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9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +000010
Chad Rosiere6291d02011-05-27 22:50:46 +000011<h1>LLVM 3.0 Release Notes</h1>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +000012
Chris Lattner0e464a92010-03-17 04:02:39 +000013<img align=right src="http://llvm.org/img/DragonSmall.png"
Gabor Greifee2187a2010-04-22 10:21:43 +000014 width="136" height="136" alt="LLVM Dragon Logo">
Chris Lattner0e464a92010-03-17 04:02:39 +000015
Chris Lattner79c3fe12003-10-02 04:57:28 +000016<ol>
Misha Brukman500bc302003-11-22 00:38:41 +000017 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +000018 <li><a href="#subproj">Sub-project Status Update</a></li>
Chad Rosiere6291d02011-05-27 22:50:46 +000019 <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 +000021 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +000022 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +000023 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +000024</ol>
25
Chris Lattner7911ce22004-05-23 21:07:27 +000026<div class="doc_author">
NAKAMURA Takumib9a33632011-04-09 02:13:37 +000027 <p>Written by the <a href="http://llvm.org/">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +000028</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +000029
Chris Lattner49123fd2011-04-06 06:29:50 +000030<!--
Chad Rosiere6291d02011-05-27 22:50:46 +000031<h1 style="color:red">These are in-progress notes for the upcoming LLVM 3.0
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000032release.<br>
33You may prefer the
Chad Rosiere6291d02011-05-27 22:50:46 +000034<a href="http://llvm.org/releases/2.9/docs/ReleaseNotes.html">LLVM 2.9
Dan Gohmanb44f6c62010-05-03 23:51:05 +000035Release Notes</a>.</h1>
Chris Lattner49123fd2011-04-06 06:29:50 +000036 -->
Jeffrey Yasskinbec48772010-01-28 01:14:43 +000037
Chris Lattner79c3fe12003-10-02 04:57:28 +000038<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000039<h2>
Misha Brukman500bc302003-11-22 00:38:41 +000040 <a name="intro">Introduction</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000041</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +000042<!-- *********************************************************************** -->
43
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +000044<div>
Misha Brukman500bc302003-11-22 00:38:41 +000045
Chris Lattnerf6662f92008-10-13 17:57:36 +000046<p>This document contains the release notes for the LLVM Compiler
Bill Wendling7b7fa742011-10-26 18:46:16 +000047 Infrastructure, release 3.0. Here we describe the status of LLVM, including
Chris Lattner1ab8ce92011-11-27 18:47:37 +000048 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 +000050 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 +000052
Chris Lattner7506b1d2004-12-07 08:04:13 +000053<p>For more information about LLVM, including information about the latest
Bill Wendling7b7fa742011-10-26 18:46:16 +000054 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 +000058
Bill Wendling7b7fa742011-10-26 18:46:16 +000059<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 +000063
64</div>
Chris Lattner61358ab2009-10-13 17:48:04 +000065
Chris Lattnere07043c2010-09-29 05:30:03 +000066
Chris Lattner96a445e2008-10-13 18:01:01 +000067<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000068<h2>
Chris Lattner96a445e2008-10-13 18:01:01 +000069 <a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000070</h2>
Chris Lattner96a445e2008-10-13 18:01:01 +000071<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +000072
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +000073<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +000074
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 +000077 supporting tools), and the Clang repository. In
Bill Wendling7b7fa742011-10-26 18:46:16 +000078 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 +000080
Chris Lattner8348b472008-06-08 21:58:17 +000081<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000082<h3>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +000083<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000084</h3>
Chris Lattner8348b472008-06-08 21:58:17 +000085
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +000086<div>
Chris Lattner8348b472008-06-08 21:58:17 +000087
Chris Lattner095539f2010-04-26 17:42:18 +000088<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
Bill Wendling7b7fa742011-10-26 18:46:16 +000089 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 +000095 (32- and 64-bit), and for Darwin/ARM targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +000096
Chad Rosiere6291d02011-05-27 22:50:46 +000097<p>In the LLVM 3.0 time-frame, the Clang team has made many improvements:</p>
Douglas Gregorba087df2011-10-15 00:48:01 +000098
99<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000100 <li>Greatly improved support for building C++ applications, with greater
101 stability and better diagnostics.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000102
Bill Wendling7b7fa742011-10-26 18:46:16 +0000103 <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 +0000105 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 +0000108 operators, among others.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000109
