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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 000c73bbfed56f5842fde2f54e9116b22629b710 / . / docs / ReleaseNotes.html
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4<head>
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Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]7 <title>LLVM 2.2 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 Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]11<div class="doc_title">LLVM 2.2 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 Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]35infrastructure, release 2.2. 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 Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]61<p>This is the thirteenth public release of the LLVM Compiler Infrastructure.
62It includes many features and refinements from LLVM 2.1.</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 Lattnera5099962003-12-06 20:22:41 +0000[diff] [blame]66<!--=========================================================================-->
Chris Lattner8a458762005-05-15 05:44:51 +0000[diff] [blame]67<div class="doc_subsection">
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]68<a name="frontends">llvm-gcc 4.0, llvm-gcc 4.2, and clang</a>
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame]69</div>
70
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]71<div class="doc_text">
Chris Lattner60893e52007-05-18 06:33:02 +0000[diff] [blame]72
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]73<p>LLVM 2.2 fully supports both the llvm-gcc 4.0 and llvm-gcc 4.2 front-ends (in
74LLVM 2.1, llvm-gcc 4.2 was beta). Since LLVM 2.1, the llvm-gcc 4.2 front-end
75has made leaps and bounds and is now at least as good as 4.0 in virtually every
76area, and is better in several areas (for example, exception handling
77correctness). We strongly recommend that you migrate from llvm-gcc 4.0 to
78llvm-gcc 4.2 in this release cycle because <b>LLVM 2.2 is the last release
79that will support llvm-gcc 4.0</b>: LLVM 2.3 will only support the llvm-gcc
804.2 front-end.</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]81
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]82<p>The <a href="http://clang.llvm.org/">clang project</a> is an effort
83to build a set of new front-end technology for the LLVM optimizer and code
84generator. Currently, its C and Objective-C support is maturing nicely, and it
85has advanced source-to-source analysis and transformation capabilities. If you
86are interested in building source-level tools for C and Objective-C (and
87eventually C++), you should take a look. However, note that clang is not an
88official part of the LLVM 2.2 release. If you are interested in this project,
89please see the web site and check it out from SVN head.</p>
Chris Lattner60893e52007-05-18 06:33:02 +0000[diff] [blame]90
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]91</div>
92
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]93<!--=========================================================================-->
94<div class="doc_subsection">
95<a name="optimizer">Optimizer Improvements</a>
96</div>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]97
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]98<div class="doc_text">
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]99
Chris Lattnerd4298712007-09-26 05:44:21 +0000[diff] [blame]100<p>Some of the most noticable feature improvements this release have been in the
101optimizer, speeding it up and making it more aggressive. For example:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]102
103<ul>
Tanya Lattnerb6ec3a92007-05-16 23:25:46 +0000[diff] [blame]104
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]105<li>.</li>
Tanya Lattnerb6ec3a92007-05-16 23:25:46 +0000[diff] [blame]106
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]107</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]108
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]109</div>
110
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]111<!--=========================================================================-->
112<div class="doc_subsection">
113<a name="codegen">Code Generator Improvements</a>
114</div>
115
116<div class="doc_text">
117
Chris Lattnerd4298712007-09-26 05:44:21 +0000[diff] [blame]118<p>One of the main focuses of this release was performance tuning and bug
119 fixing. In addition to these, several new major changes occurred:</p>
120
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]121<ul>
122
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]123<li>.</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]124
125</ul>
126
127</div>
128
129
130<!--=========================================================================-->
131<div class="doc_subsection">
132<a name="targetspecific">Target Specific Improvements</a>
133</div>
Chris Lattner60893e52007-05-18 06:33:02 +0000[diff] [blame]134
Chris Lattner738bd302006-04-18 06:32:08 +0000[diff] [blame]135<div class="doc_text">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]136<p>New features include:
137</p>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]138
139<ul>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]140<li>.</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]141</ul>
142
143</div>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]144
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]145
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]146<!--=========================================================================-->
147<div class="doc_subsection">
148<a name="llvmgccimprovements">llvm-gcc Improvements</a>
149</div>
Tanya Lattnerb6ec3a92007-05-16 23:25:46 +0000[diff] [blame]150
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]151<div class="doc_text">
152<p>New features include:
153</p>
Tanya Lattnerb6ec3a92007-05-16 23:25:46 +0000[diff] [blame]154
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]155<ul>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]156<li>.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]157</ul>
158
Chris Lattner738bd302006-04-18 06:32:08 +0000[diff] [blame]159</div>
160
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]161
162<!--=========================================================================-->
