Gitiles
Code Review Sign In
gerrit-public.fairphone.software / platform / external / llvm / 369889ac8f90a47b1e24c6ab0c6fbea70bf6ce1d / . / docs / ReleaseNotes.html
blob: 88c7de07a47c874b7440f84eabd6a1f94fb8736c [file] [log] [blame]
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4<head>
5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
6 <link rel="stylesheet" href="llvm.css" type="text/css">
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]7 <title>LLVM 2.7 Release Notes</title>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]8</head>
9<body>
10
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]11<div class="doc_title">LLVM 2.7 Release Notes</div>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]12
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]13<ol>
14 <li><a href="#intro">Introduction</a></li>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]15 <li><a href="#subproj">Sub-project Status Update</a></li>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]16 <li><a href="#externalproj">External Projects Using LLVM 2.7</a></li>
17 <li><a href="#whatsnew">What's New in LLVM 2.7?</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]18 <li><a href="GettingStarted.html">Installation Instructions</a></li>
19 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohman0de549c2008-10-14 16:23:02 +0000[diff] [blame]20 <li><a href="#knownproblems">Known Problems</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]21 <li><a href="#additionalinfo">Additional Information</a></li>
22</ol>
23
24<div class="doc_author">
Dan Gohman0de549c2008-10-14 16:23:02 +0000[diff] [blame]25 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]26</div>
27
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]28<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.7
29release.<br>
30You may prefer the
31<a href="http://llvm.org/releases/2.6/docs/ReleaseNotes.html">LLVM 2.6
32Release Notes</a>.</h1>
33
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]34<!-- *********************************************************************** -->
35<div class="doc_section">
36 <a name="intro">Introduction</a>
37</div>
38<!-- *********************************************************************** -->
39
40<div class="doc_text">
41
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]42<p>This document contains the release notes for the LLVM Compiler
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]43Infrastructure, release 2.7. Here we describe the status of LLVM, including
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]44major improvements from the previous release and significant known problems.
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]45All LLVM releases may be downloaded from the <a
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]46href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]47
48<p>For more information about LLVM, including information about the latest
49release, please check out the <a href="http://llvm.org/">main LLVM
50web site</a>. If you have questions or comments, the <a
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]51href="http://mail.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's Mailing
52List</a> is a good place to send them.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]53
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]54<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]55main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greif7c65c4f2008-10-14 11:00:32 +0000[diff] [blame]56current one. To see the release notes for a specific release, please see the
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]57<a href="http://llvm.org/releases/">releases page</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]58
59</div>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]60
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]61
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]62<!--
63Almost dead code.
64 include/llvm/Analysis/LiveValues.h => Dan
65 lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
66 llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
Chris Lattner35da3812010-01-09 22:30:40 +0000[diff] [blame]67 ABCD, SCCVN, GEPSplitterPass
Chris Lattner2bd5e652010-01-16 21:25:13 +0000[diff] [blame]68 MSIL backend?
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]69-->
70
71
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]72<!-- Features that need text if they're finished for 2.7:
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]73 gcc plugin.
74 strong phi elim
75 variable debug info for optimized code
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]76 postalloc scheduler: anti dependence breaking, hazard recognizer?
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]77 metadata
78 loop dependence analysis
79 ELF Writer? How stable?
80 <li>PostRA scheduler improvements, ARM adoption (David Goodwin).</li>
81 2.7 supports the GDB 7.0 jit interfaces for debug info.
82 2.7 eliminates ADT/iterator.h
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]83 -->
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]84
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]85 <!-- for announcement email:
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]86 Logo web page.
87 llvm devmtg
88 compiler_rt
89 KLEE web page at klee.llvm.org
90 Many new papers added to /pubs/
91 Mention gcc plugin.
92
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]93 -->
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]94
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]95<!-- *********************************************************************** -->
96<div class="doc_section">
97 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]98</div>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]99<!-- *********************************************************************** -->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]100
101<div class="doc_text">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]102<p>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]103The LLVM 2.7 distribution currently consists of code from the core LLVM
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]104repository (which roughly includes the LLVM optimizers, code generators
105and supporting tools), the Clang repository and the llvm-gcc repository. In
106addition to this code, the LLVM Project includes other sub-projects that are in
107development. Here we include updates on these subprojects.
