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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 44c933ec9a9534a624d13f66b3f0b04cddb37492 / . / docs / ReleaseNotes.html
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Misha Brukman500bc302003-11-22 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>
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]6 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]7 <title>LLVM 1.7 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]10
Chris Lattnerc30c5c72005-11-08 21:29:17 +0000[diff] [blame]11<div class="doc_title">LLVM 1.7 Release Notes</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]12
13<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]14 <li><a href="#intro">Introduction</a></li>
15 <li><a href="#whatsnew">What's New?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]16 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#portability">Portability and Supported Platforms</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]18 <li><a href="#knownproblems">Known Problems</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]19 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]20</ol>
21
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]22<div class="doc_author">
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]23 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]24</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]25
26<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]27<div class="doc_section">
28 <a name="intro">Introduction</a>
29</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]30<!-- *********************************************************************** -->
31
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]32<div class="doc_text">
33
34<p>This document contains the release notes for the LLVM compiler
Chris Lattnerc30c5c72005-11-08 21:29:17 +0000[diff] [blame]35infrastructure, release 1.7. Here we describe the status of LLVM, including any
Chris Lattner8a458762005-05-15 05:44:51 +0000[diff] [blame]36known problems and major improvements from the previous release. The most
37up-to-date version of this document can be found on the <a
Chris Lattnerc30c5c72005-11-08 21:29:17 +0000[diff] [blame]38href="http://llvm.org/releases/">LLVM releases web site</a>. If you are
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]39not reading this on the LLVM web pages, you should probably go there because
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]40this document may be updated after the release.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]41
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]42<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]43release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]44web site</a>. If you have questions or comments, the <a
45href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]46list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]47
Chris Lattner78bf32b2004-12-09 22:22:58 +0000[diff] [blame]48<p>Note that if you are reading this file from CVS or the main LLVM web page,
49this document applies to the <i>next</i> release, not the current one. To see
50the release notes for the current or previous releases, see the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]51href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]52
53</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]54
55<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]56<div class="doc_section">
57 <a name="whatsnew">What's New?</a>
58</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]59<!-- *********************************************************************** -->
60
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]61<div class="doc_text">
62
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]63<p>This is the eighth public release of the LLVM Compiler Infrastructure. This
64release incorporates a large number of enhancements and new features,
65including vector support (Intel SSE and Altivec), a new GCC4.0-based
66C/C++ front-end, Objective C/C++ support, inline assembly support, and many
67other big features.
68</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]69
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]70</div>
71
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]72<!--=========================================================================-->
Chris Lattner8a458762005-05-15 05:44:51 +0000[diff] [blame]73<div class="doc_subsection">
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]74<a name="newfeatures">New Features in LLVM 1.7</a>
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]75</div>
Brian Gaeke6b31beb2004-01-16 21:55:04 +0000[diff] [blame]76
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]77<!--_________________________________________________________________________-->
78<div class="doc_subsubsection"><a name="llvmgcc4">GCC4.0-based llvm-gcc
79front-end</a></div>
80
81<div class="doc_text">
82
83<p>LLVM 1.8 includes a brand new llvm-gcc, based on GCC 4.0.1. This version
84of llvm-gcc solves many serious long-standing problems with llvm-gcc, including
85all of those blocked by the <a href="http://llvm.org/PR498">llvm-gcc 4 meta
86bug</a>. In addition, llvm-gcc4 implements support for many new features,
87including GCC inline assembly, generic vector support, SSE and Altivec
88intrinsics, and several new GCC attributes. In addition, llvm-gcc4 is
89significantly faster than llvm-gcc3, respects -O options, its -c/-S options
90correspond to GCC's (they emit native code).</p>
91
92<p>If you can use it, llvm-gcc4 is offers significant new functionality, and we
93hope that it will replace llvm-gcc3 completely in a future release.
94Unfortunately, it does not currently support C++ exception handling at all, and
95it only works on Apple Mac OS/X machines with X86 or PowerPC processors.
