Gitiles
Code Review Sign In
gerrit-public.fairphone.software / toolchain / llvm-project / fa50a224bf722d216040ea50036983b90048bbef / . / llvm / docs / ReleaseNotes.html
blob: 73068181840198c36532a6a139f4ef8adde0f921 [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 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
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]31<div class="doc_text">
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]32 <p><b>Written by the <a href="http://llvm.cs.uiuc.edu">LLVM team</a></b><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 Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]84<!--=========================================================================-->
85<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]86<a name="newfeatures">This release implements the following new features:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]87</div>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]88
89<ol>
Chris Lattner1a7e43c2004-04-01 00:41:31 +0000[diff] [blame]90<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]91now fully implemented and supported by all transformations, native code
92generators, and the interpreter.</li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]93<li>Bugpoint can now narrow down code-generation bugs to a loop nest, where
94before it could only narrow them down to a function being miscompiled.</li>
Brian Gaekee307f8a72004-05-04 21:22:57 +0000[diff] [blame]95<li><a href="http://llvm.cs.uiuc.edu/PR40">Bugpoint can now debug arbitrary
96modes of llc</a> and lli, by passing them command line flags (e.g.,
97<tt>-regalloc=linearscan</tt>, <tt>-enable-correct-eh-support</tt>, etc.) </li>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]98<li>The Control Flow Graph in the native code generators is no longer
99constrained to be the same as the CFG for the LLVM input code.</li>
100<li>The LLVM induction variable analysis routines have been rewritten.</li>
101<li>LLVM now has new loop unrolling and loop unswitching passes.</li>
102<li>The induction variable substitution pass performs linear function test
103replacement and exit value replacement optimizations.</li>
Chris Lattner592db402003-11-19 22:05:38 +0000[diff] [blame]104</ol>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]105
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]106
107<!--=========================================================================-->
108<div class="doc_subsubsection">
109In this release, the following missing features were implemented:
110</div>
Chris Lattner4491de62003-11-08 04:28:55 +0000[diff] [blame]111
112<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]113<li><a href="http://llvm.cs.uiuc.edu/PR82">LLVM cannot handle structures with
114more than 256 elements</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]115<li><a href="http://llvm.cs.uiuc.edu/PR38">[bugpoint] External functions used in
116non-instruction entities, such as global constant initializer</a></li>
Reid Spencer45e25d82004-05-09 23:32:39 +0000[diff] [blame]117<li><a href="http://llvm.cs.uiuc.edu/PR178">Stacker does not handle targets
118with 64-bit pointers.</a></li>
Misha Brukmane7050232004-04-19 03:01:01 +0000[diff] [blame]119<li><a href="http://llvm.cs.uiuc.edu/PR290">Bugpoint doesn't support
120uses of external fns by immediate constant exprs</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]121</ol>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]122
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]123
124<!--=========================================================================-->
125<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]126<a name="qualityofimp">In this release, the following Quality of Implementation
127issues were fixed:</a>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]128</div>
129
130<ol>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]131<li><a href="http://llvm.cs.uiuc.edu/PR305">LLVM tools will happily spew
132bytecode onto your terminal</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame^]133<li><a href="http://llvm.cs.uiuc.edu/PR329">[llvmgcc] type names are not emitted
134for structure typedefs</a></li>
Chris Lattner4df78f02003-12-20 03:42:11 +0000[diff] [blame]135</ol>
136
137<!--=========================================================================-->
138<div class="doc_subsubsection">
Chris Lattner8ebf2532004-02-25 16:36:51 +0000[diff] [blame]139In this release, the following build problems were fixed:
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]140</div>
141
142<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame^]143<li><a href="http://llvm.cs.uiuc.edu/PR301">Minor configure bugs with
144-disable/enable-povray and -disable-spec</a></li>
145<li><a href="http://llvm.cs.uiuc.edu/PR289">shell scripts output by gccld don't
146work if you change PATH</a></li>
Brian Gaeke8b05e4f2004-01-16 21:55:04 +0000[diff] [blame]147</ol>
148
149<!--=========================================================================-->
150<div class="doc_subsubsection">
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]151<a name="codequality">This release includes the following Code Quality
152improvements:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]153</div>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]154
155<ol>
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]156<li>Fixed: <a href="http://llvm.cs.uiuc.edu/PR309">[vmcore] Code quality problem
157due to long operand of getelementptr</a></li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]158
159<li>The X86 backend now generates substantially better code for 64-bit integer
160and floating point operations.</li>
161
162<li>The -inline pass no longer inlines mutually recursive functions until it
163hits the inlining threshold.</li>
164
165<li>The -inline pass no longer misses obvious inlining opportunities just
166because the callee eventually calls into an external function.</li>
167
168<li>The -simplifycfg pass can now "if convert" simple statements into the new
169<tt>select</tt> instruction.</li>
