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gerrit-public.fairphone.software / toolchain / llvm-project / 25883487a11698400a8b45c8a3325545e74a03ac / . / llvm / docs / ReleaseNotes.html
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4<head>
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Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]8 <title>LLVM 2.9 Release Notes</title>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]9</head>
10<body>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]11
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]12<div class="doc_title">LLVM 2.9 Release Notes</div>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]13
Chris Lattnerc871bac2010-03-17 04:02:39 +0000[diff] [blame]14<img align=right src="http://llvm.org/img/DragonSmall.png"
Gabor Greif27b166352010-04-22 10:21:43 +0000[diff] [blame]15 width="136" height="136" alt="LLVM Dragon Logo">
Chris Lattnerc871bac2010-03-17 04:02:39 +0000[diff] [blame]16
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]17<ol>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]18 <li><a href="#intro">Introduction</a></li>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]19 <li><a href="#subproj">Sub-project Status Update</a></li>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]20 <li><a href="#externalproj">External Projects Using LLVM 2.9</a></li>
21 <li><a href="#whatsnew">What's New in LLVM 2.9?</a></li>
Chris Lattner77a51732004-04-30 22:17:12 +0000[diff] [blame]22 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Dan Gohmanad888912008-10-14 16:23:02 +0000[diff] [blame]23 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]24 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]25</ol>
26
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]27<div class="doc_author">
Dan Gohmanad888912008-10-14 16:23:02 +0000[diff] [blame]28 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]29</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]30
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]31<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.9
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]32release.<br>
33You may prefer the
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]34<a href="http://llvm.org/releases/2.8/docs/ReleaseNotes.html">LLVM 2.8
Dan Gohman62af9d22010-05-03 23:51:05 +0000[diff] [blame]35Release Notes</a>.</h1>
Jeffrey Yasskin0830b972010-01-28 01:14:43 +0000[diff] [blame]36
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]37<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]38<div class="doc_section">
39 <a name="intro">Introduction</a>
40</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]41<!-- *********************************************************************** -->
42
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]43<div class="doc_text">
44
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]45<p>This document contains the release notes for the LLVM Compiler
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]46Infrastructure, release 2.9. Here we describe the status of LLVM, including
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]47major improvements from the previous release and significant known problems.
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]48All LLVM releases may be downloaded from the <a
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]49href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner62495762003-10-02 16:38:05 +0000[diff] [blame]50
Chris Lattnerb5bb5972004-12-07 08:04:13 +0000[diff] [blame]51<p>For more information about LLVM, including information about the latest
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]52release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattnere7525b52003-10-07 21:38:31 +0000[diff] [blame]53web site</a>. If you have questions or comments, the <a
Chris Lattner0b1c9a52010-03-17 04:41:49 +0000[diff] [blame]54href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's
55Mailing List</a> is a good place to send them.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]56
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]57<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]58main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greif355f81c2008-10-14 11:00:32 +0000[diff] [blame]59current one. To see the release notes for a specific release, please see the
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]60<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]61
62</div>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]63
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]64<!--
65Almost dead code.
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]66 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.0.
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]67-->
68
69
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]70<!-- Features that need text if they're finished for 3.0:
Chris Lattnera67df2d2010-04-22 06:28:20 +0000[diff] [blame]71 combiner-aa?
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]72 strong phi elim
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]73 loop dependence analysis
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]74 CorrelatedValuePropagation
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]75 -->
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]76
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]77<!-- *********************************************************************** -->
78<div class="doc_section">
79 <a name="subproj">Sub-project Status Update</a>
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]80</div>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]81<!-- *********************************************************************** -->
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]82
83<div class="doc_text">
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]84<p>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]85The LLVM 2.9 distribution currently consists of code from the core LLVM
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]86repository (which roughly includes the LLVM optimizers, code generators
87and supporting tools), the Clang repository and the llvm-gcc repository. In
88addition to this code, the LLVM Project includes other sub-projects that are in
89development. Here we include updates on these subprojects.
