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Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]6 <title>LLVM 1.3 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]7</head>
8<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]9
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]10<div class="doc_title">LLVM 1.3 Release Notes</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]11
12<ol>
Misha Brukman80731b92003-11-22 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 Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]15 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]16 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]17 <li><a href="#knownproblems">Known Problems</a>
18 <ul>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]19 <li><a href="#experimental">Experimental features included in this
20 release</a>
Chris Lattner3d482502003-10-02 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 Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]25 <li><a href="#sparcv9-be">Known problems with the SparcV9 Back-end</a>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]27 </ul></li>
28 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]29</ol>
30
Chris Lattner020e1fc2004-05-23 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]33</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]34
35<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]36<div class="doc_section">
37 <a name="intro">Introduction</a>
38</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]39<!-- *********************************************************************** -->
40
Misha Brukman80731b92003-11-22 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 Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]44infrastructure, release 1.3. Here we describe the status of LLVM, including any
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]45known problems and bug fixes from the previous release. The most up-to-date
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]46version of this document can be found on the <a
Chris Lattner1a7e43c2004-04-01 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 Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]48not reading this on the LLVM web pages, you should probably go there because
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]49this document may be updated after the release.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]50
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]51<p>For more information about LLVM, including information about potentially more
Chris Lattnere7525b52003-10-07 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]55list</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]56
Chris Lattnere76e9ab2003-12-12 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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]60href="http://llvm.cs.uiuc.edu/releases/">releases page</a>.</p>
61
62</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]63
64<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]65<div class="doc_section">
66 <a name="whatsnew">What's New?</a>
67</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]68<!-- *********************************************************************** -->
69
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]70<div class="doc_text">
71
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]72<p>This is the fourth public release of the LLVM compiler infrastructure. This
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]73release primarily improves the <a href="#codequality">performance of the
Chris Lattner5cd40922004-08-02 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
Chris Lattnerd21e3d02004-08-05 21:53:13 +0000[diff] [blame]76bugs</a>, speeds up the compiler, and introduces a new (experimental)
77PowerPC code generator.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]78
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]79<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]80SPEC CPU95 &amp; 2000 benchmarks, the Olden benchmarks, and the Ptrdist
81benchmarks, and <b>many</b> other programs. LLVM now also works
82with a broad variety of C++ programs.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]83
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]84</div>
85
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]86<!--=========================================================================-->
87<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]88<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]89</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]90
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]91<div class="doc_text">
92
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]93<ol>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]94<li>The LLVM <a href="LangRef.html#i_select"><tt>select</tt></a> instruction is
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]95now fully implemented and supported by all transformations, native code
96generators, and the interpreter.</li>
Misha Brukman017f2f32004-04-19 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 Gaekee307f8a72004-05-04 21:22:57 +0000[diff] [blame]99<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]100modes of llc</a> and lli, by passing them command line flags (e.g.
101<tt>-regalloc=linearscan</tt>).</li>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]102<li>The Control Flow Graph in the native code generators is no longer
103constrained to be the same as the CFG for the LLVM input code.</li>
104<li>The LLVM induction variable analysis routines have been rewritten.</li>
105<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
106<li>The induction variable substitution pass performs linear function test
107replacement and exit value replacement optimizations.</li>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]108<li>LLVM now has first-class support for <a
109href="GarbageCollection.html">Accurate Garbage Collection</a>, enabling the use
110of aggressive copying and generational collectors.</li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]111<li>LLVM now includes a simple implementation of <a
112href="AliasAnalysis.html#anders-aa">Andersen's interprocedural alias
113analysis</a> algorithm.</li>
Chris Lattner57e7a4c2004-05-24 05:34:32 +0000[diff] [blame]114<li>Bugpoint can <a href="http://llvm.cs.uiuc.edu/PR327">extract individual
115basic blocks</a> to track down reduce miscompilation testcases.</li>
Brian Gaeke84c8bd02004-06-01 20:02:56 +0000[diff] [blame]116<li>LLVM and the C front-end now work under Win32 using the
117<a href="http://www.cygwin.com">Cygwin</a> runtime libraries.