170
171<li>The -loopsimplify pass can now break <a
172href="http://llvm.cs.uiuc.edu/PR35">natural loops with multiple backedges</a>
173into multiple nested loops. This enables a variety of subsequent
174optimizations.</li>
175
176<li>The -adce pass can now eliminate calls to functions that do not not write to
177memory.</li>
178
179<li>The link-time optimizer now runs the -prune-eh pass (to remove unused
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]180exception handlers).</li>
Chris Lattner54dcea82004-04-13 14:43:35 +0000[diff] [blame]181
Chris Lattner2ad48782004-05-02 04:19:15 +0000[diff] [blame]182<li>The -simplifycfg pass can now eliminate simple correlated branches (such as
183"<tt>if (A &lt; B &amp;&amp; A &lt; B)</tt>", and can turn short-circuiting
184operators into the strict versions when useful (such as "<tt>if (A &lt; B || A
185&gt; C)</tt>" into "<tt>if (A &lt; B | A &gt; C)</tt>"</li>
186
Chris Lattnerea309ff2004-05-04 17:04:09 +0000[diff] [blame]187<li>LLVM now has infrastructure for (simple and sparse conditional) constant
188propagation of function calls. It currently supports a few math library
189functions like sqrt/sin/cos/etc.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]190</ol>
Chris Lattner639579c2003-10-27 17:06:39 +0000[diff] [blame]191
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]192
193<!--=========================================================================-->
194<div class="doc_subsubsection">
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]195<a name="bugfix">In this release, the following bugs in the previous release
196were fixed:</a>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]197</div>
198
199<p>Bugs in the LLVM Core:</p>
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]200
201<ol>
John Criswell6956afa2004-05-06 22:23:24 +0000[diff] [blame]202<li><a href="http://llvm.cs.uiuc.edu/PR330">[vmcore] Linker causes erroneous
203asssertion</a></li>
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]204<li><a href="http://llvm.cs.uiuc.edu/PR306">[loopsimplify] Loop simplify
205incorrectly updates dominator information</a></li>
206<li><a href="http://llvm.cs.uiuc.edu/PR310">[tailduplicate] DemoteRegToStack
207breaks SSA form</a></li>
208<li><a href="http://llvm.cs.uiuc.edu/PR313">[X86] JIT miscompiles unsigned short
209to floating point cast</a></li>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame^]210<li><a href="http://llvm.cs.uiuc.edu/PR332">[adce] Crash handling unreachable
211code that unwinds</a></li>
212<li><a href="http://llvm.cs.uiuc.edu/PR333">[sparc] LLC can't emit 2 functions
213of the same name, both having constant pools</a></li>
214<li><a href="http://llvm.cs.uiuc.edu/PR337">[livevar] Live variables missed
215physical register use of aliased definition</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]216</ol>
217
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]218<p>Bugs in the C/C++ front-end:</p>
219
220<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame^]221<li><a href="http://llvm.cs.uiuc.edu/PR326">[llvmgcc] Crash on use of undeclared
222enum type</a></li>
223<li><a href="http://llvm.cs.uiuc.edu/PR298">[llvmgcc] Variable length array
224indexing miscompiled</a></li>
Chris Lattnerba7bd472003-12-06 20:22:41 +0000[diff] [blame]225</ol>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]226
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]227</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]228
229<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]230<div class="doc_section">
231 <a name="portability">Portability and Supported Platforms</a>
232</div>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]233<!-- *********************************************************************** -->
234
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]235<div class="doc_text">
236
Brian Gaekee3e557e2004-05-09 05:28:35 +0000[diff] [blame]237<p>LLVM has been extensively tested on Intel and AMD machines running Red Hat
238Linux. It has also been tested under FreeBSD, and on Sun UltraSPARC
239workstations running Solaris 8. Additionally, LLVM works on Mac OS X 10.3 and
240above, but only with the C backend and interpreter; no native machine-code
241generator for the PowerPC is available yet.</p>
242
243<p>The core LLVM infrastructure uses
244<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
245to the machine and operating system on which it is built. However, minor
246porting may be required to get LLVM to work on new platforms. We welcome your
247portability patches and reports of successful builds or error messages.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]248
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]249</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]250
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]251<!--=========================================================================-->
252<div class="doc_subsection">
253In this release, the following portability problems were fixed:
254</div>
255
256<ol>
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame^]257<li><a href="http://llvm.cs.uiuc.edu/PR304">warnings compiling Stacker compiler
258on Mac OS X</a></li>
259<li><a href="http://llvm.cs.uiuc.edu/PR308">Archive file reader doesn't
260understand abbreviated names in headers</a></li>
Brian Gaeke86a6c752004-04-20 18:18:46 +0000[diff] [blame]261</ol>
262
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]263<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]264<div class="doc_section">
265 <a name="knownproblems">Known Problems</a>
266</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]267<!-- *********************************************************************** -->
268
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]269<div class="doc_text">
270
271<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]272component. As new problems are discovered, they will be added to these
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]273sections. If you run into a problem, please check the <a
