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gerrit-public.fairphone.software / toolchain / llvm-project / ce6b047a1005bc1befa851b6ee68c5bf73386360 / . / 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
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]12<h1 class="doc_title">LLVM 2.9 Release Notes</h1>
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<!-- *********************************************************************** -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]38<h1>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]39 <a name="intro">Introduction</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]40</h1>
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 Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]63
Chris Lattnerce6b0472011-04-05 23:22:33 +0000[diff] [blame^]64<!-- Features that need text if they're finished for 3.1:
65 ARM EHABI
Chris Lattnera67df2d2010-04-22 06:28:20 +0000[diff] [blame]66 combiner-aa?
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]67 strong phi elim
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]68 loop dependence analysis
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]69 CorrelatedValuePropagation
Chris Lattnerce6b0472011-04-05 23:22:33 +0000[diff] [blame^]70 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]71 -->
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]72
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]73<!-- *********************************************************************** -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]74<h1>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]75 <a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]76</h1>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]77<!-- *********************************************************************** -->
Chris Lattner625a3d82008-06-08 21:34:41 +0000[diff] [blame]78
79<div class="doc_text">
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]80<p>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]81The LLVM 2.9 distribution currently consists of code from the core LLVM
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]82repository (which roughly includes the LLVM optimizers, code generators
83and supporting tools), the Clang repository and the llvm-gcc repository. In
84addition to this code, the LLVM Project includes other sub-projects that are in
85development. Here we include updates on these subprojects.
Bill Wendlingf170d2e2009-03-02 04:28:57 +0000[diff] [blame]86</p>
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]87
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]88</div>
89
Chris Lattnerf5cd9862008-10-13 18:01:01 +0000[diff] [blame]90
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]91<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]92<h2>
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]93<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]94</h2>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]95
96<div class="doc_text">
97
Chris Lattner5de7f6e2010-04-26 17:42:18 +0000[diff] [blame]98<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
99C++, and Objective-C languages. Clang aims to provide a better user experience
100through expressive diagnostics, a high level of conformance to language
101standards, fast compilation, and low memory use. Like LLVM, Clang provides a
102modular, library-based architecture that makes it suitable for creating or
103integrating with other development tools. Clang is considered a
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]104production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
105(32- and 64-bit), and for darwin-arm targets.</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]106
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]107<p>In the LLVM 2.9 time-frame, the Clang team has made many improvements in C,
108C++ and Objective-C support. C++ support is now generally rock solid, has
109been exercised on a broad variety of code, and has several new C++'0x features
110implemented (such as rvalue references and variadic templates). LLVM 2.9 has
111also brought in a large range of bug fixes and minor features (e.g. __label__
112support), and is much more compatible with the Linux Kernel.</p>
113
114<p>If Clang rejects your code that is built with another compiler, please take a
115look at the <a href="http://clang.llvm.org/compatibility.html">language
116compatibility</a> guide to make sure the issue isn't intentional or a known
117issue.
118</p>
Bill Wendlingef362462008-10-27 09:27:33 +0000[diff] [blame]119
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]120<ul>
121</ul>
Chris Lattner44c09cd2008-10-13 18:11:54 +0000[diff] [blame]122</div>
123
124<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]125<h2>
Duncan Sands1cd78982011-04-04 11:09:08 +0000[diff] [blame]126<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]127</h2>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]128
129<div class="doc_text">
130<p>
Duncan Sands1cd78982011-04-04 11:09:08 +0000[diff] [blame]131<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
132<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
133optimizers and code generators with LLVM's.
134Currently it requires a patched version of gcc-4.5.
135The plugin can target the x86-32 and x86-64 processor families and has been
136used successfully on the Darwin, FreeBSD and Linux platforms.
137The Ada, C, C++ and Fortran languages work well.
138The plugin is capable of compiling plenty of Obj-C, Obj-C++ and Java but it is
139not known whether the compiled code actually works or not!
