Gitiles
Code Review Sign In
gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 0e49cc82637ed65a42e006a36bf736dcc1108353 / . / docs / ReleaseNotes.html
blob: 2f40e47d7566c56e56c6d84082efdcc62e18215a [file] [log] [blame]
Anton Korobeynikov877b73b2008-06-08 10:23:46 +0000[diff] [blame]1
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
3 "http://www.w3.org/TR/html4/strict.dtd">
4<html>
5<head>
6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]8 <title>LLVM 2.3 Release Notes</title>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]9</head>
10<body>
11
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]12<div class="doc_title">LLVM 2.3 Release Notes</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]13
14<ol>
15 <li><a href="#intro">Introduction</a></li>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]16 <li><a href="#changes">Major Changes and Sub-project Status</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]17 <li><a href="#whatsnew">What's New?</a></li>
18 <li><a href="GettingStarted.html">Installation Instructions</a></li>
19 <li><a href="#portability">Portability and Supported Platforms</a></li>
20 <li><a href="#knownproblems">Known Problems</a>
21 <li><a href="#additionalinfo">Additional Information</a></li>
22</ol>
23
24<div class="doc_author">
25 <p>Written by the <a href="http://llvm.org">LLVM Team</a><p>
26</div>
27
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]28<!-- Done through Week-of-Mon-20080324.txt -->
29
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]30<!-- *********************************************************************** -->
31<div class="doc_section">
32 <a name="intro">Introduction</a>
33</div>
34<!-- *********************************************************************** -->
35
36<div class="doc_text">
37
38<p>This document contains the release notes for the LLVM compiler
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]39infrastructure, release 2.3. Here we describe the status of LLVM, including
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]40major improvements from the previous release and any known problems. All LLVM
41releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM
42releases web site</a>.</p>
43
44<p>For more information about LLVM, including information about the latest
45release, please check out the <a href="http://llvm.org/">main LLVM
46web site</a>. If you have questions or comments, the <a
47href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM developer's mailing
48list</a> is a good place to send them.</p>
49
50<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]51main LLVM web page, this document applies to the <i>next</i> release, not the
52current one. To see the release notes for a specific releases, please see the
53<a href="http://llvm.org/releases/">releases page</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]54
55</div>
56
57<!-- *********************************************************************** -->
58<div class="doc_section">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]59 <a name="changes">Major Changes and Sub-project Status</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]60</div>
61<!-- *********************************************************************** -->
62
63<div class="doc_text">
64
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]65<p>This is the fourteenth public release of the LLVM Compiler Infrastructure.
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]66It includes a large number of features and refinements from LLVM 2.2.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]67
68</div>
69
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]70<!-- Unfinished features in 2.3:
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]71 Machine LICM
72 Machine Sinking
73 LegalizeDAGTypes
74 -->
75
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]76<!--=========================================================================-->
77<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]78<a name="changes">Major Changes in LLVM 2.3</a>
Chris Lattner41bf8e92008-02-10 07:04:35 +0000[diff] [blame]79</div>
80
81<div class="doc_text">
82
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]83<p>LLVM 2.3 no longer supports llvm-gcc 4.0, it has been replaced with
84 llvm-gcc 4.2.</p>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]85
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]86<p>LLVM 2.3 no longer includes the <tt>llvm-upgrade</tt> tool. It was useful
87 for upgrading LLVM 1.9 files to LLVM 2.x syntax, but you can always use a
88 previous LLVM release to do this. One nice impact of this is that the LLVM
89 regression test suite no longer depends on llvm-upgrade, which makes it run
90 faster.</p>
91
92<p>The <tt>llvm2cpp</tt> tool has been folded into llc, use
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]93 <tt>llc -march=cpp</tt> instead of <tt>llvm2cpp</tt>.</p>
94
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]95<p>LLVM API Changes:</p>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]96
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]97<ul>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]98<li>Several core LLVM IR classes have migrated to use the
99 '<tt>FOOCLASS::Create(...)</tt>' pattern instead of '<tt>new
100 FOOCLASS(...)</tt>' (e.g. where FOOCLASS=<tt>BasicBlock</tt>). We hope to
101 standardize on <tt>FOOCLASS::Create</tt> for all IR classes in the future,
102 but not all of them have been moved over yet.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]103<li>LLVM 2.3 renames the LLVMBuilder and LLVMFoldingBuilder classes to
Dan Gohman8f4a6ad2008-06-08 22:57:59 +0000[diff] [blame]104 <a href="http://llvm.org/doxygen/classllvm_1_1IRBuilder.html">IRBuilder</a>.
