Gitiles
Code Review Sign In
gerrit-public.fairphone.software / toolchain / llvm-project / 14c198d09ac02617472ada158d541e38f2a59cd9 / . / llvm / docs / ReleaseNotes.html
blob: 3ceb77c8e5a8df551cc4ad2d599504c42fe1ccc4 [file] [log] [blame]
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4<head>
5 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]6 <title>LLVM 1.4 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 Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]10<div class="doc_title">LLVM 1.4 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 Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]44infrastructure, release 1.4. 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 Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]47href="http://llvm.cs.uiuc.edu/releases/1.4/">LLVM 1.4 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
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]72<p>This is the fifth public release of the LLVM compiler infrastructure.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]73
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]74<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]75SPEC CPU95 &amp; 2000 benchmarks, the Olden benchmarks, and the Ptrdist
76benchmarks, and <b>many</b> other programs. LLVM now also works
77with a broad variety of C++ programs.</p>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]78
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]79</div>
80
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]81<!--=========================================================================-->
82<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]83<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]84</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]85
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]86<div class="doc_text">
87
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]88<ol>
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]89<li></li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]90</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]91
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]92</div>
93
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]94
95<!--=========================================================================-->
96<div class="doc_subsubsection">
97In this release, the following missing features were implemented:
98</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]99
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]100<div class="doc_text">
101
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]102<ol>
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]103<li><a href="http://llvm.org/PR419">JIT interface should support arbitrary
104 calls</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]105</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]106
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]107</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]108
109<!--=========================================================================-->
110<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]111<a name="qualityofimp">In this release, the following Quality of Implementation
112issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]113</div>
114
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]115<div class="doc_text">
116
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]117<ol>
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]118<li></li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]119</ol>
120
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]121</div>
122
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]123<!--=========================================================================-->
124<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]125In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]126</div>
127
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]128<div class="doc_text">
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]129<ol>
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]130<li></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]131</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]132</div>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]133
134<!--=========================================================================-->
135<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]136<a name="codequality">This release includes the following Code Quality
137improvements:</a>
Chris Lattner23257062004-05-23 20:42:08 +0000[diff] [blame]138</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]139
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]140<div class="doc_text">
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]141<ol>
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]142<li></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]143</ol>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]144</div>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]145
146<!--=========================================================================-->
147<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]148<a name="bugfix">In this release, the following bugs in the previous release
149were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]150</div>
151
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]152<div class="doc_text">
153
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]154<p>Bugs fixed in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]155
156<ol>
Reid Spencerf03b47c2004-08-16 16:48:19 +0000[diff] [blame]157<li><a href="http://llvm.org/PR422">[asmwriter] Asmwriter is really slow for
158 functions with lots of values</a></li>
Chris Lattnera10ed3b2004-08-16 05:46:57 +0000[diff] [blame]159<li><a href="http://llvm.org/PR423">[anders-aa] Andersen's AA is completely
160 broken in LLVM 1.3</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]161</ol>
162
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]163<p>Bugs in the C/C++ front-end:</p>
164
165<ol>
Chris Lattner163c3262004-08-16 00:20:18 +0000[diff] [blame]166<li></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]167</ol>
Chris Lattner21a90402004-05-24 04:50:25 +0000[diff] [blame]168</div>
Reid Spencer3e58f582004-05-23 17:23:13 +0000[diff] [blame]169
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]170<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]171<div class="doc_section">
172 <a name="portability">Portability and Supported Platforms</a>
173</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]174<!-- *********************************************************************** -->
175
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]176<div class="doc_text">
177
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]178<p>LLVM is known to work in the following platforms:</p>
179
180<ul>
181<li>Intel and AMD machines running Red Hat Linux and FreeBSD (and probably
182 other unix-like systems).</li>
183<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]184<li>Intel and AMD machines running on Win32 with the Cygwin libraries.</li>
Chris Lattnerd21e3d02004-08-05 21:53:13 +0000[diff] [blame]185<li>PowerPC-based Mac OS X boxes, running 10.2 and above. Note that no JIT
186support is available yet, and LLC support is beta. The C backend can be used
187to produce stable code for this platform.</li>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]188</ul>
189