Duncan Sands92452b92010-04-02 09:23:15 +0000[diff] [blame]140</p>
141
142<p>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]143The 2.9 release has the following notable changes:
Duncan Sands7f9a0dc2010-09-30 17:37:34 +0000[diff] [blame]144<ul>
Duncan Sands1cd78982011-04-04 11:09:08 +0000[diff] [blame]145<li>The plugin is much more stable when compiling Fortran.</li>
146<li>Inline asm where an asm output is tied to an input of a different size is
147now supported in many more cases.</li>
148<li>Basic support for the __float128 type was added. It is now possible to
149generate LLVM IR from programs using __float128 but code generation does not
150work yet.</li>
151<li>Compiling Java programs no longer systematically crashes the plugin.</li>
Duncan Sands7f9a0dc2010-09-30 17:37:34 +0000[diff] [blame]152</ul>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]153
154</div>
155
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]156<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]157<h2>
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]158<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]159</h2>
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]160
161<div class="doc_text">
162<p>
163The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
164is a simple library that provides an implementation of the low-level
165target-specific hooks required by code generation and other runtime components.
166For example, when compiling for a 32-bit target, converting a double to a 64-bit
167unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
168function. The compiler-rt library provides highly optimized implementations of
169this and other low-level routines (some are 3x faster than the equivalent
170libgcc routines).</p>
171
172<p>
173All of the code in the compiler-rt project is available under the standard LLVM
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]174License, a "BSD-style" license.
175
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]176compiler_rt is now dual licensed under MIT and UIUC license
177
178Several minor changes for better ARM support.
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]179
180New in LLVM 2.9, UPDATE</p>
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]181
182</div>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]183
184<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]185<h2>
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]186<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]187</h2>
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]188
189<div class="doc_text">
190<p>
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]191<a href="http://lldb.llvm.org/">LLDB</a> is a brand new member of the LLVM
192umbrella of projects. LLDB is a next generation, high-performance debugger. It
193is built as a set of reusable components which highly leverage existing
194libraries in the larger LLVM Project, such as the Clang expression parser, the
195LLVM disassembler and the LLVM JIT.</p>
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]196
197<p>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]198LLDB 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]199
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]200
201
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]202<!--
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]203but is mature enough to support basic debugging scenarios on Mac OS X in C,
204Objective-C and C++. We'd really like help extending and expanding LLDB to
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]205support new platforms, new languages, new architectures, and new features.-->
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]206</p>
207
208</div>
209
210<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]211<h2>
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]212<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]213</h2>
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]214
215<div class="doc_text">
216<p>
Tobias Grosser436bc5f2010-10-06 21:07:30 +0000[diff] [blame]217<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]218family. It is an implementation of the C++ standard library, written from the
219ground up to specifically target the forthcoming C++'0X standard and focus on
220delivering great performance.</p>
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]221
222<p>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]223As of the LLVM 2.9 release, UPDATE!
224
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]225libc++ is now dual licensed under MIT and UIUC license
226
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]227<!--libc++ is virtually feature complete, but would
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]228benefit from more testing and better integration with Clang++. It is also
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]229looking forward to the C++ committee finalizing the C++'0x standard.-->
Chris Lattner342f9572010-09-29 05:30:03 +0000[diff] [blame]230</p>
231
232</div>
233
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]234
Daniel Dunbar8fbd8aa2010-10-04 17:39:47 +0000[diff] [blame]235
236<!--=========================================================================-->
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]237<!--
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]238<h2>
Daniel Dunbar8fbd8aa2010-10-04 17:39:47 +0000[diff] [blame]239<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]240</h2>
Daniel Dunbar8fbd8aa2010-10-04 17:39:47 +0000[diff] [blame]241
242<div class="doc_text">
243<p>
244<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
245programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
246through the application and records state transitions that lead to fault
247states. This allows it to construct testcases that lead to faults and can even
248be used to verify some algorithms.