105 </li>
106<li>MRegisterInfo was renamed to
107 <a href="http://llvm.org/doxygen/classllvm_1_1TargetRegisterInfo.html">
108 TargetRegisterInfo</a>.</li>
109<li>The MappedFile class is gone, please use
110 <a href="http://llvm.org/doxygen/classllvm_1_1MemoryBuffer.html">
111 MemoryBuffer</a> instead.</li>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]112<li>The '<tt>-enable-eh</tt>' flag to llc has been removed. Now code should
113 encode whether it is safe to omit unwind information for a function by
114 tagging the Function object with the '<tt>nounwind</tt>' attribute.</li>
Dan Gohmand0e1c5c2008-06-09 04:36:34 +0000[diff] [blame]115<li>The ConstantFP::get method that uses APFloat now takes one argument
116 instead of two. The type argument has been removed, and the type is
117 now inferred from the size of the given APFloat value.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]118
119</ul>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]120</div>
121
122<!--=========================================================================-->
123<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]124<a name="otherprojects">Other LLVM Sub-Projects</a>
125</div>
126
127<div class="doc_text">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]128<p>
129The core LLVM 2.3 distribution currently consists of code from the core LLVM
130repository (which roughly contains the LLVM optimizer, code generators and
131supporting tools) and the llvm-gcc repository. In addition to this code, the
132LLVM Project includes other sub-projects that are in development. The two which
133are the most actively developed are the new <a href="#vmkit">vmkit Project</a>
134and the <a href="#clang">Clang Project</a>.
135</p>
136</div>
137
138<!--=========================================================================-->
139<div class="doc_subsubsection">
140<a name="vmkit">vmkit</a>
141</div>
142
143<div class="doc_text">
144<p>
145The "vmkit" project is a new addition to the LLVM family. It is an
146implementation of a JVM and a CLI Virtual Machines (Microsoft .NET is an
147implementation of the CLI) using the Just-In-Time compiler of LLVM.</p>
148
149<p>The JVM, called JnJVM, executes real-world applications such as Apache
150projects (e.g. Felix and Tomcat) and the SpecJVM98 benchmark. It uses the GNU
151Classpath project for the base classes. The CLI implementation, called N3, is
152its in early stages but can execute simple applications and the "pnetmark"
153benchmark. It uses the pnetlib project as its core library.</p>
154
155<p>The 'vmkit' VMs compare in performance with industrial and top open-source
156VMs on scientific applications. Besides the JIT, the VMs use many features of
157the LLVM framework, including the standard set of optimizations, atomic
158operations, custom function provider and memory manager for JITed methods, and
159specific virtual machine optimizations. vmkit is not an official part of LLVM
1602.3 release. It is publicly available under the LLVM license and can be
161downloaded from:
162</p>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]163
164<p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]165<tt>svn co http://llvm.org/svn/llvm-project/vmkit/trunk vmkit</tt>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]166</p>
167
168</div>
169
170<!--=========================================================================-->
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]171<div class="doc_subsubsection">
172<a name="clang">Clang</a>
173</div>
174
175<div class="doc_text">
176
177<p>The <a href="http://clang.llvm.org/">Clang project</a> is an effort to build
178a set of new 'LLVM native' front-end technologies for the LLVM optimizer
179and code generator. Clang is continuing to make major strides forward in all
180areas. Its C and Objective-C parsing support is very solid, and the code
181generation support is far enough along to build many C applications. While not
182yet production quality, it is progressing very nicely. In addition, C++
183front-end work has started to make significant progress.</p>
184
185<p>At this point, Clang is most useful if you are interested in source-to-source
186transformations (such as refactoring) and other source-level tools for C and
187Objective-C. Clang now also includes tools for turning C code into pretty HTML,
188and includes a new <a href="http://clang.llvm.org/StaticAnalysis.html">static
Chris Lattnerefd11682008-06-08 23:40:40 +0000[diff] [blame]189analysis tool</a> in development. This tool focuses on automatically finding
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]190bugs in C and Objective-C code.</p>
191
192</div>
193
194
195<!-- *********************************************************************** -->
196<div class="doc_section">
197 <a name="whatsnew">What's New?</a>
198</div>
199<!-- *********************************************************************** -->
200
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]201<div class="doc_text">
202
203<p>LLVM 2.3 includes a huge number of bug fixes, performance tweaks and minor
204improvements. Some of the major improvements and new features are listed in
205this section.