Bill Wendlingf170d2e2009-03-02 04:28:57 +0000[diff] [blame]90</p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]91
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]92</div>
93
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]94
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]95<!--=========================================================================-->
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]96<div class="doc_subsection">
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]97<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]98</div>
99
100<div class="doc_text">
101
Chris Lattner5de7f6e2010-04-26 17:42:18 +0000[diff] [blame]102<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
103C++, and Objective-C languages. Clang aims to provide a better user experience
104through expressive diagnostics, a high level of conformance to language
105standards, fast compilation, and low memory use. Like LLVM, Clang provides a
106modular, library-based architecture that makes it suitable for creating or
107integrating with other development tools. Clang is considered a
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]108production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
109(32- and 64-bit), and for darwin-arm targets.</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]110
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]111<p>In the LLVM 2.9 time-frame, the Clang team has made many improvements in C,
112C++ and Objective-C support. C++ support is now generally rock solid, has
113been exercised on a broad variety of code, and has several new C++'0x features
114implemented (such as rvalue references and variadic templates). LLVM 2.9 has
115also brought in a large range of bug fixes and minor features (e.g. __label__
116support), and is much more compatible with the Linux Kernel.</p>
117
118<p>If Clang rejects your code that is built with another compiler, please take a
119look at the <a href="http://clang.llvm.org/compatibility.html">language
120compatibility</a> guide to make sure the issue isn't intentional or a known
121issue.
122</p>
Bill Wendlingef362462008-10-27 09:27:33 +0000[diff] [blame]123
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]124<ul>
125</ul>
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]126</div>
127
128<!--=========================================================================-->
129<div class="doc_subsection">
Duncan Sands1cd78982011-04-04 11:09:08 +0000[diff] [blame]130<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]131</div>
132
133<div class="doc_text">
134<p>
Duncan Sands1cd78982011-04-04 11:09:08 +0000[diff] [blame]135<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
136<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
137optimizers and code generators with LLVM's.
138Currently it requires a patched version of gcc-4.5.
139The plugin can target the x86-32 and x86-64 processor families and has been
140used successfully on the Darwin, FreeBSD and Linux platforms.
141The Ada, C, C++ and Fortran languages work well.
142The plugin is capable of compiling plenty of Obj-C, Obj-C++ and Java but it is
143not known whether the compiled code actually works or not!
Duncan Sands92452b92010-04-02 09:23:15 +0000[diff] [blame]144</p>
145
146<p>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]147The 2.9 release has the following notable changes:
Duncan Sands7f9a0dc2010-09-30 17:37:34 +0000[diff] [blame]148<ul>
Duncan Sands1cd78982011-04-04 11:09:08 +0000[diff] [blame]149<li>The plugin is much more stable when compiling Fortran.</li>
150<li>Inline asm where an asm output is tied to an input of a different size is
151now supported in many more cases.</li>
152<li>Basic support for the __float128 type was added. It is now possible to
153generate LLVM IR from programs using __float128 but code generation does not
154work yet.</li>
155<li>Compiling Java programs no longer systematically crashes the plugin.</li>
Duncan Sands7f9a0dc2010-09-30 17:37:34 +0000[diff] [blame]156</ul>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]157
158</div>
159
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]160<!--=========================================================================-->
161<div class="doc_subsection">
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]162<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
163</div>
164
165<div class="doc_text">
166<p>
167The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
168is a simple library that provides an implementation of the low-level
169target-specific hooks required by code generation and other runtime components.
170For example, when compiling for a 32-bit target, converting a double to a 64-bit
171unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
172function. The compiler-rt library provides highly optimized implementations of
173this and other low-level routines (some are 3x faster than the equivalent
174libgcc routines).</p>
175
176<p>
177All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]178License, a "BSD-style" license.
179
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]180compiler_rt is now dual licensed under MIT and UIUC license
181
182Several minor changes for better ARM support.
