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gerrit-public.fairphone.software / toolchain / llvm-project / 9ee0b01617e6196dcb7e3c3af423e5867c3cc555 / . / llvm / docs / ReleaseNotes.html
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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
324 random types like &lt;2 x i32&gt; are not iseld to mmx without emms.
325
326Some basic <a href="CodeGenerator.html#mc">internals documentation</a> for MC.
327
328MC Assembler support for .file and .loc.
329
330
331inline asm multiple alternative constraint support.
332
333LoopIdiom: memset/memcpy formation
334
335
336X86 support for FS/GS relative loads and stores using address space 256/257 are
337 reliable now.
338
339ARM: New code placement pass.
340
341
342PointerTracking has been removed from mainline, moved to ClamAV.
343
344EarlyCSE pass.
345
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame^]346- DIBuilder provides simpler interface for front ends like Clang to encode debug info in LLVM IR.
347 - This interface hides implementation details (e.g. DIDerivedType, existence of compile unit etc..) that any front end should not know about.
348 For example,
349 Ty = DebugFactory.CreateDerivedType(DW_TAG_volatile_type,
350 findRegion(TYPE_CONTEXT(type)),
351 StringRef(),
352 getOrCreateFile(main_input_filename),
353 0 /*line no*/,
354 NodeSizeInBits(type),
355 NodeAlignInBits(type),
356 0 /*offset */,
357 0 /* flags */,
358 MainTy);
359 can be replaced by
360 DbgTy = DBuilder.createQualifiedType(DW_TAG_volatile_type, MainTy);
361
362PPC: Switched to MCInstPrinter, and MCCodeEmitter. Ready to implement support
363 for directly writing out mach-o object files, but noone seems interested.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]364
365ARM: Improved code generation for Cortex-A8 and Cortex-A9 CPUs.
366
367Scheduler now models operand latency and pipeline forwarding.
368
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame^]369error_code + libsystem + PathV2 changes
370
371new macho-dump tool
372
373Major regalloc rewrite, not on by default for 2.9 and not advised to use it.
374 * New basic register allocator that can be used as a safe fallback when
375 debugging. Enable with -regalloc=basic.
376 * New infrastructure for live range splitting. SplitKit can break a live
377 interval into smaller pieces while preserving SSA form, and SpillPlacement
378 can help find the best split points. This is a work in progress so the API
379 is changing quickly.
380 * The inline spiller has learned to clean up after live range splitting. It
381 can hoist spills out of loops, and it can eliminate redundant spills.
382 Rematerialization works with live range splitting.
383 * New greedy register allocator using live range splitting. This will be the
384 default register allocator in the next LLVM release, but it is not turned on
385 by default in 2.9.
386
387ARM: __builtin_prefetch turns into prefetch instructions.
388
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]389MC assembler support for 3dNow! and 3DNowA instructions.
390
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame^]391tblgen support for assembler aliases: <a
392 href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
393
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]394LoopIndexSplit pass was removed, unmaintained.
395
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame^]396include/llvm/System merged into include/llvm/Support.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]397
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]398Win32 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]399 timeframe, but is still not generally useful. Please see
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]400 "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]401
402New <a href="WritingAnLLVMPass.html#RegionPass">RegionPass</a> infrastructure
403 for region-based optimizations.
404
405MicroBlaze: major updates for aggressive delay slot filler, MC-based assembly
406 printing, assembly instruction parsing, ELF .o file emission, and MC
407 instruction disassembler.
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame^]408
409Countless ARM microoptimizations.
