Gitiles
Code Review Sign In
gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / e4dc1966baf6b2b5b27c50dd0321852666788588 / . / docs / ReleaseNotes.html
blob: b25f1ae142376b187483319464c1da49a42e54d2 [file] [log] [blame]
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4<head>
Reid Spencer6454ed32004-11-18 18:38:58 +0000[diff] [blame]5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Chris Lattner2fb6e5c2010-10-03 23:09:03 +0000[diff] [blame]6 <meta encoding="utf8">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]7 <link rel="stylesheet" href="llvm.css" type="text/css">
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]8 <title>LLVM 2.9 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]9</head>
10<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]11
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]12<h1 class="doc_title">LLVM 2.9 Release Notes</h1>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]13
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]14<img align=right src="http://llvm.org/img/DragonSmall.png"
Gabor Greifee2187a2010-04-22 10:21:43 +0000[diff] [blame]15 width="136" height="136" alt="LLVM Dragon Logo">
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]16
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]17<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]18 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]19 <li><a href="#subproj">Sub-project Status Update</a></li>
Chris Lattnerbe2e1b52011-03-10 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 Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]22 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]23 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]24 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]25</ol>
26
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]27<div class="doc_author">
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]28 <p>Written by the <a href="http://llvm.org">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]29</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]30
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]31<h1 style="color:red">These are in-progress notes for the upcoming LLVM 2.9
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]32release.<br>
33You may prefer the
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]34<a href="http://llvm.org/releases/2.8/docs/ReleaseNotes.html">LLVM 2.8
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]35Release Notes</a>.</h1>
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]36
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]37<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]38<h1>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]39 <a name="intro">Introduction</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]40</h1>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]41<!-- *********************************************************************** -->
42
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]43<div class="doc_text">
44
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]45<p>This document contains the release notes for the LLVM Compiler
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]46Infrastructure, release 2.9. Here we describe the status of LLVM, including
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]47major improvements from the previous release and significant known problems.
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]48All LLVM releases may be downloaded from the <a
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]49href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]50
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]51<p>For more information about LLVM, including information about the latest
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]52release, please check out the <a href="http://llvm.org/">main LLVM
Chris Lattner47ad72c2003-10-07 21:38:31 +0000[diff] [blame]53web site</a>. If you have questions or comments, the <a
Chris Lattnerc66bfef2010-03-17 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]56
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]57<p>Note that if you are reading this file from a Subversion checkout or the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]58main LLVM web page, this document applies to the <i>next</i> release, not the
Gabor Greiffa933f82008-10-14 11:00:32 +0000[diff] [blame]59current one. To see the release notes for a specific release, please see the
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]60<a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]61
62</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]63
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame^]64<!-- Features that need text if they're finished for 3.1:
65 ARM EHABI
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]66 combiner-aa?
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]67 strong phi elim
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]68 loop dependence analysis
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]69 CorrelatedValuePropagation
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame^]70 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]71 -->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]72
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]73<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]74<h1>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]75 <a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]76</h1>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]77<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]78
79<div class="doc_text">
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]80<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]81The LLVM 2.9 distribution currently consists of code from the core LLVM
Chris Lattner61358ab2009-10-13 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 Wendling63d8c552009-03-02 04:28:57 +0000[diff] [blame]86</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]87
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]88</div>
89
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]90
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]91<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]92<h2>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]93<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]94</h2>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]95
96<div class="doc_text">
97
Chris Lattner095539f2010-04-26 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 Lattnere07043c2010-09-29 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 Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]106
Chris Lattner0a6f6d52011-04-05 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 Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]119
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]120<ul>
121</ul>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]122</div>
123
124<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]125<h2>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]126<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]127</h2>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]128
129<div class="doc_text">
130<p>
Duncan Sands528a5102011-04-04 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 Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]140</p>
141
142<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]143The 2.9 release has the following notable changes:
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]144<ul>
Duncan Sands528a5102011-04-04 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 Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]152</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]153
154</div>
155
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]156<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]157<h2>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]158<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]159</h2>
Chris Lattner75547712010-10-03 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 Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]174License, a "BSD-style" license.
175
Chris Lattner0a6f6d52011-04-05 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 Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]179
180New in LLVM 2.9, UPDATE</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]181
182</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]183
184<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]185<h2>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]186<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]187</h2>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]188
189<div class="doc_text">
190<p>
Chris Lattner75547712010-10-03 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 Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]196
197<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]198LLDB is in early development and not included as part of the LLVM 2.9 release,
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]199
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]200
201
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]202<!--
Chris Lattner75547712010-10-03 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 Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]205support new platforms, new languages, new architectures, and new features.-->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]206</p>
207
208</div>
209
210<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]211<h2>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]212<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]213</h2>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]214
215<div class="doc_text">
216<p>
Tobias Grossercdce44b2010-10-06 21:07:30 +0000[diff] [blame]217<a href="http://libcxx.llvm.org/">libc++</a> is another new member of the LLVM
Chris Lattner75547712010-10-03 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 Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]221
222<p>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]223As of the LLVM 2.9 release, UPDATE!