Bill Wendling7b7fa742011-10-26 18:46:16 +0000110 <li>Implemented support for some features of the upcoming C1x standard,
111 including static assertions and generic selections.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000112
Bill Wendling7b7fa742011-10-26 18:46:16 +0000113 <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 +0000115
David Chisnall553284e2011-11-26 10:56:17 +0000116 <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 +0000123 <li>A migration tool for moving manual retain/release code to ARC</li>
David Chisnall553284e2011-11-26 10:56:17 +0000124
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 +0000127 <li>Weak linking support for Objective-C classes</li>
David Chisnall553284e2011-11-26 10:56:17 +0000128 <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 +0000132 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 +0000135
Bill Wendling7b7fa742011-10-26 18:46:16 +0000136 <li>Implemented a number of optimizations in <tt>libclang</tt>, the Clang C
137 interface, to improve the performance of code completion and the mapping
138 from source locations to abstract syntax tree nodes.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000139</ul>
140
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000141
Duncan Sandsf3ba7af2011-04-06 08:07:40 +0000142<p>If Clang rejects your code but another compiler accepts it, please take a
Bill Wendling7b7fa742011-10-26 18:46:16 +0000143 look at the <a href="http://clang.llvm.org/compatibility.html">language
144 compatibility</a> guide to make sure this is not intentional or a known
145 issue.</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000146
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000147</div>
148
149<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000150<h3>
Duncan Sands528a5102011-04-04 11:09:08 +0000151<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000152</h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000153
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000154<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000155<p><a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
156 <a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
Duncan Sands77352c92011-11-10 18:44:29 +0000157 optimizers and code generators with LLVM's. It works with gcc-4.5 or gcc-4.6,
158 targets the x86-32 and x86-64 processor families, and has been successfully
159 used on the Darwin, FreeBSD, KFreeBSD, Linux and OpenBSD platforms. It fully
160 supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C
161 and Obj-C++.</p>
Duncan Sands749fd832010-04-02 09:23:15 +0000162
Bill Wendling7b7fa742011-10-26 18:46:16 +0000163<p>The 3.0 release has the following notable changes:</p>
164
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000165 <ul>
Duncan Sands77352c92011-11-10 18:44:29 +0000166 <li>GCC version 4.6 is now fully supported.</li>
167
168 <li>Patching and building GCC is no longer required: the plugin should work
169 with your system GCC (version 4.5 or 4.6; on Debian/Ubuntu systems the
170 gcc-4.5-plugin-dev or gcc-4.6-plugin-dev package is also needed).</li>
171
172 <li>The <tt>-fplugin-arg-dragonegg-enable-gcc-optzns</tt> option, which runs
173 GCC's optimizers as well as LLVM's, now works much better. This is the
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000174 option to use if you want ultimate performance! It is still experimental
175 though: it may cause the plugin to crash.</li>
Duncan Sands77352c92011-11-10 18:44:29 +0000176
177 <li>The type and constant conversion logic has been almost entirely rewritten,
178 fixing a multitude of obscure bugs.</li>
179
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000180</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000181
182</div>
183
Chris Lattner75547712010-10-03 23:49:06 +0000184<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000185<h3>
Chris Lattner75547712010-10-03 23:49:06 +0000186<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000187</h3>
Chris Lattner75547712010-10-03 23:49:06 +0000188
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000189<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000190
191<p>The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
192 is a simple library that provides an implementation of the low-level
193 target-specific hooks required by code generation and other runtime
194 components. For example, when compiling for a 32-bit target, converting a
195 double to a 64-bit unsigned integer is compiled into a runtime call to the
196 "__fixunsdfdi" function. The compiler-rt library provides highly optimized
197 implementations of this and other low-level routines (some are 3x faster than
198 the equivalent libgcc routines).</p>
Chris Lattner75547712010-10-03 23:49:06 +0000199
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000200<p>In the LLVM 3.0 timeframe, the target specific ARM code has converted to
201 "unified" assembly syntax, and several new functions have been added to the
202 library.</p>
Chris Lattner75547712010-10-03 23:49:06 +0000203
204</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000205
