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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
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]48 major improvements from the previous release, improvements in various
49 subprojects of LLVM, and some of the current users of the code.
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]50 All LLVM releases may be downloaded from
51 the <a href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]52
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]53<p>For more information about LLVM, including information about the latest
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]54 release, please check out the <a href="http://llvm.org/">main LLVM web
55 site</a>. If you have questions or comments,
56 the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM
57 Developer's Mailing List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]58
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]59<p>Note that if you are reading this file from a Subversion checkout or the main
60 LLVM web page, this document applies to the <i>next</i> release, not the
61 current one. To see the release notes for a specific release, please see the
62 <a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]63
64</div>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]65
66
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]67<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]68<h2>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]69 <a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]70</h2>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]71<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]72
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]73<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]74
75<p>The LLVM 3.0 distribution currently consists of code from the core LLVM
76 repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]77 supporting tools), and the Clang repository. In
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]78 addition to this code, the LLVM Project includes other sub-projects that are
79 in development. Here we include updates on these subprojects.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]80
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]81<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]82<h3>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]83<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]84</h3>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]85
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]86<div>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]87
Chris Lattner095539f2010-04-26 17:42:18 +0000[diff] [blame]88<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]89 C++, and Objective-C languages. Clang aims to provide a better user
90 experience through expressive diagnostics, a high level of conformance to
91 language standards, fast compilation, and low memory use. Like LLVM, Clang
92 provides a modular, library-based architecture that makes it suitable for
93 creating or integrating with other development tools. Clang is considered a
94 production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]95 (32- and 64-bit), and for Darwin/ARM targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]96
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]97<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]98
99<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]100 <li>Greatly improved support for building C++ applications, with greater
101 stability and better diagnostics.</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]102
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]103 <li><a href="http://clang.llvm.org/cxx_status.html">Improved support</a> for
104 the <a href="http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=50372">C++
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]105 2011</a> standard (aka "C++'0x"), including implementations of non-static data member
106 initializers, alias templates, delegating constructors, range-based
107 for loops, and implicitly-generated move constructors and move assignment
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]108 operators, among others.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]109
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]110 <li>Implemented support for some features of the upcoming C1x standard,
111 including static assertions and generic selections.</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]112
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]113 <li>Better detection of include and linking paths for system headers and
114 libraries, especially for Linux distributions.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]115
David Chisnall553284e2011-11-26 10:56:17 +0000[diff] [blame]116 <li>Several improvements to Objective-C support, including:
117
118 <ul>
119 <li><a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html">
120 Automatic Reference Counting</a> (ARC) and an improved memory model
121 cleanly separating object and C memory.</li>
122
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]123 <li>A migration tool for moving manual retain/release code to ARC</li>
David Chisnall553284e2011-11-26 10:56:17 +0000[diff] [blame]124
125 <li>Better support for data hiding, allowing instance variables to be
126 declared in implementation contexts or class extensions</li>
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]127 <li>Weak linking support for Objective-C classes</li>
David Chisnall553284e2011-11-26 10:56:17 +0000[diff] [blame]128 <li>Improved static type checking by inferring the return type of methods
129 such as +alloc and -init.</li>
130 </ul>
131
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]132 Some new Objective-C features require either the Mac OS X 10.7 / iOS 5
133 Objective-C runtime, or version 1.6 or later of the GNUstep Objective-C
134 runtime version.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]135
Peter Collingbournef7fea722011-11-28 20:04:12 +0000[diff] [blame]136 <li>Improved support for OpenCL C, including the <tt>vec_step</tt> operator,
137 address space qualifiers, improved vector literal support and code
138 generation support for the <a href="#PTX">PTX target</a>.</li>
139
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]140 <li>Implemented a number of optimizations in <tt>libclang</tt>, the Clang C
141 interface, to improve the performance of code completion and the mapping
142 from source locations to abstract syntax tree nodes.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]143</ul>
144
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]145
Duncan Sandsf3ba7af2011-04-06 08:07:40 +0000[diff] [blame]146<p>If Clang rejects your code but another compiler accepts it, please take a
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]147 look at the <a href="http://clang.llvm.org/compatibility.html">language
148 compatibility</a> guide to make sure this is not intentional or a known
149 issue.</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]150
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]151</div>
152
153<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]154<h3>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]155<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]156</h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]157
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]158<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]159<p><a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
160 <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]161 optimizers and code generators with LLVM's. It works with gcc-4.5 or gcc-4.6,
162 targets the x86-32 and x86-64 processor families, and has been successfully
163 used on the Darwin, FreeBSD, KFreeBSD, Linux and OpenBSD platforms. It fully
164 supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C
165 and Obj-C++.</p>
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]166
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]167<p>The 3.0 release has the following notable changes:</p>
168
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]169 <ul>
Duncan Sands77352c92011-11-10 18:44:29 +0000[diff] [blame]170 <li>GCC version 4.6 is now fully supported.</li>
171
172 <li>Patching and building GCC is no longer required: the plugin should work
173 with your system GCC (version 4.5 or 4.6; on Debian/Ubuntu systems the
174 gcc-4.5-plugin-dev or gcc-4.6-plugin-dev package is also needed).</li>
175
176 <li>The <tt>-fplugin-arg-dragonegg-enable-gcc-optzns</tt> option, which runs
177 GCC's optimizers as well as LLVM's, now works much better. This is the
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]178 option to use if you want ultimate performance! It is still experimental
179 though: it may cause the plugin to crash.</li>
Duncan Sands77352c92011-11-10 18:44:29 +0000[diff] [blame]180
181 <li>The type and constant conversion logic has been almost entirely rewritten,
182 fixing a multitude of obscure bugs.</li>
183
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]184</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]185
186</div>
187
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]188<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]189<h3>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]190<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]191</h3>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]192
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]193<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]194
195<p>The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
196 is a simple library that provides an implementation of the low-level
197 target-specific hooks required by code generation and other runtime
198 components. For example, when compiling for a 32-bit target, converting a
199 double to a 64-bit unsigned integer is compiled into a runtime call to the
200 "__fixunsdfdi" function. The compiler-rt library provides highly optimized
201 implementations of this and other low-level routines (some are 3x faster than
202 the equivalent libgcc routines).</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]203
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]204<p>In the LLVM 3.0 timeframe, the target specific ARM code has converted to
205 "unified" assembly syntax, and several new functions have been added to the
206 library.</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]207
208</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]209
210<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]211<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]212<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]213</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]214
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]215<div>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]216
Chris Lattner9e896712011-11-27 18:53:41 +0000[diff] [blame]217<p>LLDB is a ground-up implementation of a command line debugger, as well as a
218 debugger API that can be used from other applications. LLDB makes use of the
219 Clang parser to provide high-fidelity expression parsing (particularly for
220 C++) and uses the LLVM JIT for target support.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]221
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]222<p>LLDB has advanced by leaps and bounds in the 3.0 timeframe. It is
223 dramatically more stable and useful, and includes both a
224 new <a href="http://lldb.llvm.org/tutorial.html">tutorial</a> and
225 a <a href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
226 GDB</a>.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]227
228</div>
229
230<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]231<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]232<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]233</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]234
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]235<div>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]236
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]237<p>Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
238 licensed</a> under the MIT and UIUC license, allowing it to be used more
239 permissively.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]240
David Chisnall553284e2011-11-26 10:56:17 +0000[diff] [blame]241<p>Libc++ has been ported to FreeBSD and imported into the base system. It is
242 planned to be the default STL implementation for FreeBSD 10.</p>
243
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]244</div>
245
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]246<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]247<h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]248<a name="vmkit">VMKit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]249</h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]250
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]251<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]252
Nicolas Geoffray54d5df92011-11-10 23:37:56 +0000[diff] [blame]253 <p>The <a href="http://vmkit.llvm.org/">VMKit project</a> is an
254 implementation of a Java Virtual Machine (Java VM or JVM) that uses LLVM for
255 static and just-in-time compilation.