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]274href="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]275there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]276
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]277</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]278
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]279<!-- ======================================================================= -->
280<div class="doc_subsection">
281 <a name="experimental">Experimental features included with this release</a>
282</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]283
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]284<div class="doc_text">
285
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame^]286<p>The following components of this LLVM release are either untested, known to
287be broken or unreliable, or are in early development. These components should
288not be relied on, and bugs should not be filed against them, but they may be
289useful to some people. In particular, if you would like to work on one of these
290components, please contact us on the llvmdev list.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]291
292<ul>
293<li>The following passes are incomplete or buggy: <tt>-pgmdep, -memdep,
294 -ipmodref, -sortstructs, -swapstructs, -cee</tt></li>
295
296<li>The <tt>-pre</tt> pass is incomplete (there are cases it doesn't handle that
297 it should) and not thoroughly tested.</li>
298<li>The <tt>llvm-ar</tt> tool is incomplete and probably buggy.</li>
299<li>The <tt>llvm-db</tt> tool is in a very early stage of development.</li>
300</ul>
301
302</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]303
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]304<!-- ======================================================================= -->
305<div class="doc_subsection">
306 <a name="core">Known problems with the LLVM Core</a>
307</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]308
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]309<div class="doc_text">
310
311<ul>
312
313<li>In the JIT, <tt>dlsym</tt> on a symbol compiled by the JIT will not
314work.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]315
316<li>The JIT does not use mutexes to protect its internal data structures. As
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]317such, execution of a threaded program could cause these data structures to be
318corrupted.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]319
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]320<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]321
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]322<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]323table in the archive).</li>
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]324
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]325<li>The gccld program <a href="http://llvm.cs.uiuc.edu/PR139">does not link
326objects/archives in the order specified on the command line.</a></li>
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]327
328<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]329values live across a setjmp as volatile</a>. This missing feature only affects
Chris Lattneraebc66a2004-02-15 23:09:07 +0000[diff] [blame]330targets whose setjmp/longjmp libraries do not save and restore the entire
331register file.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]332</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]333</div>
334
335<!-- ======================================================================= -->
336<div class="doc_subsection">
337 <a name="c-fe">Known problems with the C front-end</a>
338</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]339
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]340<!-- _______________________________________________________________________ -->
Chris Lattner5a8a7282003-12-14 05:03:43 +0000[diff] [blame]341<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]342
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]343<div class="doc_text">
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]344<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]345<li>C99 Variable sized arrays do not release stack memory when they go out of
346 scope. Thus, the following program may run out of stack space:
347<pre>
348 for (i = 0; i != 1000000; ++i) {
349 int X[n];
350 foo(X);
351 }
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]352</pre></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]353
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame^]354<li>Initialization of global union variables can only be done <a
355href="http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=162">with the largest union
356member</a>.</li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]357
Misha Brukman017f2f32004-04-19 02:56:49 +0000[diff] [blame]358<li><a href="http://llvm.cs.uiuc.edu/PR244">[llvm-gcc] Error when an implicitly
359external function is re-declared as static</a></li>
Chris Lattner1ab58dd2004-03-16 21:39:04 +0000[diff] [blame]360
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]361</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]362</div>
363
364<!-- _______________________________________________________________________ -->
365<div class="doc_subsubsection">
366 Notes
367</div>
368
369<div class="doc_text">
370
371<ul>
372
373<li>Inline assembly is not yet supported.</li>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]374
375<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]376support for floating point data types of any size other than 32 and 64
377bits.</li>
378
379<li>The following Unix system functionality has not been tested and may not
380work:
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]381 <ol>
382 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
383 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
384 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
385 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
386 - These functions have not been tested.