Bill Wendlingdde41b82009-03-02 04:28:57 +0000[diff] [blame]108</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]109
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]110</div>
111
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]112
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]113<!--=========================================================================-->
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]114<div class="doc_subsection">
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]115<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]116</div>
117
118<div class="doc_text">
119
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]120<p>The <a href="http://clang.llvm.org/">Clang project</a> is ...</p>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]121
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]122<p>In the LLVM 2.7 time-frame, the Clang team has made many improvements:</p>
Bill Wendling385b0d32008-10-27 09:27:33 +0000[diff] [blame]123
Daniel Dunbarf3e35782008-10-14 23:25:09 +0000[diff] [blame]124<ul>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]125<li>...</li>
Bill Wendlinga8fb81d2009-03-02 04:28:18 +0000[diff] [blame]126</ul>
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]127</div>
128
129<!--=========================================================================-->
130<div class="doc_subsection">
131<a name="clangsa">Clang Static Analyzer</a>
132</div>
133
134<div class="doc_text">
135
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]136<p>Previously announced in the 2.4, 2.5, and 2.6 LLVM releases, the Clang project also
Ted Kremeneka0d77d72009-02-27 07:01:32 +0000[diff] [blame]137includes an early stage static source code analysis tool for <a
138href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]139in C and Objective-C programs. The tool performs checks to find
Ted Kremeneka0d77d72009-02-27 07:01:32 +0000[diff] [blame]140bugs that occur on a specific path within a program.</p>
Chris Lattnerc2d84672008-10-14 00:52:49 +0000[diff] [blame]141
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]142<p>In the LLVM 2.7 time-frame, the analyzer core has ...</p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]143
144</div>
145
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]146<!--=========================================================================-->
147<div class="doc_subsection">
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]148<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]149</div>
150
151<div class="doc_text">
152<p>
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]153The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]154a JVM and a CLI Virtual Machine (Microsoft .NET is an
155implementation of the CLI) using LLVM for static and just-in-time
156compilation.</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]157
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]158<p>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]159VMKit version ?? builds with LLVM 2.7 and you can find it on its
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]160<a href="http://vmkit.llvm.org/releases/">web page</a>. The release includes
Nicolas Geoffray20cfdd42008-10-15 20:25:04 +0000[diff] [blame]161bug fixes, cleanup and new features. The major changes are:</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]162
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]163<ul>
164
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]165<li>...</li>
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]166
167</ul>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]168</div>
169
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]170
171<!--=========================================================================-->
172<div class="doc_subsection">
173<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
174</div>
175
176<div class="doc_text">
177<p>
178The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
179is a simple library that provides an implementation of the low-level
180target-specific hooks required by code generation and other runtime components.
181For example, when compiling for a 32-bit target, converting a double to a 64-bit
182unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
183function. The compiler-rt library provides highly optimized implementations of
184this and other low-level routines (some are 3x faster than the equivalent
185libgcc routines).</p>
186
187<p>
188All of the code in the compiler-rt project is available under the standard LLVM
189License, a "BSD-style" license.</p>
190
191</div>
192
193<!--=========================================================================-->
194<div class="doc_subsection">
195<a name="klee">KLEE: Symbolic Execution and Automatic Test Case Generator</a>
196</div>
197
198<div class="doc_text">
199<p>
200The new LLVM <a href="http://klee.llvm.org/">KLEE project</a> is a symbolic
201execution framework for programs in LLVM bitcode form. KLEE tries to
202symbolically evaluate "all" paths through the application and records state
203transitions that lead to fault states. This allows it to construct testcases
204that lead to faults and can even be used to verify algorithms. For more
205details, please see the <a
206href="http://llvm.org/pubs/2008-12-OSDI-KLEE.html">OSDI 2008 paper</a> about
207KLEE.</p>
208
209</div>
210
211<!--=========================================================================-->
212<div class="doc_subsection">
213<a name="dragonegg">DragonEgg: GCC-4.5 as an LLVM frontend</a>
214</div>
215
216<div class="doc_text">
217<p>
218The goal of <a href="http://dragonegg.llvm.org/">DragonEgg</a> is to make
219gcc-4.5 act like llvm-gcc without requiring any gcc modifications whatsoever.