224
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]225libc++ is now dual licensed under MIT and UIUC license
226
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]227<!--libc++ is virtually feature complete, but would
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]228benefit from more testing and better integration with Clang++. It is also
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]229looking forward to the C++ committee finalizing the C++'0x standard.-->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]230</p>
231
232</div>
233
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]234
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]235
236<!--=========================================================================-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]237<!--
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]238<h2>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]239<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]240</h2>
Daniel Dunbar97b01a82010-10-04 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 Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]251<p>UPDATE!</p>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]252</div>-->
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]253
254
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]255<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]256<h1>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]257 <a name="externalproj">External Open Source Projects Using LLVM 2.9</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]258</h1>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]259<!-- *********************************************************************** -->
260
Chris Lattner61358ab2009-10-13 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 Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]265 projects that have already been updated to work with LLVM 2.9.</p>
Chris Lattner7c8e7962010-04-26 17:38:10 +0000[diff] [blame]266</div>
267
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]268
269
Chris Lattnere0518442010-10-01 06:34:49 +0000[diff] [blame]270
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]271<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]272<h1>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]273 <a name="whatsnew">What's New in LLVM 2.9?</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]274</h1>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]275<!-- *********************************************************************** -->
276
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]277<div class="doc_text">
278
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]279<p>This release includes a huge number of bug fixes, performance tweaks and
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]280minor improvements. Some of the major improvements and new features are listed
281in this section.
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]282</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]283
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]284</div>
285
286<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]287<h2>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]288<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]289</h2>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]290
291<div class="doc_text">
292
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]293<p>LLVM 2.9 includes several major new capabilities:</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]294
295<ul>
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]296<li><pre>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]297 last release for llvm-gcc
Chris Lattner7a8e6c52011-04-05 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 Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]301Triple::normalize is new, llvm triples are always stored in normalized form internally.
302
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]303Triple x86_64--mingw64 is obsoleted. Use x86_64--mingw32 instead.
304
Chris Lattner0a6f6d52011-04-05 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 Lattner7a8e6c52011-04-05 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 Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]318
319X86: Reimplemented all of MMX to introduce a new LLVM IR x86_mmx type. Now
Chris Lattner0f310ee2011-04-05 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 Lattner0a6f6d52011-04-05 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 Lattnere4dc1962011-04-05 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 Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]333
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]334
335TargetLibraryInfo
Chris Lattner0a6f6d52011-04-05 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 Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]342unnamed_addr + PR8927
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]343
344PointerTracking has been removed from mainline, moved to ClamAV.
345
346EarlyCSE pass.
Chris Lattner0f310ee2011-04-05 21:37:08 +0000[diff] [blame]347LoopInstSimplify pass.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]348
Chris Lattner7a8e6c52011-04-05 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 Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame^]351 For example, DIFactory DebugFactory;
Chris Lattner7a8e6c52011-04-05 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 Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame^]364DIFactory is gone now.
Chris Lattner7a8e6c52011-04-05 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 Lattner0a6f6d52011-04-05 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 Lattnere4dc1962011-04-05 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 Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]376error_code + libsystem + PathV2 changes
Chris Lattner0f310ee2011-04-05 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 Lattner7a8e6c52011-04-05 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 Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]405MC assembler support for 3dNow! and 3DNowA instructions.
406
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]407tblgen support for assembler aliases: <a
408 href="CodeGenerator.html#na_instparsing">MnemonicAlias and InstAlias</a>
409
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]410LoopIndexSplit pass was removed, unmaintained.
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame^]411LiveValues, SimplifyHalfPowrLibCalls, and GEPSplitter were removed.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]412
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]413include/llvm/System merged into include/llvm/Support.
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]414
NAKAMURA Takumi45c435a2011-04-05 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 Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]416 timeframe, but is still not generally useful. Please see
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]417 "http://llvm.org/bugs/showdependencytree.cgi?id=9100&amp;hide_resolved=1" for open bugs?
Chris Lattner0a6f6d52011-04-05 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 Lattner7a8e6c52011-04-05 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 Lattner0f310ee2011-04-05 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 Lattner51fbec92011-04-05 21:43:56 +0000[diff] [blame]432 SRoA is also much faster and doesn't use DominanceFrontier.