256
257 <p>In the LLVM 3.0 time-frame, VMKit has had significant improvements on both
258 runtime and startup performance:</p>
259
260 <ul>
261 <li>Precompilation: by compiling ahead of time a small subset of Java's core
262 library, the startup performance have been highly optimized to the point that
263 running a 'Hello World' program takes less than 30 milliseconds.</li>
264
265 <li>Customization: by customizing virtual methods for individual classes,
266 the VM can statically determine the target of a virtual call, and decide to
267 inline it.</li>
268
269 <li>Inlining: the VM does more inlining than it did before, by allowing more
270 bytecode instructions to be inlined, and thanks to customization. It also
271 inlines GC barriers, and object allocations.</li>
272
273 <li>New exception model: the generated code for a method that does not do
274 any try/catch is not penalized anymore by the eventuality of calling a
275 method that throws an exception. Instead, the method that throws the
276 exception jumps directly to the method that could catch it.</li>
277 </ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]278
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]279</div>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]280
Chris Lattner9e896712011-11-27 18:53:41 +0000[diff] [blame]281
282<!--=========================================================================-->
283<h3>
284<a name="LLBrowse">LLBrowse: IR Browser</a>
285</h3>
286
287<div>
288
289<p><a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
290 LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
291 module and displays its contents as an expandable tree view, facilitating an
292 easy way to inspect types, functions, global variables, or metadata nodes. It
293 is fully cross-platform, being based on the popular wxWidgets GUI
294 toolkit.</p>
295
296</div>
297
298
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]299<!--=========================================================================-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]300<!--
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]301<h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]302<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]303</h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]304
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]305<div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]306<p>
307<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
308programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
309through the application and records state transitions that lead to fault
310states. This allows it to construct testcases that lead to faults and can even
311be used to verify some algorithms.
312</p>
313
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]314<p>UPDATE!</p>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]315</div>-->
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]316
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]317</div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]318
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]319<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]320<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]321 <a name="externalproj">External Open Source Projects Using LLVM 3.0</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]322</h2>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]323<!-- *********************************************************************** -->
324
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]325<div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]326
327<p>An exciting aspect of LLVM is that it is used as an enabling technology for
328 a lot of other language and tools projects. This section lists some of the
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]329 projects that have already been updated to work with LLVM 3.0.</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]330
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]331<!--=========================================================================-->
Bill Wendling7be6bc52011-10-26 00:17:54 +0000[diff] [blame]332<h3>AddressSanitizer</h3>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]333
Bill Wendling7be6bc52011-10-26 00:17:54 +0000[diff] [blame]334<div>
335
336<p><a href="http://code.google.com/p/address-sanitizer/">AddressSanitizer</a>
337 uses compiler instrumentation and a specialized malloc library to find C/C++
338 bugs such as use-after-free and out-of-bound accesses to heap, stack, and
339 globals. The key feature of the tool is speed: the average slowdown
340 introduced by AddressSanitizer is less than 2x.</p>
341
342</div>
343
344<!--=========================================================================-->
Bill Wendling29817ea2011-10-26 00:14:36 +0000[diff] [blame]345<h3>ClamAV</h3>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]346
Bill Wendling29817ea2011-10-26 00:14:36 +0000[diff] [blame]347<div>
Bill Wendlingf2a78332011-10-25 01:01:42 +0000[diff] [blame]348
Bill Wendling29817ea2011-10-26 00:14:36 +0000[diff] [blame]349<p><a href="http://www.clamav.net">Clam AntiVirus</a> is an open source (GPL)
350 anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
351 gateways.</p>
352
353<p>Since version 0.96 it
354 has <a href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
Chris Lattner4f0fe432011-11-27 19:26:30 +0000[diff] [blame]355 signatures</a> that allow writing detections for complex malware.
356 It uses LLVM's JIT to speed up the execution of bytecode on X86, X86-64,
Bill Wendling29817ea2011-10-26 00:14:36 +0000[diff] [blame]357 PPC32/64, falling back to its own interpreter otherwise. The git version was
358 updated to work with LLVM 3.0.</p>
359
360</div>
361
362<!--=========================================================================-->
Tobias Grosserae5a6fd2011-11-14 09:09:26 +0000[diff] [blame]363<h3>clang_complete for VIM</h3>
364
365<div>
366
367<p><a href="https://github.com/Rip-Rip/clang_complete">clang_complete</a> is a
368 VIM plugin, that provides accurate C/C++ autocompletion using the clang front
369 end. The development version of clang complete, can directly use libclang
370 which can maintain a cache to speed up auto completion.</p>
371
372</div>
373
374<!--=========================================================================-->
Bill Wendling65d1f412011-10-26 18:23:06 +0000[diff] [blame]375<h3>clReflect</h3>
376
377<div>
378
379<p><a href="https://bitbucket.org/dwilliamson/clreflect">clReflect</a> is a C++
380 parser that uses clang/LLVM to derive a light-weight reflection database
381 suitable for use in game development. It comes with a very simple runtime
382 library for loading and querying the database, requiring no external
383 dependencies (including CRT), and an additional utility library for object
384 management and serialisation.</p>
385
386</div>
387
388<!--=========================================================================-->
Bill Wendling63507d12011-10-29 01:10:01 +0000[diff] [blame]389<h3>Cling C++ Interpreter</h3>
390
391<div>
392
393<p><a href="http://cern.ch/cling">Cling</a> is an interactive compiler interface
Chris Lattner4f0fe432011-11-27 19:26:30 +0000[diff] [blame]394 (aka C++ interpreter). It supports C++ and C, and uses LLVM's JIT and the
395 Clang parser. It has a prompt interface, runs source files, calls into shared
Bill Wendling63507d12011-10-29 01:10:01 +0000[diff] [blame]396 libraries, prints the value of expressions, even does runtime lookup of
397 identifiers (dynamic scopes). And it just behaves like one would expect from
398 an interpreter.</p>
399
400</div>
401
402<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]403<h3>Crack Programming Language</h3>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]404
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]405<div>
Bill Wendling55d6e672011-11-03 20:10:01 +0000[diff] [blame]406
407<p><a href="http://code.google.com/p/crack-language/">Crack</a> aims to provide
408 the ease of development of a scripting language with the performance of a
409 compiled language. The language derives concepts from C++, Java and Python,
410 incorporating object-oriented programming, operator overloading and strong
411 typing.</p>
412
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]413</div>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]414
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]415<!--=========================================================================-->
Bill Wendlingb99486f2011-11-08 05:22:54 +0000[diff] [blame]416<h3>Eero</h3>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]417
Bill Wendlingb99486f2011-11-08 05:22:54 +0000[diff] [blame]418<div>
419
420<p><a href="http://eerolanguage.org/">Eero</a> is a fully
421 header-and-binary-compatible dialect of Objective-C 2.0, implemented with a
422 patched version of the Clang/LLVM compiler. It features a streamlined syntax,
423 Python-like indentation, and new operators, for improved readability and
424 reduced code clutter. It also has new features such as limited forms of
425 operator overloading and namespaces, and strict (type-and-operator-safe)
426 enumerations. It is inspired by languages such as Smalltalk, Python, and
427 Ruby.</p>
428
429</div>
430
431<!--=========================================================================-->
Chris Lattneradb417a2011-11-25 20:28:16 +0000[diff] [blame]432<h3>FAUST Real-Time Audio Signal Processing Language</h3>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]433
Chris Lattneradb417a2011-11-25 20:28:16 +0000[diff] [blame]434<div>
435
436<p><a href="http://faust.grame.fr/">FAUST</a> is a compiled language for
437 real-time audio signal processing. The name FAUST stands for Functional
438 AUdio STream. Its programming model combines two approaches: functional
439 programming and block diagram composition. In addition with the C, C++, Java
440 output formats, the Faust compiler can now generate LLVM bitcode, and works
441 with LLVM 2.7-3.0.