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]118This includes the JIT compiler.</li>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]119<li>The LLVM code generator is now being <a
120href="CodeGenerator.html">documented</a>.</li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]121<li>LLVM includes a new tool, <a
122href="CommandGuide/html/llvm-bcanalyzer.html">llvm-bcanalyzer</a>, This tool
123can compute various statistics and dump information about LLVM bytecode
124encoding.</li>
125<li>The <a href="BytecodeFormat.html">LLVM bytecode file format</a> is now
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]126documented.</li>
127<li>LLVM now provides an <a
128href="LangRef.html#i_isunordered">llvm.isunordered</a> intrinsic for efficient
129implementation of unordered floating point comparisons.</li>
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]130<li>The llvmgcc front-end now supports the GCC builtins for ISO C99 floating
131point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]132<li>We now generate <a href="CommandGuide/">HTML documentation and man pages</a>
133for the tools from a single source (perl-style POD files).</li>
Chris Lattner47bafde2004-07-12 17:09:23 +0000[diff] [blame]134<li>The LLVM code generator can now dynamically load targets from shared
135objects.</li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]136<li>LLVM now includes a "skeleton" target, which makes it easier to get
137started porting LLVM to new architectures.</li>
138<li>The linear scan register allocator is now enabled by default in the
139target-independent code generator.</li>
140<li>LLVM now includes a dead store elimination pass.</li>
141<li>Bugpoint can now debug miscompilations that lead to the program going
142into an infinite loop.</li>
143<li>LLVM now provides interfaces to support ML-style pattern matching on the
144LLVM IR.</li>
145<li>LLVM now includes a <a
146href="AliasAnalysis.html#globalsmodref">context-sensitive mod/ref analysis</a>
147for global variables, which is now enabled by default in gccld.</li>
148<li>LLVM can now autogenerate assembly printers for code generators from the
149tablegen description of the target (before they were hand coded).</li>
Reid Spencer639a7022004-08-04 00:43:50 +0000[diff] [blame]150<li>All LLVM tools will now respond to the
151<a href="http://llvm.cs.uiuc.edu/PR413"><tt>--version</tt> option</a> which
152will tell you the version of LLVM on which the tool is based.</li>
Misha Brukman467ea6b2004-08-05 21:04:03 +0000[diff] [blame]153<li>An experimental PowerPC backend has been added, capable of compiling several
154SPEC benchmarks.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]155</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]156
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]157</div>
158
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]159
160<!--=========================================================================-->
161<div class="doc_subsubsection">
162In this release, the following missing features were implemented:
163</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]164
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]165<div class="doc_text">
166
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]167<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]168<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
169more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]170<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
171non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]172<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
173with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]174<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
175uses of external fns by immediate constant exprs</a></li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]176<li><a href="http://llvm.cs.uiuc.edu/PR407">Can't add function passes that
177depend on immutable passes to the FunctionPassManager</a>.</li>
178<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
179understand abbreviated names in headers</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]180</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]181
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]182</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]183
184<!--=========================================================================-->
185<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]186<a name="qualityofimp">In this release, the following Quality of Implementation
187issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]188</div>
189
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]190<div class="doc_text">
191
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]192<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]193<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
194bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]195<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
196for structure typedefs</a></li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame]197<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerbd948cf2004-06-08 07:19:29 +0000[diff] [blame]198<li>The spurious "WARNING: Found global types that are not compatible" warning
199produced when linking C++ programs has been fixed.</li>
Reid Spencer66522522004-07-07 21:06:28 +0000[diff] [blame]200<li><a href="http://llvm.cs.uiuc.edu/PR391">lli Doesn't Handle Exceptions From
201Bytecode Reader</a></li>
Reid Spencer4b7a38d2004-07-25 22:15:33 +0000[diff] [blame]202<li><a href="http://llvm.cs.uiuc.edu/PR392">Global Vars Have (Somewhat) Limited
203 Type Range</a></li>
Misha Brukman467ea6b2004-08-05 21:04:03 +0000[diff] [blame]204<li><a href="http://llvm.cs.uiuc.edu/PR341">operator&lt;&lt; on a Value* now
205prints the address of the object instead of its contents.</a></li>
Reid Spencer4b7a38d2004-07-25 22:15:33 +0000[diff] [blame]206<li><a href="http://llvm.cs.uiuc.edu/PR402">Bytecode Enhancements
Misha Brukman467ea6b2004-08-05 21:04:03 +0000[diff] [blame]207Needed</a></li>
208<li><a href="http://llvm.cs.uiuc.edu/PR404">[loopsimplify] Loop simplify is
209really slow on 252.eon</a></li>
210<li><a href="Http://llvm.cs.uiuc.edu/PR122">[code-cleanup] SymbolTable class
211cleanup, Type should not derive from Value, eliminate ConstantPointerRef
212class</a>.</li>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]213<li>The memory footprint of the LLVM IR has been reduced substantially.</li>
Chris Lattner493bdcc2004-08-04 08:00:45 +0000[diff] [blame]214<li>The LLVM linker and many core classes have been sped up substantially.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]215</ol>
216
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]217</div>
218
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]219<!--=========================================================================-->
220<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]221In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]222</div>
223
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]224<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]225<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]226<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
227-disable/enable-povray and -disable-spec</a></li>
228<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
229work if you change PATH</a></li>