163<div class="doc_subsection">
164<a name="coreimprovements">LLVM Core Improvements</a>
165</div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]166
Chris Lattner1c1a85c2006-04-19 04:02:47 +0000[diff] [blame]167<div class="doc_text">
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]168<p>New features include:
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]169</p>
170
171<ul>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]172<li>.</li>
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000[diff] [blame]173</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]174
Chris Lattnerbfb17ab2007-05-17 21:41:31 +0000[diff] [blame]175</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]176
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]177<!--=========================================================================-->
178<div class="doc_subsection">
179<a name="otherimprovements">Other Improvements</a>
180</div>
181
182<div class="doc_text">
183<p>New features include:
184</p>
185
186<ul>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]187<li>.</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]188</ul>
189
190</div>
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]191
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]192<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]193<div class="doc_section">
194 <a name="portability">Portability and Supported Platforms</a>
195</div>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]196<!-- *********************************************************************** -->
197
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]198<div class="doc_text">
199
John Criswell0b5b5e92004-12-08 20:35:47 +0000[diff] [blame]200<p>LLVM is known to work on the following platforms:</p>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]201
202<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]203<li>Intel and AMD machines running Red Hat Linux, Fedora Core and FreeBSD
Reid Spencer00812e22005-05-17 02:47:27 +0000[diff] [blame]204 (and probably other unix-like systems).</li>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]205<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]206 64-bit modes.</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]207<li>Intel and AMD machines running on Win32 using MinGW libraries (native)</li>
208<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
209 support is available for native builds with Visual C++).</li>
210<li>Sun UltraSPARC workstations running Solaris 8.</li>
John Criswell9321fa82005-05-13 20:28:15 +0000[diff] [blame]211<li>Alpha-based machines running Debian GNU/Linux.</li>
212<li>Itanium-based machines running Linux and HP-UX.</li>
Chris Lattner4654bdb2004-06-01 18:22:41 +0000[diff] [blame]213</ul>
214
Brian Gaekeb0fd7612004-05-09 05:28:35 +0000[diff] [blame]215<p>The core LLVM infrastructure uses
216<a href="http://www.gnu.org/software/autoconf/">GNU autoconf</a> to adapt itself
217to the machine and operating system on which it is built. However, minor
218porting may be required to get LLVM to work on new platforms. We welcome your
219portability patches and reports of successful builds or error messages.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]220
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]221</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]222
223<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]224<div class="doc_section">
225 <a name="knownproblems">Known Problems</a>
226</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]227<!-- *********************************************************************** -->
228
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]229<div class="doc_text">
230
231<p>This section contains all known problems with the LLVM system, listed by
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]232component. As new problems are discovered, they will be added to these
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]233sections. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]234href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]235there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]236
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]237</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]238
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]239<!-- ======================================================================= -->
240<div class="doc_subsection">
241 <a name="experimental">Experimental features included with this release</a>
242</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]243
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]244<div class="doc_text">
245
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]246<p>The following components of this LLVM release are either untested, known to
247be broken or unreliable, or are in early development. These components should
248not be relied on, and bugs should not be filed against them, but they may be
249useful to some people. In particular, if you would like to work on one of these
Chris Lattner49e693e2006-08-09 04:08:52 +0000[diff] [blame]250components, please contact us on the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]251
252<ul>
Bill Wendlingee143ad2007-09-25 20:45:10 +0000[diff] [blame]253<li>The <tt>-cee</tt> pass is known to be buggy, and may be removed in a
Chris Lattner44c933e2006-04-18 06:18:36 +0000[diff] [blame]254 future release.</li>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]255<li>The MSIL, IA64, Alpha, and MIPS backends are experimental.</li>
256<li>The LLC "<tt>-filetype=asm</tt>" (the default) is the only supported
257 value for this option.</li>
258<li>The llvmc tool is not supported.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]259</ul>
260
261</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]262
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]263<!-- ======================================================================= -->
264<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]265 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]266</div>
267
268<div class="doc_text">
269
270<ul>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]271<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]272 assembly that uses the X86 floating point stack</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]273<li>The X86 backend occasionally has <a href="http://llvm.org/PR1649">alignment
