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gerrit-public.fairphone.software / toolchain / llvm-project / 4e71aa84d58e01123588800589d9449748e94cd4 / . / llvm / docs / ReleaseNotes.html
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Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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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>
25 <li><a href="#sparc-be">Known problems with the Sparc Back-end</a>
26 <li><a href="#c-be">Known problems with the C back-end</a>
Misha 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
74code</a> produced by all aspects of the LLVM compiler and adds some <a
75href="#newfeatures">new features</a>, though it does <a href="#bugfix">fix a few
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]76bugs</a> as well.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]77
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]78<p> At this time, LLVM is known to correctly compile and run all C &amp; C++
79SPEC CPU2000 benchmarks, the Olden benchmarks, and the Ptrdist benchmarks. It
80has also been used to compile <b>many</b> other programs. LLVM now also works
81with a broad variety of C++ programs, though it has still received less testing
82than the C front-end.</p>
Chris 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
100modes of llc</a> and lli, by passing them command line flags (e.g.,
101<tt>-regalloc=linearscan</tt>, <tt>-enable-correct-eh-support</tt>, etc.) </li>
Chris 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>
Chris Lattnereda4f472004-05-24 04:45:52 +0000[diff] [blame]108<li>LLVM now has first-class support for <a href="GarbageCollection.html">Accurate
109Garbage Collection</a>, enabling the use of aggressive copying and generational
110collectors.</li>
111<li>LLVM now includes an implementation of Andersen's interprocedural alias
112analysis algorithm.</li>
Chris Lattner57e7a4c2004-05-24 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 Gaeke84c8bd02004-06-01 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 Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]117This includes the JIT compiler.</li>
Chris Lattnera7fac952004-06-04 00:40:11 +0000[diff] [blame]118<li>The LLVM code generator is now being <a
119 href="CodeGenerator.html">documented</a>.</li>
Reid Spencer850f85f2004-06-08 07:30:31 +0000[diff] [blame]120<li>There is a new tool, llvm-abcd, the Analysis of ByteCode Dumper (abcd).
121This tool can compute basic statistics and bytecode density statistics on a
122module or function basis and also dump out bytecode in a textual format that
123is lower level than assembly (values are not resolved from slot numbers).
124It should only be of interest to (a) those who are working to improve the
125bytecode format and (b) those who really want to understand or document the
126details of the bytecode format.</li>
127<li>The <a href="BytecodeFormat.html">LLVM Bytecode file format</a> is now
128 being documented.</li>
Chris Lattner4e71aa82004-06-11 04:35:21 +0000[diff] [blame^]129<li>LLVM now provides an <a href="LangRef.html#i_isnan">llvm.isnan</a> intrinsic
130for efficient implementation of unordered floating point comparisons.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]131</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]132
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]133</div>
134
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]135
136<!--=========================================================================-->
137<div class="doc_subsubsection">
138In this release, the following missing features were implemented:
139</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]140
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]141<div class="doc_text">
142
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]143<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]144<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
145more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]146<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
147non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]148<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
149with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]150<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
151uses of external fns by immediate constant exprs</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]152</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]153
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]154</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]155
156<!--=========================================================================-->
157<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]158<a name="qualityofimp">In this release, the following Quality of Implementation
159issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]160</div>
161
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]162<div class="doc_text">
163
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]164<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]165<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
166bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]167<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
168for structure typedefs</a></li>
Chris Lattnerf10ccbf2004-05-24 04:53:32 +0000[diff] [blame]169<li>All documentation is now conformant to the HTML 4.01 (Strict) level.</li>
Chris Lattnerbd948cf2004-06-08 07:19:29 +0000[diff] [blame]170<li>The spurious "WARNING: Found global types that are not compatible" warning
171produced when linking C++ programs has been fixed.</li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]172</ol>
173
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]174</div>
175
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]176<!--=========================================================================-->
177<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]178In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]179</div>
180
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]181<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]182<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]183<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
184-disable/enable-povray and -disable-spec</a></li>
185<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
186work if you change PATH</a></li>
Chris Lattner47696122004-06-09 01:09:16 +0000[diff] [blame]187<li><a href="http://llvm.cs.uiuc.edu/PR364">[llvmgcc] llvmgcc does not compile
188with gcc 3.4</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]189</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]190</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]191
192<!--=========================================================================-->
193<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]194<a name="codequality">This release includes the following Code Quality
195improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]196</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]197
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]198<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]199<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]200<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
201due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]202
203<li>The X86 backend now generates substantially better code for 64-bit integer
204and floating point operations.</li>
205
206<li>The -inline pass no longer inlines mutually recursive functions until it
207hits the inlining threshold.</li>
208
209<li>The -inline pass no longer misses obvious inlining opportunities just
210because the callee eventually calls into an external function.</li>
211
212<li>The -simplifycfg pass can now "if convert" simple statements into the new
213<tt>select</tt> instruction.</li>
214
215<li>The -loopsimplify pass can now break <a
216href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
217into multiple nested loops. This enables a variety of subsequent
218optimizations.</li>
219
220<li>The -adce pass can now eliminate calls to functions that do not not write to
221memory.</li>
222
223<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]224exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]225
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]226<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
227"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
228operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
229&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
230
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]231<li>LLVM now has infrastructure for (simple and sparse conditional) constant
232propagation of function calls. It currently supports a few math library
233functions like sqrt/sin/cos/etc.</li>
Chris Lattner249b3552004-06-03 22:35:13 +0000[diff] [blame]234
235<li>The C backend now emits <a href="http://llvm.cs.uiuc.edu/PR334">Syntactic
236loops</a> in the code to help C compilers whose optimizers do not recognize
237loops formed from gotos (like GCC).</li>
Brian Gaeke522235e2004-06-11 02:15:39 +0000[diff] [blame]238
239<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR368">[sparcv9] null
240often spilled to constant pool</a>.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]241</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]242</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]243
244<!--=========================================================================-->
245<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]246<a name="bugfix">In this release, the following bugs in the previous release
247were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]248</div>
249
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]250<div class="doc_text">
251
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]252<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]253
254<ol>
John Criswell6956afa2004-05-06 22:23:24 +0000[diff] [blame]255<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
256asssertion</a></li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]257<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
258incorrectly updates dominator information</a></li>
259<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
260breaks SSA form</a></li>
261<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
262to floating point cast</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]263<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
264code that unwinds</a></li>
265<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
266of the same name, both having constant pools</a></li>
267<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
268physical register use of aliased definition</a></li>
Chris Lattner8f7cf272004-05-21 16:48:20 +0000[diff] [blame]269<li><a href="http://llvm.cs.uiuc.edu/PR340">Verifier misses malformed switch instruction</a></li>
Chris Lattner3edb94b2004-06-01 21:52:45 +0000[diff] [blame]270<li><a href="http://llvm.cs.uiuc.edu/PR315">[jit] abort, don't warn, when missing external functions encountered</a></li>
Chris Lattner4e71aa82004-06-11 04:35:21 +0000[diff] [blame^]271<li><a href="http://llvm.cs.uiuc.edu/PR369">[X86] stackifier crash on floating point setcc X, X</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]272</ol>
273
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]274<p>Bugs in the C/C++ front-end:</p>
275
276<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]277<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
278enum type</a></li>
279<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
280indexing miscompiled</a></li>
Chris Lattner25b3a032004-06-08 07:15:52 +0000[diff] [blame]281<li><a href="http://llvm.cs.uiuc.edu/PR355">[llvmgcc] Errors handling function prototypes that take opaque structs by-value</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]282</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]283</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]284
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]285<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]286<div class="doc_section">
287 <a name="portability">Portability and Supported Platforms</a>
288</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]289<!-- *********************************************************************** -->
290
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]291<div class="doc_text">
292
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]293<p>LLVM is known to work in the following platforms:</p>
294
295<ul>
296<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
297 other unix-like systems).</li>
298<li>Sun UltraSPARC workstations running Solaris 8.</li>
299<li>PowerPC-based Mac OS X boxes, running 10.3 and above (C backend and
300 interpreter only, no native codegen is available yet).</li>
301<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
302</ul>
303
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]304
305<p>The core LLVM infrastructure uses
306<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
307to the machine and operating system on which it is built. However, minor
308porting may be required to get LLVM to work on new platforms. We welcome your
309portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]310
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]311<p>Note that the LLVM build system does not currently support directories with
312spaces on them when running on Win32/cygwin. We strongly recommend running
313LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattnerce1a3842004-06-01 19:41:30 +0000[diff] [blame]314<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
315cygwin packages. By default, many important tools are not installed that
316are needed by the LLVM build process or test suite (e.g., /bin/time).</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]317
