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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 8a57e890aaf6dec525b051a1ba95d5100c3f63bd / . / docs / ReleaseNotes.html
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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
Chris Lattnere5236102010-03-17 04:02:39 +0000[diff] [blame]13<img align=right src="http://llvm.org/img/DragonSmall.png"
14 width="136" height="136">
15
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]16<ol>
17 <li><a href="#intro">Introduction</a></li>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]18 <li><a href="#subproj">Sub-project Status Update</a></li>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]19 <li><a href="#externalproj">External Projects Using LLVM 2.7</a></li>
20 <li><a href="#whatsnew">What's New in LLVM 2.7?</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]21 <li><a href="GettingStarted.html">Installation Instructions</a></li>
22 <li><a href="#portability">Portability and Supported Platforms</a></li>
Dan Gohman0de549c2008-10-14 16:23:02 +0000[diff] [blame]23 <li><a href="#knownproblems">Known Problems</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]24 <li><a href="#additionalinfo">Additional Information</a></li>
25</ol>
26
27<div class="doc_author">
Dan Gohman0de549c2008-10-14 16:23:02 +0000[diff] [blame]28 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]29</div>
30
Chris Lattner6ba1be32010-04-13 06:37:00 +0000[diff] [blame]31<!--
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]32<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.7
33release.<br>
34You may prefer the
35<a href="http://llvm.org/releases/2.6/docs/ReleaseNotes.html">LLVM 2.6
Chris Lattner6ba1be32010-04-13 06:37:00 +0000[diff] [blame]36Release Notes</a>.</h1>-->
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]37
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]38<!-- *********************************************************************** -->
39<div class="doc_section">
40 <a name="intro">Introduction</a>
41</div>
42<!-- *********************************************************************** -->
43
44<div class="doc_text">
45
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]46<p>This document contains the release notes for the LLVM Compiler
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]47Infrastructure, release 2.7. Here we describe the status of LLVM, including
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]48major improvements from the previous release and significant known problems.
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]49All LLVM releases may be downloaded from the <a
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]50href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]51
52<p>For more information about LLVM, including information about the latest
53release, please check out the <a href="http://llvm.org/">main LLVM
54web site</a>. If you have questions or comments, the <a
Chris Lattner58b1d0f2010-03-17 04:41:49 +0000[diff] [blame]55href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's
56Mailing List</a> is a good place to send them.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]57
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]58<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]59main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greif7c65c4f2008-10-14 11:00:32 +0000[diff] [blame]60current one. To see the release notes for a specific release, please see the
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]61<a href="http://llvm.org/releases/">releases page</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]62
63</div>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]64
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]65
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]66<!--
67Almost dead code.
68 include/llvm/Analysis/LiveValues.h => Dan
69 lib/Transforms/IPO/MergeFunctions.cpp => consider for 2.8.
70 llvm/Analysis/PointerTracking.h => Edwin wants this, consider for 2.8.
Chris Lattner6ba1be32010-04-13 06:37:00 +0000[diff] [blame]71 ABCD, GEPSplitterPass
Chris Lattner2bd5e652010-01-16 21:25:13 +0000[diff] [blame]72 MSIL backend?
Chris Lattner2b656342010-03-17 06:41:58 +0000[diff] [blame]73 lib/Transforms/Utils/SSI.cpp -> ABCD depends on it.
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]74-->
75
76
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]77<!-- Features that need text if they're finished for 2.7:
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]78 strong phi elim
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]79 llvm.dbg.value: variable debug info for optimized code
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]80 loop dependence analysis
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]81 -->
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]82
Chris Lattner4f076402008-10-12 19:47:48 +0000[diff] [blame]83 <!-- for announcement email:
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]84 Logo web page.
85 llvm devmtg
86 compiler_rt
87 KLEE web page at klee.llvm.org
88 Many new papers added to /pubs/
Chris Lattner2b656342010-03-17 06:41:58 +0000[diff] [blame]89 Mention gcc plugin.
Chris Lattnera53f4972009-02-25 06:34:50 +0000[diff] [blame]90 -->
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]91
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]92<!-- *********************************************************************** -->
93<div class="doc_section">
94 <a name="subproj">Sub-project Status Update</a>
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]95</div>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]96<!-- *********************************************************************** -->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]97
98<div class="doc_text">
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]99<p>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]100The LLVM 2.7 distribution currently consists of code from the core LLVM
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]101repository (which roughly includes the LLVM optimizers, code generators
102and supporting tools), the Clang repository and the llvm-gcc repository. In
103addition to this code, the LLVM Project includes other sub-projects that are in
104development. Here we include updates on these subprojects.
