Gitiles
Code Review Sign In
gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 5733b2743c828f0efd52c30d55dbeb63330797dd / . / docs / ReleaseNotes.html
blob: 6b4bc451e1738e5e0c5750496c029b563eb28f8e [file] [log] [blame]
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 Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]7 <title>LLVM 2.3 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 Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]11<div class="doc_title">LLVM 2.3 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 Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]35infrastructure, release 2.3. Here we describe the status of LLVM, including
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]36major improvements from the previous release and any known problems. All LLVM
Chris Lattnercaf06342007-05-09 04:58:11 +0000[diff] [blame]37releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]38releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]39
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]40<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]41release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]42web site</a>. If you have questions or comments, the <a
43href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]44list</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]45
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]46<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]47main LLVM web page, this document applies to the <i>next</i> release, not the
48current one. To see the release notes for a specific releases, please see the
49<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]50
51</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]52
53<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]54<div class="doc_section">
55 <a name="whatsnew">What's New?</a>
56</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]57<!-- *********************************************************************** -->
58
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]59<div class="doc_text">
60
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]61<p>This is the fourteenth public release of the LLVM Compiler Infrastructure.
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]62It includes a large number of features and refinements from LLVM 2.2.</p>
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]63
Chris Lattner80453c92004-05-24 04:50:25 +0000[diff] [blame]64</div>
65
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]66<!-- Unfinished features in 2.3:
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]67 Index Set Splitting not enabled by default
68 Machine LICM
69 Machine Sinking
70 LegalizeDAGTypes
71 -->
72
Chris Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]73<!--=========================================================================-->
Chris Lattner8a458762005-05-15 05:44:51 +0000[diff] [blame]74<div class="doc_subsection">
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]75<a name="deprecation">Removed features in LLVM 2.3</a>
Chris Lattnerb4c68cd2008-02-10 07:04:35 +0000[diff] [blame]76</div>
77
78<div class="doc_text">
79
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]80<p>LLVM 2.2 was the last LLVM release to support llvm-gcc 4.0 and llvm-upgrade.
81llvm-gcc 4.0 has been replaced with llvm-gcc 4.2. llvm-upgrade was useful for
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]82upgrading LLVM 1.9 files to LLVM 2.x syntax, but you can always use a previous
83LLVM release to do this. One nice impact of this is that the LLVM regressionn
84test suite no longer depends on llvm-upgrade, which makes it run faster.</p>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]85
86</div>
87
88<!--=========================================================================-->
89<div class="doc_subsection">
90<a name="majorfeatures">Major New Features</a>
91</div>
92
93<div class="doc_text">
94
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]95<p>LLVM 2.3 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]96
97<ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]98<li>Multiple Return Value Support</li>
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]99</ul>
100
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]101</div>
102
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]103
104<!--=========================================================================-->
105<div class="doc_subsection">
106<a name="frontends">llvm-gcc 4.2 Improvements and Clang</a>
107</div>
108
109<div class="doc_text">
110
111<p>LLVM 2.3 fully supports llvm-gcc 4.2 front-end.</p>
112
113<p>llvm-gcc 4.2 includes numerous fixes to better support the Objective-C
114front-end. Objective-C now works very well on Mac OS/X.</p>
115
116<p>llvm-gcc 4.2 includes many other fixes which improve conformance with the
117relevant parts of the GCC testsuite.</p>
118
119<p>The <a href="http://clang.llvm.org/">clang project</a> is an effort to build
120a set of new 'llvm native' front-end technologies for the LLVM optimizer
121and code generator. Currently, its C and Objective-C support is maturing
122nicely, and it has advanced source-to-source analysis and transformation
123capabilities. If you are interested in building source-level tools for C and
124Objective-C (and eventually C++), you should take a look. However, note that
125clang is not an official part of the LLVM 2.3 release. If you are interested in
126this project, please see its <a href="http://clang.llvm.org/">web site</a>.</p>
127
128</div>
129
130
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]131<!--=========================================================================-->
132<div class="doc_subsection">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]133<a name="coreimprovements">LLVM Core Improvements</a>
134</div>
135
136<div class="doc_text">
137<p>New features include:
138</p>
139
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]140
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]141Common linkage?