96</p>
97
98</div>
99
100<!--_________________________________________________________________________-->
101<div class="doc_subsubsection"><a name="inlineasm">Inline Assembly
102Support</a></div>
103
104<div class="doc_text">
105
106<p>The LLVM IR and llvm-gcc4 front-end now fully support arbitrary GCC <a
107href="LangRef.html#inlineasm">inline assembly</a>. The LLVM X86 and PowerPC
108code generators have initial support for it,
109being able to compile basic statements, but are missing some features. Please
110report any inline asm statements that crash the compiler or that are miscompiled
111as bugs.</p>
112
113</div>
114
115<!--_________________________________________________________________________-->
116<div class="doc_subsubsection"><a name="newsparc">New SPARC backend</a></div>
117
118<div class="doc_text">
119
120<p>LLVM 1.7 includes a new, fully functional, SPARC backend built in the
121target-independent code generator. This SPARC backend includes support for
122SPARC V8 and SPARC V9 subtargets (controlling whether V9 features can be used),
123and targets the 32-bit SPARC ABI.</p>
124
125<p>The LLVM 1.7 release is the last release that will include the LLVM "SparcV9"
126backend, which was the very first LLVM native code generator. In 1.8, it will
127be removed, replaced with the new SPARC backend.</p>
128
129</div>
130
131<!--_________________________________________________________________________-->
132<div class="doc_subsubsection"><a name="genvector">Generic Vector Support
133</a></div>
134
135<div class="doc_text">
136
137<p>LLVM now includes significantly extended support for SIMD vectors in its
138core instruction set. It now includes three new instructions for manipulating
139vectors: <a href="LangRef.html#i_extractelement"><tt>extractelement</tt></a>,
140<a href="LangRef.html#i_insertelement"><tt>insertelement</tt></a>, and
141<a href="LangRef.html#i_shufflevector"><tt>shufflevector</tt></a>. Further,
142many bugs in vector handling have been fixed, and vectors are now supported by
143the target-independent code generator. For example, if a vector operation is
144not supported by a particular target, it will be correctly broken down and
145executed as scalar operations.</p>
146
147<p>Because llvm-gcc3 does not support GCC generic vectors or vector intrinsics,
148so llvm-gcc4 must be used.</p>
149</div>
150
151
152<!--_________________________________________________________________________-->
153<div class="doc_subsubsection"><a name="ssealtivec">Intel SSE and PowerPC
154Altivec support
155</a></div>
156
157<div class="doc_text">
158
159<p>The LLVM X86 backend now supports Intel SSE 1, 2, and 3, and now uses scalar
160SSE operations to implement scalar floating point math when the target supports
161SSE1 (for floats) or SSE2 (for doubles). Vector SSE instructions are generated
162by llvm-gcc4 when the generic vector mechanism or specific SSE intrinsics are
163used.
164</p>
165
166<p>The LLVM PowerPC backend now supports the Altivec instruction set, including
167both GCC -maltivec and -faltivec modes. Altivec instructions are generated
168by llvm-gcc4 when the generic vector mechanism or specific Altivec intrinsics
169are used.
170</p>
171
172</div>
173
174
175<!--_________________________________________________________________________-->
176<div class="doc_subsubsection"><a name="othernew">Other New Features</a></div>
177
Chris Lattner58504a62006-02-05 06:39:36 +0000[diff] [blame]178<div class="doc_text">
179<ul>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]180<li>foo</li>
Chris Lattner58504a62006-02-05 06:39:36 +0000[diff] [blame]181</ul>
182</div>
John Criswelle531ec52005-06-29 16:22:34 +0000[diff] [blame]183
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]184
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]185<!--=========================================================================-->
186<div class="doc_subsection">
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]187<a name="changes">Significant Changes in LLVM 1.7</a>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]188</div>
189
190<div class="doc_text">
191<ul>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]192<li>The LLVM intrinsics used to be overloaded based on type: for example,
193 <a href="LangRef.html#int_ctpop"><tt>llvm.ctpop</tt></a> could work with any
194 integer datatype. They are now separated into different intrinsics with
195 suffixes to denote their argument type (e.g. <tt>llvm.ctpop.i32</tt>)). Old
196 LLVM .ll and .bc files that use these intrinsics will continue to work with
197 new LLVM versions (they are transparently upgraded by the parsers), but will
198 cause a warning to be emitted.</li>
199<li>The <tt>llvm.readport</tt>, <tt>llvm.writeport</tt>, <tt>llvm.readio</tt>,
200 and <tt>llvm.writeio</tt> intrinsics have been removed. The first two
201 were ever only supported by the X86 backend, the last two were never
202 correctly supported by any target, and none were accessible through the
203 C front-end. Inline assembly support can now be used to
204 implement these operations.</li>
205<li>The <tt>llvm-db</tt> tool had basic support for stepping through code, which
206 used the JIT. This code has been removed, and DWARF emission support added
207 instead. <tt>llvm-db</tt> still exists in CVS if someone wanted to write a
208 <tt>ptrace</tt> backend for it.</li>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]209</ul>
210</div>
211
212
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]213<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]214<div class="doc_section">
215 <a name="portability">Portability and Supported Platforms</a>
216</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]217<!-- *********************************************************************** -->