Bill Wendlingdde41b82009-03-02 04:28:57 +0000[diff] [blame]105</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]106
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]107</div>
108
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]109
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]110<!--=========================================================================-->
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]111<div class="doc_subsection">
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]112<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]113</div>
114
115<div class="doc_text">
116
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]117<p>The <a href="http://clang.llvm.org/">Clang project</a> is ...</p>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]118
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]119<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]120
Daniel Dunbarf3e35782008-10-14 23:25:09 +0000[diff] [blame]121<ul>
Daniel Dunbar29f1e722010-03-25 16:09:18 +0000[diff] [blame]122<li>FIXME: C++! Include a link to cxx_compatibility.html</li>
123
124<li>FIXME: Static Analyzer improvements?</li>
125
126<li>CIndex API and Python bindings: Clang now includes a C API as part of the
127CIndex library. Although we make make some changes to the API in the future, it
128is intended to be stable and has been designed for use by external projects. See
129the Clang
130doxygen <a href="http://clang.llvm.org/doxygen/group__CINDEX.html">CIndex</a>
131documentation for more details. The CIndex API also includings an preliminary
132set of Python bindings.</li>
133
134<li>ARM Support: Clang now has ABI support for both the Darwin and Linux ARM
135ABIs. Coupled with many improvements to the LLVM ARM backend, Clang is now
136suitable for use as a a beta quality ARM compiler.</li>
Bill Wendlinga8fb81d2009-03-02 04:28:18 +0000[diff] [blame]137</ul>
Chris Lattnera3c683b2008-10-13 18:11:54 +0000[diff] [blame]138</div>
139
140<!--=========================================================================-->
141<div class="doc_subsection">
142<a name="clangsa">Clang Static Analyzer</a>
143</div>
144
145<div class="doc_text">
146
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]147<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]148includes an early stage static source code analysis tool for <a
149href="http://clang.llvm.org/StaticAnalysis.html">automatically finding bugs</a>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]150in C and Objective-C programs. The tool performs checks to find
Ted Kremeneka0d77d72009-02-27 07:01:32 +0000[diff] [blame]151bugs that occur on a specific path within a program.</p>
Chris Lattnerc2d84672008-10-14 00:52:49 +0000[diff] [blame]152
Chris Lattnere5236102010-03-17 04:02:39 +0000[diff] [blame]153<p>In the LLVM 2.7 time-frame, the analyzer core has sprouted legs and...</p>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]154
155</div>
156
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]157<!--=========================================================================-->
158<div class="doc_subsection">
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]159<a name="vmkit">VMKit: JVM/CLI Virtual Machine Implementation</a>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]160</div>
161
162<div class="doc_text">
163<p>
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]164The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation of
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]165a JVM and a CLI Virtual Machine (Microsoft .NET is an
166implementation of the CLI) using LLVM for static and just-in-time
167compilation.</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]168
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]169<p>
Chris Lattnerd5b62522010-03-29 18:34:13 +0000[diff] [blame]170With the release of LLVM 2.7, VMKit has shifted to a great framework for writing
171virtual machines. VMKit now offers precise and efficient garbage collection with
172multi-threading support, thanks to the MMTk memory management toolkit, as well
173as just in time and ahead of time compilation with LLVM. The major changes in
174VMKit 0.27 are:</p>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]175
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]176<ul>
177
Chris Lattnerd5b62522010-03-29 18:34:13 +0000[diff] [blame]178<li>Garbage collection: VMKit now uses the MMTk toolkit for garbage collectors.
179 The first collector to be ported is the MarkSweep collector, which is precise,
180 and drastically improves the performance of VMKit.</li>
181<li>Line number information in the JVM: by using the debug metadata of LLVM, the
182 JVM now supports precise line number information, useful when printing a stack
183 trace.</li>
184<li>Interface calls in the JVM: we implemented a variant of the Interface Method
185 Table technique for interface calls in the JVM.
186</li>
Nicolas Geoffray2b139382008-10-14 19:23:04 +0000[diff] [blame]187
188</ul>
Chris Lattner78a130b2008-10-13 18:01:01 +0000[diff] [blame]189</div>
190
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]191
192<!--=========================================================================-->
193<div class="doc_subsection">
194<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
195</div>
196
197<div class="doc_text">
198<p>
199The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
200is a simple library that provides an implementation of the low-level
201target-specific hooks required by code generation and other runtime components.
202For example, when compiling for a 32-bit target, converting a double to a 64-bit
203unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
204function. The compiler-rt library provides highly optimized implementations of
205this and other low-level routines (some are 3x faster than the equivalent
206libgcc routines).</p>
207
208<p>
209All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]210License, a "BSD-style" license. New in LLVM 2.7: compiler_rt now
211supports ARM targets.</p>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]212
213</div>
214
215<!--=========================================================================-->
216<div class="doc_subsection">
Duncan Sands2d9c3082010-04-02 09:23:15 +0000[diff] [blame]217<a name="dragonegg">DragonEgg: llvm-gcc ported to gcc-4.5</a>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]218</div>
219
220<div class="doc_text">
221<p>
Duncan Sands2d9c3082010-04-02 09:23:15 +0000[diff] [blame]222<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a port of llvm-gcc to
223gcc-4.5. Unlike llvm-gcc, which makes many intrusive changes to the underlying
224gcc-4.2 code, dragonegg in theory does not require any gcc-4.5 modifications
225whatsoever (currently one small patch is needed). This is thanks to the new
226<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin architecture</a>, which
227makes it possible to modify the behaviour of gcc at runtime by loading a plugin,
228which is nothing more than a dynamic library which conforms to the gcc plugin
229interface. DragonEgg is a gcc plugin that causes the LLVM optimizers to be run
230instead of the gcc optimizers, and the LLVM code generators instead of the gcc
231code generators, just like llvm-gcc. To use it, you add
232"-fplugin=path/dragonegg.so" to the gcc-4.5 command line, and gcc-4.5 magically
233becomes llvm-gcc-4.5!
234</p>
235
236<p>
237DragonEgg is still a work in progress. Currently C works very well, while C++,
238Ada and Fortran work fairly well. All other languages either don't work at all,
239or only work poorly. For the moment only the x86-32 and x86-64 targets are
Duncan Sands566f40b2010-04-20 19:40:58 +0000[diff] [blame]240supported, and only on linux and darwin (darwin needs an additional gcc patch).
Duncan Sands2d9c3082010-04-02 09:23:15 +0000[diff] [blame]241</p>
242
243<p>
Duncan Sands566f40b2010-04-20 19:40:58 +0000[diff] [blame]244The first dragonegg release will occur shortly after llvm-2.7 is released.
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]245</p>
246
247</div>
248
249
250<!--=========================================================================-->
251<div class="doc_subsection">
252<a name="mc">llvm-mc: Machine Code Toolkit</a>
253</div>
254
255<div class="doc_text">
256<p>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]257The LLVM Machine Code (MC) Toolkit project is ...
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]258</p>
259
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]260<p>
261MC Disassembler (with blog post), MCInstPrinter. Many X86 backend and AsmPrinter simplifications
262Can transcode from GAS to intel syntax with "llvm-mc foo.s -output-asm-variant=1"
263</p>
264
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]265</div>
266
267
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]268<!-- *********************************************************************** -->
269<div class="doc_section">
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]270 <a name="externalproj">External Open Source Projects Using LLVM 2.7</a>
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]271</div>
272<!-- *********************************************************************** -->
273
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]274<div class="doc_text">
275
276<p>An exciting aspect of LLVM is that it is used as an enabling technology for
277 a lot of other language and tools projects. This section lists some of the
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]278 projects that have already been updated to work with LLVM 2.7.</p>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]279</div>
280
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]281<!--=========================================================================-->
282<div class="doc_subsection">
283<a name="pure">Pure</a>
284</div>
285
286<div class="doc_text">
287<p>
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]288<a href="http://pure-lang.googlecode.com/">Pure</a>
289is an algebraic/functional programming language based on term rewriting.