249</p>
250
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]251<p>UPDATE!</p>
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]252</div>-->
Daniel Dunbar8fbd8aa2010-10-04 17:39:47 +0000[diff] [blame]253
254
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]255<!-- *********************************************************************** -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]256<h1>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]257 <a name="externalproj">External Open Source Projects Using LLVM 2.9</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]258</h1>
Chris Lattner53e06f92009-02-26 22:33:38 +0000[diff] [blame]259<!-- *********************************************************************** -->
260
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]261<div class="doc_text">
262
263<p>An exciting aspect of LLVM is that it is used as an enabling technology for
264 a lot of other language and tools projects. This section lists some of the
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]265 projects that have already been updated to work with LLVM 2.9.</p>
Chris Lattnerdf85c892010-04-26 17:38:10 +0000[diff] [blame]266</div>
267
Chris Lattner120804a2010-10-03 23:49:06 +0000[diff] [blame]268
269
Chris Lattnerca7c8962010-10-01 06:34:49 +0000[diff] [blame]270
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]271<!-- *********************************************************************** -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]272<h1>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]273 <a name="whatsnew">What's New in LLVM 2.9?</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]274</h1>
Chris Lattnerc75fd522008-06-08 21:58:17 +0000[diff] [blame]275<!-- *********************************************************************** -->
276
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]277<div class="doc_text">
278
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]279<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]280minor improvements. Some of the major improvements and new features are listed
281in this section.
Chris Lattnerb7bc2aa2008-06-08 22:59:35 +0000[diff] [blame]282</p>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]283
Chris Lattnera67df2d2010-04-22 06:28:20 +0000[diff] [blame]284</div>
285
286<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]287<h2>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]288<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]289</h2>
Chris Lattnercdc44ed2008-02-06 18:00:06 +0000[diff] [blame]290
291<div class="doc_text">
292
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]293<p>LLVM 2.9 includes several major new capabilities:</p>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]294
295<ul>
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]296<li><pre>
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]297 last release for llvm-gcc
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]298TBAA: On by default in clang. Disable it with -fno-strict-aliasing.
299 Could be more aggressive for structs.
300
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]301Triple::normalize is new, llvm triples are always stored in normalized form internally.
302
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]303Triple x86_64--mingw64 is obsoleted. Use x86_64--mingw32 instead.
304
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]305MC Assembler: X86 now generates much better diagnostics for common errors,
306 is much faster at matching instructions, is much more bug-compatible with
307 the GAS assembler, and is now generally useful for a broad range of X86
308 assembly.
309
310New Nvidia PTX backend, not generally useful in 2.9 though.
311
312Much better debug info generated, particularly in optimized code situations.
313
314ARM Fast ISel
315
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]316ELF MC support: on by default in clang. There are still known missing features
317 for human written assembly.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]318
319X86: Reimplemented all of MMX to introduce a new LLVM IR x86_mmx type. Now
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]320 random types like &lt;2 x i32&gt; are not iseld to mmx without emms. The
321 -disable-mmx flag is gone now.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]322
323Some basic <a href="CodeGenerator.html#mc">internals documentation</a> for MC.
324
325MC Assembler support for .file and .loc.
326
327
328inline asm multiple alternative constraint support.
329
Chris Lattnerce6b0472011-04-05 23:22:33 +0000[diff] [blame^]330LoopIdiom: memset/memcpy formation and memset_pattern on darwin. Build with
331 -ffreestanding or -fno-builtin if your memcpy is being compiled into infinite
332 recursion.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]333
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]334
335TargetLibraryInfo
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]336
337X86 support for FS/GS relative loads and stores using address space 256/257 are
338 reliable now.
339
340ARM: New code placement pass.
341
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]342unnamed_addr + PR8927
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]343
344PointerTracking has been removed from mainline, moved to ClamAV.
345
346EarlyCSE pass.
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]347LoopInstSimplify pass.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]348
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]349- DIBuilder provides simpler interface for front ends like Clang to encode debug info in LLVM IR.
350 - This interface hides implementation details (e.g. DIDerivedType, existence of compile unit etc..) that any front end should not know about.
Chris Lattnerce6b0472011-04-05 23:22:33 +0000[diff] [blame^]351 For example, DIFactory DebugFactory;
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]352 Ty = DebugFactory.CreateDerivedType(DW_TAG_volatile_type,
353 findRegion(TYPE_CONTEXT(type)),
354 StringRef(),
355 getOrCreateFile(main_input_filename),
356 0 /*line no*/,
357 NodeSizeInBits(type),
358 NodeAlignInBits(type),
359 0 /*offset */,
360 0 /* flags */,
361 MainTy);
362 can be replaced by
363 DbgTy = DBuilder.createQualifiedType(DW_TAG_volatile_type, MainTy);
Chris Lattnerce6b0472011-04-05 23:22:33 +0000[diff] [blame^]364DIFactory is gone now.