442 </p>
443
444</div>
445
446<!--=========================================================================-->
Bill Wendlingf9778192011-10-26 00:09:55 +0000[diff] [blame]447<h3>Glasgow Haskell Compiler (GHC)</h3>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]448
Bill Wendlingf9778192011-10-26 00:09:55 +0000[diff] [blame]449<div>
450
451<p>GHC is an open source, state-of-the-art programming suite for Haskell, a
452 standard lazy functional programming language. It includes an optimizing
453 static compiler generating good code for a variety of platforms, together
454 with an interactive system for convenient, quick development.</p>
455
456<p>GHC 7.0 and onwards include an LLVM code generator, supporting LLVM 2.8 and
457 later. Since LLVM 2.9, GHC now includes experimental support for the ARM
458 platform with LLVM 3.0.</p>
459
460</div>
461
462<!--=========================================================================-->
Bill Wendlingf62333d2011-10-25 20:35:31 +0000[diff] [blame]463<h3>gwXscript</h3>
464
465<div>
466
467<p><a href="http://botwars.tk/gwscript/">gwXscript</a> is an object oriented,
Bill Wendling7c38de22011-10-26 04:24:15 +0000[diff] [blame]468 aspect oriented programming language which can create both executables (ELF,
Bill Wendlingf62333d2011-10-25 20:35:31 +0000[diff] [blame]469 EXE) and shared libraries (DLL, SO, DYNLIB). The compiler is implemented in
470 its own language and translates scripts into LLVM-IR which can be optimized
471 and translated into native code by the LLVM framework. Source code in
472 gwScript contains definitions that expand the namespaces. So you can build
473 your project and simply 'plug out' features by removing a file. The remaining
474 project does not leave scars since you directly separate concerns by the
475 'template' feature of gwX. It is also possible to add new features to a
476 project by just adding files and without editing the original project. This
477 language is used for example to create games or content management systems
478 that should be extendable.</p>
479
480<p>gwXscript is strongly typed and offers comfort with its native types string,
481 hash and array. You can easily write new libraries in gwXscript or native
482 code. gwXscript is type safe and users should not be able to crash your
483 program or execute malicious code except code that is eating CPU time.</p>
484
485</div>
486
487<!--=========================================================================-->
Bill Wendling50cacc82011-10-26 22:55:18 +0000[diff] [blame]488<h3>include-what-you-use</h3>
489
490<div>
491
492<p><a href="http://code.google.com/p/include-what-you-use">include-what-you-use</a>
493 is a tool to ensure that a file directly <code>#include</code>s
494 all <code>.h</code> files that provide a symbol that the file uses. It also
495 removes superfluous <code>#include</code>s from source files.</p>
496
497</div>
498
499<!--=========================================================================-->
Bill Wendling32dc4d92011-11-07 22:05:17 +0000[diff] [blame]500<h3>ispc: The Intel SPMD Program Compiler</h3>
501
502<div>
503
504<p><a href="http://ispc.github.com">ispc</a> is a compiler for "single program,
505 multiple data" (SPMD) programs. It compiles a C-based SPMD programming
506 language to run on the SIMD units of CPUs; it often delivers 5-6x speedups on
507 a single core of a CPU with an 8-wide SIMD unit compared to serial code,
508 while still providing a clean and easy-to-understand programming model. For
509 an introduction to the language and its performance,
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]510 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]511 example program. ispc is licensed under the BSD license.</p>
512
513</div>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]514
Chris Lattnercc089772011-11-25 20:36:17 +0000[diff] [blame]515<!--=========================================================================-->
516<h3>The Julia Programming Language</h3>
517
518<div>
519
520<p><a href="http://github.com/JuliaLang/julia">Julia</a> is a high-level,
521 high-performance dynamic language for technical
522 computing. It provides a sophisticated compiler, distributed parallel
523 execution, numerical accuracy, and an extensive mathematical function
524 library. The compiler uses type inference to generate fast code
525 without any type declarations, and uses LLVM's optimization passes and
526 JIT compiler. The language is designed around multiple dispatch,
527 giving programs a large degree of flexibility. It is ready for use on many
528 kinds of problems.</p>
529</div>
Bill Wendling32dc4d92011-11-07 22:05:17 +0000[diff] [blame]530
531<!--=========================================================================-->
Bill Wendling57fd8762011-10-26 18:20:54 +0000[diff] [blame]532<h3>LanguageKit and Pragmatic Smalltalk</h3>
533
534<div>
535
536<p><a href="http://etoileos.com/etoile/features/languagekit/">LanguageKit</a> is
537 a framework for implementing dynamic languages sharing an object model with
538 Objective-C. It provides static and JIT compilation using LLVM along with
539 its own interpreter. Pragmatic Smalltalk is a dialect of Smalltalk, built on
540 top of LanguageKit, that interfaces directly with Objective-C, sharing the
541 same object representation and message sending behaviour. These projects are
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000[diff] [blame]542 developed as part of the &Eacute;toil&eacute; desktop environment.</p>
Bill Wendling57fd8762011-10-26 18:20:54 +0000[diff] [blame]543
544</div>
545
546<!--=========================================================================-->
Bill Wendling03250532011-11-01 04:08:23 +0000[diff] [blame]547<h3>LuaAV</h3>
548
549<div>
550
551<p><a href="http://lua-av.mat.ucsb.edu/blog/">LuaAV</a> is a real-time
552 audiovisual scripting environment based around the Lua language and a
553 collection of libraries for sound, graphics, and other media protocols. LuaAV
554 uses LLVM and Clang to JIT compile efficient user-defined audio synthesis
555 routines specified in a declarative syntax.</p>
556
557</div>
558
559<!--=========================================================================-->
Bill Wendlingd4821b82011-10-26 00:16:17 +0000[diff] [blame]560<h3>Mono</h3>
561
562<div>
563
564<p>An open source, cross-platform implementation of C# and the CLR that is
565 binary compatible with Microsoft.NET. Has an optional, dynamically-loaded
566 LLVM code generation backend in Mini, the JIT compiler.</p>
567
Chris Lattner4f0fe432011-11-27 19:26:30 +0000[diff] [blame]568<p>Note that we use a Git mirror of LLVM <a
569 href="https://github.com/mono/llvm">with some patches</a>.</p>
Bill Wendlingd4821b82011-10-26 00:16:17 +0000[diff] [blame]570
571</div>
572
573<!--=========================================================================-->
Tobias Grosser093cb7e2011-11-14 09:09:23 +0000[diff] [blame]574<h3>Polly</h3>
575
576<div>
577
578<p><a href="http://polly.grosser.es">Polly</a> is an advanced data-locality
579 optimizer and automatic parallelizer. It uses an advanced, mathematical
580 model to calculate detailed data dependency information which it uses to
581 optimize the loop structure of a program. Polly can speed up sequential code
582 by improving memory locality and consequently the cache use. Furthermore,
583 Polly is able to expose different kind of parallelism which it exploits by
584 introducing (basic) OpenMP and SIMD code. A mid-term goal of Polly is to
585 automatically create optimized GPU code.</p>
586
587</div>
588
589<!--=========================================================================-->
Bill Wendlingba226272011-10-25 20:37:45 +0000[diff] [blame]590<h3>Portable OpenCL (pocl)</h3>
591
592<div>
593
594<p>Portable OpenCL is an open source implementation of the OpenCL standard which
595 can be easily adapted for new targets. One of the goals of the project is
596 improving performance portability of OpenCL programs, avoiding the need for
597 target-dependent manual optimizations. A "native" target is included, which
598 allows running OpenCL kernels on the host (CPU).</p>
599
600</div>
601
602<!--=========================================================================-->
Bill Wendling0bad98c2011-10-25 20:39:06 +0000[diff] [blame]603<h3>Pure</h3>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]604
Bill Wendling0bad98c2011-10-25 20:39:06 +0000[diff] [blame]605<div>
606<p><a href="http://pure-lang.googlecode.com/">Pure</a> is an
607 algebraic/functional programming language based on term rewriting. Programs
608 are collections of equations which are used to evaluate expressions in a
609 symbolic fashion. The interpreter uses LLVM as a backend to JIT-compile Pure
610 programs to fast native code. Pure offers dynamic typing, eager and lazy
611 evaluation, lexical closures, a hygienic macro system (also based on term
612 rewriting), built-in list and matrix support (including list and matrix
613 comprehensions) and an easy-to-use interface to C and other programming
614 languages (including the ability to load LLVM bitcode modules, and inline C,
615 C++, Fortran and Faust code in Pure programs if the corresponding LLVM-enabled
616 compilers are installed).</p>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]617
Bill Wendling0bad98c2011-10-25 20:39:06 +0000[diff] [blame]618<p>Pure version 0.48 has been tested and is known to work with LLVM 3.0
619 (and continues to work with older LLVM releases &gt;= 2.5).</p>
620
621</div>
622
623<!--=========================================================================-->
Bill Wendling537d85b2011-10-26 00:12:04 +0000[diff] [blame]624<h3>Renderscript</h3>
625
626<div>
627
628<p><a href="http://developer.android.com/guide/topics/renderscript/index.html">Renderscript</a>
629 is Android's advanced 3D graphics rendering and compute API. It provides a
630 portable C99-based language with extensions to facilitate common use cases
631 for enhancing graphics and thread level parallelism. The Renderscript