206</p>
207</div>
208
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]209<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]210<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]211<a name="majorfeatures">Major New Features</a>
212</div>
213
214<div class="doc_text">
215
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]216<p>LLVM 2.3 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]217
218<ul>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]219<li><p>The biggest change in LLVM 2.3 is Multiple Return Value (MRV) support.
220 MRVs allow LLVM IR to directly represent functions that return multiple
221 values without having to pass them "by reference" in the LLVM IR. This
222 allows a front-end to generate more efficient code, as MRVs are generally
223 returned in registers if a target supports them. See the <a
224 href="LangRef.html#i_getresult">LLVM IR Reference</a> for more details.</p>
225
226 <p>MRVs are fully supported in the LLVM IR, but are not yet fully supported in
227 on all targets. However, it is generally safe to return up to 2 values from
228 a function: most targets should be able to handle at least that. MRV
229 support is a critical requirement for X86-64 ABI support, as X86-64 requires
230 the ability to return multiple registers from functions, and we use MRVs to
231 accomplish this in a direct way.</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]232
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]233<li><p>LLVM 2.3 includes a complete reimplementation of the "<tt>llvmc</tt>"
234 tool. It is designed to overcome several problems with the original
235 <tt>llvmc</tt> and to provide a superset of the features of the
236 '<tt>gcc</tt>' driver.</p>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]237
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame^]238 <p>The main features of <tt>llvmc2</tt> are:
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]239 <ul>
240 <li>Extended handling of command line options and smart rules for
241 dispatching them to different tools.</li>
242 <li>Flexible (and extensible) rules for defining different tools.</li>
243 <li>The different intermediate steps performed by tools are represented
244 as edges in the abstract graph.</li>
245 <li>The 'language' for driver behavior definition is tablegen and thus
246 it's relatively easy to add new features.</li>
247 <li>The definition of driver is transformed into set of C++ classes, thus
248 no runtime interpretation is needed.</li>
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame^]249 </ul>
250</li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]251
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]252<li><p>LLVM 2.3 includes a completely rewritten interface for <a
253 href="LinkTimeOptimization.html">Link Time Optimization</a>. This interface
254 is written in C, which allows for easier integration with C code bases, and
255 incorporates improvements we learned about from the first incarnation of the
256 interface.</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]257
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]258<li><p>The <a href="tutorial/LangImpl1.html">Kaleidoscope tutorial</a> now
259 includes a "port" of the tutorial that <a
260 href="tutorial/OCamlLangImpl1.html">uses the Ocaml bindings</a> to implement
261 the Kaleidoscope language.</p></li>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]262
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]263</ul>
264
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]265</div>
266
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]267
268<!--=========================================================================-->
269<div class="doc_subsection">
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]270<a name="llvm-gcc">llvm-gcc 4.2 Improvements</a>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]271</div>
272
273<div class="doc_text">
274
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]275<p>LLVM 2.3 fully supports the llvm-gcc 4.2 front-end, and includes support
276for the C, C++, Objective-C, Ada, and Fortran front-ends.</p>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]277
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]278<p>
279<ul>
280<li>llvm-gcc 4.2 includes numerous fixes to better support the Objective-C
281front-end. Objective-C now works very well on Mac OS/X.</li>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]282
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]283<li>Fortran EQUIVALENCEs are now supported by the gfortran front-end.</li>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]284
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]285<li>llvm-gcc 4.2 includes many other fixes which improve conformance with the
286relevant parts of the GCC testsuite.</li>
287
Gabor Greif0e49cc82008-06-09 06:06:18 +0000[diff] [blame^]288</ul>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]289
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]290</div>
291
292
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]293<!--=========================================================================-->
294<div class="doc_subsection">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]295<a name="coreimprovements">LLVM Core Improvements</a>
296</div>
297
298<div class="doc_text">
299<p>New features include:
300</p>
301
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]302<ul>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]303<li>LLVM IR now directly represents "common" linkage, instead of representing it
304as a form of weak linkage.</li>
305
306<li>LLVM IR now has support for atomic operations, and this functionality can
307be accessed through the llvm-gcc "__sync_synchronize",
308"__sync_val_compare_and_swap", and related builtins. Support for atomics are