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]365
366PPC: Switched to MCInstPrinter, and MCCodeEmitter. Ready to implement support
367 for directly writing out mach-o object files, but noone seems interested.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]368
369ARM: Improved code generation for Cortex-A8 and Cortex-A9 CPUs.
370
371Scheduler now models operand latency and pipeline forwarding.
372
Chris Lattnerce6b0472011-04-05 23:22:33 +0000[diff] [blame^]373Can optimize printf to iprintf when no floating point is used, for embedded
374 targets with smaller iprintf implementation.
375
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]376error_code + libsystem + PathV2 changes
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]377 The system_error header from C++0x was added.
378 * Use if (error_code ec = function()) to check for error conditions
379 from functions which return it.
380 * error_code::message returns a human readable description of the error.
381
382 PathV1 has been deprecated in favor of PathV2 (sorry I didn't finish
383 this before the release).
384 * No Path class, use a r-value convertible to a twine instead.
385 * Assumes all paths are UTF-8.
386
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]387new macho-dump tool
388
389Major regalloc rewrite, not on by default for 2.9 and not advised to use it.
390 * New basic register allocator that can be used as a safe fallback when
391 debugging. Enable with -regalloc=basic.
392 * New infrastructure for live range splitting. SplitKit can break a live
393 interval into smaller pieces while preserving SSA form, and SpillPlacement
394 can help find the best split points. This is a work in progress so the API
395 is changing quickly.
396 * The inline spiller has learned to clean up after live range splitting. It
397 can hoist spills out of loops, and it can eliminate redundant spills.
398 Rematerialization works with live range splitting.
399 * New greedy register allocator using live range splitting. This will be the
400 default register allocator in the next LLVM release, but it is not turned on
401 by default in 2.9.
402
403ARM: __builtin_prefetch turns into prefetch instructions.
404
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]405MC assembler support for 3dNow! and 3DNowA instructions.
406
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]407tblgen support for assembler aliases: <a
408 href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
409
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]410LoopIndexSplit pass was removed, unmaintained.
Chris Lattnerce6b0472011-04-05 23:22:33 +0000[diff] [blame^]411LiveValues, SimplifyHalfPowrLibCalls, and GEPSplitter were removed.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]412
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]413include/llvm/System merged into include/llvm/Support.
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]414
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]415Win32 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]416 timeframe, but is still not generally useful. Please see
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]417 "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]418
419New <a href="WritingAnLLVMPass.html#RegionPass">RegionPass</a> infrastructure
420 for region-based optimizations.
421
422MicroBlaze: major updates for aggressive delay slot filler, MC-based assembly
423 printing, assembly instruction parsing, ELF .o file emission, and MC
424 instruction disassembler.
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]425
426Countless ARM microoptimizations.
427
428Speedups to various mid-level passes:
429 GVN is much faster on functions with deep dominator trees / lots of BBs.
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]430 DomTree and DominatorFrontier are much faster to compute, and preserved by
431 more passes (so they are computed less often)
Chris Lattner706754c2011-04-05 21:43:56 +0000[diff] [blame]432 SRoA is also much faster and doesn't use DominanceFrontier.
Chris Lattner9ee0b012011-04-05 18:38:45 +0000[diff] [blame]433
434
435new 'hotpatch' attribute: LangRef.html#fnattrs
Chris Lattner269ef9f2011-04-05 21:37:08 +0000[diff] [blame]436
437APInt API changes, see PR5207.
438
439DSE is more aggressive with stores of different types: e.g. a large store
440 following a small one to the same address.
441
442New naming rules in coding standards: CodingStandards.html#ll_naming
443
444LiveDebugVariables is a new pass that keeps track of debugging information for
445 user variables that are kept in registers in optimized builds.
446
447We now optimize various idioms for overflow detection into check of the flag
448 register on various CPUs, e.g.:
449 unsigned long t = a+b;
450 if (t &lt; a) ...
451 into:
452 addq %rdi, %rbx
453 jno LBB0_2
454
455X86: Much better codegen for several cases using adc/sbb instead of cmovs for
456 conditional increment and other idioms.
