Gitiles
Code Review Sign In
gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 6a007d11e31c646a46c0991af0529fc94150a059 / . / docs / ReleaseNotes.html
blob: 8b533e62a43002b6deb916ed31c839b182b71b2d [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">
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]6 <link rel="stylesheet" href="llvm.css" type="text/css">
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]7 <title>LLVM 3.0 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]10
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]11<h1>LLVM 3.0 Release Notes</h1>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]12
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]13<img align=right src="http://llvm.org/img/DragonSmall.png"
Gabor Greifee2187a2010-04-22 10:21:43 +0000[diff] [blame]14 width="136" height="136" alt="LLVM Dragon Logo">
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]15
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]16<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]18 <li><a href="#subproj">Sub-project Status Update</a></li>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]19 <li><a href="#externalproj">External Projects Using LLVM 3.0</a></li>
20 <li><a href="#whatsnew">What's New in LLVM 3.0?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]21 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]22 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]23 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]24</ol>
25
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]26<div class="doc_author">
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]27 <p>Written by the <a href="http://llvm.org/">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]28</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29
Chris Lattner49123fd2011-04-06 06:29:50 +0000[diff] [blame]30<!--
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]31<h1 style="color:red">These are in-progress notes for the upcoming LLVM 3.0
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]32release.<br>
33You may prefer the
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]34<a href="http://llvm.org/releases/2.9/docs/ReleaseNotes.html">LLVM 2.9
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]35Release Notes</a>.</h1>
Chris Lattner49123fd2011-04-06 06:29:50 +0000[diff] [blame]36 -->
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]37
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]38<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]39<h2>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]40 <a name="intro">Introduction</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]41</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]42<!-- *********************************************************************** -->
43
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]44<div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]45
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]46<p>This document contains the release notes for the LLVM Compiler
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]47 Infrastructure, release 3.0. Here we describe the status of LLVM, including
48 major improvements from the previous release and significant known problems.
49 All LLVM releases may be downloaded from
50 the <a href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]51
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]52<p>For more information about LLVM, including information about the latest
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]53 release, please check out the <a href="http://llvm.org/">main LLVM web
54 site</a>. If you have questions or comments,
55 the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM
56 Developer's Mailing List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]57
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]58<p>Note that if you are reading this file from a Subversion checkout or the main
59 LLVM web page, this document applies to the <i>next</i> release, not the
60 current one. To see the release notes for a specific release, please see the
61 <a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]62
63</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]64
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame]65<!-- Features that need text if they're finished for 3.1:
66 ARM EHABI
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]67 combiner-aa?
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]68 strong phi elim
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]69 loop dependence analysis
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]70 CorrelatedValuePropagation
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame]71 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]72 -->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]73
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]74<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]75<h2>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]76 <a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]77</h2>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]78<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]79
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]80<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]81
82<p>The LLVM 3.0 distribution currently consists of code from the core LLVM
83 repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]84 supporting tools), and the Clang repository. In
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]85 addition to this code, the LLVM Project includes other sub-projects that are
86 in development. Here we include updates on these subprojects.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]87
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]88<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]89<h3>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]90<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]91</h3>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]92
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]93<div>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]94
Chris Lattner095539f2010-04-26 17:42:18 +0000[diff] [blame]95<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]96 C++, and Objective-C languages. Clang aims to provide a better user
97 experience through expressive diagnostics, a high level of conformance to
98 language standards, fast compilation, and low memory use. Like LLVM, Clang
99 provides a modular, library-based architecture that makes it suitable for
100 creating or integrating with other development tools. Clang is considered a
101 production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
102 (32- and 64-bit), and for darwin/arm targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]103
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]104<p>In the LLVM 3.0 time-frame, the Clang team has made many improvements:</p>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]105
106<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]107 <li>Greatly improved support for building C++ applications, with greater
108 stability and better diagnostics.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]109
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]110 <li><a href="http://clang.llvm.org/cxx_status.html">Improved support</a> for
111 the <a href="http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=50372">C++
112 2011</a> standard, including implementations of non-static data member
113 initializers, alias templates, delegating constructors, the range-based
114 for loop, and implicitly-generated move constructors and move assignment
115 operators, among others.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]116
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]117 <li>Implemented support for some features of the upcoming C1x standard,
118 including static assertions and generic selections.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]119
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]120 <li>Better detection of include and linking paths for system headers and
121 libraries, especially for Linux distributions.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]122
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]123 <li>Implemented support
124 for <a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html">Automatic
125 Reference Counting</a> for Objective-C.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]126
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]127 <li>Implemented a number of optimizations in <tt>libclang</tt>, the Clang C
128 interface, to improve the performance of code completion and the mapping
129 from source locations to abstract syntax tree nodes.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]130</ul>
131
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]132
Duncan Sandsf3ba7af2011-04-06 08:07:40 +0000[diff] [blame]133<p>If Clang rejects your code but another compiler accepts it, please take a
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]134 look at the <a href="http://clang.llvm.org/compatibility.html">language
135 compatibility</a> guide to make sure this is not intentional or a known
136 issue.</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]137
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]138</div>
139
140<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]141<h3>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]142<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]143</h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]144
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]145<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]146<p><a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
147 <a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
Duncan Sands77352c92011-11-10 18:44:29 +0000[diff] [blame]148 optimizers and code generators with LLVM's. It works with gcc-4.5 or gcc-4.6,
149 targets the x86-32 and x86-64 processor families, and has been successfully
150 used on the Darwin, FreeBSD, KFreeBSD, Linux and OpenBSD platforms. It fully
151 supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C
152 and Obj-C++.</p>
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]153
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]154<p>The 3.0 release has the following notable changes:</p>
155
Duncan Sands77352c92011-11-10 18:44:29 +0000[diff] [blame]156 <li>GCC version 4.6 is now fully supported.</li>
157
158 <li>Patching and building GCC is no longer required: the plugin should work
159 with your system GCC (version 4.5 or 4.6; on Debian/Ubuntu systems the
160 gcc-4.5-plugin-dev or gcc-4.6-plugin-dev package is also needed).</li>
161
162 <li>The <tt>-fplugin-arg-dragonegg-enable-gcc-optzns</tt> option, which runs
163 GCC's optimizers as well as LLVM's, now works much better. This is the
164 option to use if you want ultimate performance! It not yet completely
165 stable: it may cause the plugin to crash.</li>
166
167 <li>The type and constant conversion logic has been almost entirely rewritten,
168 fixing a multitude of obscure bugs.</li>
169
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]170<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]171<!--
172<li></li>
173-->
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]174</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]175
176</div>
177
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]178<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]179<h3>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]180<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]181</h3>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]182
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]183<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]184
185<p>The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
186 is a simple library that provides an implementation of the low-level
187 target-specific hooks required by code generation and other runtime
188 components. For example, when compiling for a 32-bit target, converting a
189 double to a 64-bit unsigned integer is compiled into a runtime call to the
190 "__fixunsdfdi" function. The compiler-rt library provides highly optimized
191 implementations of this and other low-level routines (some are 3x faster than
192 the equivalent libgcc routines).</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]193
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]194<p>In the LLVM 3.0 timeframe,</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]195
196</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]197
198<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]199<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]200<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]201</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]202
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]203<div>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]204
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]205<p>LLDB has advanced by leaps and bounds in the 3.0 timeframe. It is
206 dramatically more stable and useful, and includes both a
207 new <a href="http://lldb.llvm.org/tutorial.html">tutorial</a> and
208 a <a href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
209 GDB</a>.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]210
211</div>
212
213<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]214<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]215<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]216</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]217
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]218<div>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]219
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]220<p>Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
221 licensed</a> under the MIT and UIUC license, allowing it to be used more
222 permissively.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]223
224</div>
225
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]226
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]227<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]228<h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]229<a name="LLBrowse">LLBrowse: IR Browser</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]230</h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]231
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]232<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]233
234<p><a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
235 LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
236 module and displays its contents as an expandable tree view, facilitating an
237 easy way to inspect types, functions, global variables, or metadata nodes. It
238 is fully cross-platform, being based on the popular wxWidgets GUI
239 toolkit.</p>
240
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]241</div>
242
243<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]244<h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]245<a name="vmkit">VMKit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]246</h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]247
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]248<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]249
Nicolas Geoffray54d5df92011-11-10 23:37:56 +0000[diff] [blame]250 <p>The <a href="http://vmkit.llvm.org/">VMKit project</a> is an
251 implementation of a Java Virtual Machine (Java VM or JVM) that uses LLVM for
252 static and just-in-time compilation.
