Range</a></li>
Chris Lattner9e229b22004-07-15 02:59:24 +0000[diff] [blame]198<li><a href="http://llvm.cs.uiuc.edu/PR341">operator&lt;&lt; on a Value* now prints the address of the object instead of its contents.</a></li>
Reid Spencerf8474322004-07-25 22:15:33 +0000[diff] [blame]199<li><a href="http://llvm.cs.uiuc.edu/PR402">Bytecode Enhancements
200 Needed</a></li>
Chris Lattner6568fe82004-07-15 04:30:35 +0000[diff] [blame]201<li><a href="http://llvm.cs.uiuc.edu/PR404">[loopsimplify] Loop simplify is really slow on 252.eon</a></li>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]202<li><a href="Http://llvm.cs.uiuc.edu/PR122">[code-cleanup] SymbolTable
203 class cleanup, Type should not derive from Value, eliminate
204 ConstantPointerRef class</a>.</li>
205<li>The memory footprint of the LLVM IR has been reduced substantially.</li>
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]206</ol>
207
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]208</div>
209
Chris Lattnere29ac162003-12-20 03:42:11 +0000[diff] [blame]210<!--=========================================================================-->
211<div class="doc_subsubsection">
Chris Lattnera39719f2004-02-25 16:36:51 +0000[diff] [blame]212In this release, the following build problems were fixed:
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]213</div>
214
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]215<div class="doc_text">
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]216<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]217<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
218-disable/enable-povray and -disable-spec</a></li>
219<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
220work if you change PATH</a></li>
Chris Lattner24738a72004-06-09 01:09:16 +0000[diff] [blame]221<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
222with gcc 3.4</a></li>
Chris Lattnerf82bba92004-06-18 17:57:29 +0000[diff] [blame]223<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
224obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]225</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]226</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]227
228<!--=========================================================================-->
229<div class="doc_subsubsection">
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]230<a name="codequality">This release includes the following Code Quality
231improvements:</a>
Chris Lattneraab56d42004-05-23 20:42:08 +0000[diff] [blame]232</div>
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]233
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]234<div class="doc_text">
Chris Lattner89ca2b82003-10-27 17:06:39 +0000[diff] [blame]235<ol>
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]236<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
237due to long operand of getelementptr</a></li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]238
239<li>The X86 backend now generates substantially better code for 64-bit integer
240and floating point operations.</li>
241
242<li>The -inline pass no longer inlines mutually recursive functions until it
243hits the inlining threshold.</li>
244
245<li>The -inline pass no longer misses obvious inlining opportunities just
246because the callee eventually calls into an external function.</li>
247
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]248<li>The -simplifycfg pass can now "if convert" simple statements into the
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]249<tt>select</tt> instruction.</li>
250
251<li>The -loopsimplify pass can now break <a
252href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
253into multiple nested loops. This enables a variety of subsequent
254optimizations.</li>
255
256<li>The -adce pass can now eliminate calls to functions that do not not write to
257memory.</li>
258
259<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]260exception handlers).</li>
Chris Lattner64913402004-04-13 14:43:35 +0000[diff] [blame]261
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]262<li>The link-time optimizer now runs dead store elimination and uses a simple
263interprocedural alias analysis.</li>
264
Chris Lattner6e1ef192004-05-02 04:19:15 +0000[diff] [blame]265<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
266"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
267operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
268&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
269
Chris Lattnerd4594dc2004-05-04 17:04:09 +0000[diff] [blame]270<li>LLVM now has infrastructure for (simple and sparse conditional) constant
271propagation of function calls. It currently supports a few math library
272functions like sqrt/sin/cos/etc.</li>
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]273
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]274<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">syntactic
Chris Lattner3bff8f52004-06-03 22:35:13 +0000[diff] [blame]275loops</a> in the code to help C compilers whose optimizers do not recognize
276loops formed from gotos (like GCC).</li>
Brian Gaeke11074e32004-06-11 02:15:39 +0000[diff] [blame]277
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]278<li>The SparcV9 backend no longers <a
279href="http://llvm.cs.uiuc.edu/PR368">spills the null constant to the constant
280pool</a>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]281</ol>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]282</div>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]283
284<!--=========================================================================-->
285<div class="doc_subsubsection">
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]286<a name="bugfix">In this release, the following bugs in the previous release
287were fixed:</a>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]288</div>
289
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]290<div class="doc_text">
291
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]292<p>Bugs fixed in the LLVM Core:</p>
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]293
294<ol>
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]295<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
296incorrectly updates dominator information</a></li>
297<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
298breaks SSA form</a></li>
299<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
300to floating point cast</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]301<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
302asssertion</a></li>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]303<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
304code that unwinds</a></li>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]305<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparcv9] LLC can't emit 2 functions
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]306of the same name, both having constant pools</a></li>
307<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
308physical register use of aliased definition</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]309<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating
310point setcc X, X</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]311</ol>
312
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]313<p>Bugs in the C/C++ front-end:</p>
314
315<ol>
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]316<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
317indexing miscompiled</a></li>
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]318<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
319enum type</a></li>
Chris Lattner19019602004-06-19 01:11:02 +0000[diff] [blame]320<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
321prototypes that take opaque structs by-value</a></li>
322<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
323length array of structures</a></li>
Misha Brukman0d4b67c2004-07-02 16:23:17 +0000[diff] [blame]324<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly
Reid Spencer7b000962004-06-29 23:39:24 +0000[diff] [blame]325initialized unsigned bitfields</a></li>
Chris Lattner5171eb52004-07-07 02:25:24 +0000[diff] [blame]326<li><a href="http://llvm.cs.uiuc.edu/PR396">[llvm-gcc] Crash casting function to void</a></li>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]327</ol>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]328</div>