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]183
184New in LLVM 2.9, UPDATE</p>
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]185
186</div>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]187
188<!--=========================================================================-->
189<div class="doc_subsection">
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]190<a name="lldb">LLDB: Low Level Debugger</a>
191</div>
192
193<div class="doc_text">
194<p>
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]195<a href="http://lldb.llvm.org/">LLDB</a> is a brand new member of the LLVM
196umbrella of projects. LLDB is a next generation, high-performance debugger. It
197is built as a set of reusable components which highly leverage existing
198libraries in the larger LLVM Project, such as the Clang expression parser, the
199LLVM disassembler and the LLVM JIT.</p>
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]200
201<p>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]202LLDB is in early development and not included as part of the LLVM 2.9 release,
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]203
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]204
205
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]206<!--
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]207but is mature enough to support basic debugging scenarios on Mac OS X in C,
208Objective-C and C++. We'd really like help extending and expanding LLDB to
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]209support new platforms, new languages, new architectures, and new features.-->
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]210</p>
211
212</div>
213
214<!--=========================================================================-->
215<div class="doc_subsection">
216<a name="libc++">libc++: C++ Standard Library</a>
217</div>
218
219<div class="doc_text">
220<p>
Tobias Grosser436bc5f2010-10-06 21:07:30 +0000[diff] [blame]221<a href="http://libcxx.llvm.org/">libc++</a> is another new member of the LLVM
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]222family. It is an implementation of the C++ standard library, written from the
223ground up to specifically target the forthcoming C++'0X standard and focus on
224delivering great performance.</p>
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]225
226<p>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]227As of the LLVM 2.9 release, UPDATE!
228
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]229libc++ is now dual licensed under MIT and UIUC license
230
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]231<!--libc++ is virtually feature complete, but would
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]232benefit from more testing and better integration with Clang++. It is also
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]233looking forward to the C++ committee finalizing the C++'0x standard.-->
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]234</p>
235
236</div>
237
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]238
Daniel Dunbar8fbd8aa2010-10-04 17:39:47 +0000[diff] [blame]239
240<!--=========================================================================-->
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]241<!--
Daniel Dunbar8fbd8aa2010-10-04 17:39:47 +0000[diff] [blame]242<div class="doc_subsection">
243<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
244</div>
245
246<div class="doc_text">
247<p>
248<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
249programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
250through the application and records state transitions that lead to fault
251states. This allows it to construct testcases that lead to faults and can even
252be used to verify some algorithms.
253</p>
254
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]255<p>UPDATE!</p>
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]256</div>-->
Daniel Dunbar8fbd8aa2010-10-04 17:39:47 +0000[diff] [blame]257
258
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]259<!-- *********************************************************************** -->
260<div class="doc_section">
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]261 <a name="externalproj">External Open Source Projects Using LLVM 2.9</a>
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]262</div>
263<!-- *********************************************************************** -->
264
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]265<div class="doc_text">
266
267<p>An exciting aspect of LLVM is that it is used as an enabling technology for
268 a lot of other language and tools projects. This section lists some of the
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]269 projects that have already been updated to work with LLVM 2.9.</p>
Chris Lattnerdf85c892010-04-26 17:38:10 +0000[diff] [blame]270</div>
271
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]272
273
Chris Lattnerca7c8962010-10-01 06:34:49 +0000[diff] [blame]274
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]275<!-- *********************************************************************** -->
276<div class="doc_section">
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]277 <a name="whatsnew">What's New in LLVM 2.9?</a>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]278</div>
279<!-- *********************************************************************** -->
280
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]281<div class="doc_text">
282
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]283<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]284minor improvements. Some of the major improvements and new features are listed
285in this section.
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]286</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]287
Chris Lattnera67df2d2010-04-22 06:28:20 +0000[diff] [blame]288</div>
289
290<!--=========================================================================-->
291<div class="doc_subsection">
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]292<a name="majorfeatures">Major New Features</a>
293</div>
294
295<div class="doc_text">
296
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]297<p>LLVM 2.9 includes several major new capabilities:</p>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]298
299<ul>
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]300<li><pre>
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]301 last release for llvm-gcc
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]302TBAA: On by default in clang. Disable it with -fno-strict-aliasing.
303 Could be more aggressive for structs.
304
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]305Triple::normalize is new, llvm triples are always stored in normalized form internally.
306
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]307Triple x86_64--mingw64 is obsoleted. Use x86_64--mingw32 instead.
308
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]309MC Assembler: X86 now generates much better diagnostics for common errors,
310 is much faster at matching instructions, is much more bug-compatible with
311 the GAS assembler, and is now generally useful for a broad range of X86
312 assembly.
313
314New Nvidia PTX backend, not generally useful in 2.9 though.
315
316Much better debug info generated, particularly in optimized code situations.
317
318ARM Fast ISel
319
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]320ELF MC support: on by default in clang. There are still known missing features
321 for human written assembly.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]322
323X86: Reimplemented all of MMX to introduce a new LLVM IR x86_mmx type. Now
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]324 random types like &lt;2 x i32&gt; are not iseld to mmx without emms. The
325 -disable-mmx flag is gone now.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]326
327Some basic <a href="CodeGenerator.html#mc">internals documentation</a> for MC.