457
458MVT::Flag renamed to MVT::Glue
459
460Removed the PartialSpecialization pass, it was unmaintained and buggy.
461
Chris Lattner706754c2011-04-05 21:43:56 +0000[diff] [blame]462SPARC: Many improvements, including using the Y registers for multiplications
463 and addition of a simple delay slot filler.
464
Chris Lattnerce6b0472011-04-05 23:22:33 +0000[diff] [blame^]465
466udiv, ashr, lshr, shl now have exact and nuw/nsw bits: PR8862 / LangRef.html
467
468lib/Object and llvm-objdump
469
470
471 Target Independent Code Gen:
472 The pre-register-allocation (preRA) instruction scheduler models register pressure
473 much more accurately in some cases. This allows the adoption of more
474 aggressive scheduling heuristics.
475
476 The X86 backend has adopted a new preRA scheduling
477 mode, "list-ilp", to shorten the height of instruction schedules
478 without inducing register spills.
479
480 The ARM backend preRA scheduler now models machine resources at cycle
481 granularity. This allows the scheduler to both accurately model
482 instruction latency and avoid overcommitting functional units.
483
484
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]485</pre></li>
Chris Lattner458e79f2008-02-10 08:18:42 +0000[diff] [blame]486</ul>
Chris Lattnerfd97b882011-04-05 07:19:28 +0000[diff] [blame]487
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]488</div>
489
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]490<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]491<h2>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]492<a name="coreimprovements">LLVM IR and Core Improvements</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]493</h2>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]494
495<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]496<p>LLVM IR has several new features for better support of new targets and that
497expose new optimization opportunities:</p>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]498
Chris Lattnerb7112222008-06-05 06:25:56 +0000[diff] [blame]499<ul>
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]500</ul>
Mikhail Glushenkov024f7cf2008-10-13 02:08:34 +0000[diff] [blame]501
Chris Lattnerdd6acc02008-02-10 08:17:19 +0000[diff] [blame]502</div>
503
504<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]505<h2>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]506<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]507</h2>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]508
509<div class="doc_text">
510
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]511<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]512release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattner2b8a52e2008-02-10 07:46:44 +0000[diff] [blame]513
514<ul>
Rafael Espindola01fb4b02011-03-18 04:07:44 +0000[diff] [blame]515 <li>TBAA.</li>
516 <li>LTO has been improved to use MC for parsing inline asm and now
517 can build large programs like Firefox 4 on both OS X and Linux.</li>
Chris Lattnerfcc65a72010-10-04 02:42:39 +0000[diff] [blame]518</ul>
519
520<!--
521<p>In addition to these features that are done in 2.8, there is preliminary
522 support in the release for Type Based Alias Analysis
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]523 Preliminary work on TBAA but not usable in 2.8.
524 New CorrelatedValuePropagation pass, not on by default in 2.8 yet.
Chris Lattnerfcc65a72010-10-04 02:42:39 +0000[diff] [blame]525-->
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]526
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]527</div>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]528
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]529<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]530<h2>
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]531<a name="mc">MC Level Improvements</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]532</h2>
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]533
534<div class="doc_text">
535<p>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]536The LLVM Machine Code (aka MC) subsystem was created to solve a number
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]537of problems in the realm of assembly, disassembly, object file format handling,
538and a number of other related areas that CPU instruction-set level tools work
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]539in.</p>
540
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]541<ul>
Rafael Espindola01fb4b02011-03-18 04:07:44 +0000[diff] [blame]542 <li>MC is now used by default for ELF systems on x86 and
543 x86-64.</li>
544 <li>MC supports and CodeGen uses the <tt>.loc</tt> directives for
545 producing line number debug info. This produces more compact line
546 tables.</li>
547 <li>MC supports the <tt>.cfi_*</tt> directives for producing DWARF
548 frame information, but it is still not used by CodeGen by default.</li>
549 <li>COFF support?</li>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]550</ul>
551
552<p>For more information, please see the <a
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]553href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
554LLVM MC Project Blog Post</a>.