632 compiler frontend is based on Clang/LLVM. It emits a portable bitcode format
633 for the actual compiled script code, as well as reflects a Java interface for
634 developers to control the execution of the compiled bitcode. Executable
635 machine code is then generated from this bitcode by an LLVM backend on the
636 device. Renderscript is thus able to provide a mechanism by which Android
637 developers can improve performance of their applications while retaining
638 portability.</p>
639
640</div>
641
642<!--=========================================================================-->
Bill Wendling7d5b6212011-10-25 20:40:26 +0000[diff] [blame]643<h3>SAFECode</h3>
644
645<div>
646
647<p><a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C/C++
648 compiler built using LLVM. It takes standard, unannotated C/C++ code,
649 analyzes the code to ensure that memory accesses and array indexing
650 operations are safe, and instruments the code with run-time checks when
651 safety cannot be proven statically. SAFECode can be used as a debugging aid
652 (like Valgrind) to find and repair memory safety bugs. It can also be used
653 to protect code from security attacks at run-time.</p>
654
655</div>
656
657<!--=========================================================================-->
Bill Wendling02b77b72011-10-26 07:38:19 +0000[diff] [blame]658<h3>The Stupid D Compiler (SDC)</h3>
659
660<div>
661
662<p><a href="https://github.com/bhelyer/SDC">The Stupid D Compiler</a> is a
663 project seeking to write a self-hosting compiler for the D programming
664 language without using the frontend of the reference compiler (DMD).</p>
665
666</div>
667
668<!--=========================================================================-->
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]669<h3>TTA-based Co-design Environment (TCE)</h3>
670
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]671<div>
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]672
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]673<p>TCE is a toolset for designing application-specific processors (ASP) based on
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]674 the Transport triggered architecture (TTA). The toolset provides a complete
675 co-design flow from C/C++ programs down to synthesizable VHDL and parallel
676 program binaries. Processor customization points include the register files,
677 function units, supported operations, and the interconnection network.</p>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]678
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]679<p>TCE uses Clang and LLVM for C/C++ language support, target independent
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]680 optimizations and also for parts of code generation. It generates new
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]681 LLVM-based code generators "on the fly" for the designed TTA processors and
682 loads them in to the compiler backend as runtime libraries to avoid
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]683 per-target recompilation of larger parts of the compiler chain.</p>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]684
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]685</div>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]686
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]687<!--=========================================================================-->
Bill Wendling628c2662011-10-25 20:27:37 +0000[diff] [blame]688<h3>Tart Programming Language</h3>
689
690<div>
691
692<p><a href="http://code.google.com/p/tart/">Tart</a> is a general-purpose,
693 strongly typed programming language designed for application
694 developers. Strongly inspired by Python and C#, Tart focuses on practical
695 solutions for the professional software developer, while avoiding the clutter
696 and boilerplate of legacy languages like Java and C++. Although Tart is still
697 in development, the current implementation supports many features expected of
698 a modern programming language, such as garbage collection, powerful
699 bidirectional type inference, a greatly simplified syntax for template
700 metaprogramming, closures and function literals, reflection, operator
701 overloading, explicit mutability and immutability, and much more. Tart is
702 flexible enough to accommodate a broad range of programming styles and
703 philosophies, while maintaining a strong commitment to simplicity, minimalism
704 and elegance in design.</p>
705
706</div>
707
708<!--=========================================================================-->
Bill Wendling644ce532011-10-26 09:25:01 +0000[diff] [blame]709<h3>ThreadSanitizer</h3>
710
711<div>
712
713<p><a href="http://code.google.com/p/data-race-test/">ThreadSanitizer</a> is a
714 data race detector for (mostly) C and C++ code, available for Linux, Mac OS
715 and Windows. On different systems, we use binary instrumentation frameworks
Bill Wendlingae8538e2011-10-29 01:11:15 +0000[diff] [blame]716 (Valgrind and Pin) as frontends that generate the program events for the race
717 detection algorithm. On Linux, there's an option of using LLVM-based
718 compile-time instrumentation.</p>
Bill Wendling644ce532011-10-26 09:25:01 +0000[diff] [blame]719
720</div>
721
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]722</div>
723
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]724<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]725<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]726 <a name="whatsnew">What's New in LLVM 3.0?</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]727</h2>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]728<!-- *********************************************************************** -->
729
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]730<div>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]731
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]732<p>This release includes a huge number of bug fixes, performance tweaks and
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]733 minor improvements. Some of the major improvements and new features are
734 listed in this section.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]735
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]736<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]737<h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]738<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]739</h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]740
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]741<div>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]742
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]743 <!-- Features that need text if they're finished for 3.1:
744 ARM EHABI
745 combiner-aa?
746 strong phi elim
747 loop dependence analysis
748 CorrelatedValuePropagation
749 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]750 Integrated assembler on by default for arm/thumb?
751
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000[diff] [blame]752 -->
753
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]754 <!-- Near dead:
Chris Lattnerdec23b62011-11-15 22:13:27 +0000[diff] [blame]755 Analysis/RegionInfo.h + Dom Frontiers
756 SparseBitVector: used in LiveVar.
Chris Lattner5a1731d2011-11-27 08:32:32 +0000[diff] [blame]757 llvm/lib/Archive - replace with lib object?
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]758 -->
Chris Lattner6a007d12011-11-25 20:33:27 +0000[diff] [blame]759
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]760<p>LLVM 3.0 includes several major changes and big features:</p>
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]761
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]762<ul>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]763<li>llvm-gcc is no longer supported, and not included in the release. We
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]764 recommend switching to <a
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]765 href="http://clang.llvm.org/">Clang</a> or <a
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]766 href="http://dragonegg.llvm.org/">DragonEgg</a>.</li>
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]767
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]768<li>The linear scan register allocator has been replaced with a new "greedy"
769 register allocator, enabling live range splitting and many other
770 optimizations that lead to better code quality. Please see its <a
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]771 href="http://blog.llvm.org/2011/09/greedy-register-allocation-in-llvm-30.html">blog post</a> or its talk at the <a
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]772 href="http://llvm.org/devmtg/2011-11/">Developer Meeting</a>
773 for more information.</li>
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]774<li>LLVM IR now includes full support for <a href="Atomics.html">atomics
775 memory operations</a> intended to support the C++'11 and C'1x memory models.
776 This includes <a href="LangRef.html#memoryops">atomic load and store,
777 compare and exchange, and read/modify/write instructions</a> as well as a
778 full set of <a href="LangRef.html#ordering">memory ordering constraints</a>.
779 Please see the <a href="Atomics.html">Atomics Guide</a> for more
780 information.
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]781</li>
782<li>The LLVM IR exception handling representation has been redesigned and
783 reimplemented, making it more elegant, fixing a huge number of bugs, and
784 enabling inlining and other optimizations. Please see its blog post (XXX
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]785 not yet) and the <a href="ExceptionHandling.html">Exception Handling
786 documentation</a> for more information.</li>
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]787<li>The LLVM IR Type system has been redesigned and reimplemented, making it
788 faster and solving some long-standing problems.