387 </ol></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]388
389<li>Although many GCC extensions are supported, some are not. In particular,
390 the following extensions are known to <b>not be</b> supported:
391 <ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]392 <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]393 <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>
394 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
395 <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]396 <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]397 <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>
398 <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]399 <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>
400 <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>
401 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread-Local.html#Thread-Local">Thread-Local</a>: Per-thread variables.</li>
402 <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]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 GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]406 attribute means that the LLVM compiler ignores the presence of the attribute,
407 but the code should still work. An unsupported attribute is one which is
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]408 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]409 the program.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]410
411 <ol>
412 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
413 Arrays whose length is computed at run time.<br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]414 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]415
416 <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]417
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]418 Declaring that functions have no side effects or that they can never
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]419 return.<br>
420
421 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
422 <tt>constructor</tt>, <tt>destructor</tt>, <tt>unused</tt>,
423 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
424
425 <b>Ignored:</b> <tt>noreturn</tt>, <tt>noinline</tt>,
426 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
427 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
428
429 <b>Unsupported:</b> <tt>used</tt>, <tt>section</tt>, <tt>alias</tt>,
430 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
431 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]432
433 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
434 Specifying attributes of variables.<br>
435 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
436 <tt>deprecated</tt>, <tt>transparent_union</tt>,
437 <tt>unused</tt>, <tt>weak</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]438
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]439 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
440 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
441 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]442 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]443
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]444 <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]445 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukman8395d732003-12-12 04:37:31 +0000[diff] [blame]446 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]447
448 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
449 all target specific attributes.</li>
450
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]451 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
452 Other built-in functions.<br>
453 We support all builtins which have a C language equivalent (e.g.,
454 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
455 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]456 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt> (ignored).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]457
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]458 </ol>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]459
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]460 <p>The following extensions <b>are</b> known to be supported:</p>
461
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]462 <ol>
Chris Lattnerd3dc8502004-03-16 08:54:07 +0000[diff] [blame]463 <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]464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
465 <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>
466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
468 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
469 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
471 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
472 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
473 <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>
474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
475 <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]476 <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]477 <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]478 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
479or arrays as values.</li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]480 <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]481 <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]482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
483 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
484 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
485 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C---Comments.html#C++%20Comments">C++ Comments</a>: C++ comments are recognized.</li>
486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
487 <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>
488 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
489 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
490 <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>
491 <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>
492 <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]493 <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]494 <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>
495 <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]496 </ol></li>
497
498</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]499
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]500<p>If you run into GCC extensions which have not been included in any of these
501lists, please let us know (also including whether or not they work).</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]502
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]503</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]504
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]505<!-- ======================================================================= -->
506<div class="doc_subsection">
507 <a name="c++-fe">Known problems with the C++ front-end</a>
508</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]509
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]510<div class="doc_text">
511
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]512<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]513has not been tested as thoroughly as the C front-end. It has been tested and
514works for a number of non-trivial programs, but there may be lurking bugs.