555</p>
556
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]557</div>
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]558
Chris Lattnerf25bc192010-09-30 16:31:33 +0000[diff] [blame]559<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]560<h2>
Chris Lattnerd434bfb2009-03-02 03:24:11 +0000[diff] [blame]561<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]562</h2>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]563
564<div class="doc_text">
565
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]566<p>We have put a significant amount of work into the code generator
567infrastructure, which allows us to implement more aggressive algorithms and make
568it run faster:</p>
Chris Lattner7795ea92008-06-08 02:45:07 +0000[diff] [blame]569
570<ul>
Chris Lattner9fd1e922010-10-04 03:58:12 +0000[diff] [blame]571<!-- SplitKit -->
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]572FastISel for ARM.
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]573</ul>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]574</div>
575
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]576<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]577<h2>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]578<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]579</h2>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]580
581<div class="doc_text">
Chris Lattnerd3f45c82010-10-04 04:39:25 +0000[diff] [blame]582<p>New features and major changes in the X86 target include:
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]583</p>
584
585<ul>
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]586 <li>Several bugs have been fixed for Windows x64 code generator.</li>
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]587</ul>
588
Chris Lattnerd1094e02009-03-02 02:37:32 +0000[diff] [blame]589</div>
Chris Lattner0a1fd102007-09-21 03:54:09 +0000[diff] [blame]590
591<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]592<h2>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]593<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]594</h2>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]595
596<div class="doc_text">
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]597<p>New features of the ARM target include:
598</p>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]599
600<ul>
Bob Wilsone44f2982010-09-13 17:39:35 +0000[diff] [blame]601</ul>
Chris Lattneraa61f412009-10-13 17:48:04 +0000[diff] [blame]602</div>
Chris Lattnerc92d7692009-03-01 02:30:21 +0000[diff] [blame]603
Chris Lattner6cb64032008-06-05 08:02:49 +0000[diff] [blame]604
605<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]606<h2>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]607<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]608</h2>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]609
610<div class="doc_text">
611
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]612<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]613on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]614from the previous release.</p>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]615
616<ul>
Chris Lattner87e04952010-04-21 05:17:40 +0000[diff] [blame]617</ul>
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]618
Chris Lattnera7f45cf2010-10-04 01:29:06 +0000[diff] [blame]619
620
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]621<p>In addition, many APIs have changed in this release. Some of the major LLVM
622API changes are:</p>
Chris Lattner934e2d42008-10-13 22:06:31 +0000[diff] [blame]623<ul>
Devang Pateldbf83832008-10-14 20:03:43 +0000[diff] [blame]624</ul>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]625
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]626</div>
627
Daniel Dunbarf70898a2010-10-04 20:11:41 +0000[diff] [blame]628<!--=========================================================================-->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]629<h2>
Daniel Dunbarf70898a2010-10-04 20:11:41 +0000[diff] [blame]630<a name="devtree_changes">Development Infrastructure Changes</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]631</h2>
Daniel Dunbarf70898a2010-10-04 20:11:41 +0000[diff] [blame]632
633<div class="doc_text">
634
635<p>This section lists changes to the LLVM development infrastructure. This
636mostly impacts users who actively work on LLVM or follow development on
637mainline, but may also impact users who leverage the LLVM build infrastructure
638or are interested in LLVM qualification.</p>
639
640<ul>
Daniel Dunbarf70898a2010-10-04 20:11:41 +0000[diff] [blame]641</ul>
642</div>
Chris Lattner1e4d5bc2008-10-13 17:57:36 +0000[diff] [blame]643
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]644<!-- *********************************************************************** -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]645<h1>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]646 <a name="knownproblems">Known Problems</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]647</h1>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]648<!-- *********************************************************************** -->
649
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]650<div class="doc_text">
651
Mikhail Glushenkov25422542009-03-01 18:09:47 +0000[diff] [blame]652<p>This section contains significant known problems with the LLVM system,
Chris Lattner2a092392008-11-10 05:40:34 +0000[diff] [blame]653listed by component. If you run into a problem, please check the <a
Chris Lattnera69595e2005-10-29 07:07:09 +0000[diff] [blame]654href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]655there isn't already one.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]656
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]657</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]658
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]659<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]660<h2>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]661 <a name="experimental">Experimental features included with this release</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]662</h2>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]663
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]664<div class="doc_text">
665