309available in the Alpha, X86, X86-64, and PowerPC backends.</li>
310
311<li>The C and Ocaml bindings have extended to cover pass managers, several
312transformation passes, iteration over the LLVM IR, target data, and parameter
313attribute lists.</li>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]314</ul>
315
316</div>
317
318<!--=========================================================================-->
319<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]320<a name="optimizer">Optimizer Improvements</a>
321</div>
322
323<div class="doc_text">
324
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]325<p>In addition to a huge array of bug fixes and minor performance tweaks, the
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]326LLVM 2.3 optimizers support a few major enhancements:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]327
328<ul>
329
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]330<li><p>Loop index set splitting on by default.
331This transformation hoists conditions from loop bodies and reduces a loop's
332iteration space to improve performance. For example,</p>
333
Devang Patel67e46712008-06-05 21:44:00 +0000[diff] [blame]334<pre>
Chris Lattnerabc3b352008-06-08 20:25:30 +0000[diff] [blame]335for (i = LB; i &lt; UB; ++i)
336 if (i &lt;= NV)
Devang Patel67e46712008-06-05 21:44:00 +0000[diff] [blame]337 LOOP_BODY
338</pre>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]339
340<p>is transformed into:</p>
341
Devang Patel67e46712008-06-05 21:44:00 +0000[diff] [blame]342<pre>
343NUB = min(NV+1, UB)
Chris Lattnerabc3b352008-06-08 20:25:30 +0000[diff] [blame]344for (i = LB; i &lt; NUB; ++i)
Devang Patel67e46712008-06-05 21:44:00 +0000[diff] [blame]345 LOOP_BODY
346</pre>
347</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]348
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]349<li>LLVM now includes a new <tt>memcpy</tt> optimization pass which removes
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]350dead <tt>memcpy</tt> calls, unneeded copies of aggregates, and performs
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]351return slot optimization. The LLVM optimizer now notices long sequences of
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]352consecutive stores and merges them into <tt>memcpy</tt>'s where profitable.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]353
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]354<li>Alignment detection for vector memory references and for <tt>memcpy</tt> and
355<tt>memset</tt> is now more aggressive.</li>
Owen Anderson7f8ea062008-06-06 16:23:15 +0000[diff] [blame]356
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]357<li>The Aggressive Dead Code Elimination (ADCE) optimization has been rewritten
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]358to make it both faster and safer in the presence of code containing infinite
359loops. Some of its prior functionality has been factored out into the loop
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]360deletion pass, which <em>is</em> safe for infinite loops. The new ADCE pass is
361no longer based on control dependence, making it run faster.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]362
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]363<li>The 'SimplifyLibCalls' pass, which optimizes calls to libc and libm
364 functions for C-based languages, has been rewritten to be a FunctionPass
365 instead a ModulePass. This allows it to be run more often and to be
366 included at -O1 in llvm-gcc. It was also extended to include more
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]367 optimizations and several corner case bugs were fixed.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]368
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]369<li>LLVM now includes a simple 'Jump Threading' pass, which attempts to simplify
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]370 conditional branches using information about predecessor blocks, simplifying
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]371 the control flow graph. This pass is pretty basic at this point, but
372 catches some important cases and provides a foundation to build on.</li>
373
374<li>Several corner case bugs which could lead to deleting volatile memory
375 accesses have been fixed.</li>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]376
377<li>Several optimizations have been sped up, leading to faster code generation
378 with the same code quality.</li>
379
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]380</ul>
381
382</div>
383
384<!--=========================================================================-->
385<div class="doc_subsection">
386<a name="codegen">Code Generator Improvements</a>
387</div>
388
389<div class="doc_text">
390
391<p>We put a significant amount of work into the code generator infrastructure,
392which allows us to implement more aggressive algorithms and make it run
393faster:</p>
394
395<ul>
Dan Gohman1c0030e2008-06-08 22:49:27 +0000[diff] [blame]396<li>The code generator now has support for carrying information about memory
397 references throughout the entire code generation process, via the
398 <a href="http://llvm.org/doxygen/classllvm_1_1MachineMemOperand.html">
399 MachineMemOperand</a> class. In the future this will be used to improve
400 both pre-pass and post-pass scheduling, and to improve compiler-debugging
401 output.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]402
Dan Gohman8f4a6ad2008-06-08 22:57:59 +0000[diff] [blame]403<li>The target-independent code generator infrastructure now uses LLVM's
404 <a href="http://llvm.org/doxygen/classllvm_1_1APInt.html">APInt</a>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]405 class to handle integer values, which allows it to support integer types