Chris Lattner47696122004-06-09 01:09:16 +0000[diff] [blame]230<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
231with gcc 3.4</a></li>
Chris Lattner3daf9842004-06-18 17:57:29 +0000[diff] [blame]232<li><a href="http://llvm.cs.uiuc.edu/PR373">[llvmgcc] obstack.h relies on
233obsolete casts-as-lvalues GCC extension</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]234</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]235</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]236
237<!--=========================================================================-->
238<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]239<a name="codequality">This release includes the following Code Quality
240improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]241</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]242
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]243<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]244<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]245<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
246due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]247
248<li>The X86 backend now generates substantially better code for 64-bit integer
249and floating point operations.</li>
250
251<li>The -inline pass no longer inlines mutually recursive functions until it
252hits the inlining threshold.</li>
253
254<li>The -inline pass no longer misses obvious inlining opportunities just
255because the callee eventually calls into an external function.</li>
256
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]257<li>The -simplifycfg pass can now "if convert" simple statements into the
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]258<tt>select</tt> instruction.</li>
259
260<li>The -loopsimplify pass can now break <a
261href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
262into multiple nested loops. This enables a variety of subsequent
263optimizations.</li>
264
265<li>The -adce pass can now eliminate calls to functions that do not not write to
266memory.</li>
267
268<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]269exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]270
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]271<li>The link-time optimizer now runs dead store elimination and uses a simple
272interprocedural alias analysis.</li>
273
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]274<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
275"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
276operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
277&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
278
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]279<li>LLVM now has infrastructure for (simple and sparse conditional) constant
280propagation of function calls. It currently supports a few math library
281functions like sqrt/sin/cos/etc.</li>
Chris Lattner249b3552004-06-03 22:35:13 +0000[diff] [blame]282
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]283<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">syntactic
Chris Lattner249b3552004-06-03 22:35:13 +0000[diff] [blame]284loops</a> in the code to help C compilers whose optimizers do not recognize
285loops formed from gotos (like GCC).</li>
Brian Gaeke522235e2004-06-11 02:15:39 +0000[diff] [blame]286
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]287<li>The SparcV9 backend no longers <a
288href="http://llvm.cs.uiuc.edu/PR368">spills the null constant to the constant
289pool</a>.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]290</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]291</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]292
293<!--=========================================================================-->
294<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]295<a name="bugfix">In this release, the following bugs in the previous release
296were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]297</div>
298
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]299<div class="doc_text">
300
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]301<p>Bugs fixed in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]302
303<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]304<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
305incorrectly updates dominator information</a></li>
306<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
307breaks SSA form</a></li>
308<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
309to floating point cast</a></li>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]310<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
311asssertion</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]312<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
313code that unwinds</a></li>
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]314<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparcv9] LLC can't emit 2 functions
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]315of the same name, both having constant pools</a></li>
316<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
317physical register use of aliased definition</a></li>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]318<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating
319point setcc X, X</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]320</ol>
321
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]322<p>Bugs in the C/C++ front-end:</p>
323
324<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]325<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
326indexing miscompiled</a></li>
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]327<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
328enum type</a></li>
Chris Lattner2ef024b2004-06-19 01:11:02 +0000[diff] [blame]329<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function
330prototypes that take opaque structs by-value</a></li>
331<li><a href="http://llvm.cs.uiuc.edu/PR374">[llvmgcc] Crash compiling variable
332length array of structures</a></li>
Misha Brukman0fdfcf12004-07-02 16:23:17 +0000[diff] [blame]333<li><a href="http://llvm.cs.uiuc.edu/PR377">[llvmgcc] miscompilation of staticly
Reid Spencerb1076c42004-06-29 23:39:24 +0000[diff] [blame]334initialized unsigned bitfields</a></li>
Chris Lattnere5497172004-07-07 02:25:24 +0000[diff] [blame]335<li><a href="http://llvm.cs.uiuc.edu/PR396">[llvm-gcc] Crash casting function to void</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]336</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]337</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]338
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]339<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]340<div class="doc_section">
341 <a name="portability">Portability and Supported Platforms</a>
342</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]343<!-- *********************************************************************** -->
344
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]345<div class="doc_text">
346
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]347<p>LLVM is known to work in the following platforms:</p>
348
349<ul>
350<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
351 other unix-like systems).</li>
352<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]353<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