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]789 Please see its <a
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]790 href="http://blog.llvm.org/2011/11/llvm-30-type-system-rewrite.html">blog
791 post</a> for more information.</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]792
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]793<li>The MIPS backend has made major leaps in this release, going from an
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]794 experimental target to being virtually production quality and supporting a
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]795 wide variety of MIPS subtargets. See the <a href="#MIPS">MIPS section</a>
796 below for more information.</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]797
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]798<li>The optimizer and code generator now supports gprof and gcov-style coverage
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]799 and profiling information, and includes a new llvm-cov tool (but also works
800 with gcov). Clang exposes coverage and profiling through GCC-compatible
801 command line options.</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</div>
805
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]806
Chris Lattner4f0fe432011-11-27 19:26:30 +0000[diff] [blame]807<!--=========================================================================-->
808<h3>
809<a name="coreimprovements">LLVM IR and Core Improvements</a>
810</h3>
811
812<div>
813
814<p>LLVM IR has several new features for better support of new targets and that
815 expose new optimization opportunities:</p>
816
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]817 <ul>
818 <li><a href="Atomics.html">Atomic memory accesses and memory ordering</a> are
819 now directly expressible in the IR.</li>
820 <li>A new <a href="LangRef.html#int_fma">llvm.fma intrinsic</a> directly
821 represents floating point multiply accumulate operations without an
822 intermediate rounding stage.</li>
823 <li>A new llvm.expect intrinsic (XXX not documented in langref) allows a
824 frontend to express expected control flow (and the __builtin_expect builtin
825 from GNU C).</li>
826 <li>The <a href="LangRef.html#int_prefetch">llvm.prefetch intrinsic</a> now
827 takes a 4th argument that specifies whether the prefetch happens from the
828 icache or dcache.</li>
829 <li>The new <a href="LangRef.html#uwtable">uwtable function attribute</a>
830 allows a frontend to control emission of unwind tables.</li>
831 <li>The new <a href="LangRef.html#fnattrs">nonlazybind function
832 attribute</a> allow optimization of Global Offset Table (GOT) accesses.</li>
833 <li>The new <a href="LangRef.html#returns_twice">returns_twice attribute</a>
834 allows better modeling of functions like setjmp.</li>
835 <li>The <a href="LangRef.html#datalayout">target datalayout</a> string can now
836 encode the natural alignment of the target's stack for better optimization.
837 </li>
838 </ul>
Andrew Trick5aab6382011-11-06 17:59:24 +0000[diff] [blame]839</div>
840
841<!--=========================================================================-->
842<h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]843<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]844</h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]845
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]846<div>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]847
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]848<p>In addition to many minor performance tweaks and bug fixes, this
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]849 release includes a few major enhancements and additions to the
850 optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]851
852<ul>
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]853<li>The pass manager now has an extension API that allows front-ends and plugins
854 to insert their own optimizations in the well-known places in the standard
855 pass optimization pipeline.</li>
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]856
Benjamin Kramer933a78c2011-11-26 11:14:54 +0000[diff] [blame]857<li>Information about <a href="BranchWeightMetadata.html">branch probability</a>
858 and basic block frequency is now available within LLVM, based on a
859 combination of static branch prediction heuristics and
860 <code>__builtin_expect</code> calls. That information is currently used for
861 register spill placement and if-conversion, with additional optimizations
862 planned for future releases. The same framework is intended for eventual
863 use with profile-guided optimization.</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]864
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]865<li>The "-indvars" induction variable simplification pass only modifies
866 induction variables when profitable. Sign and zero extension
867 elimination, linear function test replacement, loop unrolling, and
868 other simplifications that require induction variable analysis have
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]869 been generalized so they no longer require loops to be rewritten into
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]870 canonical form prior to optimization. This new design
871 preserves more IR level information, avoids undoing earlier loop
872 optimizations (particularly hand-optimized loops), and no longer
873 requires the code generator to reconstruct loops into an optimal form -
874 an intractable problem.</li>
875
876<li>LLVM now includes a pass to optimize retain/release calls for the
877 <a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html">Automatic
878 Reference Counting</a> (ARC) Objective-C language feature (in
Chris Lattner2f206022011-11-27 22:03:34 +0000[diff] [blame]879 lib/Transforms/Scalar/ObjCARC.cpp). It is a decent example of implementing
880 a source-language-specific optimization in LLVM.</li>
Chris Lattner064caf92011-11-27 21:30:28 +0000[diff] [blame]881
Chris Lattner11b66112010-10-04 02:42:39 +0000[diff] [blame]882</ul>
883
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]884</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]885
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]886<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]887<h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]888<a name="mc">MC Level Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]889</h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]890
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]891<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]892
893<p>The LLVM Machine Code (aka MC) subsystem was created to solve a number of
894 problems in the realm of assembly, disassembly, object file format handling,
895 and a number of other related areas that CPU instruction-set level tools work
Chris Lattner2f206022011-11-27 22:03:34 +0000[diff] [blame]896 in. For more information, please see
897 the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro
898 to the LLVM MC Project Blog Post</a>.</p>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]899
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]900<ul>
Chris Lattner2f206022011-11-27 22:03:34 +0000[diff] [blame]901 <li>The MC layer has undergone significant refactoring to eliminate layering
902 violations that caused it to pull in the LLVM compiler backend code.</li>
903 <li>The ELF object file writers are much more full featured.</li>
904 <li>The integrated assembler now supports #line directives.</li>
905 <li>An early implementation of a JIT built on top of the MC framework (known
906 as MC-JIT) has been implemented and will eventually replace the old JIT.
907 It emits object files direct to memory and uses a runtime dynamic linker to
908 resolve references and drive lazy compilation. The MC-JIT enables much
909 greater code reuse between the JIT and the static compiler and provides
910 better integration with the platform ABI as a result.
911 </li>
912 <li>The assembly printer now makes uses of assemblers instruction aliases
913 (InstAliases) to print simplified mneumonics when possible.</li>
914 <li>TableGen can now autogenerate MC expansion logic for pseudo
915 instructions that expand to multiple MC instructions (through the
916 PseudoInstExpansion class).</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]917 <li>A new llvm-dwarfdump tool provides a start of a drop-in
918 replacement for the corresponding tool that use LLVM libraries. As part of
Chris Lattner7c224462011-11-27 22:39:23 +0000[diff] [blame]919 this, LLVM has the beginnings of a dwarf parsing library.</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]920 <li>llvm-objdump has more output including, symbol by symbol disassembly,
921 inline relocations, section headers, symbol tables, and section contents.
922 Support for archive files has also been added.</li>
923 <li>llvm-nm has gained support for archives of binary files.</li>
924 <li>llvm-size has been added. This tool prints out section sizes.</li>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]925</ul>
926
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]927</div>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]928
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]929<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]930<h3>
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]931<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]932</h3>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]933
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]934<div>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]935
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]936<p>We have put a significant amount of work into the code generator
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]937 infrastructure, which allows us to implement more aggressive algorithms and
938 make it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]939
940<ul>
Chris Lattner1cc489b2011-11-27 22:12:32 +0000[diff] [blame]941<li>XXX: Segmented stacks.</li>
Chris Lattner2f206022011-11-27 22:03:34 +0000[diff] [blame]942<li>LLVM generates substantially better code for indirect gotos due to a new
943 tail duplication pass, which can be a substantial performance win for
944 interpreter loops that use them.</li>
945<li>Exception handling and debug information is now emitted with CFI directives,
946 yielding <a href="http://blog.mozilla.com/respindola/2011/05/12/cfi-directives/">much smaller executables</a> for some C++ applications.
947</li>
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]948
Chris Lattner2f206022011-11-27 22:03:34 +0000[diff] [blame]949<li>The code generator now supports vector "select" operations on vector
950 comparisons, turning them into various optimized code sequences (e.g.