253
254 <p>In the LLVM 3.0 time-frame, VMKit has had significant improvements on both
255 runtime and startup performance:</p>
256
257 <ul>
258 <li>Precompilation: by compiling ahead of time a small subset of Java's core
259 library, the startup performance have been highly optimized to the point that
260 running a 'Hello World' program takes less than 30 milliseconds.</li>
261
262 <li>Customization: by customizing virtual methods for individual classes,
263 the VM can statically determine the target of a virtual call, and decide to
264 inline it.</li>
265
266 <li>Inlining: the VM does more inlining than it did before, by allowing more
267 bytecode instructions to be inlined, and thanks to customization. It also
268 inlines GC barriers, and object allocations.</li>
269
270 <li>New exception model: the generated code for a method that does not do
271 any try/catch is not penalized anymore by the eventuality of calling a
272 method that throws an exception. Instead, the method that throws the
273 exception jumps directly to the method that could catch it.</li>
274 </ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]275
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]276</div>
277
278
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]279<!--=========================================================================-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]280<!--
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]281<h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]282<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]283</h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]284
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]285<div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]286<p>
287<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
288programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
289through the application and records state transitions that lead to fault
290states. This allows it to construct testcases that lead to faults and can even
291be used to verify some algorithms.
292</p>
293
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]294<p>UPDATE!</p>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]295</div>-->
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]296
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]297</div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]298
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]299<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]300<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]301 <a name="externalproj">External Open Source Projects Using LLVM 3.0</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]302</h2>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]303<!-- *********************************************************************** -->
304
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]305<div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]306
307<p>An exciting aspect of LLVM is that it is used as an enabling technology for
308 a lot of other language and tools projects. This section lists some of the
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]309 projects that have already been updated to work with LLVM 3.0.</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]310
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]311<!--=========================================================================-->
Bill Wendling7be6bc52011-10-26 00:17:54 +0000[diff] [blame]312<h3>AddressSanitizer</h3>
313
314<div>
315
316<p><a href="http://code.google.com/p/address-sanitizer/">AddressSanitizer</a>
317 uses compiler instrumentation and a specialized malloc library to find C/C++
318 bugs such as use-after-free and out-of-bound accesses to heap, stack, and
319 globals. The key feature of the tool is speed: the average slowdown
320 introduced by AddressSanitizer is less than 2x.</p>
321
322</div>
323
324<!--=========================================================================-->
Bill Wendling29817ea2011-10-26 00:14:36 +0000[diff] [blame]325<h3>ClamAV</h3>
326
327<div>
Bill Wendlingf2a78332011-10-25 01:01:42 +0000[diff] [blame]328
Bill Wendling29817ea2011-10-26 00:14:36 +0000[diff] [blame]329<p><a href="http://www.clamav.net">Clam AntiVirus</a> is an open source (GPL)
330 anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
331 gateways.</p>
332
333<p>Since version 0.96 it
334 has <a href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
335 signatures</a> that allow writing detections for complex malware.</p>
336
337<p>It uses LLVM's JIT to speed up the execution of bytecode on X86, X86-64,
338 PPC32/64, falling back to its own interpreter otherwise. The git version was
339 updated to work with LLVM 3.0.</p>
340
341</div>
342
343<!--=========================================================================-->
Tobias Grosserae5a6fd2011-11-14 09:09:26 +0000[diff] [blame]344<h3>clang_complete for VIM</h3>
345
346<div>
347
348<p><a href="https://github.com/Rip-Rip/clang_complete">clang_complete</a> is a
349 VIM plugin, that provides accurate C/C++ autocompletion using the clang front
350 end. The development version of clang complete, can directly use libclang
351 which can maintain a cache to speed up auto completion.</p>
352
353</div>
354
355<!--=========================================================================-->
Bill Wendling65d1f412011-10-26 18:23:06 +0000[diff] [blame]356<h3>clReflect</h3>
357
358<div>
359
360<p><a href="https://bitbucket.org/dwilliamson/clreflect">clReflect</a> is a C++
361 parser that uses clang/LLVM to derive a light-weight reflection database
362 suitable for use in game development. It comes with a very simple runtime
363 library for loading and querying the database, requiring no external
364 dependencies (including CRT), and an additional utility library for object
365 management and serialisation.</p>
366
367</div>
368
369<!--=========================================================================-->
Bill Wendling63507d12011-10-29 01:10:01 +0000[diff] [blame]370<h3>Cling C++ Interpreter</h3>
371
372<div>
373
374<p><a href="http://cern.ch/cling">Cling</a> is an interactive compiler interface
375 (aka C++ interpreter). It uses LLVM's JIT and clang; it currently supports
376 C++ and C. It has a prompt interface, runs source files, calls into shared
377 libraries, prints the value of expressions, even does runtime lookup of
378 identifiers (dynamic scopes). And it just behaves like one would expect from
379 an interpreter.</p>
380
381</div>
382
383<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]384<h3>Crack Programming Language</h3>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]385
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]386<div>
Bill Wendling55d6e672011-11-03 20:10:01 +0000[diff] [blame]387
388<p><a href="http://code.google.com/p/crack-language/">Crack</a> aims to provide
389 the ease of development of a scripting language with the performance of a
390 compiled language. The language derives concepts from C++, Java and Python,
391 incorporating object-oriented programming, operator overloading and strong
392 typing.</p>
393
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]394</div>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]395
396<!--=========================================================================-->
Bill Wendlingb99486f2011-11-08 05:22:54 +0000[diff] [blame]397<h3>Eero</h3>
398
399<div>
400
401<p><a href="http://eerolanguage.org/">Eero</a> is a fully
402 header-and-binary-compatible dialect of Objective-C 2.0, implemented with a
403 patched version of the Clang/LLVM compiler. It features a streamlined syntax,
404 Python-like indentation, and new operators, for improved readability and
405 reduced code clutter. It also has new features such as limited forms of
406 operator overloading and namespaces, and strict (type-and-operator-safe)
407 enumerations. It is inspired by languages such as Smalltalk, Python, and
408 Ruby.</p>
409
410</div>
411
412<!--=========================================================================-->
Chris Lattneradb417a2011-11-25 20:28:16 +0000[diff] [blame]413<h3>FAUST Real-Time Audio Signal Processing Language</h3>
414
415<div>
416
417<p><a href="http://faust.grame.fr/">FAUST</a> is a compiled language for
418 real-time audio signal processing. The name FAUST stands for Functional
419 AUdio STream. Its programming model combines two approaches: functional
420 programming and block diagram composition. In addition with the C, C++, Java
421 output formats, the Faust compiler can now generate LLVM bitcode, and works
422 with LLVM 2.7-3.0.