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]433
434
435new 'hotpatch' attribute: LangRef.html#fnattrs
Chris Lattner0f310ee2011-04-05 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 Lattner51fbec92011-04-05 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 Lattnere4dc1962011-04-05 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 Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]485</pre></li>
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]486</ul>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]487
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]488</div>
489
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]490<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]491<h2>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]492<a name="coreimprovements">LLVM IR and Core Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]493</h2>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]494
495<div class="doc_text">
Chris Lattner61358ab2009-10-13 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 Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]498
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]499<ul>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]500</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]501
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]502</div>
503
504<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]505<h2>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]506<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]507</h2>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]508
509<div class="doc_text">
510
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]511<p>In addition to a large array of minor performance tweaks and bug fixes, this
Chris Lattnerf3013872008-10-13 21:50:36 +0000[diff] [blame]512release includes a few major enhancements and additions to the optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]513
514<ul>
Rafael Espindolaa26f36c2011-03-18 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 Lattner11b66112010-10-04 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 Lattner7d9b6b42010-10-02 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 Lattner11b66112010-10-04 02:42:39 +0000[diff] [blame]525-->
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]526
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]527</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]528
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]529<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]530<h2>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]531<a name="mc">MC Level Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]532</h2>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]533
534<div class="doc_text">
535<p>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]536The LLVM Machine Code (aka MC) subsystem was created to solve a number
Chris Lattner4ba2b652010-09-30 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 Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]539in.</p>
540
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]541<ul>
Rafael Espindolaa26f36c2011-03-18 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 Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]550</ul>
551
552<p>For more information, please see the <a
Chris Lattner4ba2b652010-09-30 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 Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]557</div>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]558
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]559<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]560<h2>
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]561<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]562</h2>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]563
564<div class="doc_text">
565
Mikhail Glushenkovf795ef02009-03-01 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 Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]569
570<ul>
Chris Lattner3bdcda12010-10-04 03:58:12 +0000[diff] [blame]571<!-- SplitKit -->
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]572FastISel for ARM.
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]573</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]574</div>
575
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]576<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]577<h2>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]578<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]579</h2>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]580
581<div class="doc_text">
Chris Lattner7714c912010-10-04 04:39:25 +0000[diff] [blame]582<p>New features and major changes in the X86 target include:
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]583</p>
584
585<ul>
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]586 <li>Several bugs have been fixed for Windows x64 code generator.</li>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]587</ul>
588
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]589</div>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]590
591<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]592<h2>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]593<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]594</h2>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]595
596<div class="doc_text">
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]597<p>New features of the ARM target include:
598</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]599
600<ul>
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]601</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]602</div>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]603
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]604
605<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]606<h2>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]607<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]608</h2>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]609
610<div class="doc_text">
611
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]612<p>If you're already an LLVM user or developer with out-of-tree changes based
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]613on LLVM 2.8, this section lists some "gotchas" that you may run into upgrading
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]614from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]615
616<ul>
Chris Lattnerb7c85b42010-04-21 05:17:40 +0000[diff] [blame]617</ul>
Chris Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]618
Chris Lattnerbb117712010-10-04 01:29:06 +0000[diff] [blame]619
620
Chris Lattnereeb4da02008-10-13 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 Lattnereeb4da02008-10-13 22:06:31 +0000[diff] [blame]623<ul>
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]624</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]625
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]626</div>
627
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]628<!--=========================================================================-->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]629<h2>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]630<a name="devtree_changes">Development Infrastructure Changes</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]631</h2>
Daniel Dunbarf0233c62010-10-04 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 Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]641</ul>
642</div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]643
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]644<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]645<h1>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]646 <a name="knownproblems">Known Problems</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]647</h1>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]648<!-- *********************************************************************** -->
649
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]650<div class="doc_text">
651
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]652<p>This section contains significant known problems with the LLVM system,
Chris Lattnere18b32e2008-11-10 05:40:34 +0000[diff] [blame]653listed by component. If you run into a problem, please check the <a
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]654href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]655there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]656
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]657</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]658
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]659<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]660<h2>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]661 <a name="experimental">Experimental features included with this release</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]662</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]663