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]290Programs are collections of equations which are used to evaluate expressions in
291a symbolic fashion. Pure offers dynamic typing, eager and lazy evaluation,
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]292lexical closures, a hygienic macro system (also based on term rewriting),
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]293built-in list and matrix support (including list and matrix comprehensions) and
294an easy-to-use C interface. The interpreter uses LLVM as a backend to
295 JIT-compile Pure programs to fast native code.</p>
296
Chris Lattner1f8dc512010-03-17 17:25:49 +0000[diff] [blame]297<p>Pure versions 0.43 and later have been tested and are known to work with
298LLVM 2.7 (and continue to work with older LLVM releases >= 2.5).</p>
299
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]300</div>
301
Chris Lattner1ad599a2009-02-28 18:58:01 +0000[diff] [blame]302<!--=========================================================================-->
303<div class="doc_subsection">
304<a name="RoadsendPHP">Roadsend PHP</a>
305</div>
306
307<div class="doc_text">
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]308<p>
309<a href="http://code.roadsend.com/rphp">Roadsend PHP</a> (rphp) is an open
Chris Lattner9e08de12009-03-02 19:07:24 +0000[diff] [blame]310source implementation of the PHP programming
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]311language that uses LLVM for its optimizer, JIT and static compiler. This is a
Chris Lattnere5236102010-03-17 04:02:39 +0000[diff] [blame]312reimplementation of an earlier project that is now based on LLVM.
Chris Lattner1f8dc512010-03-17 17:25:49 +0000[diff] [blame]313</p>
Chris Lattner1ad599a2009-02-28 18:58:01 +0000[diff] [blame]314</div>
Chris Lattnerb2cc5022009-02-26 22:33:38 +0000[diff] [blame]315
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]316<!--=========================================================================-->
317<div class="doc_subsection">
318<a name="UnladenSwallow">Unladen Swallow</a>
319</div>
320
321<div class="doc_text">
322<p>
323<a href="http://code.google.com/p/unladen-swallow/">Unladen Swallow</a> is a
324branch of <a href="http://python.org/">Python</a> intended to be fully
325compatible and significantly faster. It uses LLVM's optimization passes and JIT
Chris Lattnerd7db82c2010-03-18 06:52:15 +0000[diff] [blame]326compiler.
Chris Lattnere5236102010-03-17 04:02:39 +0000[diff] [blame]327</p>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]328</div>
329
330<!--=========================================================================-->
331<div class="doc_subsection">
Chris Lattner49894862010-03-29 17:50:39 +0000[diff] [blame]332<a name="tce">TTA-based Codesign Environment (TCE)</a>
333</div>
334
335<div class="doc_text">
336<p>
337<a href="http://tce.cs.tut.fi/">TCE</a> is a toolset for designing
338application-specific processors (ASP) based on the Transport triggered
339architecture (TTA). The toolset provides a complete co-design flow from C/C++
340programs down to synthesizable VHDL and parallel program binaries. Processor
341customization points include the register files, function units, supported
342operations, and the interconnection network.</p>
343
344<p>TCE uses llvm-gcc/Clang and LLVM for C/C++ language support, target
345independent optimizations and also for parts of code generation. It generates
346new LLVM-based code generators "on the fly" for the designed TTA processors and
347loads them in to the compiler backend as runtime libraries to avoid per-target
348recompilation of larger parts of the compiler chain.</p>
349
350</div>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]351
John Criswelle75f04f2010-04-06 14:52:14 +0000[diff] [blame]352<!--=========================================================================-->
353<div class="doc_subsection">
354<a name="safecode">SAFECode Compiler</a>
355</div>
356
357<div class="doc_text">
358<p>
359<a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C
360compiler built using LLVM. It takes standard, unannotated C code, analyzes the
361code to ensure that memory accesses and array indexing operations are safe, and
362instruments the code with run-time checks when safety cannot be proven
363statically.
364</p>
365</div>
366
367
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]368<!-- *********************************************************************** -->
369<div class="doc_section">
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]370 <a name="whatsnew">What's New in LLVM 2.7?</a>
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]371</div>
372<!-- *********************************************************************** -->
373
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]374<div class="doc_text">
375
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]376<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]377minor improvements. Some of the major improvements and new features are listed
378in this section.
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]379</p>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]380
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]381<p>In addition to changes to the code, between LLVM 2.6 and 2.7, a number of
382organization changes have happened:
383</p>
384
385<ul>
386<li>LLVM has a new <a href="http://llvm.org/Logo.html">official Logo</a>!</li>
387
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]388<li>Ted Kremenek and Doug Gregor have stepped forward as <a
389 href="http://llvm.org/docs/DeveloperPolicy.html#owners">Code Owners</a> of the
390 Clang static analyzer and the Clang Frontend, respectively.</li>
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]391
392<li>LLVM now has an <a href="http://blog.llvm.org">official Blog</a> at
393 <a href="http://blog.llvm.org">http://blog.llvm.org</a>. This is a great way
394 to learn about new LLVM-related features as they are implemented. Several
395 features in this release are already explained on the blog.</li>
396
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]397<li>The LLVM web pages are now checked into the SVN server, in the "www",
398 "www-pubs" and "www-releases" SVN modules. Previously they were hidden in a
399 largely inaccessible old CVS server.</p>
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]400
401<li><a href="http://llvm.org">llvm.org</a> is now hosted on a new (and much
402 faster) server. It is still graciously hosted at the University of Illinois
403 of Urbana Champaign.</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]404</ul>
Chris Lattner5cce7a52008-06-08 22:59:35 +0000[diff] [blame]405</div>
406
Chris Lattnerf6a0d382008-06-08 21:58:17 +0000[diff] [blame]407<!--=========================================================================-->
Chris Lattnerf65224f2008-06-08 21:34:41 +0000[diff] [blame]408<div class="doc_subsection">
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]409<a name="majorfeatures">Major New Features</a>
410</div>
411
412<div class="doc_text">
413
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]414<p>LLVM 2.7 includes several major new capabilities:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]415
416<ul>
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]417<li>This release includes initial support for the <a
418 href="http://en.wikipedia.org/wiki/MicroBlaze">MicroBlaze</a> target.