951 using the SSE4/AVX "blend" instructions).</li>
Jakob Stoklund Olesen09e61ca2011-11-28 01:46:19 +0000[diff] [blame]952<li>The SSE execution domain fix pass and the ARM NEON move fix pass have been
Jakob Stoklund Olesen87f95dc2011-11-28 18:03:11 +0000[diff] [blame]953 merged to a target independent execution dependency fix pass. This pass is
954 used to select alternative equivalent opcodes in a way that minimizes
955 execution domain crossings. Closely connected instructions are moved to
956 the same execution domain when possible. Targets can override the
957 <code>getExecutionDomain</code> and <code>setExecutionDomain</code> hooks
958 to use the pass.</li>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]959</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]960</div>
961
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]962<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]963<h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]964<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]965</h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]966
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]967<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]968
969<p>New features and major changes in the X86 target include:</p>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]970
971<ul>
Chris Lattner2f206022011-11-27 22:03:34 +0000[diff] [blame]972<li>The X86 backend, assembler and disassembler now have full support for AVX 1.
973 To enable it pass <code>-mavx</code> to the compiler. AVX2 implementation is
974 underway on mainline.</li>
975<li>The integrated assembler and disassembler now support a broad range of new
976 instructions including Atom, Ivy Bridge, <a
977 href="http://en.wikipedia.org/wiki/SSE4a">SSE4a/BMI</a> instructions, <a
978 href="http://en.wikipedia.org/wiki/RdRand">rdrand</a> and many others.</li>
979<li>The X86 backend now fully supports the <a href="http://llvm.org/PR879">X87
980 floating point stack inline assembly constraints</a>.</li>
981<li>The integrated assembler now supports the <tt>.code32</tt> and
982 <tt>.code64</tt> directives to switch between 32-bit and 64-bit
983 instructions.</li>
984<li>The X86 backend now synthesizes horizontal add/sub instructions from generic
985 vector code when the appropriate instructions are enabled.</li>
986<li>The X86-64 backend generates smaller and faster code at -O0 due to
987 improvements in fast instruction selection.</li>
988<li><a href="http://code.google.com/p/nativeclient/">Native Client</a>
989 subtarget support has been added.</li>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]990
Chris Lattner2f206022011-11-27 22:03:34 +0000[diff] [blame]991<li>The CRC32 intrinsics have been renamed. The intrinsics were previously
992 <code>@llvm.x86.sse42.crc32.[8|16|32]</code>
993 and <code>@llvm.x86.sse42.crc64.[8|64]</code>. They have been renamed to
994 <code>@llvm.x86.sse42.crc32.32.[8|16|32]</code> and
995 <code>@llvm.x86.sse42.crc32.64.[8|64]</code>.</li>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]996</ul>
997
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]998</div>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]999
1000<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1001<h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]1002<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1003</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1004
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1005<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1006
1007<p>New features of the ARM target include:</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1008
1009<ul>
Chris Lattner1cc489b2011-11-27 22:12:32 +0000[diff] [blame]1010<li>The ARM backend generates much faster code for Cortex-A9 chips.</li>
1011<li>The ARM backend has improved support for Cortex-M series processors.</li>
1012<li>The ARM inline assembly constraints have been implemented and are now fully
1013 supported.</li>
1014<li>NEON code produced by Clang often runs much faster due to improvements in
1015 the Scalar Replacement of Aggregates pass.</li>
1016<li>The old ARM disassembler is replaced with a new one based on autogenerated
1017 encoding information from ARM .td files.</li>
1018<li>The integrated assembler has made major leaps forward, but is still beta quality in LLVM 3.0.</li>
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]1019</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]1020</div>
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1021
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1022
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1023<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1024<h3>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1025<a name="MIPS">MIPS Target Improvements</a>
1026</h3>
1027
1028<div>
1029
Chris Lattner1cc489b2011-11-27 22:12:32 +0000[diff] [blame]1030<p>This release has seen major new work on just about every aspect of the MIPS
1031 backend. Some of the major new features include:</p>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1032
1033<ul>
1034 <li>Most MIPS32r1 and r2 instructions are now supported.</li>
1035 <li>LE/BE MIPS32r1/r2 has been tested extensively.</li>
1036 <li>O32 ABI has been fully tested.</li>
1037 <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>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1038 <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>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1039 <li>Support for old-style JIT is complete.</li>
1040 <li>Support for old architectures (MIPS1 and MIPS2) has been removed.</li>
1041 <li>Initial support for MIPS64 has been added.</li>
1042</ul>
1043</div>
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1044
1045<!--=========================================================================-->
1046<h3>
1047 <a name="PTX">PTX Target Improvements</a>
1048</h3>
1049
1050<div>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1051
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1052 <p>
1053 The PTX back-end is still experimental, but is fairly usable for compute kernels
1054 in LLVM 3.0. Most scalar arithmetic is implemented, as well as intrinsics to
1055 access the special PTX registers and sync instructions. The major missing
1056 pieces are texture/sampler support and some vector operations.</p>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1057
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1058 <p>That said, the backend is already being used for domain-specific languages
1059 and works well with the <a href="http://www.pcc.me.uk/~peter/libclc/">libclc
1060 library</a> to supply OpenCL built-ins. With it, you can use Clang to compile
1061 OpenCL code into PTX and execute it by loading the resulting PTX as a binary
1062 blob using the nVidia OpenCL library. It has been tested with several OpenCL
1063 programs, including some from the nVidia GPU Computing SDK, and the performance
1064 is on par with the nVidia compiler.</p>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1065
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1066</div>
1067
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1068<!--=========================================================================-->
1069<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1070<a name="OtherTS">Other Target Specific Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1071</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1072
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1073<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1074
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1075<ul>
Chris Lattnerd6cc2c22011-11-27 22:36:22 +0000[diff] [blame]1076<li>Many PowerPC improvements have been implemented for ELF targets, including
1077 support for varargs and initial support for direct .o file emission.</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1078
Chris Lattnerd6cc2c22011-11-27 22:36:22 +0000[diff] [blame]1079<li>MicroBlaze scheduling itineraries were added that model the
1080 3-stage and the 5-stage pipeline architectures. The 3-stage
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1081 pipeline model can be selected with <code>-mcpu=mblaze3</code>
1082 and the 5-stage pipeline model can be selected with
Chris Lattnerd6cc2c22011-11-27 22:36:22 +0000[diff] [blame]1083 <code>-mcpu=mblaze5</code>.</li>
1084
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1085</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1086
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1087</div>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]1088
1089<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1090<h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1091<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1092</h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1093
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1094<div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1095
Bill Wendling2626dba2011-08-03 22:18:20 +0000[diff] [blame]1096<p>If you're already an LLVM user or developer with out-of-tree changes based on
1097 LLVM 2.9, this section lists some "gotchas" that you may run into upgrading
1098 from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1099
1100<ul>
Chris Lattnerd6cc2c22011-11-27 22:36:22 +0000[diff] [blame]1101<li>LLVM 3.0 removes support for reading LLVM 2.8 and earlier files, and LLVM
1102 3.1 will eliminate support for reading LLVM 2.9 files. Going forward, we
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1103 aim for all future versions of LLVM to read bitcode files and .ll files
Chris Lattnerd6cc2c22011-11-27 22:36:22 +0000[diff] [blame]1104 produced by LLVM 3.0.</li>
1105<li>Tablegen has been split into a library, allowing the clang tblgen pieces
1106 now live in the clang tree. The llvm version has been renamed to
1107 llvm-tblgen instead of tblgen.</li>
Chris Lattner5a1731d2011-11-27 08:32:32 +0000[diff] [blame]1108 <li>The <code>LLVMC</code> meta compiler driver was removed.</li>
Chris Lattnerd6cc2c22011-11-27 22:36:22 +0000[diff] [blame]1109 <li>The unused PostOrder Dominator Frontiers and LowerSetJmp passes were removed.</li>
1110
1111
Rafael Espindolaf940a1a2011-08-30 23:03:45 +0000[diff] [blame]1112 <li>The old <code>TailDup</code> pass was not used in the standard pipeline
1113 and was unable to update ssa form, so it has been removed.