218
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]219<div class="doc_text">
220
John Criswell0b5b5e92004-12-08 20:35:47 +0000[diff] [blame]221<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]222
223<ul>
Reid Spencer00812e22005-05-17 02:47:27 +0000[diff] [blame]224 <li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
225 (and probably other unix-like systems).</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]226<li>Sun UltraSPARC workstations running Solaris 8.</li>
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]227<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
228 support is available for native builds with Visual C++).</li>
Chris Lattnerfeaf9602005-10-29 05:14:01 +0000[diff] [blame]229<li>PowerPC and X86-based Mac OS X systems, running 10.2 and above.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000[diff] [blame]230<li>Alpha-based machines running Debian GNU/Linux.</li>
231<li>Itanium-based machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]232</ul>
233
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]234<p>The core LLVM infrastructure uses
235<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
236to the machine and operating system on which it is built. However, minor
237porting may be required to get LLVM to work on new platforms. We welcome your
238portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]239
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]240</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]241
242<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]243<div class="doc_section">
244 <a name="knownproblems">Known Problems</a>
245</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]246<!-- *********************************************************************** -->
247
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]248<div class="doc_text">
249
250<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]251component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]252sections. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]253href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]254there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]255
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]256</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]257
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]258<!-- ======================================================================= -->
259<div class="doc_subsection">
260 <a name="experimental">Experimental features included with this release</a>
261</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]262
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]263<div class="doc_text">
264
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]265<p>The following components of this LLVM release are either untested, known to
266be broken or unreliable, or are in early development. These components should
267not be relied on, and bugs should not be filed against them, but they may be
268useful to some people. In particular, if you would like to work on one of these
269components, please contact us on the llvmdev list.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]270
271<ul>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]272<li>The <tt>-cee</tt> pass is known to be buggy, and may be removed in in a
273 future release.</li>
Chris Lattner58504a62006-02-05 06:39:36 +0000[diff] [blame]274<li>The IA64 code generator is experimental.</li>
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]275<li>The Alpha JIT is experimental.</li>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]276<li>"<tt>-filetype=asm</tt>" (the default) is the only supported value for the
277 <tt>-filetype</tt> llc option.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]278</ul>
279
280</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]281
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]282<!-- ======================================================================= -->
283<div class="doc_subsection">
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]284 <a name="build">Known problems with the Build System</a>
285</div>
286
287<div class="doc_text">
288
289<ul>
290 <li>The <a href="http://llvm.org/PR656">configure script sometimes fails on Solaris/Sparc</a>. A work around is documented in <a href="http://llvm.org/PR656">PR656.</a></li>
291</ul>
292</div>
293
294
295<!-- ======================================================================= -->
296<div class="doc_subsection">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]297 <a name="core">Known problems with the LLVM Core</a>
298</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]299
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]300<div class="doc_text">
301
302<ul>
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]303 <li>In the JIT, <tt>dlsym()</tt> on a symbol compiled by the JIT will not
304 work.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]305</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]306</div>
307
308<!-- ======================================================================= -->
309<div class="doc_subsection">
310 <a name="c-fe">Known problems with the C front-end</a>
311</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]312
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]313<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]314<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]315
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]316<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]317
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]318<p>
319llvm-gcc3 has many significant problems that are fixed by llvm-gcc4. See
320 those blocked on the <a href="http://llvm.org/PR498">llvm-gcc4 meta bug</a>.