419 MicroBlaze is a soft processor core designed for Xilinx FPGAs.</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]420
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]421<li>LLVM 2.7 includes a new LLVM IR "extensible metadata" feature. This feature
422 supports many different use cases, including allowing front-end authors to
423 encode source level information into LLVM IR, which is consumed by later
424 language-specific passes. This is a great way to do high-level optimizations
425 like devirtualization, type-based alias analysis, etc. See the <a
426 href="http://blog.llvm.org/2010/04/extensible-metadata-in-llvm-ir.html">
427 Extensible Metadata Blog Post</a> for more information.</li>
428
429<li>LLVM 2.7 encodes <a href="SourceLevelDebugging.html">debug information</a>
430in a completely new way, built on extensible metadata. The new implementation
431is much more memory efficient and paves the way for improvements to optimized
432code debugging experience.</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]433
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]434<li>LLVM 2.7 now directly supports taking the address of a label and doing an
435 indirect branch through a pointer. This is particularly useful for
436 interpreter loops, and is used to implement the GCC "address of label"
437 extension. For more information, see the <a
438href="http://blog.llvm.org/2010/01/address-of-label-and-indirect-branches.html">
439Address of Label and Indirect Branches in LLVM IR Blog Post</a>.
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]440
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]441<li>LLVM 2.7 is the first release to start supporting APIs for assembling and
442 disassembling target machine code. These APIs are useful for a variety of
443 low level clients, and are surfaced in the new "enhanced disassembly" API.
444 For more information see the <a
445 href="http://blog.llvm.org/2010/01/x86-disassembler.html">The X86
446 Disassembler Blog Post</a> for more information.</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]447
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]448<li>LLVM 2.7 includes major parts of the work required by the new MC Project,
449 which aims to rework our handling of low-level machine code. A few targets
450 have been refactored to support it, and work is underway to support a native
451 assembler in LLVM. This work is not complete in LLVM 2.7, but you has made
452 substantially more progress on LLVM mainline. You can read more about this
453 in the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">
454 Intro to the LLVM MC Project Blog Post</a>.
455</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]456
Chris Lattner5ba16862008-02-10 08:18:42 +0000[diff] [blame]457</ul>
Chris Lattner2b656342010-03-17 06:41:58 +0000[diff] [blame]458
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]459</div>
460
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]461<!--=========================================================================-->
462<div class="doc_subsection">
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]463<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]464</div>
465
466<div class="doc_text">
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]467<p>LLVM IR has several new features for better support of new targets and that
468expose new optimization opportunities:</p>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]469
Chris Lattnerc5a4e312008-06-05 06:25:56 +0000[diff] [blame]470<ul>
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]471<li>LLVM IR now supports a 16-bit "half float" data type through two new <a
472 href="LangRef.html#int_fp16">intrinsics</a> and APFloat support.</li>
473<li>LLVM IR supports two <a href="LangRef.html#fnattrs">new function
474 attributes</a>: inlinehint and alignstack(n). The former is a hint to the
475 optimizer that a function was declared 'inline' and thus it might be useful
476 to increase the chances the the inliner actually inline it. The later
477 indicates to the code generator that the function diverges from the platform
478 ABI on stack alignment.</li>
479<li>The new <a href="LangRef.html#int_objectsize">llvm.objectsize</a> intrinsic
480 allows the optimizer to infer the sizes of memory objects in some cases.
481 This intrinsic is used to implement the GCC __builtin_object_size
482 extension.</li>
483<li>LLVM 2.7 has pre-alpha support for <a
484 href="http://llvm.org/docs/LangRef.html#t_union">unions in LLVM IR</a>.
485 Unfortuantely, this support is not really usable in 2.7, so if you're
486 interested in pushing it forward, please help contribute to LLVM mainline.</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]487</li>
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]488</ul>
Mikhail Glushenkov808cd3e2008-10-13 02:08:34 +0000[diff] [blame]489
Chris Lattnerc3649452008-02-10 08:17:19 +0000[diff] [blame]490</div>
491
492<!--=========================================================================-->
493<div class="doc_subsection">
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]494<a name="optimizer">Optimizer Improvements</a>
495</div>
496
497<div class="doc_text">
498
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]499<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]500release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner8fda4952008-02-10 07:46:44 +0000[diff] [blame]501
502<ul>
503
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]504<li>...</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]505Inliner reuses arrays allocas when inlining multiple callers to reduce stack usage.
506Optimal Edge Profiling?
507Instcombine is now a library, has its own IRBuilder to simplify itself.
508Better code size analysis in loop unswitch, inliner code split out to a new
509 CodeMetrics class for reuse.
510Many changes to the pass ordering for improved optimization effectiveness.
511BasicAA improved to be less dependent on "type safe" pointers, it can now look
512 through bitcasts more aggressively.
513GVN PHI Translation improvements. blog post: http://blog.llvm.org/2009/12/advanced-topics-in-redundant-load.html
514New SCEV AA pass: -scev-aa
515Target data now has notion of 'native' integer data types which optimizations can use.
516Opt now works conservatively if no target data is set (is this fully working?)
517New Analysis/InstructionSimplify.h interface for simplifying instructions that don't exist.
518Jump threading is now much more aggressive at simplifying correlated
519 conditionals and threading blocks with otherwise complex logic. CondProp pass
520 removed (functionality merged into jump threading).
521New SSAUpdater and MachineSSAUpdater classes for unstructured ssa updating,
522 changed jump threading, GVN, etc to use it which simplified them and speed
523 them up.
524
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]525
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]526</ul>
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]527
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]528</div>
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]529
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]530
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]531<!--=========================================================================-->
532<div class="doc_subsection">
533<a name="executionengine">Interpreter and JIT Improvements</a>
534</div>
Chris Lattnerea9c2242008-10-13 21:50:36 +0000[diff] [blame]535
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]536<div class="doc_text">
537
538<ul>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]539<li>The JIT now supports generating debug information, which is compatible with
540the new GDB 7.0 (and later) interfaces for registering debug info for
541dynamically generated code.</li>
542
Jeffrey Yasskin40715142010-01-29 19:10:38 +0000[diff] [blame]543<li>The JIT now <a
544href="http://llvm.org/viewvc/llvm-project?view=rev&revision=85295">defaults
545to compiling eagerly</a> to avoid a race condition in the lazy JIT.