410
411Speedups to various mid-level passes:
412 GVN is much faster on functions with deep dominator trees / lots of BBs.
413 DomTree and DominatorFrontier are much faster to compute.
414
415
416new 'hotpatch' attribute: LangRef.html#fnattrs
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]417</pre></li>
Chris Lattner458e79f2008-02-10 08:18:42 +0000[diff] [blame]418</ul>
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]419
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame^]420Still todo: [101129-110228]
Chris Lattner10a3cc42010-03-17 06:41:58 +0000[diff] [blame]421
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]422</div>
423
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]424<!--=========================================================================-->
425<div class="doc_subsection">
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]426<a name="coreimprovements">LLVM IR and Core Improvements</a>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]427</div>
428
429<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]430<p>LLVM IR has several new features for better support of new targets and that
431expose new optimization opportunities:</p>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]432
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]433<ul>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]434</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]435
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]436</div>
437
438<!--=========================================================================-->
439<div class="doc_subsection">
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]440<a name="optimizer">Optimizer Improvements</a>
441</div>
442
443<div class="doc_text">
444
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]445<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattner25879d72008-10-13 21:50:36 +0000[diff] [blame]446release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]447
448<ul>
Rafael Espindola01fb4b02011-03-18 04:07:44 +0000[diff] [blame]449 <li>TBAA.</li>
450 <li>LTO has been improved to use MC for parsing inline asm and now
451 can build large programs like Firefox 4 on both OS X and Linux.</li>
Chris Lattnerfcc65a72010-10-04 02:42:39 +0000[diff] [blame]452</ul>
453
454<!--
455<p>In addition to these features that are done in 2.8, there is preliminary
456 support in the release for Type Based Alias Analysis
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]457 Preliminary work on TBAA but not usable in 2.8.
458 New CorrelatedValuePropagation pass, not on by default in 2.8 yet.
Chris Lattnerfcc65a72010-10-04 02:42:39 +0000[diff] [blame]459-->
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]460
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]461</div>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]462
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]463<!--=========================================================================-->
464<div class="doc_subsection">
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]465<a name="mc">MC Level Improvements</a>
466</div>
467
468<div class="doc_text">
469<p>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]470The LLVM Machine Code (aka MC) subsystem was created to solve a number
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]471of problems in the realm of assembly, disassembly, object file format handling,
472and a number of other related areas that CPU instruction-set level tools work
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]473in.</p>
474
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]475<ul>
Rafael Espindola01fb4b02011-03-18 04:07:44 +0000[diff] [blame]476 <li>MC is now used by default for ELF systems on x86 and
477 x86-64.</li>
478 <li>MC supports and CodeGen uses the <tt>.loc</tt> directives for
479 producing line number debug info. This produces more compact line
480 tables.</li>
481 <li>MC supports the <tt>.cfi_*</tt> directives for producing DWARF
482 frame information, but it is still not used by CodeGen by default.</li>
483 <li>COFF support?</li>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]484</ul>
485
486<p>For more information, please see the <a
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]487href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
488LLVM MC Project Blog Post</a>.
489</p>
490
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]491</div>
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]492
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]493<!--=========================================================================-->
494<div class="doc_subsection">
Chris Lattnerd434bfb2009-03-02 03:24:11 +0000[diff] [blame]495<a name="codegen">Target Independent Code Generator Improvements</a>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]496</div>
497
498<div class="doc_text">
499
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]500<p>We have put a significant amount of work into the code generator
501infrastructure, which allows us to implement more aggressive algorithms and make
502it run faster:</p>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]503
504<ul>
Chris Lattner9fd1e922010-10-04 03:58:12 +0000[diff] [blame]505<!-- SplitKit -->
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]506FastISel for ARM.