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]1114 <li>The syntax of volatile loads and stores in IR has been changed to
1115 "<code>load volatile</code>"/"<code>store volatile</code>". The old
1116 syntax ("<code>volatile load</code>"/"<code>volatile store</code>")
Chris Lattnerd6cc2c22011-11-27 22:36:22 +0000[diff] [blame]1117 is still accepted, but is now considered deprecated and will be removed in
1118 3.1.</li>
1119 <li>llvm-gcc's frontend tests have been removed from llvm/test/Frontend*, sunk
1120 into the clang and dragonegg testsuites.</li>
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000[diff] [blame]1121 <li>The old atomic intrinsics (<code>llvm.memory.barrier</code> and
Eli Friedman526e1bb2011-10-26 00:55:23 +0000[diff] [blame]1122 <code>llvm.atomic.*</code>) are now gone. Please use the new atomic
1123 instructions, described in the <a href="Atomics.html">atomics guide</a>.
Chris Lattnerd6cc2c22011-11-27 22:36:22 +0000[diff] [blame]1124 <li>LLVM's configure script doesn't depend on llvm-gcc anymore, eliminating a
1125 strange circular dependence between projects.</li>
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]1126</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1127
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1128<h4>Windows (32-bit)</h4>
1129<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1130
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1131<ul>
1132 <li>On Win32(MinGW32 and MSVC), Windows 2000 will not be supported.
1133 Windows XP or higher is required.</li>
1134</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1135
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1136</div>
1137
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1138</div>
1139
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1140<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1141<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1142<a name="api_changes">Internal API Changes</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1143</h3>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1144
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1145<div>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1146
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1147<p>In addition, many APIs have changed in this release. Some of the major
Bill Wendling16005252011-08-02 06:20:17 +0000[diff] [blame]1148 LLVM API changes are:</p>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1149
1150<ul>
Joe Abbey54d3b832011-11-28 22:07:12 +0000[diff] [blame^]1151 <li>The biggest and most pervasive change is that the type system has been
1152 rewritten: <code>PATypeHolder</code> and <code>OpaqueType</code> are gone,
1153 and all APIs deal with <code>Type*</code> instead of <code>const
1154 Type*</code>. If you need to create recursive structures, then create a
1155 named structure, and use <code>setBody()</code> when all its elements are
1156 built. Type merging and refining is gone too: named structures are not
1157 merged with other structures, even if their layout is identical. (of
1158 course anonymous structures are still uniqued by layout).</li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1159
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1160 <li><code>PHINode::reserveOperandSpace</code> has been removed. Instead, you
1161 must specify how many operands to reserve space for when you create the
1162 PHINode, by passing an extra argument
1163 into <code>PHINode::Create</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1164
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1165 <li>PHINodes no longer store their incoming BasicBlocks as operands. Instead,
1166 the list of incoming BasicBlocks is stored separately, and can be accessed
1167 with new functions <code>PHINode::block_begin</code>
1168 and <code>PHINode::block_end</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1169
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1170 <li>Various functions now take an <code>ArrayRef</code> instead of either a
1171 pair of pointers (or iterators) to the beginning and end of a range, or a
1172 pointer and a length. Others now return an <code>ArrayRef</code> instead
1173 of a reference to a <code>SmallVector</code>
1174 or <code>std::vector</code>. These include:
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1175<ul>
1176<!-- Please keep this list sorted. -->
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1177<li><code>CallInst::Create</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1178<li><code>ComputeLinearIndex</code> (in <code>llvm/CodeGen/Analysis.h</code>)</li>
1179<li><code>ConstantArray::get</code></li>
1180<li><code>ConstantExpr::getExtractElement</code></li>
Jay Foaddab3d292011-07-21 14:31:17 +0000[diff] [blame]1181<li><code>ConstantExpr::getGetElementPtr</code></li>
1182<li><code>ConstantExpr::getInBoundsGetElementPtr</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1183<li><code>ConstantExpr::getIndices</code></li>
1184<li><code>ConstantExpr::getInsertElement</code></li>
1185<li><code>ConstantExpr::getWithOperands</code></li>
Jay Foad1d2f5692011-07-19 13:32:40 +0000[diff] [blame]1186<li><code>ConstantFoldCall</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
1187<li><code>ConstantFoldInstOperands</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1188<li><code>ConstantVector::get</code></li>
1189<li><code>DIBuilder::createComplexVariable</code></li>
1190<li><code>DIBuilder::getOrCreateArray</code></li>
1191<li><code>ExtractValueInst::Create</code></li>
1192<li><code>ExtractValueInst::getIndexedType</code></li>
1193<li><code>ExtractValueInst::getIndices</code></li>
1194<li><code>FindInsertedValue</code> (in <code>llvm/Analysis/ValueTracking.h</code>)</li>
Jay Foadca12a212011-07-19 14:42:50 +0000[diff] [blame]1195<li><code>gep_type_begin</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
1196<li><code>gep_type_end</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
Jay Foada9203102011-07-25 09:48:08 +0000[diff] [blame]1197<li><code>GetElementPtrInst::Create</code></li>
1198<li><code>GetElementPtrInst::CreateInBounds</code></li>
1199<li><code>GetElementPtrInst::getIndexedType</code></li>
Jay Foadb60e8512011-07-21 14:42:51 +0000[diff] [blame]1200<li><code>InsertValueInst::Create</code></li>
1201<li><code>InsertValueInst::getIndices</code></li>
1202<li><code>InvokeInst::Create</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1203<li><code>IRBuilder::CreateCall</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1204<li><code>IRBuilder::CreateExtractValue</code></li>
Jay Foad0a2a60a2011-07-22 08:16:57 +0000[diff] [blame]1205<li><code>IRBuilder::CreateGEP</code></li>
1206<li><code>IRBuilder::CreateInBoundsGEP</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1207<li><code>IRBuilder::CreateInsertValue</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1208<li><code>IRBuilder::CreateInvoke</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1209<li><code>MDNode::get</code></li>
1210<li><code>MDNode::getIfExists</code></li>
1211<li><code>MDNode::getTemporary</code></li>
1212<li><code>MDNode::getWhenValsUnresolved</code></li>
Jay Foadb9b54eb2011-07-19 15:07:52 +0000[diff] [blame]1213<li><code>SimplifyGEPInst</code> (in <code>llvm/Analysis/InstructionSimplify.h</code>)</li>
Jay Foad8fbbb392011-07-19 14:01:37 +0000[diff] [blame]1214<li><code>TargetData::getIndexedOffset</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1215</ul></li>
1216
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1217 <li>All forms of <code>StringMap::getOrCreateValue</code> have been remove
1218 except for the one which takes a <code>StringRef</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1219
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1220 <li>The <code>LLVMBuildUnwind</code> function from the C API was removed. The
1221 LLVM <code>unwind</code> instruction has been deprecated for a long time
1222 and isn't used by the current front-ends. So this was removed during the
1223 exception handling rewrite.</li>
Bill Wendling16005252011-08-02 06:20:17 +0000[diff] [blame]1224
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1225 <li>The <code>LLVMAddLowerSetJmpPass</code> function from the C API was
1226 removed because the <code>LowerSetJmp</code> pass was removed.</li>
Bill Wendling2626dba2011-08-03 22:18:20 +0000[diff] [blame]1227
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1228 <li>The <code>DIBuilder</code> interface used by front ends to encode
1229 debugging information in the LLVM IR now expects clients to
1230 use <code>DIBuilder::finalize()</code> at the end of translation unit to
1231 complete debugging information encoding.</li>
Devang Patel6326a422011-08-15 23:00:00 +0000[diff] [blame]1232
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1233 <li>TargetSelect.h moved to Support/ from Target/</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1234
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1235 <li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls (for
1236 example <code>llvm.memset.i32</code>).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1237
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1238 <li>It is mandatory to initialize all out-of-tree passes too and their dependencies now with
1239 <code>INITIALIZE_PASS{BEGIN,END,}</code>
1240 and <code>INITIALIZE_{PASS,AG}_DEPENDENCY</code>.</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1241
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1242 <li>The interface for MemDepResult in MemoryDependenceAnalysis has been
1243 enhanced with new return types Unknown and NonFuncLocal, in addition to
1244 the existing types Clobber, Def, and NonLocal.</li>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1245</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1246
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1247</div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1248
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1249</div>
1250
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1251<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1252<h2>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1253 <a name="knownproblems">Known Problems</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1254</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1255<!-- *********************************************************************** -->
1256
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1257<div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1258
Chris Lattner70e22012011-11-27 19:38:20 +0000[diff] [blame]1259<p>LLVM is generally a production quality compiler, and is used by a broad range
1260 of applications and shipping in many products. That said, not every
1261 subsystem is as mature as the aggregate, particularly the more obscure
1262 targets. If you run into a problem, please check the <a
1263 href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
1264 there isn't already one or ask on the <a
1265 href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev
1266 list</a>.</p>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1267
Chris Lattner70e22012011-11-27 19:38:20 +0000[diff] [blame]1268 <p>Known problem areas include:</p>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1269
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1270<ul>
Chris Lattner70e22012011-11-27 19:38:20 +0000[diff] [blame]1271 <li>The Alpha, Blackfin, CellSPU, MSP430, PTX, SystemZ and
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]1272 XCore backends are experimental, and the Alpha, Blackfin and SystemZ
1273 targets have already been removed from mainline.</li>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1274
Chris Lattner70e22012011-11-27 19:38:20 +0000[diff] [blame]1275 <li>The integrated assembler, disassembler, and JIT is not supported by
1276 several targets. If an integrated assembler is not supported, then a
1277 system assembler is required. For more details, see the <a
1278 href="CodeGenerator.html#targetfeatures">Target Features Matrix</a>.