328
329MC Assembler support for .file and .loc.
330
331
332inline asm multiple alternative constraint support.
333
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]334LoopIdiom: memset/memcpy formation. Build with -ffreestanding or -fno-builtin
335 if your memcpy is being compiled into infinite recursion.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]336
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]337
338TargetLibraryInfo
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]339
340X86 support for FS/GS relative loads and stores using address space 256/257 are
341 reliable now.
342
343ARM: New code placement pass.
344
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]345unnamed_addr + PR8927
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]346
347PointerTracking has been removed from mainline, moved to ClamAV.
348
349EarlyCSE pass.
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]350LoopInstSimplify pass.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]351
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]352- DIBuilder provides simpler interface for front ends like Clang to encode debug info in LLVM IR.
353 - This interface hides implementation details (e.g. DIDerivedType, existence of compile unit etc..) that any front end should not know about.
354 For example,
355 Ty = DebugFactory.CreateDerivedType(DW_TAG_volatile_type,
356 findRegion(TYPE_CONTEXT(type)),
357 StringRef(),
358 getOrCreateFile(main_input_filename),
359 0 /*line no*/,
360 NodeSizeInBits(type),
361 NodeAlignInBits(type),
362 0 /*offset */,
363 0 /* flags */,
364 MainTy);
365 can be replaced by
366 DbgTy = DBuilder.createQualifiedType(DW_TAG_volatile_type, MainTy);
367
368PPC: Switched to MCInstPrinter, and MCCodeEmitter. Ready to implement support
369 for directly writing out mach-o object files, but noone seems interested.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]370
371ARM: Improved code generation for Cortex-A8 and Cortex-A9 CPUs.
372
373Scheduler now models operand latency and pipeline forwarding.
374
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]375error_code + libsystem + PathV2 changes
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]376 The system_error header from C++0x was added.
377 * Use if (error_code ec = function()) to check for error conditions
378 from functions which return it.
379 * error_code::message returns a human readable description of the error.
380
381 PathV1 has been deprecated in favor of PathV2 (sorry I didn't finish
382 this before the release).
383 * No Path class, use a r-value convertible to a twine instead.
384 * Assumes all paths are UTF-8.
385
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]386new macho-dump tool
387
388Major regalloc rewrite, not on by default for 2.9 and not advised to use it.
389 * New basic register allocator that can be used as a safe fallback when
390 debugging. Enable with -regalloc=basic.
391 * New infrastructure for live range splitting. SplitKit can break a live
392 interval into smaller pieces while preserving SSA form, and SpillPlacement
393 can help find the best split points. This is a work in progress so the API
394 is changing quickly.
395 * The inline spiller has learned to clean up after live range splitting. It
396 can hoist spills out of loops, and it can eliminate redundant spills.
397 Rematerialization works with live range splitting.
398 * New greedy register allocator using live range splitting. This will be the
399 default register allocator in the next LLVM release, but it is not turned on
400 by default in 2.9.
401
402ARM: __builtin_prefetch turns into prefetch instructions.
403
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]404MC assembler support for 3dNow! and 3DNowA instructions.
405
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]406tblgen support for assembler aliases: <a
407 href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
408
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]409LoopIndexSplit pass was removed, unmaintained.
410
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]411include/llvm/System merged into include/llvm/Support.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]412
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]413Win32 PE-COFF support in the MC assembler has made a lot of progress in the 2.9
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]414 timeframe, but is still not generally useful. Please see
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]415 "http://llvm.org/bugs/showdependencytree.cgi?id=9100&amp;hide_resolved=1" for open bugs?
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]416
417New <a href="WritingAnLLVMPass.html#RegionPass">RegionPass</a> infrastructure
418 for region-based optimizations.
419
420MicroBlaze: major updates for aggressive delay slot filler, MC-based assembly
421 printing, assembly instruction parsing, ELF .o file emission, and MC
422 instruction disassembler.
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]423
424Countless ARM microoptimizations.
425
426Speedups to various mid-level passes:
427 GVN is much faster on functions with deep dominator trees / lots of BBs.
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]428 DomTree and DominatorFrontier are much faster to compute, and preserved by
429 more passes (so they are computed less often)
Chris Lattner706754c2011-04-05 21:43:56 +0000[diff] [blame]430 SRoA is also much faster and doesn't use DominanceFrontier.