Duncan Sandsf6fb7142009-10-15 08:17:44 +0000[diff] [blame]220<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a shared library (dragonegg.so)
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]221that is loaded by gcc at runtime. It ...
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]222</p>
223
224</div>
225
226
227<!--=========================================================================-->
228<div class="doc_subsection">
229<a name="mc">llvm-mc: Machine Code Toolkit</a>
230</div>
231
232<div class="doc_text">
233<p>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]234The LLVM Machine Code (MC) Toolkit project is ...
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]235</p>
236
237</div>
238
239
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]240<!-- *********************************************************************** -->
241<div class="doc_section">
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]242 <a name="externalproj">External Open Source Projects Using LLVM 2.7</a>
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]243</div>
244<!-- *********************************************************************** -->
245
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]246<div class="doc_text">
247
248<p>An exciting aspect of LLVM is that it is used as an enabling technology for
249 a lot of other language and tools projects. This section lists some of the
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]250 projects that have already been updated to work with LLVM 2.7.</p>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]251</div>
252
253
254<!--=========================================================================-->
255<div class="doc_subsection">
256<a name="Rubinius">Rubinius</a>
257</div>
258
259<div class="doc_text">
260<p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment
261for running Ruby code which strives to write as much of the core class
262implementation in Ruby as possible. Combined with a bytecode interpreting VM, it
263uses LLVM to optimize and compile ruby code down to machine code. Techniques
264such as type feedback, method inlining, and uncommon traps are all used to
265remove dynamism from ruby execution and increase performance.</p>
266
267<p>Since LLVM 2.5, Rubinius has made several major leaps forward, implementing
268a counter based JIT, type feedback and speculative method inlining.
269</p>
270
271</div>
272
273<!--=========================================================================-->
274<div class="doc_subsection">
275<a name="macruby">MacRuby</a>
276</div>
277
278<div class="doc_text">
279
280<p>
281<a href="http://macruby.org">MacRuby</a> is an implementation of Ruby on top of
282core Mac OS X technologies, such as the Objective-C common runtime and garbage
283collector and the CoreFoundation framework. It is principally developed by
284Apple and aims at enabling the creation of full-fledged Mac OS X applications.
285</p>
286
287<p>
288MacRuby uses LLVM for optimization passes, JIT and AOT compilation of Ruby
289expressions. It also uses zero-cost DWARF exceptions to implement Ruby exception
290handling.</p>
291
292</div>
293
294
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]295<!--=========================================================================-->
296<div class="doc_subsection">
297<a name="pure">Pure</a>
298</div>
299
300<div class="doc_text">
301<p>
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]302<a href="http://pure-lang.googlecode.com/">Pure</a>
303is an algebraic/functional programming language based on term rewriting.
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]304Programs are collections of equations which are used to evaluate expressions in
305a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]306lexical closures, a hygienic macro system (also based on term rewriting),
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]307built-in list and matrix support (including list and matrix comprehensions) and
308an easy-to-use C interface. The interpreter uses LLVM as a backend to
309 JIT-compile Pure programs to fast native code.</p>
310
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]311<p>Pure versions ??? and later have been tested and are known to work with
312LLVM 2.7 (and continue to work with older LLVM releases >= 2.3 as well).
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]313</p>
314</div>
315
316
317<!--=========================================================================-->
318<div class="doc_subsection">
319<a name="ldc">LLVM D Compiler</a>
320</div>
321
322<div class="doc_text">
323<p>
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]324<a href="http://www.dsource.org/projects/ldc">LDC</a> is an implementation of
325the D Programming Language using the LLVM optimizer and code generator.
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]326The LDC project works great with the LLVM 2.6 release. General improvements in
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]327this
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]328cycle have included new inline asm constraint handling, better debug info
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]329support, general bug fixes and better x86-64 support. This has allowed
330some major improvements in LDC, getting it much closer to being as
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]331fully featured as the original DMD compiler from DigitalMars.