546Clients that still want the lazy JIT can switch it on by calling
547<tt>ExecutionEngine::DisableLazyCompilation(false)</tt>.</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]548
Jeffrey Yasskinc0577082010-02-11 01:07:39 +0000[diff] [blame]549<li>It is now possible to create more than one JIT instance in the same process.
550These JITs can generate machine code in parallel,
551although <a href="http://llvm.org/docs/ProgrammersManual.html#jitthreading">you
552still have to obey the other threading restrictions</a>.</li>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]553
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]554</ul>
555
556</div>
557
558<!--=========================================================================-->
559<div class="doc_subsection">
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]560<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]561</div>
562
563<div class="doc_text">
564
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]565<p>We have put a significant amount of work into the code generator
566infrastructure, which allows us to implement more aggressive algorithms and make
567it run faster:</p>
Chris Lattner0eef6e42008-06-08 02:45:07 +0000[diff] [blame]568
569<ul>
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]570<li>New instruction selector [blog post?].</li>
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]571
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]572Code generator MC'ized except for debug info and EH.
573
574New CodeGen Level CSE
575Combiner-AA improvements, why not on by default?
576Pre-regalloc tail duplication
577New LSR with "full strength reduction" mode. Description?
578Codegen level OptimizeExtsPass pass, takes advantage of x86 subregs.
579Support for the GCC option -fno-schedule-insns
580non-temporal load/store
581MachineSSAUpdater.h
582X86 and XCore supports returning arbitrary return values, returning too many values is
583 supported by returning through a hidden pointer.
584verbose-asm now produces information about spill slots and loop nests
585GHC Haskell ABI / calling conv support.
586Many improvements to debug info
587
588
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]589<li>...</li>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]590</ul>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]591</div>
592
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]593<!--=========================================================================-->
594<div class="doc_subsection">
595<a name="x86">X86-32 and X86-64 Target Improvements</a>
596</div>
597
598<div class="doc_text">
599<p>New features of the X86 target include:
600</p>
601
602<ul>
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]603
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]604<li>PostRA scheduler for X86?</li>
605<li>x86 sibcall / tailcall optimization in CCC mode.</li>
606<li>X86: XMM subreg modeling for extraction of the low element.</li>
Chris Lattner5f393542009-03-02 03:24:11 +0000[diff] [blame]607
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]608</ul>
609
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]610</div>
Chris Lattnerb0d6c502007-09-21 03:54:09 +0000[diff] [blame]611
612<!--=========================================================================-->
613<div class="doc_subsection">
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]614<a name="ARM">ARM Target Improvements</a>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]615</div>
616
617<div class="doc_text">
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]618<p>New features of the ARM target include:
619</p>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]620
621<ul>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]622
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]623<li>The ARM backend now generates instructions in unified assembly syntax.</li>
624
625<li>llvm-gcc now has complete support for the ARM v7 NEON instruction set. This
626 support differs slightly from the GCC implementation. Please see the
627 <a
628href="http://blog.llvm.org/2010/04/arm-advanced-simd-neon-intrinsics-and.html">
629 ARM Advanced SIMD (NEON) Intrinsics and Types in LLVM Blog Post</a> for
630 helpful information if migrating code from GCC to LLVM-GCC.</li>
631
632<li>The ARM and Thumb code generators now using register scavenging for stack
633 object address materialization.(FIXME: WHAT BENEFIT DOES THIS PROVIDE?)</li>
634
635<li>The ARM backend now has good support for ARMv4 targets, and has been tested
636 on StrongARM hardware. Previously, LLVM only supported ARMv4T and
637 newer chips.</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]638</ul>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]639
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]640
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]641</div>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]642
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]643<!--=========================================================================-->
644<div class="doc_subsection">
645<a name="OtherTarget">Other Target Specific Improvements</a>
646</div>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]647
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]648<div class="doc_text">
649<p>New features of other targets include:
650</p>
651
652<ul>
Jeffrey Yasskin8ee1b0a2010-01-28 01:14:43 +0000[diff] [blame]653<li>...</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]654</ul>
655
656</div>
657
658<!--=========================================================================-->
659<div class="doc_subsection">
660<a name="newapis">New Useful APIs</a>
661</div>
662
663<div class="doc_text">
664
665<p>This release includes a number of new APIs that are used internally, which
666 may also be useful for external clients.
667</p>
668
669<ul>
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]670<li>The llvm/Support/Regex.h header exposes a platform independent regular
671 expression API. Building on this, the <a
672 href="TestingGuide.html#FileCheck">FileCheck</a> utility now supports
673 regular exressions.</li>
674<li>raw_ostream now supports a circular "debug stream" accessed with "dbgs()".