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]664<div class="doc_text">
665
Misha Brukman6df9e2c2004-05-12 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 Lattner2b659ef2008-02-12 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 Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]672
673<ul>
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]674<li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ
Chris Lattnerbb117712010-10-04 01:29:06 +0000[diff] [blame]675 and XCore backends are experimental.</li>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]676<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]677 other than darwin-i386 and darwin-x86_64. FIXME: Not true on ELF anymore?</li>
678
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]679</ul>
680
681</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]682
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]683<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]684<h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]685 <a name="x86-be">Known problems with the X86 back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]686</h2>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]687
688<div class="doc_text">
689
690<ul>
Anton Korobeynikova6094be2008-06-08 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 Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]695 <li>The X86-64 backend does not yet support the LLVM IR instruction
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]696 <tt>va_arg</tt>. Currently, front-ends support variadic
Dan Gohman8207ba92008-06-08 23:05:11 +0000[diff] [blame]697 argument constructs on X86-64 by lowering them manually.</li>
NAKAMURA Takumi45c435a2011-04-05 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 Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]712</ul>
713
714</div>
715
716<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]717<h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]718 <a name="ppc-be">Known problems with the PowerPC back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]719</h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]720
721<div class="doc_text">
722
723<ul>
Nicolas Geoffraye4285dc2007-05-15 09:21:28 +0000[diff] [blame]724<li>The Linux PPC32/ABI support needs testing for the interpreter and static
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]725compilation, and lacks support for debug information.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]726</ul>
727
728</div>
729
730<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]731<h2>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]732 <a name="arm-be">Known problems with the ARM back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]733</h2>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]734
735<div class="doc_text">
736
737<ul>
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]738<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
Duncan Sandsc90d68b2007-09-26 15:59:54 +0000[diff] [blame]739processors, thumb programs can crash or produce wrong
Chris Lattner57a460e2007-05-23 04:39:32 +0000[diff] [blame]740results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]741<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]742</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]743</ul>
744
745</div>
746
747<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]748<h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]749 <a name="sparc-be">Known problems with the SPARC back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]750</h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]751
752<div class="doc_text">
753
754<ul>
John Criswell524a5dd2009-03-02 15:28:15 +0000[diff] [blame]755<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]756 support the 64-bit SPARC ABI (-m64).</li>
757</ul>
758
759</div>
760
761<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]762<h2>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]763 <a name="mips-be">Known problems with the MIPS back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]764</h2>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]765
766<div class="doc_text">
767
768<ul>
Bruno Cardoso Lopesb7e1a4f2008-10-25 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 Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]775<h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]776 <a name="alpha-be">Known problems with the Alpha back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]777</h2>
Chris Lattner26299222006-11-18 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 Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]786</ul>
787</div>
788
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]789<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]790<h2>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]791 <a name="c-be">Known problems with the C back-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]792</h2>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]793
794<div class="doc_text">
795
Chris Lattner3016ee92010-09-29 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 Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]799<ul>
Chris Lattner5733b272008-06-05 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 Lattner725a0d82007-09-26 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 Greif4906abe2009-03-02 12:02:51 +0000[diff] [blame]804 C++ code compiled with <tt>llc</tt> or native compilers.</li>
Duncan Sandsf74c0cc2008-02-10 13:40:55 +0000[diff] [blame]805<li>The C backend does not support all exception handling constructs.</li>
Duncan Sands50723a92009-02-25 11:51:54 +0000[diff] [blame]806<li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]807</ul>
808
809</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]810
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]811
812<!-- ======================================================================= -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]813<h2>
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]814 <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]815</h2>
Chris Lattner47588f92003-10-02 05:07:23 +0000[diff] [blame]816
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]817<div class="doc_text">
Chris Lattnerc5d658a2006-03-03 00:34:26 +0000[diff] [blame]818
Chris Lattner3016ee92010-09-29 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 Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]825
Chris Lattner3016ee92010-09-29 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]832
Duncan Sands3af96332010-10-04 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 Lattner2b659ef2008-02-12 06:29:45 +0000[diff] [blame]836</div>
837
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]838<!-- *********************************************************************** -->
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]839<h1>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]840 <a name="additionalinfo">Additional Information</a>
NAKAMURA Takumic6319312011-04-05 21:55:14 +0000[diff] [blame]841</h1>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]842<!-- *********************************************************************** -->
843
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]844<div class="doc_text">
845
Chris Lattner416db102005-05-16 17:13:10 +0000[diff] [blame]846<p>A wide variety of additional information is available on the <a
Chris Lattnerb4b0ce72007-05-18 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 Spencer669ed452007-07-09 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 Brukman109d9e82005-03-30 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 Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]853
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]854<p>If you have any questions or comments about LLVM, please feel free to contact
Chris Lattnerc463b272005-10-29 07:07:09 +0000[diff] [blame]855us via the <a href="http://llvm.org/docs/#maillist"> mailing
Chris Lattner5eccca42003-12-12 21:22:16 +0000[diff] [blame]856lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]857
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]858</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]859
860<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]861
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]862<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]863<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]864 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]865 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]866 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]867 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]868
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]869 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]870 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]871</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]872
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]873</body>
874</html>