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]190<p>The core LLVM infrastructure uses
191<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
192to the machine and operating system on which it is built. However, minor
193porting may be required to get LLVM to work on new platforms. We welcome your
194portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]195
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]196<p>Note that the LLVM build system does not currently support directories with
197spaces on them when running on Win32/cygwin. We strongly recommend running
198LLVM and the C frontend out of a top-level directory without spaces (e.g.,
Chris Lattnerce1a3842004-06-01 19:41:30 +0000[diff] [blame]199<tt>/cygdrive/c/llvm</tt>). Also, make sure to install <b>all</b> of the
200cygwin packages. By default, many important tools are not installed that
Chris Lattnera752fce2004-08-16 20:20:46 +0000[diff] [blame]201are needed by the LLVM build process or test suite (e.g., /bin/time). Finally,
202please make sure that there are no directories with spaces in them in your
203PATH environment variable.</p>
Chris Lattner2c7b0872004-06-01 18:22:41 +0000[diff] [blame]204
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]205</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]206
207<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]208<div class="doc_section">
209 <a name="knownproblems">Known Problems</a>
210</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]211<!-- *********************************************************************** -->
212
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]213<div class="doc_text">
214
215<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]216component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]217sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]218href="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]219there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]220
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]221</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]222
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]223<!-- ======================================================================= -->
224<div class="doc_subsection">
225 <a name="experimental">Experimental features included with this release</a>
226</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]227
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]228<div class="doc_text">
229
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]230<p>The following components of this LLVM release are either untested, known to
231be broken or unreliable, or are in early development. These components should
232not be relied on, and bugs should not be filed against them, but they may be
233useful to some people. In particular, if you would like to work on one of these
234components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]235
236<ul>
Misha Brukman467ea6b2004-08-05 21:04:03 +0000[diff] [blame]237<li>The PowerPC backend is incomplete and is known to miscompile several SPEC
238benchmarks. The file <tt>llvm/lib/Target/PowerPC/README.txt</tt> has
239details.</li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]240<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
Chris Lattner99583502004-06-28 00:44:45 +0000[diff] [blame]241 -ipmodref, -cee</tt></li>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]242<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
243 it should) and not thoroughly tested.</li>
244<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
245<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
246</ul>
247
248</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]249
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]250<!-- ======================================================================= -->
251<div class="doc_subsection">
252 <a name="core">Known problems with the LLVM Core</a>
253</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]254
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]255<div class="doc_text">
256
257<ul>
258
259<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
260work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]261
262<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]263such, execution of a threaded program could cause these data structures to be
264corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]265
Chris Lattnerc0171082004-08-08 03:33:07 +0000[diff] [blame]266<li>Linking in static archive files (.a files) is slow (there is no symbol
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]267table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]268
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]269<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
270objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]271
272<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]273values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]274targets whose setjmp/longjmp libraries do not save and restore the entire
275register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]276</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]277</div>
278
279<!-- ======================================================================= -->
280<div class="doc_subsection">
281 <a name="c-fe">Known problems with the C front-end</a>
282</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]283
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]284<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]285<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]286
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]287<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]288<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]289<li>C99 Variable sized arrays do not release stack memory when they go out of
290 scope. Thus, the following program may run out of stack space:
291<pre>
292 for (i = 0; i != 1000000; ++i) {
293 int X[n];
294 foo(X);
295 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]296</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]297
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]298<li>Initialization of global union variables can only be done <a
299href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
300member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]301
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]302<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
303external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]304
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]305</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]306</div>
307
308<!-- _______________________________________________________________________ -->
309<div class="doc_subsubsection">
310 Notes
311</div>
312
313<div class="doc_text">
314
315<ul>
316
317<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]318
319<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]320support for floating point data types of any size other than 32 and 64
321bits.</li>
322
323<li>The following Unix system functionality has not been tested and may not
324work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]325 <ol>
326 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
327 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
328 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
329 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
330 - These functions have not been tested.