675 By default, this stream works the same way as "errs()", but if you pass
676 <tt>-debug-buffer-size=1000</tt> to opt, the debug stream is capped to a
677 fixed sized circular buffer and the output is printed at the end of the
678 program's execution. This is helpful if you have a long lived compiler
679 process and you're interested in seeing snapshots in time.</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]680</ul>
681
682
683</div>
684
685<!--=========================================================================-->
686<div class="doc_subsection">
687<a name="otherimprovements">Other Improvements and New Features</a>
688</div>
689
690<div class="doc_text">
691<p>Other miscellaneous features include:</p>
692
693<ul>
Chris Lattner8a57e892010-04-21 06:23:40 +0000[diff] [blame^]694<li>You can now build LLVM as a big dynamic library (e.g. "libllvm2.7.so"). To
695 get this, configure LLVM with the --enable-shared option.</li>
696
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]697<li>LLVM command line tools now overwrite their output by default, before they
698 would only do this with -f. This makes them more convenient to use, and
699 behave more like standard unix tools.</li>
700
701<li>The opt and llc tools now autodetect whether their input is a .ll or .bc
702 file, and automatically do the right thing. This means you don't need to
703 explicitly use the llvm-as tool for most things.</li>
Chris Lattner7ccc40d2009-03-01 02:30:21 +0000[diff] [blame]704</ul>
705
706</div>
707
Chris Lattnere45f18b2008-06-05 08:02:49 +0000[diff] [blame]708
709<!--=========================================================================-->
710<div class="doc_subsection">
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]711<a name="changes">Major Changes and Removed Features</a>
712</div>
713
714<div class="doc_text">
715
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]716<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]717on LLVM 2.6, this section lists some "gotchas" that you may run into upgrading
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]718from the previous release.</p>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]719
720<ul>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]721
722<li>
723The Andersen's alias analysis ("anders-aa") pass, the Predicate Simplifier
724("predsimplify") pass, the LoopVR pass, the GVNPRE pass, and the random sampling
725profiling ("rsprofiling") passes have all been removed. They were not being
726actively maintained and had substantial problems. If you are interested in
727these components, you are welcome to ressurect them from SVN, fix the
728correctness problems, and resubmit them to mainline.</li>
729
730<li>LLVM now defaults to building most libraries with RTTI turned off, providing
731a code size reduction. Packagers who are interested in building LLVM to support
732plugins that require RTTI information should build with "make REQUIRE_RTTI=1"
733and should read the new <a href="Packaging.html">Advice on Packaging LLVM</a>
734document.</li>
735
Jeffrey Yasskin260af332010-02-09 23:03:44 +0000[diff] [blame]736<li>The LLVM interpreter now defaults to <em>not</em> using <tt>libffi</tt> even
737if you have it installed. This makes it more likely that an LLVM built on one
738system will work when copied to a similar system. To use <tt>libffi</tt>,
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]739configure with <tt>--enable-libffi</tt></li>.
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]740
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]741<li>Debug information uses a completely different representation, an LLVM 2.6
742.bc file should work with LLVM 2.7, but debug info won't come forward.</li>
743
744<li>The LLVM 2.6 (and earlier) "malloc" and "free" instructions got removed,
745 along with LowerAllocations pass. Now you should just use a call to the
746 malloc and free functions in libc. These calls are optimized as well as
747 the old instructions were.</li>
748</ul>
Chris Lattnercc64a322008-10-13 22:06:31 +0000[diff] [blame]749
750<p>In addition, many APIs have changed in this release. Some of the major LLVM
751API changes are:</p>
752
753<ul>
Chris Lattner6fd928d2010-04-21 05:17:40 +0000[diff] [blame]754<li>Just about everything has been converted to use raw_ostream instead of
755 std::ostream.</li>
756<li>llvm/ADT/iterator.h has been removed, just use &lt;iterator&gt;
757 instead.</li>
758<li>The Streams.h file and "DOUT" got removed, use "DEBUG(errs() &lt;&lt; ...);"
759 instead.</li>
Jeffrey Yasskin2ca16212010-01-28 01:41:20 +0000[diff] [blame]760<li><tt>ModuleProvider</tt> has been <a
761href="http://llvm.org/viewvc/llvm-project?view=rev&revision=94686">removed</a>
762and its methods moved to <tt>Module</tt> and <tt>GlobalValue</tt>.
763Most clients can remove uses of <tt>ExistingModuleProvider</tt>,
764replace <tt>getBitcodeModuleProvider</tt> with
765<tt>getLazyBitcodeModule</tt>, and pass their <tt>Module</tt> to
766functions that used to accept <tt>ModuleProvider</tt>. Clients who
767wrote their own <tt>ModuleProvider</tt>s will need to derive from
768<tt>GVMaterializer</tt> instead and use
769<tt>Module::setMaterializer</tt> to attach it to a
770<tt>Module</tt>.</li>
771
772<li><tt>GhostLinkage</tt> has given up the ghost.
773<tt>GlobalValue</tt>s that have not yet been read from their backing
774storage have the same linkage they will have after being read in.
775Clients must replace calls to
776<tt>GlobalValue::hasNotBeenReadFromBitcode</tt> with
777<tt>GlobalValue::isMaterializable</tt>.</li>
Daniel Dunbar61f41422010-02-10 04:09:52 +0000[diff] [blame]778
Daniel Dunbar369889a2010-02-14 01:47:19 +0000[diff] [blame]779<li>The <tt>llvm/Support/DataTypes.h</tt> header has moved
780to <tt>llvm/System/DataTypes.h</tt>.</li>
781
Duncan Sandsdd29fc82010-02-17 17:20:17 +0000[diff] [blame]782<li>The <tt>isInteger</tt>, <tt>isIntOrIntVector</tt>, <tt>isFloatingPoint</tt>,
783<tt>isFPOrFPVector</tt> and <tt>isFPOrFPVector</tt> methods have been renamed
784<tt>isIntegerTy</tt>, <tt>isIntOrIntVectorTy</tt>, <tt>isFloatingPointTy</tt>,
785<tt>isFPOrFPVectorTy</tt> and <tt>isFPOrFPVectorTy</tt> respectively.</li>
Devang Patel0e3da1a2008-10-14 20:03:43 +0000[diff] [blame]786</ul>
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]787
Chris Lattner92eacf82008-10-13 17:57:36 +0000[diff] [blame]788</div>
789
790
791
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]792<!-- *********************************************************************** -->
793<div class="doc_section">
794 <a name="portability">Portability and Supported Platforms</a>
795</div>
796<!-- *********************************************************************** -->
797
798<div class="doc_text">
799
800<p>LLVM is known to work on the following platforms:</p>
801
802<ul>
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]803<li>Intel and AMD machines (IA32, X86-64, AMD64, EMT-64) running Red Hat
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]804 Linux, Fedora Core, FreeBSD and AuroraUX (and probably other unix-like
805 systems).</li>
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]806<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]807 and 64-bit modes.</li>
Chris Lattnere0798082008-02-06 18:00:06 +0000[diff] [blame]808<li>Intel and AMD machines running on Win32 using MinGW libraries (native).</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]809<li>Intel and AMD machines running on Win32 with the Cygwin libraries (limited
810 support is available for native builds with Visual C++).</li>
Chris Lattner9235ce52009-10-16 16:30:58 +0000[diff] [blame]811<li>Sun x86 and AMD64 machines running Solaris 10, OpenSolaris 0906.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]812<li>Alpha-based machines running Debian GNU/Linux.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]813</ul>
814
Chris Lattnerba948522008-06-05 06:57:39 +0000[diff] [blame]815<p>The core LLVM infrastructure uses GNU autoconf to adapt itself
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]816to the machine and operating system on which it is built. However, minor
817porting may be required to get LLVM to work on new platforms. We welcome your
818portability patches and reports of successful builds or error messages.</p>
819
820</div>
821
822<!-- *********************************************************************** -->
823<div class="doc_section">
824 <a name="knownproblems">Known Problems</a>
825</div>
826<!-- *********************************************************************** -->
827
828<div class="doc_text">
829
Mikhail Glushenkovf61066a2009-03-01 18:09:47 +0000[diff] [blame]830<p>This section contains significant known problems with the LLVM system,
Chris Lattnerb1ad47c2008-11-10 05:40:34 +0000[diff] [blame]831listed by component. If you run into a problem, please check the <a
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]832href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
833there isn't already one.</p>
834
Chris Lattner1f8dc512010-03-17 17:25:49 +0000[diff] [blame]835<ul>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]836<li>LLVM will not correctly compile on Solaris and/or OpenSolaris
837using the stock GCC 3.x.x series 'out the box',
Chris Lattnerc09ffd22009-11-03 21:50:09 +0000[diff] [blame]838See: <a href="GettingStarted.html#brokengcc">Broken versions of GCC and other tools</a>.