206<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000207<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000208<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000209</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000210
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000211<div>
Chris Lattner9e896712011-11-27 18:53:41 +0000212
213<p>LLDB is a ground-up implementation of a command line debugger, as well as a
214 debugger API that can be used from other applications. LLDB makes use of the
215 Clang parser to provide high-fidelity expression parsing (particularly for
216 C++) and uses the LLVM JIT for target support.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000217
Bill Wendling7b7fa742011-10-26 18:46:16 +0000218<p>LLDB has advanced by leaps and bounds in the 3.0 timeframe. It is
219 dramatically more stable and useful, and includes both a
220 new <a href="http://lldb.llvm.org/tutorial.html">tutorial</a> and
221 a <a href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
222 GDB</a>.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000223
224</div>
225
226<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000227<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000228<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000229</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000230
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000231<div>
Chris Lattnere07043c2010-09-29 05:30:03 +0000232
Bill Wendling7b7fa742011-10-26 18:46:16 +0000233<p>Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
234 licensed</a> under the MIT and UIUC license, allowing it to be used more
235 permissively.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000236
David Chisnall553284e2011-11-26 10:56:17 +0000237<p>Libc++ has been ported to FreeBSD and imported into the base system. It is
238 planned to be the default STL implementation for FreeBSD 10.</p>
239
Chris Lattnere07043c2010-09-29 05:30:03 +0000240</div>
241
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000242<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000243<h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000244<a name="vmkit">VMKit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000245</h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000246
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000247<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000248
Nicolas Geoffray54d5df92011-11-10 23:37:56 +0000249 <p>The <a href="http://vmkit.llvm.org/">VMKit project</a> is an
250 implementation of a Java Virtual Machine (Java VM or JVM) that uses LLVM for
251 static and just-in-time compilation.
252
253 <p>In the LLVM 3.0 time-frame, VMKit has had significant improvements on both
254 runtime and startup performance:</p>
255
256 <ul>
257 <li>Precompilation: by compiling ahead of time a small subset of Java's core
258 library, the startup performance have been highly optimized to the point that
259 running a 'Hello World' program takes less than 30 milliseconds.</li>
260
261 <li>Customization: by customizing virtual methods for individual classes,
262 the VM can statically determine the target of a virtual call, and decide to
263 inline it.</li>
264
265 <li>Inlining: the VM does more inlining than it did before, by allowing more
266 bytecode instructions to be inlined, and thanks to customization. It also
267 inlines GC barriers, and object allocations.</li>
268
269 <li>New exception model: the generated code for a method that does not do
270 any try/catch is not penalized anymore by the eventuality of calling a
271 method that throws an exception. Instead, the method that throws the
272 exception jumps directly to the method that could catch it.</li>
273 </ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000274
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000275</div>
276
Chris Lattner9e896712011-11-27 18:53:41 +0000277
278<!--=========================================================================-->
279<h3>
280<a name="LLBrowse">LLBrowse: IR Browser</a>
281</h3>
282
283<div>
284
285<p><a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
286 LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
287 module and displays its contents as an expandable tree view, facilitating an
288 easy way to inspect types, functions, global variables, or metadata nodes. It
289 is fully cross-platform, being based on the popular wxWidgets GUI
290 toolkit.</p>
291
292</div>
293
294
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000295<!--=========================================================================-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000296<!--
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000297<h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000298<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000299</h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000300
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000301<div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000302<p>
303<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
304programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
305through the application and records state transitions that lead to fault
306states. This allows it to construct testcases that lead to faults and can even
307be used to verify some algorithms.