423 </p>
424
425</div>
426
427<!--=========================================================================-->
Bill Wendlingf9778192011-10-26 00:09:55 +0000[diff] [blame]428<h3>Glasgow Haskell Compiler (GHC)</h3>
429
430<div>
431
432<p>GHC is an open source, state-of-the-art programming suite for Haskell, a
433 standard lazy functional programming language. It includes an optimizing
434 static compiler generating good code for a variety of platforms, together
435 with an interactive system for convenient, quick development.</p>
436
437<p>GHC 7.0 and onwards include an LLVM code generator, supporting LLVM 2.8 and
438 later. Since LLVM 2.9, GHC now includes experimental support for the ARM
439 platform with LLVM 3.0.</p>
440
441</div>
442
443<!--=========================================================================-->
Bill Wendlingf62333d2011-10-25 20:35:31 +0000[diff] [blame]444<h3>gwXscript</h3>
445
446<div>
447
448<p><a href="http://botwars.tk/gwscript/">gwXscript</a> is an object oriented,
Bill Wendling7c38de22011-10-26 04:24:15 +0000[diff] [blame]449 aspect oriented programming language which can create both executables (ELF,
Bill Wendlingf62333d2011-10-25 20:35:31 +0000[diff] [blame]450 EXE) and shared libraries (DLL, SO, DYNLIB). The compiler is implemented in
451 its own language and translates scripts into LLVM-IR which can be optimized
452 and translated into native code by the LLVM framework. Source code in
453 gwScript contains definitions that expand the namespaces. So you can build
454 your project and simply 'plug out' features by removing a file. The remaining
455 project does not leave scars since you directly separate concerns by the
456 'template' feature of gwX. It is also possible to add new features to a
457 project by just adding files and without editing the original project. This
458 language is used for example to create games or content management systems
459 that should be extendable.</p>
460
461<p>gwXscript is strongly typed and offers comfort with its native types string,
462 hash and array. You can easily write new libraries in gwXscript or native
463 code. gwXscript is type safe and users should not be able to crash your
464 program or execute malicious code except code that is eating CPU time.</p>
465
466</div>
467
468<!--=========================================================================-->
Bill Wendling50cacc82011-10-26 22:55:18 +0000[diff] [blame]469<h3>include-what-you-use</h3>
470
471<div>
472
473<p><a href="http://code.google.com/p/include-what-you-use">include-what-you-use</a>
474 is a tool to ensure that a file directly <code>#include</code>s
475 all <code>.h</code> files that provide a symbol that the file uses. It also
476 removes superfluous <code>#include</code>s from source files.</p>
477
478</div>
479
480<!--=========================================================================-->
Bill Wendling32dc4d92011-11-07 22:05:17 +0000[diff] [blame]481<h3>ispc: The Intel SPMD Program Compiler</h3>
482
483<div>
484
485<p><a href="http://ispc.github.com">ispc</a> is a compiler for "single program,
486 multiple data" (SPMD) programs. It compiles a C-based SPMD programming
487 language to run on the SIMD units of CPUs; it often delivers 5-6x speedups on
488 a single core of a CPU with an 8-wide SIMD unit compared to serial code,
489 while still providing a clean and easy-to-understand programming model. For
490 an introduction to the language and its performance,
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]491 see <a href="http://ispc.github.com/example.html">the walkthrough</a> of a short
Bill Wendling32dc4d92011-11-07 22:05:17 +0000[diff] [blame]492 example program. ispc is licensed under the BSD license.</p>
493
494</div>
495
496<!--=========================================================================-->
Bill Wendling57fd8762011-10-26 18:20:54 +0000[diff] [blame]497<h3>LanguageKit and Pragmatic Smalltalk</h3>
498
499<div>
500
501<p><a href="http://etoileos.com/etoile/features/languagekit/">LanguageKit</a> is
502 a framework for implementing dynamic languages sharing an object model with
503 Objective-C. It provides static and JIT compilation using LLVM along with
504 its own interpreter. Pragmatic Smalltalk is a dialect of Smalltalk, built on
505 top of LanguageKit, that interfaces directly with Objective-C, sharing the
506 same object representation and message sending behaviour. These projects are
507 developed as part of the &Eacute;toi&eacute; desktop environment.</p>
508
509</div>
510
511<!--=========================================================================-->
Bill Wendling03250532011-11-01 04:08:23 +0000[diff] [blame]512<h3>LuaAV</h3>
513
514<div>
515
516<p><a href="http://lua-av.mat.ucsb.edu/blog/">LuaAV</a> is a real-time
517 audiovisual scripting environment based around the Lua language and a
518 collection of libraries for sound, graphics, and other media protocols. LuaAV
519 uses LLVM and Clang to JIT compile efficient user-defined audio synthesis
520 routines specified in a declarative syntax.</p>
521
522</div>
523
524<!--=========================================================================-->
Bill Wendlingd4821b82011-10-26 00:16:17 +0000[diff] [blame]525<h3>Mono</h3>
526
527<div>
528
529<p>An open source, cross-platform implementation of C# and the CLR that is
530 binary compatible with Microsoft.NET. Has an optional, dynamically-loaded
531 LLVM code generation backend in Mini, the JIT compiler.</p>
532
533<p>Note that we use a Git mirror of LLVM with some patches. See:
534 https://github.com/mono/llvm</p>
535
536</div>
537
538<!--=========================================================================-->
Tobias Grosser093cb7e2011-11-14 09:09:23 +0000[diff] [blame]539<h3>Polly</h3>
540
541<div>
542
543<p><a href="http://polly.grosser.es">Polly</a> is an advanced data-locality
544 optimizer and automatic parallelizer. It uses an advanced, mathematical
545 model to calculate detailed data dependency information which it uses to
546 optimize the loop structure of a program. Polly can speed up sequential code
547 by improving memory locality and consequently the cache use. Furthermore,
548 Polly is able to expose different kind of parallelism which it exploits by
549 introducing (basic) OpenMP and SIMD code. A mid-term goal of Polly is to
550 automatically create optimized GPU code.</p>
551
552</div>
553
554<!--=========================================================================-->
Bill Wendlingba226272011-10-25 20:37:45 +0000[diff] [blame]555<h3>Portable OpenCL (pocl)</h3>
556
557<div>
558
559<p>Portable OpenCL is an open source implementation of the OpenCL standard which
560 can be easily adapted for new targets. One of the goals of the project is
561 improving performance portability of OpenCL programs, avoiding the need for
562 target-dependent manual optimizations. A "native" target is included, which
563 allows running OpenCL kernels on the host (CPU).</p>
564
565</div>
566
567<!--=========================================================================-->
Bill Wendling0bad98c2011-10-25 20:39:06 +0000[diff] [blame]568<h3>Pure</h3>
569
570<div>
571<p><a href="http://pure-lang.googlecode.com/">Pure</a> is an
572 algebraic/functional programming language based on term rewriting. Programs
573 are collections of equations which are used to evaluate expressions in a
574 symbolic fashion. The interpreter uses LLVM as a backend to JIT-compile Pure
575 programs to fast native code. Pure offers dynamic typing, eager and lazy
576 evaluation, lexical closures, a hygienic macro system (also based on term
577 rewriting), built-in list and matrix support (including list and matrix
578 comprehensions) and an easy-to-use interface to C and other programming
579 languages (including the ability to load LLVM bitcode modules, and inline C,
580 C++, Fortran and Faust code in Pure programs if the corresponding LLVM-enabled
581 compilers are installed).</p>
582
583<p>Pure version 0.48 has been tested and is known to work with LLVM 3.0
584 (and continues to work with older LLVM releases &gt;= 2.5).</p>
585
586</div>
587
588<!--=========================================================================-->
Bill Wendling537d85b2011-10-26 00:12:04 +0000[diff] [blame]589<h3>Renderscript</h3>