321Two signicant ones include:</p>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]322
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]323<ul>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]324<li>With llvm-gcc3,
325 C99 variable sized arrays do not release stack memory when they go out of
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]326 scope. Thus, the following program may run out of stack space:
327<pre>
328 for (i = 0; i != 1000000; ++i) {
329 int X[n];
330 foo(X);
331 }
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]332</pre></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]333
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]334<li>With llvm-gcc3, Initialization of global union variables can only be done <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]335href="http://llvm.org/PR162">with the largest union member</a>.</li>
Chris Lattnerf580cdc2004-03-16 21:39:04 +0000[diff] [blame]336
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]337</ul>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]338</div>
339
340<!-- _______________________________________________________________________ -->
341<div class="doc_subsubsection">
342 Notes
343</div>
344
345<div class="doc_text">
346
347<ul>
348
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]349<li>"long double" is transformed by the front-end into "double". There is no
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]350support for floating point data types of any size other than 32 and 64
351bits.</li>
352
353<li>The following Unix system functionality has not been tested and may not
354work:
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]355 <ol>
356 <li><tt>sigsetjmp</tt>, <tt>siglongjmp</tt> - These are not turned into the
357 appropriate <tt>invoke</tt>/<tt>unwind</tt> instructions. Note that
358 <tt>setjmp</tt> and <tt>longjmp</tt> <em>are</em> compiled correctly.
359 <li><tt>getcontext</tt>, <tt>setcontext</tt>, <tt>makecontext</tt>
360 - These functions have not been tested.
361 </ol></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]362
363<li>Although many GCC extensions are supported, some are not. In particular,
364 the following extensions are known to <b>not be</b> supported:
365 <ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]366 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]367 <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>
368 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</li>
369 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended%20Asm">Extended Asm</a>: Assembler instructions with C expressions as operands.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]370 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]371 <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>
372 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Explicit-Reg-Vars.html#Explicit%20Reg%20Vars">Explicit Reg Vars</a>: Defining variables residing in specified registers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]373 <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>
374 <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>
Tanya Lattner014e5f52004-12-08 18:25:34 +0000[diff] [blame]375 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread_002dLocal.html">Thread-Local</a>: Per-thread variables.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]376 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]377 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]378
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]379 <p>The following GCC extensions are <b>partially</b> supported. An ignored
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]380 attribute means that the LLVM compiler ignores the presence of the attribute,
381 but the code should still work. An unsupported attribute is one which is
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]382 ignored by the LLVM compiler and will cause a different interpretation of
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]383 the program.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]384
385 <ol>
386 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
387 Arrays whose length is computed at run time.<br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]388 Supported, but allocated stack space is not freed until the function returns (noted above).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]389
390 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#Function%20Attributes">Function Attributes</a>:
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]391
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]392 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]393 return.<br>
394
395 <b>Supported:</b> <tt>format</tt>, <tt>format_arg</tt>, <tt>non_null</tt>,
John Criswell0b5b5e92004-12-08 20:35:47 +0000[diff] [blame]396 <tt>noreturn</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
Chris Lattneraef8c642005-12-05 05:23:06 +0000[diff] [blame]397 <tt>unused</tt>, <tt>used</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]398 <tt>deprecated</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
399
John Criswell0b5b5e92004-12-08 20:35:47 +0000[diff] [blame]400 <b>Ignored:</b> <tt>noinline</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]401 <tt>always_inline</tt>, <tt>pure</tt>, <tt>const</tt>, <tt>nothrow</tt>,
402 <tt>malloc</tt>, <tt>no_instrument_function</tt>, <tt>cdecl</tt><br>
403
Chris Lattneraef8c642005-12-05 05:23:06 +0000[diff] [blame]404 <b>Unsupported:</b> <tt>section</tt>, <tt>alias</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]405 <tt>visibility</tt>, <tt>regparm</tt>, <tt>stdcall</tt>,
406 <tt>fastcall</tt>, all other target specific attributes</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]407
408 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
409 Specifying attributes of variables.<br>
410 <b>Supported:</b> <tt>cleanup</tt>, <tt>common</tt>, <tt>nocommon</tt>,
411 <tt>deprecated</tt>, <tt>transparent_union</tt>,