332</p>
333</div>
334
Chris Lattner1ad599a2009-02-28 18:58:01 +0000[diff] [blame]335<!--=========================================================================-->
336<div class="doc_subsection">
337<a name="RoadsendPHP">Roadsend PHP</a>
338</div>
339
340<div class="doc_text">
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]341<p>
342<a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
Chris Lattner9e08de12009-03-02 19:07:24 +0000[diff] [blame]343source implementation of the PHP programming
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]344language that uses LLVM for its optimizer, JIT and static compiler. This is a
Chris Lattner9e08de12009-03-02 19:07:24 +0000[diff] [blame]345reimplementation of an earlier project that is now based on LLVM.</p>
Chris Lattner1ad599a2009-02-28 18:58:01 +0000[diff] [blame]346</div>
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]347
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]348<!--=========================================================================-->
349<div class="doc_subsection">
350<a name="UnladenSwallow">Unladen Swallow</a>
351</div>
352
353<div class="doc_text">
354<p>
355<a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a
356branch of <a href="http://python.org/">Python</a> intended to be fully
357compatible and significantly faster. It uses LLVM's optimization passes and JIT
358compiler.</p>
359</div>
360
361<!--=========================================================================-->
362<div class="doc_subsection">
363<a name="llvm-lua">llvm-lua</a>
364</div>
365
366<div class="doc_text">
367<p>
368<a href="http://code.google.com/p/llvm-lua/">LLVM-Lua</a> uses LLVM to add JIT
369and static compiling support to the Lua VM. Lua bytecode is analyzed to
370remove type checks, then LLVM is used to compile the bytecode down to machine
371code.</p>
372</div>
373
374<!--=========================================================================-->
375<div class="doc_subsection">
376<a name="icedtea">IcedTea Java Virtual Machine Implementation</a>
377</div>
378
379<div class="doc_text">
380<p>
381<a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a
382harness to build OpenJDK using only free software build tools and to provide
383replacements for the not-yet free parts of OpenJDK. One of the extensions that
384IcedTea provides is a new JIT compiler named <a
385href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM
386to provide native code generation without introducing processor-dependent
387code.
388</p>
389</div>
390
391
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]392
393<!-- *********************************************************************** -->
394<div class="doc_section">
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]395 <a name="whatsnew">What's New in LLVM 2.7?</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]396</div>
397<!-- *********************************************************************** -->
398
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]399<div class="doc_text">
400
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]401<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]402minor improvements. Some of the major improvements and new features are listed
403in this section.
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]404</p>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]405
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]406</div>
407
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]408<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]409<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]410<a name="majorfeatures">Major New Features</a>
411</div>
412
413<div class="doc_text">
414
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]415<p>LLVM 2.7 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]416
417<ul>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]418<li>...</li>
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]419</ul>
420
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]421</div>
422
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]423<!--=========================================================================-->
424<div class="doc_subsection">
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]425<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]426</div>
427
428<div class="doc_text">
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]429<p>LLVM IR has several new features for better support of new targets and that
430expose new optimization opportunities:</p>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]431
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]432<ul>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]433<li>...</li>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]434</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]435
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]436</div>
437
438<!--=========================================================================-->
439<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]440<a name="optimizer">Optimizer Improvements</a>
441</div>
442
443<div class="doc_text">
444
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]445<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattnerea9c2242008-10-13 21:50:36 +0000[diff] [blame]446release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]447
448<ul>
449
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]450<li>...</li>
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]451
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]452</ul>
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]453
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]454</div>
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]455
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]456
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]457<!--=========================================================================-->
458<div class="doc_subsection">
459<a name="executionengine">Interpreter and JIT Improvements</a>
460</div>
Chris Lattnerea9c2242008-10-13 21:50:36 +0000[diff] [blame]461
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]462<div class="doc_text">
463
464<ul>
Jeffrey Yasskin40715142010-01-29 19:10:38 +0000[diff] [blame]465<li>The JIT now <a
466href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
467to compiling eagerly</a> to avoid a race condition in the lazy JIT.
468Clients that still want the lazy JIT can switch it on by calling
469<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
Jeffrey Yasskinc0577082010-02-11 01:07:39 +0000[diff] [blame]470<li>It is now possible to create more than one JIT instance in the same process.