274 problems</a> on operating systems that don't require 16-byte stack alignment
275 (including most non-darwin OS's like linux).</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]276</ul>
277
278</div>
279
280<!-- ======================================================================= -->
281<div class="doc_subsection">
282 <a name="ppc-be">Known problems with the PowerPC back-end</a>
283</div>
284
285<div class="doc_text">
286
287<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]288<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]289compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]290</ul>
291
292</div>
293
294<!-- ======================================================================= -->
295<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]296 <a name="arm-be">Known problems with the ARM back-end</a>
297</div>
298
299<div class="doc_text">
300
301<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]302<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]303processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]304results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]305<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
306</li>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]307<li>There is a bug in QEMU-ARM (<= 0.9.0) which causes it to incorrectly execute
308programs compiled with LLVM. Please use more recent versions of QEMU.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]309</ul>
310
311</div>
312
313<!-- ======================================================================= -->
314<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]315 <a name="sparc-be">Known problems with the SPARC back-end</a>
316</div>
317
318<div class="doc_text">
319
320<ul>
321<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
322 support the 64-bit SPARC ABI (-m64).</li>
323</ul>
324
325</div>
326
327<!-- ======================================================================= -->
328<div class="doc_subsection">
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]329 <a name="alpha-be">Known problems with the Alpha back-end</a>
330</div>
331
332<div class="doc_text">
333
334<ul>
335
336<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
337appropriate nops inserted to ensure restartability.</li>
338
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]339</ul>
340</div>
341
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]342<!-- ======================================================================= -->
343<div class="doc_subsection">
344 <a name="ia64-be">Known problems with the IA64 back-end</a>
345</div>
346
347<div class="doc_text">
348
349<ul>
350
351<li>C++ programs are likely to fail on IA64, as calls to <tt>setjmp</tt> are
352made where the argument is not 16-byte aligned, as required on IA64. (Strictly
353speaking this is not a bug in the IA64 back-end; it will also be encountered
354when building C++ programs using the C back-end.)</li>
355
356<li>The C++ front-end does not use <a href="http://llvm.org/PR406">IA64
357ABI compliant layout of v-tables</a>. In particular, it just stores function
358pointers instead of function descriptors in the vtable. This bug prevents
359mixing C++ code compiled with LLVM with C++ objects compiled by other C++
360compilers.</li>
361
362<li>There are a few ABI violations which will lead to problems when mixing LLVM
363output with code built with other compilers, particularly for floating-point
364programs.</li>
365
366<li>Defining vararg functions is not supported (but calling them is ok).</li>
367
Chris Lattnercaf06342007-05-09 04:58:11 +0000[diff] [blame]368<li>The Itanium backend has bitrotted somewhat.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]369</ul>
370
371</div>
372
373<!-- ======================================================================= -->
374<div class="doc_subsection">
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]375 <a name="c-be">Known problems with the C back-end</a>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]376</div>
377
378<div class="doc_text">
379
380<ul>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]381<li><a href="http://llvm.org/PR802">The C backend does not support inline
382 assembly code</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]383<li><a href="http://llvm.org/PR1126">The C backend does not support vectors
384 yet</a>.</li>
Chris Lattner725a0d82007-09-26 06:01:35 +0000[diff] [blame]385<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
386 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
387 C++ code compiled with LLC or native compilers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]388</ul>
389
390</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]391
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]392
393<!-- ======================================================================= -->
394<div class="doc_subsection">
395 <a name="c-fe">Known problems with the C front-end</a>
396</div>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]397
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]398<!-- _______________________________________________________________________ -->
Chris Lattnerb40efb32003-12-14 05:03:43 +0000[diff] [blame]399<div class="doc_subsubsection">Bugs</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]400
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]401<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]402
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]403<p>llvm-gcc4 does not currently support <a href="http://llvm.org/PR869">Link-Time
404Optimization</a> on most platforms "out-of-the-box". Please inquire on the
405llvmdev mailing list if you are interested.</p>
Chris Lattnerd9ea0172006-08-08 17:27:28 +0000[diff] [blame]406
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]407</div>
408
409<!-- _______________________________________________________________________ -->
410<div class="doc_subsubsection">
411 Notes
412</div>
413
414<div class="doc_text">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]415<ul>
416
Chris Lattnerd09c4ec2007-05-17 22:02:24 +0000[diff] [blame]417<li><p>llvm-gcc does <b>not</b> support <tt>__builtin_apply</tt> yet.