Chris Lattner00682df2008-06-08 23:06:47 +0000[diff] [blame]406 larger than 64 bits (for example i128). Note that support for such types is
407 also dependent on target-specific support. Use of APInt is also a step
408 toward support for non-power-of-2 integer sizes.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]409
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]410<li>LLVM 2.3 includes several compile time speedups for code with large basic
Dan Gohmanf3d8f8d2008-06-08 22:44:43 +0000[diff] [blame]411 blocks, particularly in the instruction selection phase, register
412 allocation, scheduling, and tail merging/jump threading.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]413
Chris Lattner00682df2008-06-08 23:06:47 +0000[diff] [blame]414<li>LLVM 2.3 includes several improvements which make llc's
415 <tt>--view-sunit-dags</tt> visualization of scheduling dependency graphs
416 easier to understand.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]417
418<li>The code generator allows targets to write patterns that generate subreg
419 references directly in .td files now.</li>
420
421<li><tt>memcpy</tt> lowering in the backend is more aggressive, particularly for
422 <tt>memcpy</tt> calls introduced by the code generator when handling
423 pass-by-value structure argument copies.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]424
425<li>Inline assembly with multiple register results now returns those results
426 directly in the appropriate registers, rather than going through memory.
427 Inline assembly that uses constraints like "ir" with immediates now use the
428 'i' form when possible instead of always loading the value in a register.
429 This saves an instruction and reduces register use.</li>
430
Chris Lattner4c2d42e2008-06-09 04:00:08 +0000[diff] [blame]431<li>Added support for PIC/GOT style <a
432 href="CodeGenerator.html#tailcallopt">tail calls</a> on X86/32 and initial
433 support for tail calls on PowerPC 32 (it may also work on PowerPC 64 but is
434 not thoroughly tested).</li>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]435</ul>
436
437</div>
438
439
440<!--=========================================================================-->
441<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]442<a name="x86specific">X86/X86-64 Specific Improvements</a>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]443</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]444
445<div class="doc_text">
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]446<p>New target-specific features include:
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]447</p>
448
449<ul>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]450<li>llvm-gcc's X86-64 ABI conformance is far improved, particularly in the
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]451 area of passing and returning structures by value. llvm-gcc compiled code
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]452 now interoperates very well on X86-64 systems with other compilers.</li>
453
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]454<li>Support for Win64 was added. This includes code generation itself, JIT
Chris Lattner00682df2008-06-08 23:06:47 +0000[diff] [blame]455 support, and necessary changes to llvm-gcc.</li>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]456
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]457<li>The LLVM X86 backend now supports the support SSE 4.1 instruction set, and
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]458 the llvm-gcc 4.2 front-end supports the SSE 4.1 compiler builtins. Various
459 generic vector operations (insert/extract/shuffle) are much more efficient
460 when SSE 4.1 is enabled. The JIT automatically takes advantage of these
461 instructions, but llvm-gcc must be explicitly told to use them, e.g. with
462 <tt>-march=penryn</tt>.</li>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]463
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]464<li>The X86 backend now does a number of optimizations that aim to avoid
465 converting numbers back and forth from SSE registers to the X87 floating
Chris Lattner00682df2008-06-08 23:06:47 +0000[diff] [blame]466 point stack. This is important because most X86 ABIs require return values
467 to be on the X87 Floating Point stack, but most CPUs prefer computation in
468 the SSE units.</li>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]469
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]470<li>The X86 backend supports stack realignment, which is particularly useful for
Chris Lattner00682df2008-06-08 23:06:47 +0000[diff] [blame]471 vector code on OS's without 16-byte aligned stacks, such as Linux and
472 Windows.</li>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]473
474<li>The X86 backend now supports the "sseregparm" options in GCC, which allow
475 functions to be tagged as passing floating point values in SSE
476 registers.</li>
477
478<li>Trampolines (taking the address of a nested function) now work on
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]479 Linux/X86-64.</li>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]480
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]481<li><tt>__builtin_prefetch</tt> is now compiled into the appropriate prefetch
482 instructions instead of being ignored.</li>
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]483
Chris Lattner00682df2008-06-08 23:06:47 +0000[diff] [blame]484<li>128-bit integers are now supported on X86-64 targets. This can be used
485 through <tt>__attribute__((TImode))</tt> in llvm-gcc.</li>
Dan Gohman74e1ff52008-06-05 16:15:39 +0000[diff] [blame]486
Chris Lattner00682df2008-06-08 23:06:47 +0000[diff] [blame]487<li>The register allocator can now rematerialize PIC-base computations, which is