Chris Lattnerd21e3d02004-08-05 21:53:13 +0000[diff] [blame]354<li>PowerPC-based Mac OS X boxes, running 10.2 and above. Note that no JIT
355support is available yet, and LLC support is beta. The C backend can be used
356to produce stable code for this platform.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]357</ul>
358
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]359<p>The core LLVM infrastructure uses
360<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
361to the machine and operating system on which it is built. However, minor
362porting may be required to get LLVM to work on new platforms. We welcome your
363portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]364
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]365<p>Note that the LLVM build system does not currently support directories with
366spaces on them when running on Win32/cygwin. We strongly recommend running
367LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattnerce1a3842004-06-01 19:41:30 +0000[diff] [blame]368<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
369cygwin packages. By default, many important tools are not installed that
370are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]371
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]372</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]373
374<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]375<div class="doc_section">
376 <a name="knownproblems">Known Problems</a>
377</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]378<!-- *********************************************************************** -->
379
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]380<div class="doc_text">
381
382<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]383component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]384sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]385href="http://llvm.cs.uiuc.edu/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]386there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]387
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]388</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]389
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]390<!-- ======================================================================= -->
391<div class="doc_subsection">
392 <a name="experimental">Experimental features included with this release</a>
393</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]394
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]395<div class="doc_text">
396
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]397<p>The following components of this LLVM release are either untested, known to
398be broken or unreliable, or are in early development. These components should
399not be relied on, and bugs should not be filed against them, but they may be
400useful to some people. In particular, if you would like to work on one of these
401components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]402
403<ul>
Misha Brukman467ea6b2004-08-05 21:04:03 +0000[diff] [blame]404<li>The PowerPC backend is incomplete and is known to miscompile several SPEC
405benchmarks. The file <tt>llvm/lib/Target/PowerPC/README.txt</tt> has
406details.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]407<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattner99583502004-06-28 00:44:45 +0000[diff] [blame]408 -ipmodref, -cee</tt></li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]409<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
410 it should) and not thoroughly tested.</li>
411<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
412<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
413</ul>
414
415</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]416
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]417<!-- ======================================================================= -->
418<div class="doc_subsection">
419 <a name="core">Known problems with the LLVM Core</a>
420</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]421
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]422<div class="doc_text">
423
424<ul>
425
426<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
427work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]428
429<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]430such, execution of a threaded program could cause these data structures to be
431corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]432
Chris Lattnerc0171082004-08-08 03:33:07 +0000[diff] [blame^]433<li>Linking in static archive files (.a files) is slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]434table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]435
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]436<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
437objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]438
439<li><a href="http://llvm.cs.uiuc.edu/PR240">The lower-invoke pass does not mark
John Criswell5d6345a2004-03-12 21:29:42 +0000[diff] [blame]440values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]441targets whose setjmp/longjmp libraries do not save and restore the entire
442register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]443</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]444</div>
445
446<!-- ======================================================================= -->
447<div class="doc_subsection">
448 <a name="c-fe">Known problems with the C front-end</a>
449</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]450
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]451<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]452<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]453
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]454<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]455<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]456<li>C99 Variable sized arrays do not release stack memory when they go out of
457 scope. Thus, the following program may run out of stack space:
458<pre>
459 for (i = 0; i != 1000000; ++i) {
460 int X[n];
461 foo(X);
462 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]463</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]464
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]465<li>Initialization of global union variables can only be done <a
466href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
467member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]468
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]469<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
470external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]471
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]472</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]473</div>
474
475<!-- _______________________________________________________________________ -->
476<div class="doc_subsubsection">
477 Notes
478</div>
479
480<div class="doc_text">
481
482<ul>
483
484<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]485
486<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]487support for floating point data types of any size other than 32 and 64
488bits.</li>
489
490<li>The following Unix system functionality has not been tested and may not
491work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]492 <ol>
493 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
494 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