142
143Atomic operation support, Alpha, X86, PowerPC. "__sync_syncronize"
144
145<ul>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]146</ul>
147
148</div>
149
150<!--=========================================================================-->
151<div class="doc_subsection">
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]152<a name="codegen">Code Generator Improvements</a>
153</div>
154
155<div class="doc_text">
156
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]157<p>We put a significant amount of work into the code generator infrastructure,
158which allows us to implement more aggressive algorithms and make it run
159faster:</p>
Chris Lattnerd4298712007-09-26 05:44:21 +0000[diff] [blame]160
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]161<ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]162<li>MemOperand in the code generator: describe me!.</li>
163<li>i128 support and APInt through most of codegen.</li>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]164</ul>
165
166</div>
167
168<!--=========================================================================-->
169<div class="doc_subsection">
170<a name="optimizer">Optimizer Improvements</a>
171</div>
172
173<div class="doc_text">
174
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]175<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]176LLVM 2.3 optimizers support a few major enhancements:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]177
178<ul>
179
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]180<li>Loop index set splitting on by default: describe me.</li>
181<li>LLVM includes a new memcpy optimization pass which optimizes out dead
182memcpy calls and unneeded copies of aggregates.</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]183</ul>
184
185</div>
186
187
188<!--=========================================================================-->
189<div class="doc_subsection">
190<a name="targetspecific">Target Specific Improvements</a>
191</div>
Chris Lattner60893e52007-05-18 06:33:02 +0000[diff] [blame]192
Chris Lattner738bd302006-04-18 06:32:08 +0000[diff] [blame]193<div class="doc_text">
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]194<p>New target-specific features include:
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]195</p>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]196
197<ul>
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]198<li>llvm-gcc's X86-64 ABI conformance is far improved, particularly in the
199 area of passing and returning structures by value. llvm-gcc Compiled code
200 now interoperates very well on X86-64 systems with other compilers.</li>
201
202<li>The LLVM X86 backend now supports the support SSE 4.1 instruction set, and
203 the llvm-gcc 4.2 front-end supports the SSE 4.1 compiler builtins.</li>
204
205<li>The X86 backend now does a number of optimizations that aim to avoid
206 converting numbers back and forth from SSE registers to the X87 floating
207 point stack.</li>
208
209<li>The X86 backend now supports the "sseregparm" options in GCC, which allow
210 functions to be tagged as passing floating point values in SSE
211 registers.</li>
212
213<li>Trampolines (taking the address of a nested function) now work on
214 Linux/x86-64.</li>
215
216
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000[diff] [blame]217</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]218
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000[diff] [blame]219</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]220
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]221<!--=========================================================================-->
222<div class="doc_subsection">
223<a name="otherimprovements">Other Improvements</a>
224</div>
225
226<div class="doc_text">
227<p>New features include:
228</p>
229
230<ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]231</ul>
232
233</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]234
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]235<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]236<div class="doc_section">
237 <a name="portability">Portability and Supported Platforms</a>
238</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]239<!-- *********************************************************************** -->
240
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]241<div class="doc_text">
242
John Criswell0b5b5e92004-12-08 20:35:47 +0000[diff] [blame]243<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]244
245<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]246<li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
Reid Spencer00812e22005-05-17 02:47:27 +0000[diff] [blame]247 (and probably other unix-like systems).</li>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame]248<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]249 64-bit modes.</li>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]250<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]251<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
252 support is available for native builds with Visual C++).</li>
253<li>Sun UltraSPARC workstations running Solaris 8.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000[diff] [blame]254<li>Alpha-based machines running Debian GNU/Linux.</li>
255<li>Itanium-based machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]256</ul>
257
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]258<p>The core LLVM infrastructure uses
259<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
260to the machine and operating system on which it is built. However, minor
261porting may be required to get LLVM to work on new platforms. We welcome your
262portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]263
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]264</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]265
266<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]267<div class="doc_section">
268 <a name="knownproblems">Known Problems</a>
269</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]270<!-- *********************************************************************** -->
271
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]272<div class="doc_text">
273
274<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]275component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]276sections. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]277href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]278there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]279
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]280</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]281
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]282<!-- ======================================================================= -->
283<div class="doc_subsection">
284 <a name="experimental">Experimental features included with this release</a>
285</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]286
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]287<div class="doc_text">
288
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]289<p>The following components of this LLVM release are either untested, known to
290be broken or unreliable, or are in early development. These components should