488 an important optimization for register use.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]489
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]490<li>The "t" and "f" inline assembly constraints for the X87 floating point stack
491 now work. However, the "u" constraint is still not fully supported.</li>
492
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]493</ul>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]494
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]495</div>
496
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]497<!--=========================================================================-->
498<div class="doc_subsection">
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]499<a name="targetspecific">Other Target Specific Improvements</a>
500</div>
501
502<div class="doc_text">
503<p>New target-specific features include:
504</p>
505
506<ul>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]507<li>The LLVM C backend now supports vector code.</li>
Chris Lattner00682df2008-06-08 23:06:47 +0000[diff] [blame]508<li>The Cell SPU backend includes a number of improvements. It generates better
509 code and its stability/completeness is improving.</li>
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]510</ul>
511
512</div>
513
514
515
516<!--=========================================================================-->
517<div class="doc_subsection">
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]518<a name="otherimprovements">Other Improvements</a>
519</div>
520
521<div class="doc_text">
522<p>New features include:
523</p>
524
525<ul>
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]526<li>LLVM now builds with GCC 4.3.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]527<li>Bugpoint now supports running custom scripts (with the <tt>-run-custom</tt>
528 option) to determine how to execute the command and whether it is making
529 forward process.</li>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]530</ul>
531
532</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]533
534<!-- *********************************************************************** -->
535<div class="doc_section">
536 <a name="portability">Portability and Supported Platforms</a>
537</div>
538<!-- *********************************************************************** -->
539
540<div class="doc_text">
541
542<p>LLVM is known to work on the following platforms:</p>
543
544<ul>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]545<li>Intel and AMD machines (IA32) running Red Hat Linux, Fedora Core and FreeBSD
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]546 (and probably other unix-like systems).</li>
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]547<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit and
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]548 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]549<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]550<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
551 support is available for native builds with Visual C++).</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]552<li>Sun UltraSPARC workstations running Solaris 10.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]553<li>Alpha-based machines running Debian GNU/Linux.</li>
Gabor Greif5e75e652008-06-05 18:39:01 +0000[diff] [blame]554<li>Itanium-based (IA64) machines running Linux and HP-UX.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]555</ul>
556
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]557<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]558to the machine and operating system on which it is built. However, minor
559porting may be required to get LLVM to work on new platforms. We welcome your
560portability patches and reports of successful builds or error messages.</p>
561
562</div>
563
564<!-- *********************************************************************** -->
565<div class="doc_section">
566 <a name="knownproblems">Known Problems</a>
567</div>
568<!-- *********************************************************************** -->
569
570<div class="doc_text">
571
572<p>This section contains all known problems with the LLVM system, listed by
573component. As new problems are discovered, they will be added to these
574sections. If you run into a problem, please check the <a
575href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
576there isn't already one.</p>
577
578</div>
579
580<!-- ======================================================================= -->
581<div class="doc_subsection">
582 <a name="experimental">Experimental features included with this release</a>
583</div>
584
585<div class="doc_text">
586
587<p>The following components of this LLVM release are either untested, known to
588be broken or unreliable, or are in early development. These components should
589not be relied on, and bugs should not be filed against them, but they may be
590useful to some people. In particular, if you would like to work on one of these
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]591components, please contact us on the <a
592href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]593
594<ul>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]595<li>The MSIL, IA64, Alpha, SPU, and MIPS backends are experimental.</li>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]596<li>The llc "<tt>-filetype=asm</tt>" (the default) is the only supported
Chris Lattnerbd633de92008-02-06 06:30:34 +0000[diff] [blame]597 value for this option.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]598</ul>
599
600</div>
601
602<!-- ======================================================================= -->
603<div class="doc_subsection">
604 <a name="x86-be">Known problems with the X86 back-end</a>
605</div>
606