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]318</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]319
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]320<!--=========================================================================-->
321<div class="doc_subsection">
322In this release, the following portability problems were fixed:
323</div>
324
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]325<div class="doc_text">
326
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]327<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]328<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
329on Mac OS X</a></li>
330<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
331understand abbreviated names in headers</a></li>
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]332</ol>
333
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]334</div>
335
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]336<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]337<div class="doc_section">
338 <a name="knownproblems">Known Problems</a>
339</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]340<!-- *********************************************************************** -->
341
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]342<div class="doc_text">
343
344<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]345component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]346sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]347href="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]348there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]349
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]350</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]351
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]352<!-- ======================================================================= -->
353<div class="doc_subsection">
354 <a name="experimental">Experimental features included with this release</a>
355</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]356
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]357<div class="doc_text">
358
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]359<p>The following components of this LLVM release are either untested, known to
360be broken or unreliable, or are in early development. These components should
361not be relied on, and bugs should not be filed against them, but they may be
362useful to some people. In particular, if you would like to work on one of these
363components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]364
365<ul>
366<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
367 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
368
369<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
370 it should) and not thoroughly tested.</li>
371<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
372<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
373</ul>
374
375</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]376
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]377<!-- ======================================================================= -->
378<div class="doc_subsection">
379 <a name="core">Known problems with the LLVM Core</a>
380</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]381
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]382<div class="doc_text">
383
384<ul>
385
386<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
387work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]388
389<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]390such, execution of a threaded program could cause these data structures to be
391corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]392
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]393<li>It is not possible to <tt>dlopen</tt> an LLVM bytecode file in the JIT.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]394
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]395<li>Linking in static archive files (.a files) is very slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]396table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]397
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]398<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
399objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]400
401<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]402values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]403targets whose setjmp/longjmp libraries do not save and restore the entire
404register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]405</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]406</div>
407
408<!-- ======================================================================= -->
409<div class="doc_subsection">
410 <a name="c-fe">Known problems with the C front-end</a>
411</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]412
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]413<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]414<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]415
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]416<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]417<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]418<li>C99 Variable sized arrays do not release stack memory when they go out of
419 scope. Thus, the following program may run out of stack space:
420<pre>
421 for (i = 0; i != 1000000; ++i) {
422 int X[n];
423 foo(X);
424 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]425</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]426
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]427<li>Initialization of global union variables can only be done <a
428href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
429member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]430
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]431<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
432external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]433
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]434</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]435</div>
436
437<!-- _______________________________________________________________________ -->
438<div class="doc_subsubsection">
439 Notes
440</div>
441
442<div class="doc_text">
443
444<ul>
445
446<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]447
448<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]449support for floating point data types of any size other than 32 and 64
450bits.</li>
451
452<li>The following Unix system functionality has not been tested and may not
453work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]454 <ol>
455 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
456 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
457 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
458 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
459 - These functions have not been tested.