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]431
432
433new 'hotpatch' attribute: LangRef.html#fnattrs
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]434
435APInt API changes, see PR5207.
436
437DSE is more aggressive with stores of different types: e.g. a large store
438 following a small one to the same address.
439
440New naming rules in coding standards: CodingStandards.html#ll_naming
441
442LiveDebugVariables is a new pass that keeps track of debugging information for
443 user variables that are kept in registers in optimized builds.
444
445We now optimize various idioms for overflow detection into check of the flag
446 register on various CPUs, e.g.:
447 unsigned long t = a+b;
448 if (t &lt; a) ...
449 into:
450 addq %rdi, %rbx
451 jno LBB0_2
452
453X86: Much better codegen for several cases using adc/sbb instead of cmovs for
454 conditional increment and other idioms.
455
456MVT::Flag renamed to MVT::Glue
457
458Removed the PartialSpecialization pass, it was unmaintained and buggy.
459
Chris Lattner706754c2011-04-05 21:43:56 +0000[diff] [blame]460SPARC: Many improvements, including using the Y registers for multiplications
461 and addition of a simple delay slot filler.
462
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]463</pre></li>
Chris Lattner458e79f2008-02-10 08:18:42 +0000[diff] [blame]464</ul>
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]465
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]466Still todo: [110117-110228]
Chris Lattner10a3cc42010-03-17 06:41:58 +0000[diff] [blame]467
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]468
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]469</div>
470
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]471<!--=========================================================================-->
472<div class="doc_subsection">
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]473<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]474</div>
475
476<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]477<p>LLVM IR has several new features for better support of new targets and that
478expose new optimization opportunities:</p>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]479
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]480<ul>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]481</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]482
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]483</div>
484
485<!--=========================================================================-->
486<div class="doc_subsection">
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]487<a name="optimizer">Optimizer Improvements</a>
488</div>
489
490<div class="doc_text">
491
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]492<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame]493release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]494
495<ul>
Rafael Espindola01fb4b02011-03-18 04:07:44 +0000[diff] [blame]496 <li>TBAA.</li>
497 <li>LTO has been improved to use MC for parsing inline asm and now
498 can build large programs like Firefox 4 on both OS X and Linux.</li>
Chris Lattnerfcc65a72010-10-04 02:42:39 +0000[diff] [blame]499</ul>
500
501<!--
502<p>In addition to these features that are done in 2.8, there is preliminary
503 support in the release for Type Based Alias Analysis
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]504 Preliminary work on TBAA but not usable in 2.8.
505 New CorrelatedValuePropagation pass, not on by default in 2.8 yet.
Chris Lattnerfcc65a72010-10-04 02:42:39 +0000[diff] [blame]506-->
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]507
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]508</div>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]509
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]510<!--=========================================================================-->
511<div class="doc_subsection">
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]512<a name="mc">MC Level Improvements</a>
513</div>
514
515<div class="doc_text">
516<p>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]517The LLVM Machine Code (aka MC) subsystem was created to solve a number
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]518of problems in the realm of assembly, disassembly, object file format handling,
519and a number of other related areas that CPU instruction-set level tools work
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]520in.</p>
521
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]522<ul>
Rafael Espindola01fb4b02011-03-18 04:07:44 +0000[diff] [blame]523 <li>MC is now used by default for ELF systems on x86 and
524 x86-64.</li>
525 <li>MC supports and CodeGen uses the <tt>.loc</tt> directives for
526 producing line number debug info. This produces more compact line
527 tables.</li>
528 <li>MC supports the <tt>.cfi_*</tt> directives for producing DWARF
529 frame information, but it is still not used by CodeGen by default.</li>
530 <li>COFF support?</li>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]531</ul>
532
533<p>For more information, please see the <a
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]534href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
535LLVM MC Project Blog Post</a>.
536</p>
537
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]538</div>
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]539
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]540<!--=========================================================================-->
541<div class="doc_subsection">
Chris Lattnerd434bfb2009-03-02 03:24:11 +0000[diff] [blame]542<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]543</div>
544
545<div class="doc_text">
546
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]547<p>We have put a significant amount of work into the code generator
548infrastructure, which allows us to implement more aggressive algorithms and make
549it run faster:</p>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]550
551<ul>
Chris Lattner9fd1e922010-10-04 03:58:12 +0000[diff] [blame]552<!-- SplitKit -->
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]553FastISel for ARM.