607<div class="doc_text">
608
609<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]610 <li>The X86 backend does not yet support
611 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
612 floating point stack</a>. It supports the 'f' and 't' constraints, but not
613 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]614 <li>The X86 backend generates inefficient floating point code when configured
615 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]616 <li>Win64 code generation wasn't widely tested. Everything should work, but we
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]617 expect small issues to happen. Also, llvm-gcc cannot build mingw64 runtime
618 currently due
619 to <a href="http://llvm.org/PR2255">several</a>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]620 <a href="http://llvm.org/PR2257">bugs</a> due to lack of support for the
621 'u' inline assembly constraint and X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]622 <li>The X86-64 backend does not yet support position-independent code (PIC)
623 generation on Linux targets.</li>
624 <li>The X86-64 backend does not yet support the LLVM IR instruction
625 <tt>va_arg</tt>. Currently, the llvm-gcc front-end supports variadic
626 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]627</ul>
628
629</div>
630
631<!-- ======================================================================= -->
632<div class="doc_subsection">
633 <a name="ppc-be">Known problems with the PowerPC back-end</a>
634</div>
635
636<div class="doc_text">
637
638<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]639<li>The Linux PPC32/ABI support needs testing for the interpreter and static
640compilation, and lacks support for debug information.</li>
641</ul>
642
643</div>
644
645<!-- ======================================================================= -->
646<div class="doc_subsection">
647 <a name="arm-be">Known problems with the ARM back-end</a>
648</div>
649
650<div class="doc_text">
651
652<ul>
653<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]654processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]655results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
656<li>Compilation for ARM Linux OABI (old ABI) is supported, but not fully tested.
657</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]658<li>There is a bug in QEMU-ARM (&lt;= 0.9.0) which causes it to incorrectly
659 execute
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]660programs compiled with LLVM. Please use more recent versions of QEMU.</li>
661</ul>
662
663</div>
664
665<!-- ======================================================================= -->
666<div class="doc_subsection">
667 <a name="sparc-be">Known problems with the SPARC back-end</a>
668</div>
669
670<div class="doc_text">
671
672<ul>
673<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32), it does not
674 support the 64-bit SPARC ABI (-m64).</li>
675</ul>
676
677</div>
678
679<!-- ======================================================================= -->
680<div class="doc_subsection">
681 <a name="alpha-be">Known problems with the Alpha back-end</a>
682</div>
683
684<div class="doc_text">
685
686<ul>
687
688<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
689appropriate nops inserted to ensure restartability.</li>
690
691</ul>
692</div>
693
694<!-- ======================================================================= -->
695<div class="doc_subsection">
696 <a name="ia64-be">Known problems with the IA64 back-end</a>
697</div>
698
699<div class="doc_text">
700
701<ul>
Chris Lattnerf06141a2008-06-08 23:12:47 +0000[diff] [blame]702<li>The Itanium backend is highly experimental, and has a number of known
703 issues. We are looking for a maintainer for the Itanium backend. If you
704 are interested, please contact the llvmdev mailing list.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]705</ul>
706
707</div>
708
709<!-- ======================================================================= -->
710<div class="doc_subsection">
711 <a name="c-be">Known problems with the C back-end</a>
712</div>
713
714<div class="doc_text">
715
716<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]717<li><a href="http://llvm.org/PR802">The C backend has only basic support for
718 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]719<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
720 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]721 C++ code compiled with llc or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]722<li>The C backend does not support all exception handling constructs.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]723</ul>
724
725</div>
726
727
728<!-- ======================================================================= -->
729<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]730 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]731</div>
732
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]733<div class="doc_text">
734
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]735<p>llvm-gcc does not currently support <a href="http://llvm.org/PR869">Link-Time
736Optimization</a> on most platforms "out-of-the-box". Please inquire on the
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]737llvmdev mailing list if you are interested.</p>
738
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]739<p>The only major language feature of GCC not supported by llvm-gcc is
740 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
741 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]742 supported on some targets (these are used when you take the address of a
743 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]744
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]745<p>If you run into GCC extensions which are not supported, please let us know.