Reid Spencer8e0262f2004-05-23 17:23:13 +0000[diff] [blame]329
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]330<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]331<div class="doc_section">
332 <a name="portability">Portability and Supported Platforms</a>
333</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]334<!-- *********************************************************************** -->
335
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]336<div class="doc_text">
337
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]338<p>LLVM is known to work in the following platforms:</p>
339
340<ul>
341<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
342 other unix-like systems).</li>
343<li>Sun UltraSPARC workstations running Solaris 8.</li>
344<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
345 interpreter only, no native codegen is available yet).</li>
346<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
347</ul>
348
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]349
350<p>The core LLVM infrastructure uses
351<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
352to the machine and operating system on which it is built. However, minor
353porting may be required to get LLVM to work on new platforms. We welcome your
354portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]355
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]356<p>Note that the LLVM build system does not currently support directories with
357spaces on them when running on Win32/cygwin. We strongly recommend running
358LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattner74032a52004-06-01 19:41:30 +0000[diff] [blame]359<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
360cygwin packages. By default, many important tools are not installed that
361are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]362
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]363</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]364
365<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]366<div class="doc_section">
367 <a name="knownproblems">Known Problems</a>
368</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]369<!-- *********************************************************************** -->
370
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]371<div class="doc_text">
372
373<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]374component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]375sections. If you run into a problem, please check the <a
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]376href="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]377there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]378
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]379</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]380
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]381<!-- ======================================================================= -->
382<div class="doc_subsection">
383 <a name="experimental">Experimental features included with this release</a>
384</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]385
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]386<div class="doc_text">
387
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]388<p>The following components of this LLVM release are either untested, known to
389be broken or unreliable, or are in early development. These components should
390not be relied on, and bugs should not be filed against them, but they may be
391useful to some people. In particular, if you would like to work on one of these
392components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]393
394<ul>
395<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattnercbabe702004-06-28 00:44:45 +0000[diff] [blame]396 -ipmodref, -cee</tt></li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]397
398<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
399 it should) and not thoroughly tested.</li>
400<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
401<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
402</ul>
403
404</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]405
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]406<!-- ======================================================================= -->
407<div class="doc_subsection">
408 <a name="core">Known problems with the LLVM Core</a>
409</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]410
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]411<div class="doc_text">
412
413<ul>
414
415<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
416work.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]417
418<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]419such, execution of a threaded program could cause these data structures to be
420corrupted.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]421
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]422<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]423
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]424<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]425table in the archive).</li>
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]426
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]427<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
428objects/archives in the order specified on the command line.</a></li>
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]429
430<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]431values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattner2e6fcaf2004-02-15 23:09:07 +0000[diff] [blame]432targets whose setjmp/longjmp libraries do not save and restore the entire
433register file.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]434</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]435</div>
436
437<!-- ======================================================================= -->
438<div class="doc_subsection">
439 <a name="c-fe">Known problems with the C front-end</a>
440</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]441
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]442<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]443<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]444
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]445<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]446<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]447<li>C99 Variable sized arrays do not release stack memory when they go out of
448 scope. Thus, the following program may run out of stack space:
449<pre>
450 for (i = 0; i != 1000000; ++i) {
451 int X[n];
452 foo(X);
453 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]454</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]455
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]456<li>Initialization of global union variables can only be done <a
457href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
458member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]459
Misha Brukmana7aadf12004-04-19 02:56:49 +0000[diff] [blame]460<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
461external function is re-declared as static</a></li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]462
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]463</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]464</div>
465
466<!-- _______________________________________________________________________ -->
467<div class="doc_subsubsection">
468 Notes
469</div>
470
471<div class="doc_text">
472
473<ul>
474
475<li>Inline assembly is not yet supported.</li>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]476
477<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]478support for floating point data types of any size other than 32 and 64
479bits.</li>
480
481<li>The following Unix system functionality has not been tested and may not
482work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]483 <ol>
484 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
485 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
486 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
487 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
488 - These functions have not been tested.