308</p>
309
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000310<p>UPDATE!</p>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000311</div>-->
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000312
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000313</div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000314
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000315<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000316<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000317 <a name="externalproj">External Open Source Projects Using LLVM 3.0</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000318</h2>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000319<!-- *********************************************************************** -->
320
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000321<div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000322
323<p>An exciting aspect of LLVM is that it is used as an enabling technology for
324 a lot of other language and tools projects. This section lists some of the
Chad Rosiere6291d02011-05-27 22:50:46 +0000325 projects that have already been updated to work with LLVM 3.0.</p>
Chris Lattner75547712010-10-03 23:49:06 +0000326
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000327<!--=========================================================================-->
Bill Wendling7be6bc52011-10-26 00:17:54 +0000328<h3>AddressSanitizer</h3>
329
330<div>
331
332<p><a href="http://code.google.com/p/address-sanitizer/">AddressSanitizer</a>
333 uses compiler instrumentation and a specialized malloc library to find C/C++
334 bugs such as use-after-free and out-of-bound accesses to heap, stack, and
335 globals. The key feature of the tool is speed: the average slowdown
336 introduced by AddressSanitizer is less than 2x.</p>
337
338</div>
339
340<!--=========================================================================-->
Bill Wendling29817ea2011-10-26 00:14:36 +0000341<h3>ClamAV</h3>
342
343<div>
Bill Wendlingf2a78332011-10-25 01:01:42 +0000344
Bill Wendling29817ea2011-10-26 00:14:36 +0000345<p><a href="http://www.clamav.net">Clam AntiVirus</a> is an open source (GPL)
346 anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
347 gateways.</p>
348
349<p>Since version 0.96 it
350 has <a href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
351 signatures</a> that allow writing detections for complex malware.</p>
352
353<p>It uses LLVM's JIT to speed up the execution of bytecode on X86, X86-64,
354 PPC32/64, falling back to its own interpreter otherwise. The git version was
355 updated to work with LLVM 3.0.</p>
356
357</div>
358
359<!--=========================================================================-->
Tobias Grosserae5a6fd2011-11-14 09:09:26 +0000360<h3>clang_complete for VIM</h3>
361
362<div>
363
364<p><a href="https://github.com/Rip-Rip/clang_complete">clang_complete</a> is a
365 VIM plugin, that provides accurate C/C++ autocompletion using the clang front
366 end. The development version of clang complete, can directly use libclang
367 which can maintain a cache to speed up auto completion.</p>
368
369</div>
370
371<!--=========================================================================-->
Bill Wendling65d1f412011-10-26 18:23:06 +0000372<h3>clReflect</h3>
373
374<div>
375
376<p><a href="https://bitbucket.org/dwilliamson/clreflect">clReflect</a> is a C++
377 parser that uses clang/LLVM to derive a light-weight reflection database
378 suitable for use in game development. It comes with a very simple runtime
379 library for loading and querying the database, requiring no external
380 dependencies (including CRT), and an additional utility library for object
381 management and serialisation.</p>
382
383</div>
384
385<!--=========================================================================-->
Bill Wendling63507d12011-10-29 01:10:01 +0000386<h3>Cling C++ Interpreter</h3>
387
388<div>
389
390<p><a href="http://cern.ch/cling">Cling</a> is an interactive compiler interface
391 (aka C++ interpreter). It uses LLVM's JIT and clang; it currently supports
392 C++ and C. It has a prompt interface, runs source files, calls into shared
393 libraries, prints the value of expressions, even does runtime lookup of
394 identifiers (dynamic scopes). And it just behaves like one would expect from
395 an interpreter.</p>
396