Misha Brukmanfa50a222004-05-12 21:46:05 +0000[diff] [blame]666<p>The following components of this LLVM release are either untested, known to
667be broken or unreliable, or are in early development. These components should
668not be relied on, and bugs should not be filed against them, but they may be
669useful 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]670components, please contact us on the <a
671href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]672
673<ul>
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]674<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ
Chris Lattnera7f45cf2010-10-04 01:29:06 +0000[diff] [blame]675 and XCore backends are experimental.</li>
Chris Lattnerbf1cf672010-10-02 21:59:30 +0000[diff] [blame]676<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
Chris Lattner0d364302011-03-10 07:43:44 +0000[diff] [blame]677 other than darwin-i386 and darwin-x86_64. FIXME: Not true on ELF anymore?</li>
678
Chris Lattnerb911de42004-03-14 02:03:02 +0000[diff] [blame]679</ul>
680
681</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]682
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]683<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]684<h2>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]685 <a name="x86-be">Known problems with the X86 back-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]686</h2>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]687
688<div class="doc_text">
689
690<ul>
Anton Korobeynikov486c7d32008-06-08 10:24:13 +0000[diff] [blame]691 <li>The X86 backend does not yet support
692 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
693 floating point stack</a>. It supports the 'f' and 't' constraints, but not
694 'u'.</li>
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]695 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattnera67df2d2010-04-22 06:28:20 +0000[diff] [blame]696 <tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman721b3722008-06-08 23:05:11 +0000[diff] [blame]697 argument constructs on X86-64 by lowering them manually.</li>
NAKAMURA Takumi8d89b8e2011-04-05 08:24:22 +0000[diff] [blame]698 <li>Windows x64 (aka Win64) code generator has a few issues.
699 <ul>
700 <li>llvm-gcc cannot build the mingw-w64 runtime currently
701 due to lack of support for the 'u' inline assembly
702 constraint and for X87 floating point inline assembly.</li>
703 <li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt>
704 due to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
705 It is fixed in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
706 <li>Miss-aligned MOVDQA might crash your program. It is due to
707 <a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>,
708 lack of handling aligned internal globals.</li>
709 </ul>
710 </li>
711
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]712</ul>
713
714</div>
715
716<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]717<h2>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]718 <a name="ppc-be">Known problems with the PowerPC back-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]719</h2>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]720
721<div class="doc_text">
722
723<ul>
Nicolas Geoffray77d99502007-05-15 09:21:28 +0000[diff] [blame]724<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]725compilation, and lacks support for debug information.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]726</ul>
727
728</div>
729
730<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]731<h2>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]732 <a name="arm-be">Known problems with the ARM back-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]733</h2>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]734
735<div class="doc_text">
736
737<ul>
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]738<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sands47fc0a22007-09-26 15:59:54 +0000[diff] [blame]739processors, thumb programs can crash or produce wrong
Chris Lattnerbee7b322007-05-23 04:39:32 +0000[diff] [blame]740results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]741<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]742</li>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]743</ul>
744
745</div>
746
747<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]748<h2>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]749 <a name="sparc-be">Known problems with the SPARC back-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]750</h2>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]751
752<div class="doc_text">
753
754<ul>
John Criswellea03c9d2009-03-02 15:28:15 +0000[diff] [blame]755<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]756 support the 64-bit SPARC ABI (-m64).</li>
757</ul>
758
759</div>
760
761<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]762<h2>
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]763 <a name="mips-be">Known problems with the MIPS back-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]764</h2>
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]765
766<div class="doc_text">
767
768<ul>
Bruno Cardoso Lopes24eb3de2008-10-25 14:56:26 +0000[diff] [blame]769<li>64-bit MIPS targets are not supported yet.</li>
770</ul>
771
772</div>
773
774<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]775<h2>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]776 <a name="alpha-be">Known problems with the Alpha back-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]777</h2>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]778
779<div class="doc_text">
780
781<ul>
782
783<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
784appropriate nops inserted to ensure restartability.</li>
785
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]786</ul>
787</div>
788
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]789<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]790<h2>
Chris Lattner97beb512007-05-14 06:56:09 +0000[diff] [blame]791 <a name="c-be">Known problems with the C back-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]792</h2>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]793
794<div class="doc_text">
795
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]796<p>The C backend has numerous problems and is not being actively maintained.