590
591<div>
592
593<p><a href="http://developer.android.com/guide/topics/renderscript/index.html">Renderscript</a>
594 is Android's advanced 3D graphics rendering and compute API. It provides a
595 portable C99-based language with extensions to facilitate common use cases
596 for enhancing graphics and thread level parallelism. The Renderscript
597 compiler frontend is based on Clang/LLVM. It emits a portable bitcode format
598 for the actual compiled script code, as well as reflects a Java interface for
599 developers to control the execution of the compiled bitcode. Executable
600 machine code is then generated from this bitcode by an LLVM backend on the
601 device. Renderscript is thus able to provide a mechanism by which Android
602 developers can improve performance of their applications while retaining
603 portability.</p>
604
605</div>
606
607<!--=========================================================================-->
Bill Wendling7d5b6212011-10-25 20:40:26 +0000[diff] [blame]608<h3>SAFECode</h3>
609
610<div>
611
612<p><a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C/C++
613 compiler built using LLVM. It takes standard, unannotated C/C++ code,
614 analyzes the code to ensure that memory accesses and array indexing
615 operations are safe, and instruments the code with run-time checks when
616 safety cannot be proven statically. SAFECode can be used as a debugging aid
617 (like Valgrind) to find and repair memory safety bugs. It can also be used
618 to protect code from security attacks at run-time.</p>
619
620</div>
621
622<!--=========================================================================-->
Bill Wendling02b77b72011-10-26 07:38:19 +0000[diff] [blame]623<h3>The Stupid D Compiler (SDC)</h3>
624
625<div>
626
627<p><a href="https://github.com/bhelyer/SDC">The Stupid D Compiler</a> is a
628 project seeking to write a self-hosting compiler for the D programming
629 language without using the frontend of the reference compiler (DMD).</p>
630
631</div>
632
633<!--=========================================================================-->
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]634<h3>TTA-based Co-design Environment (TCE)</h3>
635
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]636<div>
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]637
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]638<p>TCE is a toolset for designing application-specific processors (ASP) based on
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]639 the Transport triggered architecture (TTA). The toolset provides a complete
640 co-design flow from C/C++ programs down to synthesizable VHDL and parallel
641 program binaries. Processor customization points include the register files,
642 function units, supported operations, and the interconnection network.</p>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]643
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]644<p>TCE uses Clang and LLVM for C/C++ language support, target independent
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]645 optimizations and also for parts of code generation. It generates new
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]646 LLVM-based code generators "on the fly" for the designed TTA processors and
647 loads them in to the compiler backend as runtime libraries to avoid
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]648 per-target recompilation of larger parts of the compiler chain.</p>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]649
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]650</div>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]651
652<!--=========================================================================-->
Bill Wendling628c2662011-10-25 20:27:37 +0000[diff] [blame]653<h3>Tart Programming Language</h3>
654
655<div>
656
657<p><a href="http://code.google.com/p/tart/">Tart</a> is a general-purpose,
658 strongly typed programming language designed for application
659 developers. Strongly inspired by Python and C#, Tart focuses on practical
660 solutions for the professional software developer, while avoiding the clutter
661 and boilerplate of legacy languages like Java and C++. Although Tart is still
662 in development, the current implementation supports many features expected of
663 a modern programming language, such as garbage collection, powerful
664 bidirectional type inference, a greatly simplified syntax for template
665 metaprogramming, closures and function literals, reflection, operator
666 overloading, explicit mutability and immutability, and much more. Tart is
667 flexible enough to accommodate a broad range of programming styles and
668 philosophies, while maintaining a strong commitment to simplicity, minimalism
669 and elegance in design.</p>
670
671</div>
672
673<!--=========================================================================-->
Bill Wendling644ce532011-10-26 09:25:01 +0000[diff] [blame]674<h3>ThreadSanitizer</h3>
675
676<div>
677
678<p><a href="http://code.google.com/p/data-race-test/">ThreadSanitizer</a> is a
679 data race detector for (mostly) C and C++ code, available for Linux, Mac OS
680 and Windows. On different systems, we use binary instrumentation frameworks
Bill Wendlingae8538e2011-10-29 01:11:15 +0000[diff] [blame]681 (Valgrind and Pin) as frontends that generate the program events for the race
682 detection algorithm. On Linux, there's an option of using LLVM-based
683 compile-time instrumentation.</p>
Bill Wendling644ce532011-10-26 09:25:01 +0000[diff] [blame]684
685</div>
686
687<!--=========================================================================-->
Bill Wendling8a924c62011-10-26 07:42:45 +0000[diff] [blame]688<h3>The ZooLib C++ Cross-Platform Application Framework</h3>
689
690<div>
691
692<p><a href="http://www.zoolib.org/">ZooLib</a> is Open Source under the MIT
693 License. It provides GUI, filesystem access, TCP networking, thread-safe
694 memory management, threading and locking for Mac OS X, Classic Mac OS,
695 Microsoft Windows, POSIX operating systems with X11, BeOS, Haiku, Apple's iOS
696 and Research in Motion's BlackBerry.</p>
697
698<p>My current work is to use CLang's static analyzer to improve ZooLib's code
699 quality. I also plan to set up LLVM compiles of the demo programs and test
700 programs using CLang and LLVM on all the platforms that CLang, LLVM and
701 ZooLib all support.</p>
702
703</div>
Chris Lattnera844a3e2011-04-07 03:09:21 +0000[diff] [blame]704
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]705</div>
706
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]707<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]708<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]709 <a name="whatsnew">What's New in LLVM 3.0?</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]710</h2>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]711<!-- *********************************************************************** -->
712
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]713<div>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]714
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]715<p>This release includes a huge number of bug fixes, performance tweaks and
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]716 minor improvements. Some of the major improvements and new features are
717 listed in this section.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]718
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]719<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]720<h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]721<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]722</h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]723
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]724<div>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]725
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]726<p><b>llvm-gcc is gone</b></p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]727
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]728<p>LLVM 3.0 includes several major new capabilities:</p>
729
Chris Lattnerdec23b62011-11-15 22:13:27 +0000[diff] [blame]730<!-- Near dead:
731 Analysis/RegionInfo.h + Dom Frontiers
732 SparseBitVector: used in LiveVar.
733
734 -->
735
736<!--
737 Type system rewrite.
738 Better performance for Neon code in clang due to SRoA improvements.
739 New regalloc on by default. Lin scan going away in 3.1
740 PGO / builtin_expect improvements (summary needed)
741 Big EH rewrite.
742 AVX support, assembler, compiler and disassembler.
743 IndVar improvements: andy
744 PTX backend improvements: Justin
745 llvm-rtdyld & MC JIT: JimG
746 InstAliases now automatically used in the asmprinter where they are shorter.
747 Integrated assembler on by default for arm/thumb?
748 PostOrder Dominator frontiers were removed.
749 Line Profiling / gcov support
750 EH and debug information produced with CFI directives, yielding smaller executables: http://blog.mozilla.com/respindola/2011/05/12/cfi-directives/
751 X86-64 generates smaller and faster code at -O0 (fast isel improvements)
752 Better code generation for Cortex-A9
753 Many APIs take ArrayRef's now.
754 Pass manager extension API.
Chris Lattner6a007d12011-11-25 20:33:27 +0000[diff] [blame^]755
756
757Information about branch probability and basic block frequency is now available within LLVM based on a combination of static branch prediction heuristics and __builtin_expect calls. That information is currently used for register spill placement and if-conversion, with additional optimizations planned for future releases. The same frameworks are intended for eventual use with profile-guided optimization, but that is not yet implemented.
Chris Lattnerdec23b62011-11-15 22:13:27 +0000[diff] [blame]758
759 -->
760
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]761<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]762
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]763<!--
764<li></li>
765-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]766
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]767</ul>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]768
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]769</div>
770
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]771<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]772<h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]773<a name="coreimprovements">LLVM IR and Core Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]774</h3>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]775
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]776<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]777
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]778<p>LLVM IR has several new features for better support of new targets and that
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]779 expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]780
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]781<p>One of the biggest changes is that 3.0 has a new exception handling
782 system. The old system used LLVM intrinsics to convey the exception handling
783 information to the code generator. It worked in most cases, but not
784 all. Inlining was especially difficult to get right. Also, the intrinsics
785 could be moved away from the <code>invoke</code> instruction, making it hard
786 to recover that information.</p>
787
788<p>The new EH system makes exception handling a first-class member of the IR. It
789 adds two new instructions:</p>
790
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]791<ul>
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]792 <li><a href="LangRef.html#i_landingpad"><code>landingpad</code></a> &mdash;
793 this instruction defines a landing pad basic block. It contains all of the
794 information that's needed by the code generator. It's also required to be
795 the first non-PHI instruction in the landing pad. In addition, a landing
796 pad may be jumped to only by the unwind edge of an <code>invoke</code>
797 instruction.</li>
798
799 <li><a href="LangRef.html#i_resume"><code>resume</code></a> &mdash; this
800 instruction causes the current exception to resume traveling up the
801 stack. It replaces the <code>@llvm.eh.resume</code> intrinsic.</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]802</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]803
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]804<p>Converting from the old EH API to the new EH API is rather simple, because a
805 lot of complexity has been removed. The two intrinsics,
806 <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code> have been
807 superceded by the <code>landingpad</code> instruction. Instead of generating
808 a call to <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code>:
809
810<div class="doc_code">
811<pre>
812Function *ExcIntr = Intrinsic::getDeclaration(TheModule,
813 Intrinsic::eh_exception);
814Function *SlctrIntr = Intrinsic::getDeclaration(TheModule,
815 Intrinsic::eh_selector);
816
817// The exception pointer.
818Value *ExnPtr = Builder.CreateCall(ExcIntr, "exc_ptr");
819
820std::vector&lt;Value*&gt; Args;
821Args.push_back(ExnPtr);
822Args.push_back(Builder.CreateBitCast(Personality,
823 Type::getInt8PtrTy(Context)));
824
825<i>// Add selector clauses to Args.</i>
826
827// The selector call.
828Builder.CreateCall(SlctrIntr, Args, "exc_sel");
829</pre>
830</div>
831
832<p>You should instead generate a <code>landingpad</code> instruction, that
833 returns an exception object and selector value:</p>
834
835<div class="doc_code">
836<pre>
837LandingPadInst *LPadInst =
838 Builder.CreateLandingPad(StructType::get(Int8PtrTy, Int32Ty, NULL),
839 Personality, 0);
840
841Value *LPadExn = Builder.CreateExtractValue(LPadInst, 0);
842Builder.CreateStore(LPadExn, getExceptionSlot());
843
844Value *LPadSel = Builder.CreateExtractValue(LPadInst, 1);
845Builder.CreateStore(LPadSel, getEHSelectorSlot());
846</pre>
847</div>
848
849<p>It's now trivial to add the individual clauses to the <code>landingpad</code>
850 instruction.</p>
851
852<div class="doc_code">
853<pre>
854<i><b>// Adding a catch clause</b></i>
855Constant *TypeInfo = getTypeInfo();
856LPadInst-&gt;addClause(TypeInfo);
857
858<i><b>// Adding a C++ catch-all</b></i>
859LPadInst-&gt;addClause(Constant::getNullValue(Builder.getInt8PtrTy()));
860
861<i><b>// Adding a cleanup</b></i>
862LPadInst-&gt;setCleanup(true);
863
864<i><b>// Adding a filter clause</b></i>
865std::vector&lt;Constant*&gt; TypeInfos;
866Constant *TypeInfo = getFilterTypeInfo();
867TypeInfos.push_back(Builder.CreateBitCast(TypeInfo, Builder.getInt8PtrTy()));
868
869ArrayType *FilterTy = ArrayType::get(Int8PtrTy, TypeInfos.size());
870LPadInst-&gt;addClause(ConstantArray::get(FilterTy, TypeInfos));
871</pre>
872</div>
873
874<p>Converting from using the <code>@llvm.eh.resume</code> intrinsic to
875 the <code>resume</code> instruction is trivial. It takes the exception
876 pointer and exception selector values returned by
877 the <code>landingpad</code> instruction:</p>
878
879<div class="doc_code">
880<pre>
881Type *UnwindDataTy = StructType::get(Builder.getInt8PtrTy(),
882 Builder.getInt32Ty(), NULL);
883Value *UnwindData = UndefValue::get(UnwindDataTy);
884Value *ExcPtr = Builder.CreateLoad(getExceptionObjSlot());
885Value *ExcSel = Builder.CreateLoad(getExceptionSelSlot());
886UnwindData = Builder.CreateInsertValue(UnwindData, ExcPtr, 0, "exc_ptr");
887UnwindData = Builder.CreateInsertValue(UnwindData, ExcSel, 1, "exc_sel");
888Builder.CreateResume(UnwindData);
889</pre>
890</div>
891
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]892</div>
893
894<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]895<h3>
Andrew Trick5aab6382011-11-06 17:59:24 +0000[diff] [blame]896<a name="loopoptimization">Loop Optimization Improvements</a>
897</h3>
898
899<div>
900<p>The induction variable simplification pass in 3.0 only modifies
901 induction variables when profitable. Sign and zero extension
902 elimination, linear function test replacement, loop unrolling, and
903 other simplifications that require induction variable analysis have
904 been generalized so they no longer require loops to be rewritten in a
905 typically suboptimal form prior to optimization. This new design
906 preserves more IR level information, avoids undoing earlier loop
907 optimizations (particularly hand-optimized loops), and no longer
908 strongly depends on the code generator rewriting loops a second time
909 in a now optimal form--an intractable problem.</p>
910
911<p>The original behavior can be restored with -mllvm -enable-iv-rewrite;
912 however, support for this mode will be short lived. As such, bug
913 reports should be filed for any significant performance regressions
914 when moving from -mllvm -enable-iv-rewrite to the 3.0 default mode.</p>
915</div>
916
917<!--=========================================================================-->
918<h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]919<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]920</h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]921
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]922<div>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]923
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]924<p>In addition to a large array of minor performance tweaks and bug fixes, this
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]925 release includes a few major enhancements and additions to the
926 optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]927
928<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]929<!--
930<li></li>
931-->
Chris Lattnerc5ac61d2011-04-06 05:50:04 +0000[diff] [blame]932</li>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]933
Chris Lattner11b66112010-10-04 02:42:39 +0000[diff] [blame]934</ul>
935
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]936</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]937
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]938<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]939<h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]940<a name="mc">MC Level Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]941</h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]942