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]507</ul>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]508</div>
509
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]510<!--=========================================================================-->
511<div class="doc_subsection">
512<a name="x86">X86-32 and X86-64 Target Improvements</a>
513</div>
514
515<div class="doc_text">
Chris Lattnerd3f45c82010-10-04 04:39:25 +0000[diff] [blame]516<p>New features and major changes in the X86 target include:
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]517</p>
518
519<ul>
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]520 <li>Several bugs have been fixed for Windows x64 code generator.</li>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]521</ul>
522
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]523</div>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]524
525<!--=========================================================================-->
526<div class="doc_subsection">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]527<a name="ARM">ARM Target Improvements</a>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]528</div>
529
530<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]531<p>New features of the ARM target include:
532</p>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]533
534<ul>
Bob Wilsone44f2982010-09-13 17:39:35 +0000[diff] [blame]535</ul>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]536</div>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]537
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]538
539<!--=========================================================================-->
540<div class="doc_subsection">
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]541<a name="changes">Major Changes and Removed Features</a>
542</div>
543
544<div class="doc_text">
545
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]546<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]547on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]548from the previous release.</p>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]549
550<ul>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]551</ul>
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]552
Chris Lattnera7f45cf2010-10-04 01:29:06 +0000[diff] [blame]553
554
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]555<p>In addition, many APIs have changed in this release. Some of the major LLVM
556API changes are:</p>
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]557<ul>
Devang Pateldbf83832008-10-14 20:03:43 +0000[diff] [blame]558</ul>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]559
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]560</div>
561
Daniel Dunbarf70898a2010-10-04 20:11:41 +0000[diff] [blame]562<!--=========================================================================-->
563<div class="doc_subsection">
564<a name="devtree_changes">Development Infrastructure Changes</a>
565</div>
566
567<div class="doc_text">
568
569<p>This section lists changes to the LLVM development infrastructure. This
570mostly impacts users who actively work on LLVM or follow development on
571mainline, but may also impact users who leverage the LLVM build infrastructure
572or are interested in LLVM qualification.</p>
573
574<ul>
Daniel Dunbarf70898a2010-10-04 20:11:41 +0000[diff] [blame]575</ul>
576</div>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]577
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]578<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]579<div class="doc_section">
580 <a name="knownproblems">Known Problems</a>
581</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]582<!-- *********************************************************************** -->
583
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]584<div class="doc_text">
585
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]586<p>This section contains significant known problems with the LLVM system,
Chris Lattner2a092392008-11-10 05:40:34 +0000[diff] [blame]587listed by component. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]588href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]589there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]590
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]591</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]592
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]593<!-- ======================================================================= -->
594<div class="doc_subsection">
595 <a name="experimental">Experimental features included with this release</a>
596</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]597
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]598<div class="doc_text">
599
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]600<p>The following components of this LLVM release are either untested, known to
601be broken or unreliable, or are in early development. These components should
602not be relied on, and bugs should not be filed against them, but they may be
603useful 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]604components, please contact us on the <a
605href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]606
607<ul>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]608<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ
Chris Lattnera7f45cf2010-10-04 01:29:06 +0000[diff] [blame]609 and XCore backends are experimental.</li>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]610<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]611 other than darwin-i386 and darwin-x86_64. FIXME: Not true on ELF anymore?</li>
612
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]613</ul>
614
615</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]616
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]617<!-- ======================================================================= -->
618<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]619 <a name="x86-be">Known problems with the X86 back-end</a>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]620</div>
621
622<div class="doc_text">
623
624<ul>
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]625 <li>The X86 backend does not yet support
626 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
627 floating point stack</a>. It supports the 'f' and 't' constraints, but not
628 'u'.</li>
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]629 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattnera67df2d2010-04-22 06:28:20 +0000[diff] [blame]630 <tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]631 argument constructs on X86-64 by lowering them manually.</li>
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]632 <li>Windows x64 (aka Win64) code generator has a few issues.