Chris Lattneraef8c642005-12-05 05:23:06 +0000[diff] [blame]412 <tt>unused</tt>, <tt>used</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]413
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]414 <b>Unsupported:</b> <tt>aligned</tt>, <tt>mode</tt>, <tt>packed</tt>,
415 <tt>section</tt>, <tt>shared</tt>, <tt>tls_model</tt>,
416 <tt>vector_size</tt>, <tt>dllimport</tt>,
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]417 <tt>dllexport</tt>, all target specific attributes.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]418
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]419 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.<br>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]420 <b>Supported:</b> <tt>transparent_union</tt>, <tt>unused</tt>,
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]421 <tt>deprecated</tt>, <tt>may_alias</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]422
423 <b>Unsupported:</b> <tt>aligned</tt>, <tt>packed</tt>,
424 all target specific attributes.</li>
425
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]426 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
427 Other built-in functions.<br>
428 We support all builtins which have a C language equivalent (e.g.,
429 <tt>__builtin_cos</tt>), <tt>__builtin_alloca</tt>,
430 <tt>__builtin_types_compatible_p</tt>, <tt>__builtin_choose_expr</tt>,
Chris Lattnerceebeb62004-06-18 06:26:29 +0000[diff] [blame]431 <tt>__builtin_constant_p</tt>, and <tt>__builtin_expect</tt>
432 (currently ignored). We also support builtins for ISO C99 floating
Chris Lattner7939b782005-05-07 02:21:21 +0000[diff] [blame]433 point comparison macros (e.g., <tt>__builtin_islessequal</tt>),
434 <tt>__builtin_prefetch</tt>, <tt>__builtin_popcount[ll]</tt>,
435 <tt>__builtin_clz[ll]</tt>, and <tt>__builtin_ctz[ll]</tt>.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]436 </ol>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]437
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]438 <p>The following extensions <b>are</b> known to be supported:</p>
439
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]440 <ol>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]441 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html#Labels%20as%20Values">Labels as Values</a>: Getting pointers to labels and computed gotos.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]442 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
443 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Typeof.html#Typeof">Typeof</a>: <code>typeof</code>: referring to the type of an expression.</li>
Tanya Lattnerca26c3e2004-06-22 03:48:17 +0000[diff] [blame]444 <li><a href="http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/Lvalues.html#Lvalues">Lvalues</a>: Using <code>?:</code>, "<code>,</code>" and casts in lvalues.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]445 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
446 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
447 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
448 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
449 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
450 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
451 <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>
452 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
453 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Subscripting.html#Subscripting">Subscripting</a>: Any array can be subscripted, even if not an lvalue.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]454 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html#Pointer%20Arith">Pointer Arith</a>: Arithmetic on <code>void</code>-pointers and function pointers.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]455 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Initializers.html#Initializers">Initializers</a>: Non-constant initializers.</li>
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]456 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
457or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]458 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html#Designated%20Inits">Designated Inits</a>: Labeling elements of initializers.</li>
Misha Brukmanc4b7bee2003-12-12 04:37:31 +0000[diff] [blame]459 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Cast-to-Union.html#Cast%20to%20Union">Cast to Union</a>: Casting to union type from any member of the union.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]460 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
461 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
462 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Prototypes.html#Function%20Prototypes">Function Prototypes</a>: Prototype declarations and old-style definitions.</li>
Tanya Lattner78537e42004-12-08 18:29:38 +0000[diff] [blame]463 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Comments.html#C_002b_002b-Comments">C++ Comments</a>: C++ comments are recognized.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]464 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
465 <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>
466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
468 <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>
469 <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>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Function-Names.html#Function%20Names">Function Names</a>: Printable strings which are the name of the current function.</li>
Chris Lattner25795bc2004-02-14 04:08:29 +0000[diff] [blame]471 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Return-Address.html#Return%20Address">Return Address</a>: Getting the return or frame address of a function.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]472 <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>
473 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute%20Syntax">Attribute Syntax</a>: Formal syntax for attributes.</li>
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]474 </ol></li>
475
476</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]477