397</div>
398
399<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000400<h3>Crack Programming Language</h3>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000401
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000402<div>
Bill Wendling55d6e672011-11-03 20:10:01 +0000403
404<p><a href="http://code.google.com/p/crack-language/">Crack</a> aims to provide
405 the ease of development of a scripting language with the performance of a
406 compiled language. The language derives concepts from C++, Java and Python,
407 incorporating object-oriented programming, operator overloading and strong
408 typing.</p>
409
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000410</div>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000411
412<!--=========================================================================-->
Bill Wendlingb99486f2011-11-08 05:22:54 +0000413<h3>Eero</h3>
414
415<div>
416
417<p><a href="http://eerolanguage.org/">Eero</a> is a fully
418 header-and-binary-compatible dialect of Objective-C 2.0, implemented with a
419 patched version of the Clang/LLVM compiler. It features a streamlined syntax,
420 Python-like indentation, and new operators, for improved readability and
421 reduced code clutter. It also has new features such as limited forms of
422 operator overloading and namespaces, and strict (type-and-operator-safe)
423 enumerations. It is inspired by languages such as Smalltalk, Python, and
424 Ruby.</p>
425
426</div>
427
428<!--=========================================================================-->
Chris Lattneradb417a2011-11-25 20:28:16 +0000429<h3>FAUST Real-Time Audio Signal Processing Language</h3>
430
431<div>
432
433<p><a href="http://faust.grame.fr/">FAUST</a> is a compiled language for
434 real-time audio signal processing. The name FAUST stands for Functional
435 AUdio STream. Its programming model combines two approaches: functional
436 programming and block diagram composition. In addition with the C, C++, Java
437 output formats, the Faust compiler can now generate LLVM bitcode, and works
438 with LLVM 2.7-3.0.
439 </p>
440
441</div>
442
443<!--=========================================================================-->
Bill Wendlingf9778192011-10-26 00:09:55 +0000444<h3>Glasgow Haskell Compiler (GHC)</h3>
445
446<div>
447
448<p>GHC is an open source, state-of-the-art programming suite for Haskell, a
449 standard lazy functional programming language. It includes an optimizing
450 static compiler generating good code for a variety of platforms, together
451 with an interactive system for convenient, quick development.</p>
452
453<p>GHC 7.0 and onwards include an LLVM code generator, supporting LLVM 2.8 and
454 later. Since LLVM 2.9, GHC now includes experimental support for the ARM
455 platform with LLVM 3.0.</p>
456
457</div>
458
459<!--=========================================================================-->
Bill Wendlingf62333d2011-10-25 20:35:31 +0000460<h3>gwXscript</h3>
461
462<div>
463
464<p><a href="http://botwars.tk/gwscript/">gwXscript</a> is an object oriented,
Bill Wendling7c38de22011-10-26 04:24:15 +0000465 aspect oriented programming language which can create both executables (ELF,
Bill Wendlingf62333d2011-10-25 20:35:31 +0000466 EXE) and shared libraries (DLL, SO, DYNLIB). The compiler is implemented in
467 its own language and translates scripts into LLVM-IR which can be optimized
468 and translated into native code by the LLVM framework. Source code in
469 gwScript contains definitions that expand the namespaces. So you can build
470 your project and simply 'plug out' features by removing a file. The remaining
471 project does not leave scars since you directly separate concerns by the
472 'template' feature of gwX. It is also possible to add new features to a
473 project by just adding files and without editing the original project. This
474 language is used for example to create games or content management systems
475 that should be extendable.</p>
476
477<p>gwXscript is strongly typed and offers comfort with its native types string,
478 hash and array. You can easily write new libraries in gwXscript or native
479 code. gwXscript is type safe and users should not be able to crash your
480 program or execute malicious code except code that is eating CPU time.</p>
481
482</div>
483
484<!--=========================================================================-->