797Depending on it for anything serious is not advised.</p>
798
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]799<ul>
Chris Lattnera1a4c9a2008-06-05 06:35:40 +0000[diff] [blame]800<li><a href="http://llvm.org/PR802">The C backend has only basic support for
801 inline assembly code</a>.</li>
Chris Lattner8e061162007-09-26 06:01:35 +0000[diff] [blame]802<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
803 C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
Gabor Greif75b2f762009-03-02 12:02:51 +0000[diff] [blame]804 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandse09506a2008-02-10 13:40:55 +0000[diff] [blame]805<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands3aa36732009-02-25 11:51:54 +0000[diff] [blame]806<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattnerb81f10e2006-11-18 07:51:14 +0000[diff] [blame]807</ul>
808
809</div>
John Criswell3bdbd302005-11-08 21:11:33 +0000[diff] [blame]810
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]811
812<!-- ======================================================================= -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]813<h2>
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]814 <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]815</h2>
Chris Lattner178f3db2003-10-02 05:07:23 +0000[diff] [blame]816
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]817<div class="doc_text">
Chris Lattner72a269f2006-03-03 00:34:26 +0000[diff] [blame]818
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]819<p>llvm-gcc is generally very stable for the C family of languages. The only
820 major language feature of GCC not supported by llvm-gcc is the
821 <tt>__builtin_apply</tt> family of builtins. However, some extensions
822 are only supported on some targets. For example, trampolines are only
823 supported on some targets (these are used when you take the address of a
824 nested function).</p>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]825
Chris Lattner086d2692010-09-29 05:34:42 +0000[diff] [blame]826<p>Fortran support generally works, but there are still several unresolved bugs
827 in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the
828 tools/gfortran component for details. Note that llvm-gcc is missing major
829 Fortran performance work in the frontend and library that went into GCC after
830 4.2. If you are interested in Fortran, we recommend that you consider using
831 <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]832
Duncan Sandsd63e1c82010-10-04 10:06:56 +0000[diff] [blame]833<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
834actively maintained. If you are interested in Ada, we recommend that you
835consider using <a href="#dragonegg">dragonegg</a> instead.</p>
Chris Lattnere38ac152008-02-12 06:29:45 +0000[diff] [blame]836</div>
837
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]838<!-- *********************************************************************** -->
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]839<h1>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]840 <a name="additionalinfo">Additional Information</a>
NAKAMURA Takumi530d7392011-04-05 21:55:14 +0000[diff] [blame]841</h1>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]842<!-- *********************************************************************** -->
843
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]844<div class="doc_text">
845
Chris Lattnercb5596d2005-05-16 17:13:10 +0000[diff] [blame]846<p>A wide variety of additional information is available on the <a
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]847href="http://llvm.org">LLVM web page</a>, in particular in the <a
848href="http://llvm.org/docs/">documentation</a> section. The web page also
Reid Spencerc7f87f22007-07-09 08:04:31 +0000[diff] [blame]849contains versions of the API documentation which is up-to-date with the
850Subversion version of the source code.
Misha Brukman96158092005-03-30 19:14:24 +0000[diff] [blame]851You can access versions of these documents specific to this release by going
852into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]853
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]854<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]855us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattnerb84f3322003-12-12 21:22:16 +0000[diff] [blame]856lists</a>.</p>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]857
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]858</div>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]859
860<!-- *********************************************************************** -->
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]861
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]862<hr>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]863<address>
Misha Brukman8834af92003-12-21 22:53:21 +0000[diff] [blame]864 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]865 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]866 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]867 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]868
Chris Lattnere0c1df42007-05-18 00:44:29 +0000[diff] [blame]869 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]870 Last modified: $Date$
Misha Brukman68aab3b2003-11-22 01:23:39 +0000[diff] [blame]871</address>
Chris Lattner3d482502003-10-02 04:57:28 +0000[diff] [blame]872
Misha Brukman80731b92003-11-22 00:38:41 +0000[diff] [blame]873</body>
874</html>