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]478<p>If you run into GCC extensions which have not been included in any of these
479lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]480
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]481</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]482
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]483<!-- ======================================================================= -->
484<div class="doc_subsection">
485 <a name="c++-fe">Known problems with the C++ front-end</a>
486</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]487
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]488<div class="doc_text">
489
Reid Spencere09ca642004-12-07 08:39:08 +0000[diff] [blame]490<p>For this release, the C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]491tested and works for a number of non-trivial programs, including LLVM
492itself.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]493
494</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]495
496<!-- _______________________________________________________________________ -->
Chris Lattner3a51be12004-02-14 04:12:41 +0000[diff] [blame]497<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]498
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]499<div class="doc_text">
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]500
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]501<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]502<li>The C++ front-end inherits all problems afflicting the <a href="#c-fe">C
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]503 front-end</a>.</li>
Chris Lattner7962f712004-07-17 02:04:41 +0000[diff] [blame]504
Chris Lattnerd5713882004-08-02 20:28:44 +0000[diff] [blame]505</ul>
506
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]507</div>
508
509<!-- _______________________________________________________________________ -->
510<div class="doc_subsubsection">
511 Notes
512</div>
513
514<div class="doc_text">
515
516<ul>
Chris Lattnere01fcfb2003-10-27 18:30:37 +0000[diff] [blame]517
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]518<li>Destructors for local objects are not always run when a <tt>longjmp</tt> is
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]519 performed. In particular, destructors for objects in the <tt>longjmp</tt>ing
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]520 function and in the <tt>setjmp</tt> receiver function may not be run.
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]521 Objects in intervening stack frames will be destroyed, however (which is
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]522 better than most compilers).</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]523
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]524<li>The LLVM C++ front-end follows the <a
525 href="http://www.codesourcery.com/cxx-abi">Itanium C++ ABI</a>.
526 This document, which is not Itanium specific, specifies a standard for name
527 mangling, class layout, v-table layout, RTTI formats, and other C++
528 representation issues. Because we use this API, code generated by the LLVM
529 compilers should be binary compatible with machine code generated by other
530 Itanium ABI C++ compilers (such as G++, the Intel and HP compilers, etc).
531 <i>However</i>, the exception handling mechanism used by LLVM is very
532 different from the model used in the Itanium ABI, so <b>exceptions will not
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]533 interact correctly</b>. </li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]534
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]535</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]536
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]537</div>
538
539<!-- ======================================================================= -->
540<div class="doc_subsection">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]541 <a name="c-be">Known problems with the C back-end</a>
542</div>
543
544<div class="doc_text">
545
546<ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
548<li>The C back-end produces code that violates the ANSI C Type-Based Alias
549Analysis rules. As such, special options may be necessary to compile the code
550(for example, GCC requires the <tt>-fno-strict-aliasing</tt> option). This
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]551problem probably cannot be fixed.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]552
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]553<li><a href="http://llvm.org/PR56">Zero arg vararg functions are not
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]554supported</a>. This should not affect LLVM produced by the C or C++
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]555frontends.</li>
Chris Lattner2af46052003-10-24 04:03:19 +0000[diff] [blame]556
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]557<li>The C backend does not correctly implement the <a
558href="LangRef.html#i_stacksave"><tt>llvm.stacksave</tt></a> or
559<a href="LangRef.html#i_stackrestore"><tt>llvm.stackrestore</tt></a>
560intrinsics. This means that some code compiled by it can run out of stack
561space if they depend on these (e.g. C99 varargs).</li>
562
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]563</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]564
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]565</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]566
Andrew Lenharth30a1f8f2005-05-03 16:59:09 +0000[diff] [blame]567<!-- ======================================================================= -->
568<div class="doc_subsection">
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000[diff] [blame]569 <a name="x86-be">Known problems with the X86 back-end</a>
570</div>
571
572<div class="doc_text">
573
574<ul>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]575<li><a href="http://llvm.org/PR736">Indirect calls crash JIT on
576Darwin/x86</a>.</li>
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000[diff] [blame]577</ul>