633 <ul>
634 <li>llvm-gcc cannot build the mingw-w64 runtime currently
635 due to lack of support for the 'u' inline assembly
636 constraint and for X87 floating point inline assembly.</li>
637 <li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt>
638 due to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
639 It is fixed in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
640 <li>Miss-aligned MOVDQA might crash your program. It is due to
641 <a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>,
642 lack of handling aligned internal globals.</li>
643 </ul>
644 </li>
645
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]646</ul>
647
648</div>
649
650<!-- ======================================================================= -->
651<div class="doc_subsection">
652 <a name="ppc-be">Known problems with the PowerPC back-end</a>
653</div>
654
655<div class="doc_text">
656
657<ul>
Nicolas Geoffray77d99502007-05-15 09:21:28 +0000[diff] [blame]658<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]659compilation, and lacks support for debug information.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]660</ul>
661
662</div>
663
664<!-- ======================================================================= -->
665<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]666 <a name="arm-be">Known problems with the ARM back-end</a>
667</div>
668
669<div class="doc_text">
670
671<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]672<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]673processors, thumb programs can crash or produce wrong
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]674results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]675<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]676</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]677</ul>
678
679</div>
680
681<!-- ======================================================================= -->
682<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]683 <a name="sparc-be">Known problems with the SPARC back-end</a>
684</div>
685
686<div class="doc_text">
687
688<ul>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]689<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]690 support the 64-bit SPARC ABI (-m64).</li>
691</ul>
692
693</div>
694
695<!-- ======================================================================= -->
696<div class="doc_subsection">
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]697 <a name="mips-be">Known problems with the MIPS back-end</a>
698</div>
699
700<div class="doc_text">
701
702<ul>
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]703<li>64-bit MIPS targets are not supported yet.</li>
704</ul>
705
706</div>
707
708<!-- ======================================================================= -->
709<div class="doc_subsection">
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]710 <a name="alpha-be">Known problems with the Alpha back-end</a>
711</div>
712
713<div class="doc_text">
714
715<ul>
716
717<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
718appropriate nops inserted to ensure restartability.</li>
719
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]720</ul>
721</div>
722
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]723<!-- ======================================================================= -->
724<div class="doc_subsection">
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]725 <a name="c-be">Known problems with the C back-end</a>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]726</div>
727
728<div class="doc_text">
729
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]730<p>The C backend has numerous problems and is not being actively maintained.
731Depending on it for anything serious is not advised.</p>
732
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]733<ul>
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]734<li><a href="http://llvm.org/PR802">The C backend has only basic support for
735 inline assembly code</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]736<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
737 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif75b2f762009-03-02 12:02:51 +0000[diff] [blame]738 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandse09506a2008-02-10 13:40:55 +0000[diff] [blame]739<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands3aa36732009-02-25 11:51:54 +0000[diff] [blame]740<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]741</ul>
742
743</div>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]744
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]745
746<!-- ======================================================================= -->
747<div class="doc_subsection">
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]748 <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]749</div>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]750
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]751<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]752
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]753<p>llvm-gcc is generally very stable for the C family of languages. The only
754 major language feature of GCC not supported by llvm-gcc is the
755 <tt>__builtin_apply</tt> family of builtins. However, some extensions
756 are only supported on some targets. For example, trampolines are only
757 supported on some targets (these are used when you take the address of a
758 nested function).</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]759
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]760<p>Fortran support generally works, but there are still several unresolved bugs
761 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
762 tools/gfortran component for details. Note that llvm-gcc is missing major
763 Fortran performance work in the frontend and library that went into GCC after
764 4.2. If you are interested in Fortran, we recommend that you consider using
765 <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]766
Duncan Sandsd63e1c82010-10-04 10:06:56 +0000[diff] [blame]767<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
768actively maintained. If you are interested in Ada, we recommend that you
769consider using <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]770</div>
771
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]772<!-- *********************************************************************** -->
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]773<div class="doc_section">
774 <a name="additionalinfo">Additional Information</a>
775</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]776<!-- *********************************************************************** -->
777
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]778<div class="doc_text">
779
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]780<p>A wide variety of additional information is available on the <a
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]781href="http://llvm.org">LLVM web page</a>, in particular in the <a
782href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencerc7f87f22007-07-09 08:04:31 +0000[diff] [blame]783contains versions of the API documentation which is up-to-date with the
784Subversion version of the source code.
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]785You can access versions of these documents specific to this release by going
786into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]787
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]788<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]789us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]790lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]791
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]792</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]793
794<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]795
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]796<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]797<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]798 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]799 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]800 <a href="http://validator.w3.org/check/referer"><img
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Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]802
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]803 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]804 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]805</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]806
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]807</body>
808</html>