495 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
496 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
497 - These functions have not been tested.
498 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]499
500<li>Although many GCC extensions are supported, some are not. In particular,
501 the following extensions are known to <b>not be</b> supported:
502 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]503 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]504 <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>
505 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
506 <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 Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]507 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]508 <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>
509 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]510 <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>
511 <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>
512 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
513 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]514 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]515
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]516 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]517 attribute means that the LLVM compiler ignores the presence of the attribute,
518 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]519 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]520 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]521
522 <ol>
523 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
524 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]525 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]526
527 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]528
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]529 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]530 return.<br>
531
532 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
533 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
534 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
535
536 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
537 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
538 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
539
540 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
541 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
542 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]543
544 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
545 Specifying attributes of variables.<br>
546 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
547 <tt>deprecated</tt>, <tt>transparent_union</tt>,
548 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]549
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]550 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
551 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
552 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]553 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]554
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]555 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]556 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]557 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]558
559 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
560 all target specific attributes.</li>
561
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]562 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
563 Other built-in functions.<br>
564 We support all builtins which have a C language equivalent (e.g.,
565 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
566 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]567 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
568 (currently ignored). We also support builtins for ISO C99 floating
569 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]570 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]571
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]572 <p>The following extensions <b>are</b> known to be supported:</p>
573
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]574 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]575 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]576 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
577 <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 Lattnerce33a1b2004-06-22 03:48:17 +0000[diff] [blame]578 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]579 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
580 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
581 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
582 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
583 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
584 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
585 <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>
586 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
587 <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 Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]588 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]589 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]590 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
591or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]592 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]593 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]594 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
595 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
596 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
597 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
598 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
599 <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>
600 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
601 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
602 <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>
603 <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>
604 <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 Lattner3646dad2004-02-14 04:08:29 +0000[diff] [blame]605 <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 Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]606 <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>
607 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]608 </ol></li>
609
610</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]611
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]612<p>If you run into GCC extensions which have not been included in any of these
613lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]614
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]615</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]616
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]617<!-- ======================================================================= -->
618<div class="doc_subsection">
619 <a name="c++-fe">Known problems with the C++ front-end</a>
620</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]621
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]622<div class="doc_text">
623
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]624<p>For this release, the C++ front-end is considered to be fully functional but
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]625has not been tested as thoroughly as the C front-end. It has been tested and
626works for a number of non-trivial programs, but there may be lurking bugs.
627Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]628
629</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]630
631<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]632<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]634<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]635
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]636<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]637<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]638 front-end</a>.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]639
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]640<li><b>IA-64 specific</b>: The C++ front-end does not use <a
641href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]642In particular, it just stores function pointers instead of function
643descriptors in the vtable. This bug prevents mixing C++ code compiled with
Chris Lattner2fd93492004-08-02 20:29:51 +0000[diff] [blame]644LLVM with C++ objects compiled by other C++ compilers.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]645
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]646</ul>
647
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]648</div>
649
650<!-- _______________________________________________________________________ -->
651<div class="doc_subsubsection">
652 Notes
653</div>
654
655<div class="doc_text">
656
657<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]658
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]659<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
660parser is significantly more standards compliant (and picky) than prior GCC
661versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]662href="http://gcc.gnu.org/gcc-3.4/changes.html">GCC 3.4 release notes</a>.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]663
664<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]665 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]666 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]667 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]668 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]669
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]670<li>The LLVM C++ front-end follows the <a
671 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
672 This document, which is not Itanium specific, specifies a standard for name
673 mangling, class layout, v-table layout, RTTI formats, and other C++
674 representation issues. Because we use this API, code generated by the LLVM
675 compilers should be binary compatible with machine code generated by other
676 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
677 <i>However</i>, the exception handling mechanism used by LLVM is very
678 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]679 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]680
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]681</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]682
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]683</div>
684
685<!-- ======================================================================= -->
686<div class="doc_subsection">
687 <a name="x86-be">Known problems with the X86 back-end</a>
688</div>
689
690<div class="doc_text">
691
692<ul>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]693 <li>none yet</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]694</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]695
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]696</div>
697
698<!-- ======================================================================= -->
699<div class="doc_subsection">
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]700 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]701</div>
702
703<div class="doc_text">
704
705<ul>
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]706<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
707several programs in the LLVM test suite</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]708</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]709
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]710</div>
711
712<!-- ======================================================================= -->
713<div class="doc_subsection">
714 <a name="c-be">Known problems with the C back-end</a>
715</div>
716
717<div class="doc_text">
718
719<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]720
721<li>The C back-end produces code that violates the ANSI C Type-Based Alias
722Analysis rules. As such, special options may be necessary to compile the code
723(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]724problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]725
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]726<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]727cannot include special floating point numbers like Not-A-Number or
728Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]729
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]730<li><a href="http://llvm.cs.uiuc.edu/PR56">Zero arg vararg functions are not
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]731supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]732frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]733
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]734</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]735
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]736</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]737
738<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]739<div class="doc_section">
740 <a name="additionalinfo">Additional Information</a>
741</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]742<!-- *********************************************************************** -->
743
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]744<div class="doc_text">
745
746<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]747including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]748implemented in LLVM. The web page also contains versions of the API
749documentation which is up-to-date with the CVS version of the source code. You
750can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]751the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]752
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]753<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]754us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
755lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]756
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]757</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]758
759<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]760
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]761<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]762<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]763 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]764 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
765 <a href="http://validator.w3.org/check/referer"><img
766 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
767
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]768 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]769 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]770</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]771
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]772</body>
773</html>