291not be relied on, and bugs should not be filed against them, but they may be
292useful to some people. In particular, if you would like to work on one of these
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]293components, please contact us on the <a
294href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]295
296<ul>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]297<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame]298<li>The LLC "<tt>-filetype=asm</tt>" (the default) is the only supported
299 value for this option.</li>
300<li>The llvmc tool is not supported.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]301</ul>
302
303</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]304
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]305<!-- ======================================================================= -->
306<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]307 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]308</div>
309
310<div class="doc_text">
311
312<ul>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]313<li>The X86 backend does not yet support <a href="http://llvm.org/PR879">inline
Chris Lattnercaf06342007-05-09 04:58:11 +0000[diff] [blame]314 assembly that uses the X86 floating point stack</a>.</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]315<li>The X86 backend generates inefficient floating point code when configured to
316 generate code for systems that don't have SSE2.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]317</ul>
318
319</div>
320
321<!-- ======================================================================= -->
322<div class="doc_subsection">
323 <a name="ppc-be">Known problems with the PowerPC back-end</a>
324</div>
325
326<div class="doc_text">
327
328<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]329<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]330compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]331</ul>
332
333</div>
334
335<!-- ======================================================================= -->
336<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]337 <a name="arm-be">Known problems with the ARM back-end</a>
338</div>
339
340<div class="doc_text">
341
342<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]343<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]344processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]345results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]346<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
347</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]348<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly execute
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]349programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]350</ul>
351
352</div>
353
354<!-- ======================================================================= -->
355<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]356 <a name="sparc-be">Known problems with the SPARC back-end</a>
357</div>
358
359<div class="doc_text">
360
361<ul>
362<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
363 support the 64-bit SPARC ABI (-m64).</li>
364</ul>
365
366</div>
367
368<!-- ======================================================================= -->
369<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]370 <a name="alpha-be">Known problems with the Alpha back-end</a>
371</div>
372
373<div class="doc_text">
374
375<ul>
376
377<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
378appropriate nops inserted to ensure restartability.</li>
379
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]380</ul>
381</div>
382
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]383<!-- ======================================================================= -->
384<div class="doc_subsection">
385 <a name="ia64-be">Known problems with the IA64 back-end</a>
386</div>
387
388<div class="doc_text">
389
390<ul>
391
392<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
393made where the argument is not 16-byte aligned, as required on IA64. (Strictly
394speaking this is not a bug in the IA64 back-end; it will also be encountered
395when building C++ programs using the C back-end.)</li>
396
397<li>The C++ front-end does not use <a href="http://llvm.org/PR406">IA64
398ABI compliant layout of v-tables</a>. In particular, it just stores function
399pointers instead of function descriptors in the vtable. This bug prevents
400mixing C++ code compiled with LLVM with C++ objects compiled by other C++
401compilers.</li>
402
403<li>There are a few ABI violations which will lead to problems when mixing LLVM
404output with code built with other compilers, particularly for floating-point
405programs.</li>
406
407<li>Defining vararg functions is not supported (but calling them is ok).</li>
408
Chris Lattnercaf06342007-05-09 04:58:11 +0000[diff] [blame]409<li>The Itanium backend has bitrotted somewhat.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]410</ul>
411
412</div>
413
414<!-- ======================================================================= -->
415<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]416 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]417</div>
418
419<div class="doc_text">
420
421<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame^]422<li><a href="http://llvm.org/PR802">The C backend has only basic support for
423 inline assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]424<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
425 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
426 C++ code compiled with LLC or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]427<li>The C backend does not support all exception handling constructs.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]428</ul>
429
430</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]431
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]432
433<!-- ======================================================================= -->
434<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame^]435 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]436</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]437
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]438<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]439<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]440
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]441<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]442
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]443<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
444Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]445llvmdev mailing list if you are interested.</p>
Chris Lattnerd9ea0172006-08-08 17:27:28 +0000[diff] [blame]446
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame^]447<p>The only major language feature of GCC not supported by llvm-gcc is
448 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
449 are only supported on some targets. For example, trampolines are only
450 supported on some targets, which are used when you take the address of a
451 nested function.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]452
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame^]453<p>If you run into GCC extensions which are not supported, please let us know.