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]943<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]944
945<p>The LLVM Machine Code (aka MC) subsystem was created to solve a number of
946 problems in the realm of assembly, disassembly, object file format handling,
947 and a number of other related areas that CPU instruction-set level tools work
948 in.</p>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]949
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]950<ul>
Jim Grosbach2552de02011-11-24 00:49:21 +0000[diff] [blame]951 <li>The ELF object streamers are much more full featured.</li>
952 <li>Target dependent relocation handling has been refactored into the Targets.</li>
953 <li>Early stage MC-JIT infrastructure has been implemented.</li>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]954</ul>
955
Jim Grosbach2552de02011-11-24 00:49:21 +0000[diff] [blame]956<p>The MC-JIT is a major new feature for MC, and will eventually grow to replace
957the current JIT implementation. It emits object files direct to memory and
958uses a runtime dynamic linker to resolve references and drive lazy compilation.
959The MC-JIT enables much greater code reuse between the JIT and the static
960compiler and provides better integration with the platform ABI as a result.</p>
961
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]962<p>For more information, please see
963 the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro
964 to the LLVM MC Project Blog Post</a>.</p>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]965
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]966</div>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]967
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]968<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]969<h3>
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]970<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]971</h3>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]972
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]973<div>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]974
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]975<p>We have put a significant amount of work into the code generator
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]976 infrastructure, which allows us to implement more aggressive algorithms and
977 make it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]978
979<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]980<!--
981<li></li>
982-->
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]983</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]984</div>
985
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]986<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]987<h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]988<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]989</h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]990
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]991<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]992
993<p>New features and major changes in the X86 target include:</p>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]994
995<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]996
Chris Lattner62f009a2011-11-15 22:48:24 +0000[diff] [blame]997 <li>The X86 backend now supports
998 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
999 floating point stack</a>.</li>
1000
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1001 <li>The CRC32 intrinsics have been renamed. The intrinsics were previously
1002 <code>@llvm.x86.sse42.crc32.[8|16|32]</code>
1003 and <code>@llvm.x86.sse42.crc64.[8|64]</code>. They have been renamed to
1004 <code>@llvm.x86.sse42.crc32.32.[8|16|32]</code> and
1005 <code>@llvm.x86.sse42.crc32.64.[8|64]</code>.</li>
Chad Rosierf94c9c12011-05-27 20:13:10 +0000[diff] [blame]1006
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]1007</ul>
1008
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]1009</div>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]1010
1011<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1012<h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]1013<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1014</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1015
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1016<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1017
1018<p>New features of the ARM target include:</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1019
1020<ul>
Jim Grosbach2552de02011-11-24 00:49:21 +0000[diff] [blame]1021 <li>Reworked Set Jump Long Jump EH Lowering,</li>
1022 <li>improved support for Cortex-M series processors, and</li>
1023 <li>beta quality integrated assembler support.</li>
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]1024</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]1025</div>
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1026
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1027
1028<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1029<h3>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1030<a name="MIPS">MIPS Target Improvements</a>
1031</h3>
1032
1033<div>
1034
1035<p>New features and major changes in the MIPS target include:</p>
1036
1037<ul>
1038 <li>Most MIPS32r1 and r2 instructions are now supported.</li>
1039 <li>LE/BE MIPS32r1/r2 has been tested extensively.</li>
1040 <li>O32 ABI has been fully tested.</li>
1041 <li>MIPS backend has migrated to using the MC infrastructure for assembly printing. Initial support for direct object code emission has been implemented too.</li>
1042 <li>Delay slot filler has been updated. Now it tries to fill delay slots with useful instructions instead of always filling them with NOPs.</li>
1043 <li>Support for old-style JIT is complete.</li>
1044 <li>Support for old architectures (MIPS1 and MIPS2) has been removed.</li>
1045 <li>Initial support for MIPS64 has been added.</li>
1046</ul>
1047</div>
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1048
1049<!--=========================================================================-->
1050<h3>
1051 <a name="PTX">PTX Target Improvements</a>
1052</h3>
1053
1054<div>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1055
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1056 <p>
1057 The PTX back-end is still experimental, but is fairly usable for compute kernels
1058 in LLVM 3.0. Most scalar arithmetic is implemented, as well as intrinsics to
1059 access the special PTX registers and sync instructions. The major missing
1060 pieces are texture/sampler support and some vector operations.</p>
1061
1062 <p>That said, the backend is already being used for domain-specific languages
1063 and works well with the <a href="http://www.pcc.me.uk/~peter/libclc/">libclc
1064 library</a> to supply OpenCL built-ins. With it, you can use Clang to compile
1065 OpenCL code into PTX and execute it by loading the resulting PTX as a binary
1066 blob using the nVidia OpenCL library. It has been tested with several OpenCL
1067 programs, including some from the nVidia GPU Computing SDK, and the performance
1068 is on par with the nVidia compiler.</p>
1069
1070</div>
1071
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1072<!--=========================================================================-->
1073<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1074<a name="OtherTS">Other Target Specific Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1075</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1076
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1077<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1078
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]1079 <p>PPC32/ELF va_arg was implemented.</p>
1080 <p>PPC32 initial support for .o file writing was implemented.</p>
Wesley Peck3ff16db2011-11-14 18:56:41 +0000[diff] [blame]1081 <p>MicroBlaze scheduling itineraries were added that model the
1082 3-stage and the 5-stage pipeline architectures. The 3-stage
1083 pipeline model can be selected with <code>-mcpu=mblaze3</code>
1084 and the 5-stage pipeline model can be selected with
1085 <code>-mcpu=mblaze5</code>.</p>
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]1086
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1087<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]1088<!--
1089<li></li>
1090-->
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1091</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1092
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1093</div>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]1094
1095<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1096<h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1097<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1098</h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1099
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1100<div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1101
Bill Wendling2626dba2011-08-03 22:18:20 +0000[diff] [blame]1102<p>If you're already an LLVM user or developer with out-of-tree changes based on
1103 LLVM 2.9, this section lists some "gotchas" that you may run into upgrading
1104 from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1105
1106<ul>
Eric Christopher90d6ec52011-09-28 19:47:28 +0000[diff] [blame]1107 <li>The <code>LLVMC</code> front end code was removed while separating
1108 out language independence.</li>
Jay Foadf42e9b22011-08-04 10:43:43 +0000[diff] [blame]1109 <li>The <code>LowerSetJmp</code> pass wasn't used effectively by any
1110 target and has been removed.</li>
Rafael Espindolaf940a1a2011-08-30 23:03:45 +0000[diff] [blame]1111 <li>The old <code>TailDup</code> pass was not used in the standard pipeline
1112 and was unable to update ssa form, so it has been removed.