471These JITs can generate machine code in parallel,
472although <a href="http://llvm.org/docs/ProgrammersManual.html#jitthreading">you
473still have to obey the other threading restrictions</a>.</li>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]474</ul>
475
476</div>
477
478<!--=========================================================================-->
479<div class="doc_subsection">
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]480<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]481</div>
482
483<div class="doc_text">
484
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]485<p>We have put a significant amount of work into the code generator
486infrastructure, which allows us to implement more aggressive algorithms and make
487it run faster:</p>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]488
489<ul>
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]490
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]491<li>...</li>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]492</ul>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]493</div>
494
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]495<!--=========================================================================-->
496<div class="doc_subsection">
497<a name="x86">X86-32 and X86-64 Target Improvements</a>
498</div>
499
500<div class="doc_text">
501<p>New features of the X86 target include:
502</p>
503
504<ul>
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]505
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]506<li>...</li>
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]507
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]508</ul>
509
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]510</div>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]511
512<!--=========================================================================-->
513<div class="doc_subsection">
Chris Lattnere1fbd752009-02-26 07:32:11 +0000[diff] [blame]514<a name="pic16">PIC16 Target Improvements</a>
515</div>
516
517<div class="doc_text">
518<p>New features of the PIC16 target include:
519</p>
520
521<ul>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]522<li>...</li>
Chris Lattnere1fbd752009-02-26 07:32:11 +0000[diff] [blame]523</ul>
524
525<p>Things not yet supported:</p>
526
527<ul>
Chris Lattnere1fbd752009-02-26 07:32:11 +0000[diff] [blame]528<li>Variable arguments.</li>
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]529<li>Interrupts/programs.</li>
Chris Lattnere1fbd752009-02-26 07:32:11 +0000[diff] [blame]530</ul>
531
532</div>
533
Chris Lattnere1fbd752009-02-26 07:32:11 +0000[diff] [blame]534<!--=========================================================================-->
535<div class="doc_subsection">
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]536<a name="ARM">ARM Target Improvements</a>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]537</div>
538
539<div class="doc_text">
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]540<p>New features of the ARM target include:
541</p>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]542
543<ul>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]544
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]545<li>...</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]546</ul>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]547
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]548
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]549</div>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]550
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]551<!--=========================================================================-->
552<div class="doc_subsection">
553<a name="OtherTarget">Other Target Specific Improvements</a>
554</div>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]555
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]556<div class="doc_text">
557<p>New features of other targets include:
558</p>
559
560<ul>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]561<li>...</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]562</ul>
563
564</div>
565
566<!--=========================================================================-->
567<div class="doc_subsection">
568<a name="newapis">New Useful APIs</a>
569</div>
570
571<div class="doc_text">
572
573<p>This release includes a number of new APIs that are used internally, which
574 may also be useful for external clients.
575</p>
576
577<ul>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]578<li>...</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]579</ul>
580
581
582</div>
583
584<!--=========================================================================-->
585<div class="doc_subsection">
586<a name="otherimprovements">Other Improvements and New Features</a>
587</div>
588
589<div class="doc_text">
590<p>Other miscellaneous features include:</p>
591
592<ul>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]593<li>...</li>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]594</ul>
595
596</div>
597
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]598
599<!--=========================================================================-->
600<div class="doc_subsection">
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]601<a name="changes">Major Changes and Removed Features</a>
602</div>
603
604<div class="doc_text">
605
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]606<p>If you're already an LLVM user or developer with out-of-tree changes based
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]607on LLVM 2.6, this section lists some "gotchas" that you may run into upgrading
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]608from the previous release.</p>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]609
610<ul>
Jeffrey Yasskin260af332010-02-09 23:03:44 +0000[diff] [blame]611<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
612if you have it installed. This makes it more likely that an LLVM built on one
613system will work when copied to a similar system. To use <tt>libffi</tt>,
614configure with <tt>--enable-libffi</tt>.