418 See <a href="http://gcc.gnu.org/onlinedocs/gcc/Constructing-Calls.html#Constructing%20Calls">Constructing Calls</a>: Dispatching a call to another function.</p>
419</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]420
Duncan Sands32a83442007-05-18 09:04:20 +0000[diff] [blame]421<li><p>llvm-gcc <b>partially</b> supports these GCC extensions:</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]422 <ol>
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]423 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html#Nested%20Functions">Nested Functions</a>:
424
425 As in Algol and Pascal, lexical scoping of functions.
426 Nested functions are supported, but llvm-gcc does not support
Duncan Sands0869f4a2007-09-26 16:24:52 +0000[diff] [blame]427 taking the address of a nested function (except on the X86-32 target)
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]428 or non-local gotos.</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]429
430 <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]431
John Criswelld000e1d2003-12-18 16:43:17 +0000[diff] [blame]432 Declaring that functions have no side effects or that they can never
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]433 return.<br>
434
Anton Korobeynikovbe6fe282007-11-16 11:12:01 +0000[diff] [blame]435 <b>Supported:</b> <tt>alias</tt>, <tt>always_inline</tt>, <tt>cdecl</tt>,
436 <tt>const</tt>, <tt>constructor</tt>, <tt>destructor</tt>,
Anton Korobeynikov9413de32006-11-18 08:04:48 +0000[diff] [blame]437 <tt>deprecated</tt>, <tt>fastcall</tt>, <tt>format</tt>,
Anton Korobeynikovbe6fe282007-11-16 11:12:01 +0000[diff] [blame]438 <tt>format_arg</tt>, <tt>non_null</tt>, <tt>noinline</tt>,
439 <tt>noreturn</tt>, <tt>pure</tt>, <tt>regparm</tt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]440 <tt>section</tt>, <tt>stdcall</tt>, <tt>unused</tt>, <tt>used</tt>,
441 <tt>visibility</tt>, <tt>warn_unused_result</tt>, <tt>weak</tt><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]442
Anton Korobeynikovbe6fe282007-11-16 11:12:01 +0000[diff] [blame]443 <b>Ignored:</b> <tt>nothrow</tt>, <tt>malloc</tt>,
444 <tt>no_instrument_function</tt></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]445 </ol>
Chris Lattnerd09c4ec2007-05-17 22:02:24 +0000[diff] [blame]446</li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]447
Chris Lattnerd09c4ec2007-05-17 22:02:24 +0000[diff] [blame]448<li><p>llvm-gcc supports the vast majority of GCC extensions, including:</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]449
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]450 <ol>
Chris Lattnerd09c4ec2007-05-17 22:02:24 +0000[diff] [blame]451 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Pragmas.html#Pragmas">Pragmas</a>: Pragmas accepted by GCC.</li>
452 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Local-Labels.html#Local%20Labels">Local Labels</a>: Labels local to a block.</li>
453 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#Other%20Builtins">Other Builtins</a>:
454 Other built-in functions.</li>
455 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html#Variable%20Attributes">Variable Attributes</a>:
456 Specifying attributes of variables.</li>
457 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html#Type%20Attributes">Type Attributes</a>: Specifying attributes of types.</li>
458 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Thread_002dLocal.html">Thread-Local</a>: Per-thread variables.</li>
459 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html#Variable%20Length">Variable Length</a>:
460 Arrays whose length is computed at run time.</li>
Chris Lattner7fe97dd2004-03-16 08:54:07 +0000[diff] [blame]461 <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]462 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement%20Exprs">Statement Exprs</a>: Putting statements and declarations inside expressions.</li>
463 <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]464 <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]465 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Conditionals.html#Conditionals">Conditionals</a>: Omitting the middle operand of a <code>?:</code> expression.</li>
466 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Long-Long.html#Long%20Long">Long Long</a>: Double-word integers.</li>
467 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Complex.html#Complex">Complex</a>: Data types for complex numbers.</li>
468 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Hex-Floats.html#Hex%20Floats">Hex Floats</a>:Hexadecimal floating-point constants.</li>
469 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html#Zero%20Length">Zero Length</a>: Zero-length arrays.</li>
470 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html#Empty%20Structures">Empty Structures</a>: Structures with no members.</li>
471 <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>
472 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Escaped-Newlines.html#Escaped%20Newlines">Escaped Newlines</a>: Slightly looser rules for escaped newlines.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]473 <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>
474 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Constraints.html#Constraints">Constraints</a>: Constraints for asm operands.</li>
475 <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>
476 <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>
477 <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>
