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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 791f77b2d4359d619b4fc48814c129e087c48e89 / . / docs / ReleaseNotes.html
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4<head>
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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 Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]315<li>The X86 backend occasionally has <a href="http://llvm.org/PR1649">alignment
316 problems</a> on operating systems that don't require 16-byte stack alignment
317 (including most non-darwin OS's like linux).</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]318<li>The X86 backend generates inefficient floating point code when configured to
319 generate code for systems that don't have SSE2.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]320</ul>
321
322</div>
323
324<!-- ======================================================================= -->
325<div class="doc_subsection">
326 <a name="ppc-be">Known problems with the PowerPC back-end</a>
327</div>
328
329<div class="doc_text">
330
331<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]332<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]333compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]334</ul>
335
336</div>
337
338<!-- ======================================================================= -->
339<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]340 <a name="arm-be">Known problems with the ARM back-end</a>
341</div>
342
343<div class="doc_text">
344
345<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]346<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]347processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]348results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]349<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
350</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]351<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]352programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]353</ul>
354
355</div>
356
357<!-- ======================================================================= -->
358<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]359 <a name="sparc-be">Known problems with the SPARC back-end</a>
360</div>
361
362<div class="doc_text">
363
364<ul>
365<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
366 support the 64-bit SPARC ABI (-m64).</li>
367</ul>
368
369</div>
370
371<!-- ======================================================================= -->
372<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]373 <a name="alpha-be">Known problems with the Alpha back-end</a>
374</div>
375
376<div class="doc_text">
377
378<ul>
379
380<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
381appropriate nops inserted to ensure restartability.</li>
382
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]383</ul>
384</div>
385
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]386<!-- ======================================================================= -->
387<div class="doc_subsection">
388 <a name="ia64-be">Known problems with the IA64 back-end</a>
389</div>
390
391<div class="doc_text">
392
393<ul>
394
395<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
396made where the argument is not 16-byte aligned, as required on IA64. (Strictly
397speaking this is not a bug in the IA64 back-end; it will also be encountered
398when building C++ programs using the C back-end.)</li>
399
400<li>The C++ front-end does not use <a href="http://llvm.org/PR406">IA64
401ABI compliant layout of v-tables</a>. In particular, it just stores function
402pointers instead of function descriptors in the vtable. This bug prevents
403mixing C++ code compiled with LLVM with C++ objects compiled by other C++
404compilers.</li>
405
406<li>There are a few ABI violations which will lead to problems when mixing LLVM
407output with code built with other compilers, particularly for floating-point
408programs.</li>
409
410<li>Defining vararg functions is not supported (but calling them is ok).</li>
411
Chris Lattnercaf06342007-05-09 04:58:11 +0000[diff] [blame]412<li>The Itanium backend has bitrotted somewhat.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]413</ul>
414
415</div>
416
417<!-- ======================================================================= -->
418<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]419 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]420</div>
421
422<div class="doc_text">
423
424<ul>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]425<li><a href="http://llvm.org/PR802">The C backend does not support inline
426 assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]427<li><a href="http://llvm.org/PR1126">The C backend does not support vectors
428 yet</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]429<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
430 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
431 C++ code compiled with LLC or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]432<li>The C backend does not support all exception handling constructs.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]433</ul>
434
435</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]436
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]437
438<!-- ======================================================================= -->
439<div class="doc_subsection">
440 <a name="c-fe">Known problems with the C front-end</a>
441</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]442
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]443<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]444<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]445
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]446<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]447
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]448<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
449Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]450llvmdev mailing list if you are interested.</p>
Chris Lattnerd9ea0172006-08-08 17:27:28 +0000[diff] [blame]451
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]452</div>
453
454<!-- _______________________________________________________________________ -->
455<div class="doc_subsubsection">
456 Notes
457</div>
458
459<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]460<ul>
461
Chris Lattnerd09c4ec2007-05-17 22:02:24 +0000[diff] [blame]462<li><p>llvm-gcc does <b>not</b> support <tt>__builtin_apply</tt> yet.