515Please report any bugs or problems.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]516
517</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]518
519<!-- _______________________________________________________________________ -->
Chris Lattner141ebb62004-02-14 04:12:41 +0000[diff] [blame]520<div class="doc_subsubsection">Bugs</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]521
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]522<div class="doc_text">
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]523
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]524<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]525<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]526 front-end</a>.</li>
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]527</ul>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]528</div>
529
530<!-- _______________________________________________________________________ -->
531<div class="doc_subsubsection">
532 Notes
533</div>
534
535<div class="doc_text">
536
537<ul>
Chris Lattnerd2a74272003-10-27 18:30:37 +0000[diff] [blame]538
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]539<li>The C++ front-end is based on a pre-release of the GCC 3.4 C++ parser. This
540parser is significantly more standards compliant (and picky) than prior GCC
541versions. For more information, see the C++ section of the <a
Chris Lattnere76e9ab2003-12-12 04:25:33 +0000[diff] [blame]542href="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]543
544<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]545 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]546 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]547 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]548 better than most compilers).</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]549
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]550<li>The LLVM C++ front-end follows the <a
551 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
552 This document, which is not Itanium specific, specifies a standard for name
553 mangling, class layout, v-table layout, RTTI formats, and other C++
554 representation issues. Because we use this API, code generated by the LLVM
555 compilers should be binary compatible with machine code generated by other
556 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
557 <i>However</i>, the exception handling mechanism used by LLVM is very
558 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]559 interact correctly</b>. </li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]560
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]561</ul>
Chris Lattner46ecf612003-10-07 22:14:37 +0000[diff] [blame]562
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]563</div>
564
565<!-- ======================================================================= -->
566<div class="doc_subsection">
567 <a name="x86-be">Known problems with the X86 back-end</a>
568</div>
569
570<div class="doc_text">
571
572<ul>
Chris Lattnerc5b7b242004-02-08 22:23:33 +0000[diff] [blame]573<li>None so far.
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]574</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]575
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]576</div>
577
578<!-- ======================================================================= -->
579<div class="doc_subsection">
580 <a name="sparc-be">Known problems with the Sparc back-end</a>
581</div>
582
583<div class="doc_text">
584
585<ul>
Chris Lattner9e0b81c2004-03-19 19:22:28 +0000[diff] [blame]586<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]587</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]588
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]589</div>
590
591<!-- ======================================================================= -->
592<div class="doc_subsection">
593 <a name="c-be">Known problems with the C back-end</a>
594</div>
595
596<div class="doc_text">
597
598<ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]599
600<li>The C back-end produces code that violates the ANSI C Type-Based Alias
601Analysis rules. As such, special options may be necessary to compile the code
602(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]603problem probably cannot be fixed.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]604
Chris Lattnera623e482003-10-20 19:05:03 +0000[diff] [blame]605<li><a href="http://llvm.cs.uiuc.edu/PR33">Initializers for global variables</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]606cannot include special floating point numbers like Not-A-Number or
607Infinity.</li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]608
Chris Lattnerc679fbb2003-11-04 20:06:53 +0000[diff] [blame]609<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]610supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]611frontends.</li>
Chris Lattnerb28c3282003-10-24 04:03:19 +0000[diff] [blame]612
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]613</ul>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]614
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]615</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]616
617<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]618<div class="doc_section">
619 <a name="additionalinfo">Additional Information</a>
620</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]621<!-- *********************************************************************** -->
622
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]623<div class="doc_text">
624
625<p>A wide variety of additional information is available on the LLVM web page,
John Criswell86a3a482003-12-18 16:43:17 +0000[diff] [blame]626including mailing lists and publications describing algorithms and components
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]627implemented in LLVM. The web page also contains versions of the API
628documentation which is up-to-date with the CVS version of the source code. You
629can access versions of these documents specific to this release by going into
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]630the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]631
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]632<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]633us via the <a href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">mailing
634lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]635
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]636</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]637
638<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]639
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]640<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]641<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]642 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]643 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
644 <a href="http://validator.w3.org/check/referer"><img
645 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
646
Misha Brukman7cb4e382003-11-22 01:00:11 +0000[diff] [blame]647 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]648 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]649</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]650
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]651</body>
652</html>