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]554</ul>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]555</div>
556
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]557<!--=========================================================================-->
558<div class="doc_subsection">
559<a name="x86">X86-32 and X86-64 Target Improvements</a>
560</div>
561
562<div class="doc_text">
Chris Lattnerd3f45c82010-10-04 04:39:25 +0000[diff] [blame]563<p>New features and major changes in the X86 target include:
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]564</p>
565
566<ul>
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]567 <li>Several bugs have been fixed for Windows x64 code generator.</li>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]568</ul>
569
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]570</div>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]571
572<!--=========================================================================-->
573<div class="doc_subsection">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]574<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]575</div>
576
577<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]578<p>New features of the ARM target include:
579</p>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]580
581<ul>
Bob Wilsone44f2982010-09-13 17:39:35 +0000[diff] [blame]582</ul>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]583</div>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]584
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]585
586<!--=========================================================================-->
587<div class="doc_subsection">
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]588<a name="changes">Major Changes and Removed Features</a>
589</div>
590
591<div class="doc_text">
592
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]593<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]594on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]595from the previous release.</p>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]596
597<ul>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]598</ul>
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]599
Chris Lattnera7f45cf2010-10-04 01:29:06 +0000[diff] [blame]600
601
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]602<p>In addition, many APIs have changed in this release. Some of the major LLVM
603API changes are:</p>
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]604<ul>
Devang Pateldbf83832008-10-14 20:03:43 +0000[diff] [blame]605</ul>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]606
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]607</div>
608
Daniel Dunbarf70898a2010-10-04 20:11:41 +0000[diff] [blame]609<!--=========================================================================-->
610<div class="doc_subsection">
611<a name="devtree_changes">Development Infrastructure Changes</a>
612</div>
613
614<div class="doc_text">
615
616<p>This section lists changes to the LLVM development infrastructure. This
617mostly impacts users who actively work on LLVM or follow development on
618mainline, but may also impact users who leverage the LLVM build infrastructure
619or are interested in LLVM qualification.</p>
620
621<ul>
Daniel Dunbarf70898a2010-10-04 20:11:41 +0000[diff] [blame]622</ul>
623</div>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]624
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]625<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]626<div class="doc_section">
627 <a name="knownproblems">Known Problems</a>
628</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]629<!-- *********************************************************************** -->
630
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]631<div class="doc_text">
632
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]633<p>This section contains significant known problems with the LLVM system,
Chris Lattner2a092392008-11-10 05:40:34 +0000[diff] [blame]634listed by component. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]635href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]636there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]637
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]638</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]639
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]640<!-- ======================================================================= -->
641<div class="doc_subsection">
642 <a name="experimental">Experimental features included with this release</a>
643</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]644
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]645<div class="doc_text">
646
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]647<p>The following components of this LLVM release are either untested, known to
648be broken or unreliable, or are in early development. These components should
649not be relied on, and bugs should not be filed against them, but they may be
650useful to some people. In particular, if you would like to work on one of these
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]651components, please contact us on the <a
652href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]653
654<ul>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]655<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ
Chris Lattnera7f45cf2010-10-04 01:29:06 +0000[diff] [blame]656 and XCore backends are experimental.</li>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]657<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]658 other than darwin-i386 and darwin-x86_64. FIXME: Not true on ELF anymore?</li>
659
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]660</ul>
661
662</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]663
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]664<!-- ======================================================================= -->
665<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]666 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]667</div>
668
669<div class="doc_text">
670
671<ul>
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]672 <li>The X86 backend does not yet support
673 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
674 floating point stack</a>. It supports the 'f' and 't' constraints, but not
675 'u'.</li>
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]676 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattnera67df2d2010-04-22 06:28:20 +0000[diff] [blame]677 <tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]678 argument constructs on X86-64 by lowering them manually.</li>
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]679 <li>Windows x64 (aka Win64) code generator has a few issues.