1279 </li>
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1280
Chris Lattner70e22012011-11-27 19:38:20 +0000[diff] [blame]1281 <li>The C backend has numerous problems and is not being actively maintained.
1282 Depending on it for anything serious is not advised.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1283</ul>
1284
1285</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1286
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1287</div>
1288
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1289<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1290<h2>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1291 <a name="additionalinfo">Additional Information</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1292</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1293<!-- *********************************************************************** -->
1294
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1295<div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1296
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1297<p>A wide variety of additional information is available on
1298 the <a href="http://llvm.org/">LLVM web page</a>, in particular in
1299 the <a href="http://llvm.org/docs/">documentation</a> section. The web page
1300 also contains versions of the API documentation which is up-to-date with the
1301 Subversion version of the source code. You can access versions of these
1302 documents specific to this release by going into the "<tt>llvm/doc/</tt>"
1303 directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1304
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1305<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]1306 us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1307
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1308</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1309
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]1310<!--=========================================================================-->
1311
1312<!-- EH details: to be moved to a blog post:
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]1313
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1314
1315
1316
Chris Lattner1c80fbf2011-11-27 20:51:47 +0000[diff] [blame]1317<p>One of the biggest changes is that 3.0 has a new exception handling
1318 system. The old system used LLVM intrinsics to convey the exception handling
1319 information to the code generator. It worked in most cases, but not
1320 all. Inlining was especially difficult to get right. Also, the intrinsics
1321 could be moved away from the <code>invoke</code> instruction, making it hard
1322 to recover that information.</p>
1323
1324<p>The new EH system makes exception handling a first-class member of the IR. It
1325 adds two new instructions:</p>
1326
1327<ul>
1328 <li><a href="LangRef.html#i_landingpad"><code>landingpad</code></a> &mdash;
1329 this instruction defines a landing pad basic block. It contains all of the
1330 information that's needed by the code generator. It's also required to be
1331 the first non-PHI instruction in the landing pad. In addition, a landing
1332 pad may be jumped to only by the unwind edge of an <code>invoke</code>
1333 instruction.</li>
1334
1335 <li><a href="LangRef.html#i_resume"><code>resume</code></a> &mdash; this
1336 instruction causes the current exception to resume traveling up the
1337 stack. It replaces the <code>@llvm.eh.resume</code> intrinsic.</li>
1338</ul>
1339
1340<p>Converting from the old EH API to the new EH API is rather simple, because a
1341 lot of complexity has been removed. The two intrinsics,
1342 <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code> have been
1343 superseded by the <code>landingpad</code> instruction. Instead of generating
1344 a call to <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code>:
1345
1346<div class="doc_code">
1347<pre>
1348Function *ExcIntr = Intrinsic::getDeclaration(TheModule,
1349 Intrinsic::eh_exception);
1350Function *SlctrIntr = Intrinsic::getDeclaration(TheModule,
1351 Intrinsic::eh_selector);
1352
1353// The exception pointer.
1354Value *ExnPtr = Builder.CreateCall(ExcIntr, "exc_ptr");
1355
1356std::vector&lt;Value*&gt; Args;
1357Args.push_back(ExnPtr);
1358Args.push_back(Builder.CreateBitCast(Personality,
1359 Type::getInt8PtrTy(Context)));
1360
1361<i>// Add selector clauses to Args.</i>
1362
1363// The selector call.
1364Builder.CreateCall(SlctrIntr, Args, "exc_sel");
1365</pre>
1366</div>
1367
1368<p>You should instead generate a <code>landingpad</code> instruction, that
1369 returns an exception object and selector value:</p>
1370
1371<div class="doc_code">
1372<pre>
1373LandingPadInst *LPadInst =
1374 Builder.CreateLandingPad(StructType::get(Int8PtrTy, Int32Ty, NULL),
1375 Personality, 0);
1376
1377Value *LPadExn = Builder.CreateExtractValue(LPadInst, 0);
1378Builder.CreateStore(LPadExn, getExceptionSlot());
1379
1380Value *LPadSel = Builder.CreateExtractValue(LPadInst, 1);
1381Builder.CreateStore(LPadSel, getEHSelectorSlot());
1382</pre>
1383</div>
1384
1385<p>It's now trivial to add the individual clauses to the <code>landingpad</code>
1386 instruction.</p>
1387
1388<div class="doc_code">
1389<pre>
1390<i><b>// Adding a catch clause</b></i>
1391Constant *TypeInfo = getTypeInfo();
1392LPadInst-&gt;addClause(TypeInfo);
1393
1394<i><b>// Adding a C++ catch-all</b></i>
1395LPadInst-&gt;addClause(Constant::getNullValue(Builder.getInt8PtrTy()));
1396
1397<i><b>// Adding a cleanup</b></i>
1398LPadInst-&gt;setCleanup(true);
1399
1400<i><b>// Adding a filter clause</b></i>
1401std::vector&lt;Constant*&gt; TypeInfos;
1402Constant *TypeInfo = getFilterTypeInfo();
1403TypeInfos.push_back(Builder.CreateBitCast(TypeInfo, Builder.getInt8PtrTy()));
1404
1405ArrayType *FilterTy = ArrayType::get(Int8PtrTy, TypeInfos.size());
1406LPadInst-&gt;addClause(ConstantArray::get(FilterTy, TypeInfos));
1407</pre>
1408</div>
1409
1410<p>Converting from using the <code>@llvm.eh.resume</code> intrinsic to
1411 the <code>resume</code> instruction is trivial. It takes the exception
1412 pointer and exception selector values returned by
1413 the <code>landingpad</code> instruction:</p>
1414
1415<div class="doc_code">
1416<pre>
1417Type *UnwindDataTy = StructType::get(Builder.getInt8PtrTy(),
1418 Builder.getInt32Ty(), NULL);
1419Value *UnwindData = UndefValue::get(UnwindDataTy);
1420Value *ExcPtr = Builder.CreateLoad(getExceptionObjSlot());
1421Value *ExcSel = Builder.CreateLoad(getExceptionSelSlot());
1422UnwindData = Builder.CreateInsertValue(UnwindData, ExcPtr, 0, "exc_ptr");
1423UnwindData = Builder.CreateInsertValue(UnwindData, ExcSel, 1, "exc_sel");
1424Builder.CreateResume(UnwindData);
1425</pre>
1426</div>
1427
1428
Michael J. Spencer60f790c2011-11-28 18:20:09 +0000[diff] [blame]1429
1430
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1432
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