454</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]455
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]456</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]457
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]458<!-- ======================================================================= -->
459<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame^]460 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]461</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]462
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]463<div class="doc_text">
464
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]465<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]466tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]467itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]468
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]469<ul>
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame^]470<li>Exception handling works well on the X86 and PowerPC targets, including
471x86-64 darwin. This works when linking to a libstdc++ compiled by GCC. It is
472supported on x86-64 linux, but that is disabled by default in this release.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]473</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]474
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]475</div>
476
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]477
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]478<!-- ======================================================================= -->
479<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame^]480 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]481</div>
482
483<div class="doc_text">
484The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
485technology and problems should be expected.
486<ul>
487<li>The Ada front-end currently only builds on x86-32. This is mainly due
488to lack of trampoline support (pointers to nested functions) on other platforms,
489however it <a href="http://llvm.org/PR2006">also fails to build on x86-64</a>
490which does support trampolines.</li>
491<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
492Workaround: configure with --disable-bootstrap.</li>
493<li>The c380004 and <a href="http://llvm.org/PR2010">c393010</a> ACATS tests
494fail (c380004 also fails with gcc-4.2 mainline).</li>
495<li>Many gcc specific Ada tests continue to crash the compiler.</li>
496<li>The -E binder option (exception backtraces)
497<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
498crashing if an exception is raised. Workaround: do not use -E.</li>
499<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
500or finish at a non-byte offset</a> in a record. Workaround: do not pack records
501or use representation clauses that result in a field of a non-discrete type
502starting or finishing in the middle of a byte.</li>
503<li>The lli interpreter <a href="http://llvm.org/PR2009">considers 'main'
504as generated by the Ada binder to be invalid</a>.
505Workaround: hand edit the file to use pointers for argv and envp rather than
506integers.</li>
507<li>The -fstack-check option <a href="http://llvm.org/PR2008">is ignored</a>.</li>
508</ul>
509</div>
510
511<!-- ======================================================================= -->
512<div class="doc_subsection">
Chris Lattner5733b272008-06-05 06:35:40 +0000[diff] [blame^]513 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]514</div>
515
516<div class="doc_text">
517
518<ul>
519<li>The llvm-gcc 4.2 gfortran front-end supports a broad range of Fortran code, but does
520<a href="http://llvm.org/PR1971">not support EQUIVALENCE yet</a>.</li>
521</ul>
522</div>
523
524
Chris Lattner98a493c2005-05-15 16:01:20 +0000[diff] [blame]525
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]526<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]527<div class="doc_section">
528 <a name="additionalinfo">Additional Information</a>
529</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]530<!-- *********************************************************************** -->
531
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]532<div class="doc_text">
533
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]534<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]535href="http://llvm.org">LLVM web page</a>, in particular in the <a
536href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]537contains versions of the API documentation which is up-to-date with the
538Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]539You can access versions of these documents specific to this release by going
540into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]541
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]542<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]543us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]544lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]545
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]546</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
548<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]549
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]550<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]551<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]552 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]553 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
554 <a href="http://validator.w3.org/check/referer"><img
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]555 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]556
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]557 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]558 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]559</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]560
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]561</body>
562</html>