680 <ul>
681 <li>llvm-gcc cannot build the mingw-w64 runtime currently
682 due to lack of support for the 'u' inline assembly
683 constraint and for X87 floating point inline assembly.</li>
684 <li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt>
685 due to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
686 It is fixed in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
687 <li>Miss-aligned MOVDQA might crash your program. It is due to
688 <a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>,
689 lack of handling aligned internal globals.</li>
690 </ul>
691 </li>
692
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]693</ul>
694
695</div>
696
697<!-- ======================================================================= -->
698<div class="doc_subsection">
699 <a name="ppc-be">Known problems with the PowerPC back-end</a>
700</div>
701
702<div class="doc_text">
703
704<ul>
Nicolas Geoffray77d99502007-05-15 09:21:28 +0000[diff] [blame]705<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]706compilation, and lacks support for debug information.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]707</ul>
708
709</div>
710
711<!-- ======================================================================= -->
712<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]713 <a name="arm-be">Known problems with the ARM back-end</a>
714</div>
715
716<div class="doc_text">
717
718<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]719<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]720processors, thumb programs can crash or produce wrong
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]721results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]722<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]723</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]724</ul>
725
726</div>
727
728<!-- ======================================================================= -->
729<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]730 <a name="sparc-be">Known problems with the SPARC back-end</a>
731</div>
732
733<div class="doc_text">
734
735<ul>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]736<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]737 support the 64-bit SPARC ABI (-m64).</li>
738</ul>
739
740</div>
741
742<!-- ======================================================================= -->
743<div class="doc_subsection">
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]744 <a name="mips-be">Known problems with the MIPS back-end</a>
745</div>
746
747<div class="doc_text">
748
749<ul>
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]750<li>64-bit MIPS targets are not supported yet.</li>
751</ul>
752
753</div>
754
755<!-- ======================================================================= -->
756<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]757 <a name="alpha-be">Known problems with the Alpha back-end</a>
758</div>
759
760<div class="doc_text">
761
762<ul>
763
764<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
765appropriate nops inserted to ensure restartability.</li>
766
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]767</ul>
768</div>
769
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]770<!-- ======================================================================= -->
771<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]772 <a name="c-be">Known problems with the C back-end</a>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]773</div>
774
775<div class="doc_text">
776
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]777<p>The C backend has numerous problems and is not being actively maintained.
778Depending on it for anything serious is not advised.</p>
779
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]780<ul>
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]781<li><a href="http://llvm.org/PR802">The C backend has only basic support for
782 inline assembly code</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]783<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
784 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif75b2f762009-03-02 12:02:51 +0000[diff] [blame]785 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandse09506a2008-02-10 13:40:55 +0000[diff] [blame]786<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands3aa36732009-02-25 11:51:54 +0000[diff] [blame]787<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]788</ul>
789
790</div>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]791
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]792
793<!-- ======================================================================= -->
794<div class="doc_subsection">
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]795 <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]796</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]797
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]798<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]799
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]800<p>llvm-gcc is generally very stable for the C family of languages. The only
801 major language feature of GCC not supported by llvm-gcc is the
802 <tt>__builtin_apply</tt> family of builtins. However, some extensions
803 are only supported on some targets. For example, trampolines are only
804 supported on some targets (these are used when you take the address of a
805 nested function).</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]806
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]807<p>Fortran support generally works, but there are still several unresolved bugs
808 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
809 tools/gfortran component for details. Note that llvm-gcc is missing major
810 Fortran performance work in the frontend and library that went into GCC after
811 4.2. If you are interested in Fortran, we recommend that you consider using
812 <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]813
Duncan Sandsd63e1c82010-10-04 10:06:56 +0000[diff] [blame]814<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
815actively maintained. If you are interested in Ada, we recommend that you
816consider using <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]817</div>
818
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]819<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]820<div class="doc_section">
821 <a name="additionalinfo">Additional Information</a>
822</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]823<!-- *********************************************************************** -->
824
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]825<div class="doc_text">
826
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]827<p>A wide variety of additional information is available on the <a
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]828href="http://llvm.org">LLVM web page</a>, in particular in the <a
829href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencerc7f87f22007-07-09 08:04:31 +0000[diff] [blame]830contains versions of the API documentation which is up-to-date with the
831Subversion version of the source code.
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]832You can access versions of these documents specific to this release by going
833into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]834
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]835<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]836us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]837lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]838
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]839</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]840
841<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]842
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]843<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]844<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]845 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]846 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]847 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]848 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]849
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]850 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]851 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]852</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]853
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]854</body>
855</html>