615</li>
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]616</ul>
617
618
619<p>In addition, many APIs have changed in this release. Some of the major LLVM
620API changes are:</p>
621
622<ul>
Jeffrey Yasskin2ca16212010-01-28 01:41:20 +0000[diff] [blame]623<li><tt>ModuleProvider</tt> has been <a
624href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
625and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
626Most clients can remove uses of <tt>ExistingModuleProvider</tt>,
627replace <tt>getBitcodeModuleProvider</tt> with
628<tt>getLazyBitcodeModule</tt>, and pass their <tt>Module</tt> to
629functions that used to accept <tt>ModuleProvider</tt>. Clients who
630wrote their own <tt>ModuleProvider</tt>s will need to derive from
631<tt>GVMaterializer</tt> instead and use
632<tt>Module::setMaterializer</tt> to attach it to a
633<tt>Module</tt>.</li>
634
635<li><tt>GhostLinkage</tt> has given up the ghost.
636<tt>GlobalValue</tt>s that have not yet been read from their backing
637storage have the same linkage they will have after being read in.
638Clients must replace calls to
639<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
640<tt>GlobalValue::isMaterializable</tt>.</li>
Daniel Dunbar61f41422010-02-10 04:09:52 +0000[diff] [blame]641
642<li>FIXME: Debug info has been totally redone. Add pointers to new APIs. Substantial caveats about compatibility of .ll and .bc files.</li>
643
Daniel Dunbar369889a2010-02-14 01:47:19 +0000[diff] [blame^]644<li>The <tt>llvm/Support/DataTypes.h</tt> header has moved
645to <tt>llvm/System/DataTypes.h</tt>.</li>
646
Devang Patel0e3da1a2008-10-14 20:03:43 +0000[diff] [blame]647</ul>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]648
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]649</div>
650
651
652
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]653<!-- *********************************************************************** -->
654<div class="doc_section">
655 <a name="portability">Portability and Supported Platforms</a>
656</div>
657<!-- *********************************************************************** -->
658
659<div class="doc_text">
660
661<p>LLVM is known to work on the following platforms:</p>
662
663<ul>
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]664<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]665 Linux, Fedora Core, FreeBSD and AuroraUX (and probably other unix-like
666 systems).</li>
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]667<li>PowerPC and X86-based Mac OS X systems, running 10.3 and above in 32-bit
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]668 and 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]669<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]670<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
671 support is available for native builds with Visual C++).</li>
Chris Lattner9235ce52009-10-16 16:30:58 +0000[diff] [blame]672<li>Sun x86 and AMD64 machines running Solaris 10, OpenSolaris 0906.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]673<li>Alpha-based machines running Debian GNU/Linux.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]674</ul>
675
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]676<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]677to the machine and operating system on which it is built. However, minor
678porting may be required to get LLVM to work on new platforms. We welcome your
679portability patches and reports of successful builds or error messages.</p>
680
681</div>
682
683<!-- *********************************************************************** -->
684<div class="doc_section">
685 <a name="knownproblems">Known Problems</a>
686</div>
687<!-- *********************************************************************** -->
688
689<div class="doc_text">
690
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]691<p>This section contains significant known problems with the LLVM system,
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]692listed by component. If you run into a problem, please check the <a
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]693href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
694there isn't already one.</p>
695
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]696<ul>
697<li>The llvm-gcc bootstrap will fail with some versions of binutils (e.g. 2.15)
698 with a message of "<tt><a href="http://llvm.org/PR5004">Error: can not do 8
699 byte pc-relative relocation</a></tt>" when building C++ code. We intend to
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]700 fix this on mainline, but a workaround is to upgrade to binutils 2.17 or
701 later.</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]702
703<li>LLVM will not correctly compile on Solaris and/or OpenSolaris
704using the stock GCC 3.x.x series 'out the box',
Chris Lattnerc09ffd22009-11-03 21:50:09 +0000[diff] [blame]705See: <a href="GettingStarted.html#brokengcc">Broken versions of GCC and other tools</a>.