478 <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>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]479 <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]480 <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]481 <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]482 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Compound-Literals.html#Compound%20Literals">Compound Literals</a>: Compound literals give structures, unions,
483or arrays as values.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]484 <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]485 <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]486 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Case-Ranges.html#Case%20Ranges">Case Ranges</a>: `case 1 ... 9' and such.</li>
487 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Mixed-Declarations.html#Mixed%20Declarations">Mixed Declarations</a>: Mixing declarations and code.</li>
488 <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]489 <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]490 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Dollar-Signs.html#Dollar%20Signs">Dollar Signs</a>: Dollar sign is allowed in identifiers.</li>
491 <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>
492 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Alignment.html#Alignment">Alignment</a>: Inquiring about the alignment of a type or variable.</li>
493 <li><a href="http://gcc.gnu.org/onlinedocs/gcc/Inline.html#Inline">Inline</a>: Defining inline functions (as fast as macros).</li>
494 <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>
495 <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>
496 <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]497 <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]498 <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>
499 <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]500 </ol></li>
501
502</ul>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]503
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]504<p>If you run into GCC extensions which have not been included in any of these
505lists, please let us know (also including whether or not they work).</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]506
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]507</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]508
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]509<!-- ======================================================================= -->
510<div class="doc_subsection">
511 <a name="c++-fe">Known problems with the C++ front-end</a>
512</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]513
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]514<div class="doc_text">
515
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]516<p>The C++ front-end is considered to be fully
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]517tested and works for a number of non-trivial programs, including LLVM
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]518itself, Qt, Mozilla, etc.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]519
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]520<ul>
Chris Lattner000c73b2008-02-06 06:30:34 +0000[diff] [blame^]521<li>Exception handling only works well on the X86 and PowerPC targets.</li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]522</ul>
Chris Lattnerfcc54b32003-10-07 22:14:37 +0000[diff] [blame]523
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]524</div>
525
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]526
Chris Lattner98a493c2005-05-15 16:01:20 +0000[diff] [blame]527
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]528<!-- *********************************************************************** -->
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]529<div class="doc_section">
530 <a name="additionalinfo">Additional Information</a>
531</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]532<!-- *********************************************************************** -->
533
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]534<div class="doc_text">
535
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]536<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]537href="http://llvm.org">LLVM web page</a>, in particular in the <a
538href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencer669ed452007-07-09 08:04:31 +0000[diff] [blame]539contains versions of the API documentation which is up-to-date with the
540Subversion version of the source code.
Misha Brukman109d9e82005-03-30 19:14:24 +0000[diff] [blame]541You can access versions of these documents specific to this release by going
542into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]543
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]544<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]545us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]546lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]547
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]548</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]549
550<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]551
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]552<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]553<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]554 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]555 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
556 <a href="http://validator.w3.org/check/referer"><img
557 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
558
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]559 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]560 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]561</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]562
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]563</body>
564</html>