331 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]332
333<li>Although many GCC extensions are supported, some are not. In particular,
334 the following extensions are known to <b>not be</b> supported:
335 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]336 <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]337 <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>
338 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
339 <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]340 <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]341 <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>
342 <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]343 <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>
344 <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>
345 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
346 <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]347 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]348
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]349 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]350 attribute means that the LLVM compiler ignores the presence of the attribute,
351 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]352 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]353 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]354
355 <ol>
356 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
357 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]358 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]359
360 <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]361
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]362 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]363 return.<br>
364
365 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
366 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
367 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
368
369 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
370 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
371 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
372
373 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
374 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
375 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]376
377 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
378 Specifying attributes of variables.<br>
379 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
380 <tt>deprecated</tt>, <tt>transparent_union</tt>,
381 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]382
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]383 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
384 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
385 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]386 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]387
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]388 <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]389 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]390 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]391
392 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
393 all target specific attributes.</li>
394
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]395 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
396 Other built-in functions.<br>
397 We support all builtins which have a C language equivalent (e.g.,
398 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
399 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerb7c4bac2004-06-18 06:26:29 +0000[diff] [blame]400 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
401 (currently ignored). We also support builtins for ISO C99 floating
402 point comparison macros (e.g., <tt>__builtin_islessequal</tt>).</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]403 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]404
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]405 <p>The following extensions <b>are</b> known to be supported:</p>
406
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]407 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]408 <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]409 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
410 <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]411 <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]412 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
413 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
414 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
415 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
416 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
417 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
418 <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>
419 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
420 <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]421 <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]422 <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]423 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
424or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]425 <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]426 <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]427 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
428 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
429 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
430 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
431 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
432 <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>
433 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
434 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
435 <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>
436 <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>
437 <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]438 <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]439 <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>
440 <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]441 </ol></li>
442
443</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]444
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]445<p>If you run into GCC extensions which have not been included in any of these
446lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]447
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]448</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]449
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]450<!-- ======================================================================= -->
451<div class="doc_subsection">
452 <a name="c++-fe">Known problems with the C++ front-end</a>
453</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]454
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]455<div class="doc_text">
456
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]457<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]458has not been tested as thoroughly as the C front-end. It has been tested and
459works for a number of non-trivial programs, but there may be lurking bugs.
460Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]461
462</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]463
464<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]465<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]466
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]467<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]468
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]469<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]470<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]471 front-end</a>.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]472
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]473<li><b>IA-64 specific</b>: The C++ front-end does not use <a
474href="http://llvm.cs.uiuc.edu/PR406">IA64 ABI compliant layout of v-tables</a>.
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]475In particular, it just stores function pointers instead of function
476descriptors in the vtable. This bug prevents mixing C++ code compiled with
Chris Lattner2fd93492004-08-02 20:29:51 +0000[diff] [blame]477LLVM with C++ objects compiled by other C++ compilers.</li>
Chris Lattner041e6c92004-07-17 02:04:41 +0000[diff] [blame]478
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]479</ul>
480
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]481</div>
482
483<!-- _______________________________________________________________________ -->
484<div class="doc_subsubsection">
485 Notes
486</div>
487
488<div class="doc_text">
489
490<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]491
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]492<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
493parser is significantly more standards compliant (and picky) than prior GCC
494versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]495href="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]496
497<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]498 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]499 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]500 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]501 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]502
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]503<li>The LLVM C++ front-end follows the <a
504 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
505 This document, which is not Itanium specific, specifies a standard for name
506 mangling, class layout, v-table layout, RTTI formats, and other C++
507 representation issues. Because we use this API, code generated by the LLVM
508 compilers should be binary compatible with machine code generated by other
509 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
510 <i>However</i>, the exception handling mechanism used by LLVM is very
511 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]512 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]513
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]514</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]515
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]516</div>
517
518<!-- ======================================================================= -->
519<div class="doc_subsection">
520 <a name="x86-be">Known problems with the X86 back-end</a>
521</div>
522
523<div class="doc_text">
524
525<ul>
Chris Lattner5cd40922004-08-02 20:28:44 +0000[diff] [blame]526 <li>none yet</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]527</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]528
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]529</div>
530
531<!-- ======================================================================= -->
532<div class="doc_subsection">
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]533 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]534</div>
535
536<div class="doc_text">
537
538<ul>
Misha Brukmana516e992004-07-12 16:55:41 +0000[diff] [blame]539<li><a href="http://llvm.cs.uiuc.edu/PR60">[sparcv9] SparcV9 backend miscompiles
540several programs in the LLVM test suite</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]541</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]542
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]543</div>
544
545<!-- ======================================================================= -->
546<div class="doc_subsection">
547 <a name="c-be">Known problems with the C back-end</a>
548</div>
549
550<div class="doc_text">
551
552<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]553
554<li>The C back-end produces code that violates the ANSI C Type-Based Alias
555Analysis rules. As such, special options may be necessary to compile the code
556(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]557problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]558
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]559<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]560cannot include special floating point numbers like Not-A-Number or
561Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]562
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]563<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]564supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]565frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]566
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]567</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]568
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]569</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]570
571<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]572<div class="doc_section">
573 <a name="additionalinfo">Additional Information</a>
574</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]575<!-- *********************************************************************** -->
576
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]577<div class="doc_text">
578
579<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]580including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]581implemented in LLVM. The web page also contains versions of the API
582documentation which is up-to-date with the CVS version of the source code. You
583can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]584the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]585
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]586<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]587us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
588lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]589
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]590</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]591
592<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]593
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]594<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]595<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]596 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]597 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
598 <a href="http://validator.w3.org/check/referer"><img
599 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
600
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]601 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]602 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]603</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]604
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]605</body>
606</html>