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]706However, A <a href="http://pkg.auroraux.org/GCC">Modern GCC Build</a>
707for x86/x86-64 has been made available from the third party AuroraUX Project
708that has been meticulously tested for bootstrapping LLVM &amp; Clang.</li>
709</ul>
710
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]711</div>
712
713<!-- ======================================================================= -->
714<div class="doc_subsection">
715 <a name="experimental">Experimental features included with this release</a>
716</div>
717
718<div class="doc_text">
719
720<p>The following components of this LLVM release are either untested, known to
721be broken or unreliable, or are in early development. These components should
722not be relied on, and bugs should not be filed against them, but they may be
723useful 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]724components, please contact us on the <a
725href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]726
727<ul>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]728<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430 and SystemZ backends are
729 experimental.</li>
Bill Wendling9c7c4382009-03-02 07:54:14 +0000[diff] [blame]730<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]731 supported value for this option. The ELF writer is experimental.</li>
732<li>The implementation of Andersen's Alias Analysis has many known bugs.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]733</ul>
734
735</div>
736
737<!-- ======================================================================= -->
738<div class="doc_subsection">
739 <a name="x86-be">Known problems with the X86 back-end</a>
740</div>
741
742<div class="doc_text">
743
744<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]745 <li>The X86 backend does not yet support
746 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
747 floating point stack</a>. It supports the 'f' and 't' constraints, but not
748 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]749 <li>The X86 backend generates inefficient floating point code when configured
750 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]751 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]752 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
753 runtime currently due
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]754 to <a href="http://llvm.org/PR2255">several</a>
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]755 <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for
756 the
757 'u' inline assembly constraint and for X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]758 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]759 <tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]760 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]761</ul>
762
763</div>
764
765<!-- ======================================================================= -->
766<div class="doc_subsection">
767 <a name="ppc-be">Known problems with the PowerPC back-end</a>
768</div>
769
770<div class="doc_text">
771
772<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]773<li>The Linux PPC32/ABI support needs testing for the interpreter and static
774compilation, and lacks support for debug information.</li>
775</ul>
776
777</div>
778
779<!-- ======================================================================= -->
780<div class="doc_subsection">
781 <a name="arm-be">Known problems with the ARM back-end</a>
782</div>
783
784<div class="doc_text">
785
786<ul>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]787<li>Support for the Advanced SIMD (Neon) instruction set is still incomplete
788and not well tested. Some features may not work at all, and the code quality
789may be poor in some cases.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]790<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]791processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]792results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]793<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]794</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]795</ul>
796
797</div>
798
799<!-- ======================================================================= -->
800<div class="doc_subsection">
801 <a name="sparc-be">Known problems with the SPARC back-end</a>
802</div>
803
804<div class="doc_text">
805
806<ul>
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]807<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]808 support the 64-bit SPARC ABI (-m64).</li>
809</ul>
810
811</div>
812
813<!-- ======================================================================= -->
814<div class="doc_subsection">
Bruno Cardoso Lopes62d45d72008-10-25 14:56:26 +0000[diff] [blame]815 <a name="mips-be">Known problems with the MIPS back-end</a>
816</div>
817
818<div class="doc_text">
819
820<ul>
Bruno Cardoso Lopes62d45d72008-10-25 14:56:26 +0000[diff] [blame]821<li>64-bit MIPS targets are not supported yet.</li>
822</ul>
823
824</div>
825
826<!-- ======================================================================= -->
827<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]828 <a name="alpha-be">Known problems with the Alpha back-end</a>
829</div>
830
831<div class="doc_text">
832
833<ul>
834
835<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
836appropriate nops inserted to ensure restartability.</li>
837
838</ul>
839</div>
840
841<!-- ======================================================================= -->
842<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]843 <a name="c-be">Known problems with the C back-end</a>
844</div>
845
846<div class="doc_text">
847
848<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]849<li><a href="http://llvm.org/PR802">The C backend has only basic support for
850 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]851<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
852 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greife33c5322009-03-02 12:02:51 +0000[diff] [blame]853 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]854<li>The C backend does not support all exception handling constructs.</li>
Duncan Sandse6e264c2009-02-25 11:51:54 +0000[diff] [blame]855<li>The C backend does not support arbitrary precision integers.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]856</ul>
857
858</div>
859
860
861<!-- ======================================================================= -->
862<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]863 <a name="c-fe">Known problems with the llvm-gcc C front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]864</div>
865
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]866<div class="doc_text">
867
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]868<p>The only major language feature of GCC not supported by llvm-gcc is
869 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
870 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]871 supported on some targets (these are used when you take the address of a
872 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]873
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]874<p>If you run into GCC extensions which are not supported, please let us know.