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]1113 <li>The syntax of volatile loads and stores in IR has been changed to
1114 "<code>load volatile</code>"/"<code>store volatile</code>". The old
1115 syntax ("<code>volatile load</code>"/"<code>volatile store</code>")
1116 is still accepted, but is now considered deprecated.</li>
Eli Friedman526e1bb2011-10-26 00:55:23 +0000[diff] [blame]1117 <li>The old atomic intrinscs (<code>llvm.memory.barrier</code> and
1118 <code>llvm.atomic.*</code>) are now gone. Please use the new atomic
1119 instructions, described in the <a href="Atomics.html">atomics guide</a>.
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]1120</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1121
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1122<h4>Windows (32-bit)</h4>
1123<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1124
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1125<ul>
1126 <li>On Win32(MinGW32 and MSVC), Windows 2000 will not be supported.
1127 Windows XP or higher is required.</li>
1128</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1129
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1130</div>
1131
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1132</div>
1133
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1134<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1135<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1136<a name="api_changes">Internal API Changes</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1137</h3>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1138
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1139<div>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1140
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1141<p>In addition, many APIs have changed in this release. Some of the major
Bill Wendling16005252011-08-02 06:20:17 +0000[diff] [blame]1142 LLVM API changes are:</p>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1143
1144<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1145 <li>The biggest and most pervasive change is that llvm::Type's are no longer
1146 returned or accepted as 'const' values. Instead, just pass around
1147 non-const Type's.</li>
Chris Lattnerd1324302011-07-18 04:56:02 +0000[diff] [blame]1148
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1149 <li><code>PHINode::reserveOperandSpace</code> has been removed. Instead, you
1150 must specify how many operands to reserve space for when you create the
1151 PHINode, by passing an extra argument
1152 into <code>PHINode::Create</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1153
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1154 <li>PHINodes no longer store their incoming BasicBlocks as operands. Instead,
1155 the list of incoming BasicBlocks is stored separately, and can be accessed
1156 with new functions <code>PHINode::block_begin</code>
1157 and <code>PHINode::block_end</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1158
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1159 <li>Various functions now take an <code>ArrayRef</code> instead of either a
1160 pair of pointers (or iterators) to the beginning and end of a range, or a
1161 pointer and a length. Others now return an <code>ArrayRef</code> instead
1162 of a reference to a <code>SmallVector</code>
1163 or <code>std::vector</code>. These include:
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1164<ul>
1165<!-- Please keep this list sorted. -->
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1166<li><code>CallInst::Create</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1167<li><code>ComputeLinearIndex</code> (in <code>llvm/CodeGen/Analysis.h</code>)</li>
1168<li><code>ConstantArray::get</code></li>
1169<li><code>ConstantExpr::getExtractElement</code></li>
Jay Foaddab3d292011-07-21 14:31:17 +0000[diff] [blame]1170<li><code>ConstantExpr::getGetElementPtr</code></li>
1171<li><code>ConstantExpr::getInBoundsGetElementPtr</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1172<li><code>ConstantExpr::getIndices</code></li>
1173<li><code>ConstantExpr::getInsertElement</code></li>
1174<li><code>ConstantExpr::getWithOperands</code></li>
Jay Foad1d2f5692011-07-19 13:32:40 +0000[diff] [blame]1175<li><code>ConstantFoldCall</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
1176<li><code>ConstantFoldInstOperands</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1177<li><code>ConstantVector::get</code></li>
1178<li><code>DIBuilder::createComplexVariable</code></li>
1179<li><code>DIBuilder::getOrCreateArray</code></li>
1180<li><code>ExtractValueInst::Create</code></li>
1181<li><code>ExtractValueInst::getIndexedType</code></li>
1182<li><code>ExtractValueInst::getIndices</code></li>
1183<li><code>FindInsertedValue</code> (in <code>llvm/Analysis/ValueTracking.h</code>)</li>
Jay Foadca12a212011-07-19 14:42:50 +0000[diff] [blame]1184<li><code>gep_type_begin</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
1185<li><code>gep_type_end</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
Jay Foada9203102011-07-25 09:48:08 +0000[diff] [blame]1186<li><code>GetElementPtrInst::Create</code></li>
1187<li><code>GetElementPtrInst::CreateInBounds</code></li>
1188<li><code>GetElementPtrInst::getIndexedType</code></li>
Jay Foadb60e8512011-07-21 14:42:51 +0000[diff] [blame]1189<li><code>InsertValueInst::Create</code></li>
1190<li><code>InsertValueInst::getIndices</code></li>
1191<li><code>InvokeInst::Create</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1192<li><code>IRBuilder::CreateCall</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1193<li><code>IRBuilder::CreateExtractValue</code></li>
Jay Foad0a2a60a2011-07-22 08:16:57 +0000[diff] [blame]1194<li><code>IRBuilder::CreateGEP</code></li>
1195<li><code>IRBuilder::CreateInBoundsGEP</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1196<li><code>IRBuilder::CreateInsertValue</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1197<li><code>IRBuilder::CreateInvoke</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1198<li><code>MDNode::get</code></li>
1199<li><code>MDNode::getIfExists</code></li>
1200<li><code>MDNode::getTemporary</code></li>
1201<li><code>MDNode::getWhenValsUnresolved</code></li>
Jay Foadb9b54eb2011-07-19 15:07:52 +0000[diff] [blame]1202<li><code>SimplifyGEPInst</code> (in <code>llvm/Analysis/InstructionSimplify.h</code>)</li>
Jay Foad8fbbb392011-07-19 14:01:37 +0000[diff] [blame]1203<li><code>TargetData::getIndexedOffset</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1204</ul></li>
1205
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1206 <li>All forms of <code>StringMap::getOrCreateValue</code> have been remove
1207 except for the one which takes a <code>StringRef</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1208
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1209 <li>The <code>LLVMBuildUnwind</code> function from the C API was removed. The
1210 LLVM <code>unwind</code> instruction has been deprecated for a long time
1211 and isn't used by the current front-ends. So this was removed during the
1212 exception handling rewrite.</li>
Bill Wendling16005252011-08-02 06:20:17 +0000[diff] [blame]1213
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1214 <li>The <code>LLVMAddLowerSetJmpPass</code> function from the C API was
1215 removed because the <code>LowerSetJmp</code> pass was removed.</li>
Bill Wendling2626dba2011-08-03 22:18:20 +0000[diff] [blame]1216
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1217 <li>The <code>DIBuilder</code> interface used by front ends to encode
1218 debugging information in the LLVM IR now expects clients to
1219 use <code>DIBuilder::finalize()</code> at the end of translation unit to
1220 complete debugging information encoding.</li>
Devang Patel6326a422011-08-15 23:00:00 +0000[diff] [blame]1221
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1222 <li>The way the type system works has been
1223 rewritten: <code>PATypeHolder</code> and <code>OpaqueType</code> are gone,
1224 and all APIs deal with <code>Type*</code> instead of <code>const
1225 Type*</code>. If you need to create recursive structures, then create a
1226 named structure, and use <code>setBody()</code> when all its elements are
1227 built. Type merging and refining is gone too: named structures are not
1228 merged with other structures, even if their layout is identical. (of
1229 course anonymous structures are still uniqued by layout).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1230
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1231 <li>TargetSelect.h moved to Support/ from Target/</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1232
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1233 <li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls (for
1234 example <code>llvm.memset.i32</code>).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1235
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1236 <li>It is mandatory to initialize all out-of-tree passes too and their dependencies now with
1237 <code>INITIALIZE_PASS{BEGIN,END,}</code>
1238 and <code>INITIALIZE_{PASS,AG}_DEPENDENCY</code>.</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1239
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1240 <li>The interface for MemDepResult in MemoryDependenceAnalysis has been
1241 enhanced with new return types Unknown and NonFuncLocal, in addition to
1242 the existing types Clobber, Def, and NonLocal.</li>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1243</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1244
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1245</div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1246
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1247</div>
1248
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1249<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1250<h2>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1251 <a name="knownproblems">Known Problems</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1252</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1253<!-- *********************************************************************** -->