578
579</div>
580
581<!-- ======================================================================= -->
582<div class="doc_subsection">
583 <a name="ppc-be">Known problems with the PowerPC back-end</a>
584</div>
585
586<div class="doc_text">
587
588<ul>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]589<li><a href="http://llvm.org/PR642">PowerPC backend does not correctly
590implement ordered FP comparisons</a>.</li>
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000[diff] [blame]591</ul>
592
593</div>
594
595<!-- ======================================================================= -->
596<div class="doc_subsection">
Andrew Lenharth30a1f8f2005-05-03 16:59:09 +0000[diff] [blame]597 <a name="alpha-be">Known problems with the Alpha back-end</a>
598</div>
599
600<div class="doc_text">
601
602<ul>
603
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000[diff] [blame]604<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
605appropriate nops inserted to ensure restartability.</li>
Andrew Lenharth30a1f8f2005-05-03 16:59:09 +0000[diff] [blame]606
Andrew Lenharth30a1f8f2005-05-03 16:59:09 +0000[diff] [blame]607</ul>
608
609</div>
610
Duraid Madina2e36d6e2005-05-14 05:48:13 +0000[diff] [blame]611<!-- ======================================================================= -->
612<div class="doc_subsection">
613 <a name="ia64-be">Known problems with the IA64 back-end</a>
614</div>
615
616<div class="doc_text">
617
618<ul>
619
620<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
621made where the argument is not 16-byte aligned, as required on IA64. (Strictly
622speaking this is not a bug in the IA64 back-end; it will also be encountered
623when building C++ programs using the C back-end.)</li>
624
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]625<li>The C++ front-end does not use <a href="http://llvm.org/PR406">IA64
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000[diff] [blame]626ABI compliant layout of v-tables</a>. In particular, it just stores function
627pointers instead of function descriptors in the vtable. This bug prevents
628mixing C++ code compiled with LLVM with C++ objects compiled by other C++
629compilers.</li>
Duraid Madina2e36d6e2005-05-14 05:48:13 +0000[diff] [blame]630
Chris Lattnerf9b1f462005-05-16 17:06:29 +0000[diff] [blame]631<li>There are a few ABI violations which will lead to problems when mixing LLVM
632output with code built with other compilers, particularly for floating-point
633programs.</li>
634
635<li>Defining vararg functions is not supported (but calling them is ok).</li>
Duraid Madina2e36d6e2005-05-14 05:48:13 +0000[diff] [blame]636
637</ul>
638
639</div>
640
Chris Lattner98a493c2005-05-15 16:01:20 +0000[diff] [blame]641<!-- ======================================================================= -->
642<div class="doc_subsection">
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]643 <a name="sparc-be">Known problems with the SPARC back-end</a>
Chris Lattner98a493c2005-05-15 16:01:20 +0000[diff] [blame]644</div>
645
646<div class="doc_text">
647
648<ul>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]649<li>None yet</li>
Chris Lattner98a493c2005-05-15 16:01:20 +0000[diff] [blame]650</ul>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame^]651
652</div>
653
654
655<!-- ======================================================================= -->
656<div class="doc_subsection">
657 <a name="sparcv9-be">Known problems with the SparcV9 back-end</a>
658</div>
659
660<div class="doc_text">
661
662<ul>
663<li><a href="http://llvm.org/PR60">[sparcv9] SparcV9 backend miscompiles
664several programs in the LLVM test suite</a></li>
665<li>The SparcV9 backend is slated to be removed before the LLVM 1.8
666 release.</li>
667</ul>
668
Chris Lattner98a493c2005-05-15 16:01:20 +0000[diff] [blame]669</div>
670
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]671<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]672<div class="doc_section">
673 <a name="additionalinfo">Additional Information</a>
674</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]675<!-- *********************************************************************** -->
676
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]677<div class="doc_text">
678
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]679<p>A wide variety of additional information is available on the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]680href="http://llvm.org">LLVM web page</a>, including <a
681href="http://llvm.org/docs/">documentation</a> and <a
682href="http://llvm.org/pubs/">publications describing algorithms and
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]683components implemented in LLVM</a>. The web page also contains versions of the
684API documentation which is up-to-date with the CVS version of the source code.
685You can access versions of these documents specific to this release by going
686into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]687
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]688<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]689us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]690lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]691
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]692</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]693
694<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]695
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]696<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]697<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]698 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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700 <a href="http://validator.w3.org/check/referer"><img
701 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
702
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]703 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]704 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]705</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]706
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]707</body>
708</html>