746</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]747
748</div>
749
750<!-- ======================================================================= -->
751<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]752 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]753</div>
754
755<div class="doc_text">
756
757<p>The C++ front-end is considered to be fully
758tested and works for a number of non-trivial programs, including LLVM
759itself, Qt, Mozilla, etc.</p>
760
761<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]762<li>Exception handling works well on the X86 and PowerPC targets, including
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]763X86-64 darwin. This works when linking to a libstdc++ compiled by GCC. It is
764supported on X86-64 linux, but that is disabled by default in this release.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]765</ul>
766
767</div>
768
769
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]770<!-- ======================================================================= -->
771<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]772 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]773</div>
774
775<div class="doc_text">
776The llvm-gcc 4.2 Ada compiler works fairly well, however this is not a mature
777technology and problems should be expected.
778<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]779<li>The Ada front-end currently only builds on X86-32. This is mainly due
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]780to lack of trampoline support (pointers to nested functions) on other platforms,
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]781however it <a href="http://llvm.org/PR2006">also fails to build on X86-64</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]782which does support trampolines.</li>
783<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
784Workaround: configure with --disable-bootstrap.</li>
785<li>The c380004 and <a href="http://llvm.org/PR2010">c393010</a> ACATS tests
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]786fail (c380004 also fails with gcc-4.2 mainline). When built at -O3, the
787<a href="http://llvm.org/PR2421">cxg2021</a> ACATS test also fails.</li>
788<li>Some gcc specific Ada tests continue to crash the compiler. The testsuite
789reports most tests as having failed even though they pass.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]790<li>The -E binder option (exception backtraces)
791<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
792crashing if an exception is raised. Workaround: do not use -E.</li>
793<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
794or finish at a non-byte offset</a> in a record. Workaround: do not pack records
795or use representation clauses that result in a field of a non-discrete type
796starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]797<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
798'main' as generated by the Ada binder to be invalid</a>.
799Workaround: hand edit the file to use pointers for <tt>argv</tt> and
800<tt>envp</tt> rather than integers.</li>
801<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
802ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]803</ul>
804</div>
805
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]806<!-- *********************************************************************** -->
807<div class="doc_section">
808 <a name="additionalinfo">Additional Information</a>
809</div>
810<!-- *********************************************************************** -->
811
812<div class="doc_text">
813
814<p>A wide variety of additional information is available on the <a
815href="http://llvm.org">LLVM web page</a>, in particular in the <a
816href="http://llvm.org/docs/">documentation</a> section. The web page also
817contains versions of the API documentation which is up-to-date with the
818Subversion version of the source code.
819You can access versions of these documents specific to this release by going
820into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
821
822<p>If you have any questions or comments about LLVM, please feel free to contact
823us via the <a href="http://llvm.org/docs/#maillist"> mailing
824lists</a>.</p>
825
826</div>
827
828<!-- *********************************************************************** -->
829
830<hr>
831<address>
832 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
833 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
834 <a href="http://validator.w3.org/check/referer"><img
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]835 src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]836
837 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
838 Last modified: $Date$
839</address>
840
841</body>
842</html>