460 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]461
462<li>Although many GCC extensions are supported, some are not. In particular,
463 the following extensions are known to <b>not be</b> supported:
464 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]465 <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]466 <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>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
468 <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]469 <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]470 <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>
471 <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]472 <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>
473 <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>
474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
475 <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]476 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]477
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]478 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]479 attribute means that the LLVM compiler ignores the presence of the attribute,
480 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]481 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]482 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]483
484 <ol>
485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
486 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]487 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]488
489 <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]490
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]491 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]492 return.<br>
493
494 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
495 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
496 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
497
498 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
499 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
500 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
501
502 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
503 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
504 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]505
506 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
507 Specifying attributes of variables.<br>
508 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
509 <tt>deprecated</tt>, <tt>transparent_union</tt>,
510 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]511
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]512 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
513 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
514 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]515 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]516
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]517 <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]518 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]519 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]520
521 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
522 all target specific attributes.</li>
523
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]524 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
525 Other built-in functions.<br>
526 We support all builtins which have a C language equivalent (e.g.,
527 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
528 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]529 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]530
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]531 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]532
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]533 <p>The following extensions <b>are</b> known to be supported:</p>
534
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]535 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]536 <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]537 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
538 <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>
539 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
540 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
541 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
542 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
543 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
544 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
545 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
546 <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>
547 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
548 <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]549 <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]550 <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]551 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
552or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]553 <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]554 <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]555 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
556 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
557 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
558 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
559 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
560 <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>
561 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
562 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
563 <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>
564 <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>
565 <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]566 <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]567 <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>
568 <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]569 </ol></li>
570
571</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]572
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]573<p>If you run into GCC extensions which have not been included in any of these
574lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]575
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]576</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]577
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]578<!-- ======================================================================= -->
579<div class="doc_subsection">
580 <a name="c++-fe">Known problems with the C++ front-end</a>
581</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]582
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]583<div class="doc_text">
584
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]585<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]586has not been tested as thoroughly as the C front-end. It has been tested and
587works for a number of non-trivial programs, but there may be lurking bugs.
588Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]589
590</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]591
592<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]593<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]594
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]595<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]596
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]597<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]598<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]599 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]600</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]601</div>
602
603<!-- _______________________________________________________________________ -->
604<div class="doc_subsubsection">
605 Notes
606</div>
607
608<div class="doc_text">
609
610<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]611
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]612<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
613parser is significantly more standards compliant (and picky) than prior GCC
614versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]615href="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]616
617<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]618 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]619 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]620 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]621 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]622
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]623<li>The LLVM C++ front-end follows the <a
624 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
625 This document, which is not Itanium specific, specifies a standard for name
626 mangling, class layout, v-table layout, RTTI formats, and other C++
627 representation issues. Because we use this API, code generated by the LLVM
628 compilers should be binary compatible with machine code generated by other
629 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
630 <i>However</i>, the exception handling mechanism used by LLVM is very
631 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]632 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]633
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]634</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]635
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]636</div>
637
638<!-- ======================================================================= -->
639<div class="doc_subsection">
640 <a name="x86-be">Known problems with the X86 back-end</a>
641</div>
642
643<div class="doc_text">
644
645<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]646<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]647</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]648
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]649</div>
650
651<!-- ======================================================================= -->
652<div class="doc_subsection">
653 <a name="sparc-be">Known problems with the Sparc back-end</a>
654</div>
655
656<div class="doc_text">
657
658<ul>
Chris Lattner9e0b81c2004-03-19 19:22:28 +0000[diff] [blame]659<li>There are several programs in the LLVM testsuite that the Sparc code generator is known to miscompile.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]660</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]661
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]662</div>
663
664<!-- ======================================================================= -->
665<div class="doc_subsection">
666 <a name="c-be">Known problems with the C back-end</a>
667</div>
668
669<div class="doc_text">
670
671<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]672
673<li>The C back-end produces code that violates the ANSI C Type-Based Alias
674Analysis rules. As such, special options may be necessary to compile the code
675(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]676problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]677
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]678<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]679cannot include special floating point numbers like Not-A-Number or
680Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]681
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]682<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]683supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]684frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]685
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]686</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]687
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]688</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]689
690<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]691<div class="doc_section">
692 <a name="additionalinfo">Additional Information</a>
693</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]694<!-- *********************************************************************** -->
695
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]696<div class="doc_text">
697
698<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]699including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]700implemented in LLVM. The web page also contains versions of the API
701documentation which is up-to-date with the CVS version of the source code. You
702can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]703the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]704
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]705<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]706us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
707lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]708
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]709</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]710
711<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]712
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]713<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]714<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]715 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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717 <a href="http://validator.w3.org/check/referer"><img
718 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
719
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]720 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]721 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]722</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]723
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]724</body>
725</html>