875</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]876
877</div>
878
879<!-- ======================================================================= -->
880<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]881 <a name="c++-fe">Known problems with the llvm-gcc C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]882</div>
883
884<div class="doc_text">
885
886<p>The C++ front-end is considered to be fully
887tested and works for a number of non-trivial programs, including LLVM
888itself, Qt, Mozilla, etc.</p>
889
890<ul>
Anton Korobeynikovd9a17932008-10-11 18:27:16 +0000[diff] [blame]891<li>Exception handling works well on the X86 and PowerPC targets. Currently
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]892 only Linux and Darwin targets are supported (both 32 and 64 bit).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]893</ul>
894
895</div>
896
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]897<!-- ======================================================================= -->
898<div class="doc_subsection">
899 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
900</div>
901
902<div class="doc_text">
Gabor Greif1fc8fbc2008-11-04 21:50:59 +0000[diff] [blame]903<ul>
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]904<li>Fortran support generally works, but there are still several unresolved bugs
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]905 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
906 tools/gfortran component for details.</li>
Gabor Greif1fc8fbc2008-11-04 21:50:59 +0000[diff] [blame]907</ul>
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]908</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]909
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]910<!-- ======================================================================= -->
911<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]912 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]913</div>
914
915<div class="doc_text">
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]916The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
917technology, and problems should be expected.
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]918<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]919<li>The Ada front-end currently only builds on X86-32. This is mainly due
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]920to lack of trampoline support (pointers to nested functions) on other platforms.
921However, 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]922which does support trampolines.</li>
923<li>The Ada front-end <a href="http://llvm.org/PR2007">fails to bootstrap</a>.
Duncan Sandsf73473e2009-02-25 11:59:06 +0000[diff] [blame]924This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
925exception handling, which is used internally by the compiler.
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]926Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands2dbc2e82008-10-13 17:27:23 +0000[diff] [blame]927<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
928and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sandsf73473e2009-02-25 11:59:06 +0000[diff] [blame]929(c380004 also fails with gcc-4.2 mainline).
930If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
931causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsc2a29a02009-03-02 16:35:57 +0000[diff] [blame]932<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]933<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]934<a href="http://llvm.org/PR1982">does not work</a> and will result in programs
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]935crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]936<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
937or finish at a non-byte offset</a> in a record. Workaround: do not pack records
938or use representation clauses that result in a field of a non-discrete type
939starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]940<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
941'main' as generated by the Ada binder to be invalid</a>.
942Workaround: hand edit the file to use pointers for <tt>argv</tt> and
943<tt>envp</tt> rather than integers.</li>
944<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
945ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]946</ul>
947</div>
948
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]949<!-- ======================================================================= -->
950<div class="doc_subsection">
951 <a name="ocaml-bindings">Known problems with the O'Caml bindings</a>
952</div>
953
954<div class="doc_text">
955
956<p>The <tt>Llvm.Linkage</tt> module is broken, and has incorrect values. Only
957<tt>Llvm.Linkage.External</tt>, <tt>Llvm.Linkage.Available_externally</tt>, and
958<tt>Llvm.Linkage.Link_once</tt> will be correct. If you need any of the other linkage
959modes, you'll have to write an external C library in order to expose the
960functionality. This has been fixed in the trunk.</p>
961</div>
962
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]963<!-- *********************************************************************** -->
964<div class="doc_section">
965 <a name="additionalinfo">Additional Information</a>
966</div>
967<!-- *********************************************************************** -->
968
969<div class="doc_text">
970
971<p>A wide variety of additional information is available on the <a
972href="http://llvm.org">LLVM web page</a>, in particular in the <a
973href="http://llvm.org/docs/">documentation</a> section. The web page also
974contains versions of the API documentation which is up-to-date with the
975Subversion version of the source code.
976You can access versions of these documents specific to this release by going
977into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
978
979<p>If you have any questions or comments about LLVM, please feel free to contact
980us via the <a href="http://llvm.org/docs/#maillist"> mailing
981lists</a>.</p>
982
983</div>
984
985<!-- *********************************************************************** -->
986
987<hr>
988<address>
989 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman947321d2008-12-11 17:34:48 +0000[diff] [blame]990 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]991 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman947321d2008-12-11 17:34:48 +0000[diff] [blame]992 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]993
994 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
995 Last modified: $Date$
996</address>
997
998</body>
999</html>