463 See <a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</p>
464</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]465
Duncan Sands32a83442007-05-18 09:04:20 +0000[diff] [blame]466<li><p>llvm-gcc <b>partially</b> supports these GCC extensions:</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]467 <ol>
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]468 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>:
469
470 As in Algol and Pascal, lexical scoping of functions.
471 Nested functions are supported, but llvm-gcc does not support
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]472 taking the address of a nested function (except on X86 targets)
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]473 or non-local gotos.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]474
475 <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]476
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]477 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]478 return.<br>
479
Anton Korobeynikovbe6fe282007-11-16 11:12:01 +0000[diff] [blame]480 <b>Supported:</b> <tt>alias</tt>, <tt>always_inline</tt>, <tt>cdecl</tt>,
481 <tt>const</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
Anton Korobeynikov9413de32006-11-18 08:04:48 +0000[diff] [blame]482 <tt>deprecated</tt>, <tt>fastcall</tt>, <tt>format</tt>,
Anton Korobeynikovbe6fe282007-11-16 11:12:01 +0000[diff] [blame]483 <tt>format_arg</tt>, <tt>non_null</tt>, <tt>noinline</tt>,
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]484 <tt>noreturn</tt>, <tt>nothrow</tt>, <tt>pure</tt>, <tt>regparm</tt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]485 <tt>section</tt>, <tt>stdcall</tt>, <tt>unused</tt>, <tt>used</tt>,
486 <tt>visibility</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]487
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]488 <b>Ignored:</b> <tt>malloc</tt>,
Anton Korobeynikovbe6fe282007-11-16 11:12:01 +0000[diff] [blame]489 <tt>no_instrument_function</tt></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]490 </ol>
Chris Lattnerd09c4ec2007-05-17 22:02:24 +0000[diff] [blame]491</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]492
Misha Brukmane0c891c2003-11-22 01:00:11 +0000[diff] [blame]493</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]494
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]495<p>If you run into GCC extensions which have not been included in any of these
496lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]497
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]498</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]499
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]500<!-- ======================================================================= -->
501<div class="doc_subsection">
502 <a name="c++-fe">Known problems with the C++ front-end</a>
503</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]504
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]505<div class="doc_text">
506
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]507<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]508tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]509itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]510
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]511<ul>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]512<li>Exception handling only works well on the X86 and PowerPC targets.
513It works well for x86-64 darwin but not x86-64 linux.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]514</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]515
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]516</div>
517
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]518
Chris Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]519<!-- ======================================================================= -->
520<div class="doc_subsection">
521 <a name="ada-fe">Known problems with the Ada front-end</a>
522</div>
523
524<div class="doc_text">
525The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
526technology and problems should be expected.
527<ul>
528<li>The Ada front-end currently only builds on x86-32. This is mainly due
529to lack of trampoline support (pointers to nested functions) on other platforms,
530however it <a href="http://llvm.org/PR2006">also fails to build on x86-64</a>
531which does support trampolines.</li>
532<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
533Workaround: configure with --disable-bootstrap.</li>
534<li>The c380004 and <a href="http://llvm.org/PR2010">c393010</a> ACATS tests
535fail (c380004 also fails with gcc-4.2 mainline).</li>
536<li>Many gcc specific Ada tests continue to crash the compiler.</li>
537<li>The -E binder option (exception backtraces)
538<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
539crashing if an exception is raised. Workaround: do not use -E.</li>
540<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
541or finish at a non-byte offset</a> in a record. Workaround: do not pack records
542or use representation clauses that result in a field of a non-discrete type
543starting or finishing in the middle of a byte.</li>
544<li>The lli interpreter <a href="http://llvm.org/PR2009">considers 'main'
545as generated by the Ada binder to be invalid</a>.
546Workaround: hand edit the file to use pointers for argv and envp rather than
547integers.</li>
548<li>The -fstack-check option <a href="http://llvm.org/PR2008">is ignored</a>.</li>
549</ul>
550</div>
551
552<!-- ======================================================================= -->
553<div class="doc_subsection">
554 <a name="fortran-fe">Known problems with the Fortran front-end</a>
555</div>
556
557<div class="doc_text">
558
559<ul>
560<li>The llvm-gcc 4.2 gfortran front-end supports a broad range of Fortran code, but does
561<a href="http://llvm.org/PR1971">not support EQUIVALENCE yet</a>.</li>
562</ul>
563</div>
564
565
Chris Lattner98a493c2005-05-15 16:01:20 +0000[diff] [blame]566
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]567<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]568<div class="doc_section">
569 <a name="additionalinfo">Additional Information</a>
570</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]571<!-- *********************************************************************** -->
572
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]573<div class="doc_text">
574
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]575<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]576href="http://llvm.org">LLVM web page</a>, in particular in the <a
577href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]578contains versions of the API documentation which is up-to-date with the
579Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]580You can access versions of these documents specific to this release by going
581into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]582
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]583<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]584us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]585lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]586
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]587</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]588
589<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]591<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]592<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]593 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]594 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
595 <a href="http://validator.w3.org/check/referer"><img
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]596 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]597
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]598 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]599 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]600</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]601
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]602</body>
603</html>