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]839However, A <a href="http://pkg.auroraux.org/GCC">Modern GCC Build</a>
840for x86/x86-64 has been made available from the third party AuroraUX Project
841that has been meticulously tested for bootstrapping LLVM &amp; Clang.</li>
842</ul>
843
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]844</div>
845
846<!-- ======================================================================= -->
847<div class="doc_subsection">
848 <a name="experimental">Experimental features included with this release</a>
849</div>
850
851<div class="doc_text">
852
853<p>The following components of this LLVM release are either untested, known to
854be broken or unreliable, or are in early development. These components should
855not be relied on, and bugs should not be filed against them, but they may be
856useful 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]857components, please contact us on the <a
858href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]859
860<ul>
Wesley Peckbe6dc822010-03-18 14:31:30 +0000[diff] [blame]861<li>The MSIL, Alpha, SPU, MIPS, PIC16, Blackfin, MSP430, SystemZ and MicroBlaze
862 backends are experimental.</li>
Bill Wendling9c7c4382009-03-02 07:54:14 +0000[diff] [blame]863<li>The <tt>llc</tt> "<tt>-filetype=asm</tt>" (the default) is the only
Chris Lattner58b1d0f2010-03-17 04:41:49 +0000[diff] [blame]864 supported value for this option. The MachO writer is experimental, and
865 works much better in mainline SVN.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]866</ul>
867
868</div>
869
870<!-- ======================================================================= -->
871<div class="doc_subsection">
872 <a name="x86-be">Known problems with the X86 back-end</a>
873</div>
874
875<div class="doc_text">
876
877<ul>
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]878 <li>The X86 backend does not yet support
879 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
880 floating point stack</a>. It supports the 'f' and 't' constraints, but not
881 'u'.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]882 <li>The X86 backend generates inefficient floating point code when configured
883 to generate code for systems that don't have SSE2.</li>
Duncan Sands8b4f3772008-06-08 19:38:43 +0000[diff] [blame]884 <li>Win64 code generation wasn't widely tested. Everything should work, but we
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]885 expect small issues to happen. Also, llvm-gcc cannot build the mingw64
886 runtime currently due
Anton Korobeynikov77d15e22008-06-08 10:24:13 +0000[diff] [blame]887 to <a href="http://llvm.org/PR2255">several</a>
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]888 <a href="http://llvm.org/PR2257">bugs</a> and due to lack of support for
889 the
890 'u' inline assembly constraint and for X87 floating point inline assembly.</li>
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]891 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner47202c32009-03-02 02:37:32 +0000[diff] [blame]892 <tt>va_arg</tt>. Currently, the llvm-gcc and front-ends support variadic
Dan Gohman3882ecb2008-06-08 23:05:11 +0000[diff] [blame]893 argument constructs on X86-64 by lowering them manually.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]894</ul>
895
896</div>
897
898<!-- ======================================================================= -->
899<div class="doc_subsection">
900 <a name="ppc-be">Known problems with the PowerPC back-end</a>
901</div>
902
903<div class="doc_text">
904
905<ul>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]906<li>The Linux PPC32/ABI support needs testing for the interpreter and static
907compilation, and lacks support for debug information.</li>
908</ul>
909
910</div>
911
912<!-- ======================================================================= -->
913<div class="doc_subsection">
914 <a name="arm-be">Known problems with the ARM back-end</a>
915</div>
916
917<div class="doc_text">
918
919<ul>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]920<li>Support for the Advanced SIMD (Neon) instruction set is still incomplete
921and not well tested. Some features may not work at all, and the code quality
922may be poor in some cases.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]923<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands1827fa62007-09-26 15:59:54 +0000[diff] [blame]924processors, thumb programs can crash or produce wrong
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]925results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]926<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]927</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]928</ul>
929
930</div>
931
932<!-- ======================================================================= -->
933<div class="doc_subsection">
934 <a name="sparc-be">Known problems with the SPARC back-end</a>
935</div>
936
937<div class="doc_text">
938
939<ul>
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]940<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]941 support the 64-bit SPARC ABI (-m64).</li>
942</ul>
943
944</div>
945
946<!-- ======================================================================= -->
947<div class="doc_subsection">
Bruno Cardoso Lopes62d45d72008-10-25 14:56:26 +0000[diff] [blame]948 <a name="mips-be">Known problems with the MIPS back-end</a>
949</div>
950
951<div class="doc_text">
952
953<ul>
Bruno Cardoso Lopes62d45d72008-10-25 14:56:26 +0000[diff] [blame]954<li>64-bit MIPS targets are not supported yet.</li>
955</ul>
956
957</div>
958
959<!-- ======================================================================= -->
960<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]961 <a name="alpha-be">Known problems with the Alpha back-end</a>
962</div>
963
964<div class="doc_text">
965
966<ul>
967
968<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
969appropriate nops inserted to ensure restartability.</li>
970
971</ul>
972</div>
973
974<!-- ======================================================================= -->
975<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]976 <a name="c-be">Known problems with the C back-end</a>
977</div>
978
979<div class="doc_text">
980
981<ul>
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]982<li><a href="http://llvm.org/PR802">The C backend has only basic support for
983 inline assembly code</a>.</li>
Chris Lattnere0194462007-09-26 06:01:35 +0000[diff] [blame]984<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
985 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greife33c5322009-03-02 12:02:51 +0000[diff] [blame]986 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsbd0ad6e2008-02-10 13:40:55 +0000[diff] [blame]987<li>The C backend does not support all exception handling constructs.</li>
Duncan Sandse6e264c2009-02-25 11:51:54 +0000[diff] [blame]988<li>The C backend does not support arbitrary precision integers.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]989</ul>
990
991</div>
992
993
994<!-- ======================================================================= -->
995<div class="doc_subsection">
Chris Lattner58b1d0f2010-03-17 04:41:49 +0000[diff] [blame]996 <a name="c-fe">Known problems with the llvm-gcc C and C++ front-end</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]997</div>
998
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]999<div class="doc_text">
1000
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]1001<p>The only major language feature of GCC not supported by llvm-gcc is
1002 the <tt>__builtin_apply</tt> family of builtins. However, some extensions
1003 are only supported on some targets. For example, trampolines are only
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]1004 supported on some targets (these are used when you take the address of a
1005 nested function).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1006
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]1007<p>If you run into GCC extensions which are not supported, please let us know.