1254
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1255<div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1256
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1257<p>This section contains significant known problems with the LLVM system, listed
1258 by component. If you run into a problem, please check
1259 the <a href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
1260 there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1261
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1262<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1263<h3>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1264 <a name="experimental">Experimental features included with this release</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1265</h3>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1266
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1267<div>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1268
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]1269<p>The following components of this LLVM release are either untested, known to
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1270 be broken or unreliable, or are in early development. These components
1271 should not be relied on, and bugs should not be filed against them, but they
1272 may be useful to some people. In particular, if you would like to work on
1273 one of these components, please contact us on
1274 the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev
1275 list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1276
1277<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1278 <li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ and
1279 XCore backends are experimental.</li>
1280
1281 <li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets other
1282 than darwin and ELF X86 systems.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1283</ul>
1284
1285</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1286
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1287<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1288<h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1289 <a name="x86-be">Known problems with the X86 back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1290</h3>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1291
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1292<div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1293
1294<ul>
Chris Lattnerc78daaf2011-11-17 01:42:23 +0000[diff] [blame]1295 <li>The X86-64 backend <a href="http://llvm.org/PR1740">does not yet support
1296 the <tt>va_arg</tt> LLVM IR instruction</a>. Currently, front-ends support
1297 variadic argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1298</ul>
1299
1300</div>
1301
1302<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1303<h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1304 <a name="ppc-be">Known problems with the PowerPC back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1305</h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1306
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1307<div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1308
1309<ul>
Roman Divacky223764c2011-10-30 07:49:04 +0000[diff] [blame]1310 <li>The PPC32/ELF support lacks PIC support.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1311</ul>
1312
1313</div>
1314
1315<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1316<h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1317 <a name="arm-be">Known problems with the ARM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1318</h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1319
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1320<div>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1321
1322<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1323 <li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
1324 processors, thumb programs can crash or produce wrong results
1325 (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
1326
1327 <li>Compilation for ARM Linux OABI (old ABI) is supported but not fully
1328 tested.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1329</ul>
1330
1331</div>
1332
1333<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1334<h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1335 <a name="sparc-be">Known problems with the SPARC back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1336</h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1337
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1338<div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1339
1340<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1341 <li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
1342 support the 64-bit SPARC ABI (-m64).</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1343</ul>
1344
1345</div>
1346
1347<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1348<h3>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]1349 <a name="mips-be">Known problems with the MIPS back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1350</h3>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]1351
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1352<div>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]1353
1354<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1355 <li>64-bit MIPS targets are not supported yet.</li>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]1356</ul>
1357
1358</div>
1359
1360<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1361<h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1362 <a name="alpha-be">Known problems with the Alpha back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1363</h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1364
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1365<div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1366
1367<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1368 <li>On 21164s, some rare FP arithmetic sequences which may trap do not have
1369 the appropriate nops inserted to ensure restartability.</li>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1370</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1371
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1372</div>
1373
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1374<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1375<h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1376 <a name="c-be">Known problems with the C back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1377</h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1378
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1379<div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1380
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]1381<p>The C backend has numerous problems and is not being actively maintained.
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1382 Depending on it for anything serious is not advised.</p>
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]1383
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1384<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1385 <li><a href="http://llvm.org/PR802">The C backend has only basic support for
1386 inline assembly code</a>.</li>
1387
1388 <li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
1389 C++ programs</a>, preventing intermixing between C++ compiled by the CBE
1390 and C++ code compiled with <tt>llc</tt> or native compilers.</li>
1391
1392 <li>The C backend does not support all exception handling constructs.</li>
1393
1394 <li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1395</ul>
1396
1397</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1398
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1399</div>
1400
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1401<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1402<h2>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1403 <a name="additionalinfo">Additional Information</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1404</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1405<!-- *********************************************************************** -->
1406
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1407<div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1408
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1409<p>A wide variety of additional information is available on
1410 the <a href="http://llvm.org/">LLVM web page</a>, in particular in
1411 the <a href="http://llvm.org/docs/">documentation</a> section. The web page
1412 also contains versions of the API documentation which is up-to-date with the
1413 Subversion version of the source code. You can access versions of these
1414 documents specific to this release by going into the "<tt>llvm/doc/</tt>"
1415 directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1416
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1417<p>If you have any questions or comments about LLVM, please feel free to contact
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1418 us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1419
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1420</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1421
1422<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1423
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1424<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1425<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]1426 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1427 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1428 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1429 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]1430
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]1431 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1432 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1433</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1434
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1435</body>
1436</html>