489 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]490
491<li>Although many GCC extensions are supported, some are not. In particular,
492 the following extensions are known to <b>not be</b> supported:
493 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]494 <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]495 <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>
496 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
497 <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]498 <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]499 <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>
500 <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]501 <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>
502 <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>
503 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
504 <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]505 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]506
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]507 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]508 attribute means that the LLVM compiler ignores the presence of the attribute,
509 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]510 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]511 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]512
513 <ol>
514 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
515 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]516 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]517
518 <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]519
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]520 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]521 return.<br>
522
523 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
524 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
525 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
526
527 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
528 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
529 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
530
531 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
532 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
533 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]534
535 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
536 Specifying attributes of variables.<br>
537 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
538 <tt>deprecated</tt>, <tt>transparent_union</tt>,
539 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]540
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]541 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
542 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
543 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]544 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]545
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]546 <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]547 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]548 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]549
550 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
551 all target specific attributes.</li>
552
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]553 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
554 Other built-in functions.<br>
555 We support all builtins which have a C language equivalent (e.g.,
556 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
557 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]558 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
559 (currently ignored). We also support builtins for ISO C99 floating
560 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]561 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]562
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]563 <p>The following extensions <b>are</b> known to be supported:</p>
564
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]565 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]566 <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]567 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
568 <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]569 <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]570 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
571 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
572 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
573 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
574 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
575 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
576 <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>
577 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
578 <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]579 <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]580 <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]581 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
582or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]583 <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]584 <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]585 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
586 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
587 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
588 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
589 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
590 <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>
591 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
592 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
593 <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>
594 <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>
595 <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]596 <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]597 <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>
598 <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]599 </ol></li>
600
601</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]602
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]603<p>If you run into GCC extensions which have not been included in any of these
604lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]605
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]606</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]607
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]608<!-- ======================================================================= -->
609<div class="doc_subsection">
610 <a name="c++-fe">Known problems with the C++ front-end</a>
611</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]612
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]613<div class="doc_text">
614
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]615<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]616has not been tested as thoroughly as the C front-end. It has been tested and
617works for a number of non-trivial programs, but there may be lurking bugs.
618Please report any bugs or problems.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]619
620</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]621
622<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]623<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]624
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]625<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]626
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]627<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]628<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]629 front-end</a>.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]630
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]631<li><b>IA-64 specific</b>: The C++ front-end does not use <a
632href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]633In particular, it just stores function pointers instead of function
634descriptors in the vtable. This bug prevents mixing C++ code compiled with
635LLVM with C++ objects compiled by other C++ compilers.</p>
636
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]637</ul>
638
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]639</div>
640
641<!-- _______________________________________________________________________ -->
642<div class="doc_subsubsection">
643 Notes
644</div>
645
646<div class="doc_text">
647
648<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]649
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]650<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
651parser is significantly more standards compliant (and picky) than prior GCC
652versions. For more information, see the C++ section of the <a
Chris Lattner9e848092003-12-12 04:25:33 +0000[diff] [blame]653href="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]654
655<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]656 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]657 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]658 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]659 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]660
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]661<li>The LLVM C++ front-end follows the <a
662 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
663 This document, which is not Itanium specific, specifies a standard for name
664 mangling, class layout, v-table layout, RTTI formats, and other C++
665 representation issues. Because we use this API, code generated by the LLVM
666 compilers should be binary compatible with machine code generated by other
667 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
668 <i>However</i>, the exception handling mechanism used by LLVM is very
669 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]670 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]671
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]672</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]673
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]674</div>
675
676<!-- ======================================================================= -->
677<div class="doc_subsection">
678 <a name="x86-be">Known problems with the X86 back-end</a>
679</div>
680
681<div class="doc_text">
682
683<ul>
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame^]684 <li>none yet</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]685</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]686
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]687</div>
688
689<!-- ======================================================================= -->
690<div class="doc_subsection">
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]691 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]692</div>
693
694<div class="doc_text">
695
696<ul>
Misha Brukmanadb1c392004-07-12 16:55:41 +0000[diff] [blame]697<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
698several programs in the LLVM test suite</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]699</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]700
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]701</div>
702
703<!-- ======================================================================= -->
704<div class="doc_subsection">
705 <a name="c-be">Known problems with the C back-end</a>
706</div>
707
708<div class="doc_text">
709
710<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]711
712<li>The C back-end produces code that violates the ANSI C Type-Based Alias
713Analysis rules. As such, special options may be necessary to compile the code
714(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]715problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]716
Chris Lattnere84843b2003-10-20 19:05:03 +0000[diff] [blame]717<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]718cannot include special floating point numbers like Not-A-Number or
719Infinity.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]720
Chris Lattner2855ecd2003-11-04 20:06:53 +0000[diff] [blame]721<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]722supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]723frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]724
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]725</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]726
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]727</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]728
729<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]730<div class="doc_section">
731 <a name="additionalinfo">Additional Information</a>
732</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]733<!-- *********************************************************************** -->
734
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]735<div class="doc_text">
736
737<p>A wide variety of additional information is available on the LLVM web page,
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]738including mailing lists and publications describing algorithms and components
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]739implemented in LLVM. The web page also contains versions of the API
740documentation which is up-to-date with the CVS version of the source code. You
741can access versions of these documents specific to this release by going into
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]742the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]743
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]744<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]745us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
746lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]747
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]748</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]749
750<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]751
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]752<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]753<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]754 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]755 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
756 <a href="http://validator.w3.org/check/referer"><img
757 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
758
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]759 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]760 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]761</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]762
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]763</body>
764</html>