1008</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1009
1010</div>
1011
1012<!-- ======================================================================= -->
1013<div class="doc_subsection">
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]1014 <a name="fortran-fe">Known problems with the llvm-gcc Fortran front-end</a>
1015</div>
1016
1017<div class="doc_text">
Gabor Greif1fc8fbc2008-11-04 21:50:59 +0000[diff] [blame]1018<ul>
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]1019<li>Fortran support generally works, but there are still several unresolved bugs
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]1020 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
1021 tools/gfortran component for details.</li>
Gabor Greif1fc8fbc2008-11-04 21:50:59 +0000[diff] [blame]1022</ul>
Chris Lattner6c8a1b82008-10-30 03:58:13 +0000[diff] [blame]1023</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1024
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]1025<!-- ======================================================================= -->
1026<div class="doc_subsection">
Chris Lattner499c07c2008-06-05 06:35:40 +0000[diff] [blame]1027 <a name="ada-fe">Known problems with the llvm-gcc Ada front-end</a>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]1028</div>
1029
1030<div class="doc_text">
John Criswellaea8c752009-03-02 15:28:15 +0000[diff] [blame]1031The llvm-gcc 4.2 Ada compiler works fairly well; however, this is not a mature
1032technology, and problems should be expected.
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]1033<ul>
Duncan Sandsa73561c2008-06-08 20:18:35 +0000[diff] [blame]1034<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]1035to lack of trampoline support (pointers to nested functions) on other platforms.
1036However, 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]1037which does support trampolines.</li>
1038<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]1039This is due to lack of LLVM support for <tt>setjmp</tt>/<tt>longjmp</tt> style
1040exception handling, which is used internally by the compiler.
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]1041Workaround: configure with <tt>--disable-bootstrap</tt>.</li>
Duncan Sands2dbc2e82008-10-13 17:27:23 +0000[diff] [blame]1042<li>The c380004, <a href="http://llvm.org/PR2010">c393010</a>
1043and <a href="http://llvm.org/PR2421">cxg2021</a> ACATS tests fail
Duncan Sandsf73473e2009-02-25 11:59:06 +0000[diff] [blame]1044(c380004 also fails with gcc-4.2 mainline).
1045If the compiler is built with checks disabled then <a href="http://llvm.org/PR2010">c393010</a>
1046causes the compiler to go into an infinite loop, using up all system memory.</li>
Duncan Sandsc2a29a02009-03-02 16:35:57 +0000[diff] [blame]1047<li>Some GCC specific Ada tests continue to crash the compiler.</li>
Chris Lattner0b6ea7a2009-10-13 17:48:04 +0000[diff] [blame]1048<li>The <tt>-E</tt> binder option (exception backtraces)
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]1049<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]1050crashing if an exception is raised. Workaround: do not use <tt>-E</tt>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]1051<li>Only discrete types <a href="http://llvm.org/PR1981">are allowed to start
1052or finish at a non-byte offset</a> in a record. Workaround: do not pack records
1053or use representation clauses that result in a field of a non-discrete type
1054starting or finishing in the middle of a byte.</li>
Chris Lattnerd95b5962008-06-08 21:19:07 +0000[diff] [blame]1055<li>The <tt>lli</tt> interpreter <a href="http://llvm.org/PR2009">considers
1056'main' as generated by the Ada binder to be invalid</a>.
1057Workaround: hand edit the file to use pointers for <tt>argv</tt> and
1058<tt>envp</tt> rather than integers.</li>
1059<li>The <tt>-fstack-check</tt> option <a href="http://llvm.org/PR2008">is
1060ignored</a>.</li>
Chris Lattnerdaeb3232008-02-12 06:29:45 +0000[diff] [blame]1061</ul>
1062</div>
1063
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1064<!-- *********************************************************************** -->
1065<div class="doc_section">
1066 <a name="additionalinfo">Additional Information</a>
1067</div>
1068<!-- *********************************************************************** -->
1069
1070<div class="doc_text">
1071
1072<p>A wide variety of additional information is available on the <a
1073href="http://llvm.org">LLVM web page</a>, in particular in the <a
1074href="http://llvm.org/docs/">documentation</a> section. The web page also
1075contains versions of the API documentation which is up-to-date with the
1076Subversion version of the source code.
1077You can access versions of these documents specific to this release by going
1078into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
1079
1080<p>If you have any questions or comments about LLVM, please feel free to contact
1081us via the <a href="http://llvm.org/docs/#maillist"> mailing
1082lists</a>.</p>
1083
1084</div>
1085
1086<!-- *********************************************************************** -->
1087
1088<hr>
1089<address>
1090 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman947321d2008-12-11 17:34:48 +0000[diff] [blame]1091 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1092 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman947321d2008-12-11 17:34:48 +0000[diff] [blame]1093 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]1094
1095 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
1096 Last modified: $Date$
1097</address>
1098
1099</body>
1100</html>