Bill Wendling50cacc82011-10-26 22:55:18 +0000485<h3>include-what-you-use</h3>
486
487<div>
488
489<p><a href="http://code.google.com/p/include-what-you-use">include-what-you-use</a>
490 is a tool to ensure that a file directly <code>#include</code>s
491 all <code>.h</code> files that provide a symbol that the file uses. It also
492 removes superfluous <code>#include</code>s from source files.</p>
493
494</div>
495
496<!--=========================================================================-->
Bill Wendling32dc4d92011-11-07 22:05:17 +0000497<h3>ispc: The Intel SPMD Program Compiler</h3>
498
499<div>
500
501<p><a href="http://ispc.github.com">ispc</a> is a compiler for "single program,
502 multiple data" (SPMD) programs. It compiles a C-based SPMD programming
503 language to run on the SIMD units of CPUs; it often delivers 5-6x speedups on
504 a single core of a CPU with an 8-wide SIMD unit compared to serial code,
505 while still providing a clean and easy-to-understand programming model. For
506 an introduction to the language and its performance,
Chris Lattnerc343e312011-11-10 20:15:40 +0000507 see <a href="http://ispc.github.com/example.html">the walkthrough</a> of a short
Bill Wendling32dc4d92011-11-07 22:05:17 +0000508 example program. ispc is licensed under the BSD license.</p>
509
510</div>
Chris Lattnercc089772011-11-25 20:36:17 +0000511
512<!--=========================================================================-->
513<h3>The Julia Programming Language</h3>
514
515<div>
516
517<p><a href="http://github.com/JuliaLang/julia">Julia</a> is a high-level,
518 high-performance dynamic language for technical
519 computing. It provides a sophisticated compiler, distributed parallel
520 execution, numerical accuracy, and an extensive mathematical function
521 library. The compiler uses type inference to generate fast code
522 without any type declarations, and uses LLVM's optimization passes and
523 JIT compiler. The language is designed around multiple dispatch,
524 giving programs a large degree of flexibility. It is ready for use on many
525 kinds of problems.</p>
526</div>
Bill Wendling32dc4d92011-11-07 22:05:17 +0000527
528<!--=========================================================================-->
Bill Wendling57fd8762011-10-26 18:20:54 +0000529<h3>LanguageKit and Pragmatic Smalltalk</h3>
530
531<div>
532
533<p><a href="http://etoileos.com/etoile/features/languagekit/">LanguageKit</a> is
534 a framework for implementing dynamic languages sharing an object model with
535 Objective-C. It provides static and JIT compilation using LLVM along with
536 its own interpreter. Pragmatic Smalltalk is a dialect of Smalltalk, built on
537 top of LanguageKit, that interfaces directly with Objective-C, sharing the
538 same object representation and message sending behaviour. These projects are
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000539 developed as part of the &Eacute;toil&eacute; desktop environment.</p>
Bill Wendling57fd8762011-10-26 18:20:54 +0000540
541</div>
542
543<!--=========================================================================-->
Bill Wendling03250532011-11-01 04:08:23 +0000544<h3>LuaAV</h3>
545
546<div>
547
548<p><a href="http://lua-av.mat.ucsb.edu/blog/">LuaAV</a> is a real-time
549 audiovisual scripting environment based around the Lua language and a
550 collection of libraries for sound, graphics, and other media protocols. LuaAV
551 uses LLVM and Clang to JIT compile efficient user-defined audio synthesis
552 routines specified in a declarative syntax.</p>
553
554</div>
555
556<!--=========================================================================-->
Bill Wendlingd4821b82011-10-26 00:16:17 +0000557<h3>Mono</h3>
558
559<div>
560
561<p>An open source, cross-platform implementation of C# and the CLR that is
562 binary compatible with Microsoft.NET. Has an optional, dynamically-loaded
563 LLVM code generation backend in Mini, the JIT compiler.</p>
564
565<p>Note that we use a Git mirror of LLVM with some patches. See:
566 https://github.com/mono/llvm</p>
567
568</div>
569
570<!--=========================================================================-->
Tobias Grosser093cb7e2011-11-14 09:09:23 +0000571<h3>Polly</h3>
572
573<div>
574
575<p><a href="http://polly.grosser.es">Polly</a> is an advanced data-locality
576 optimizer and automatic parallelizer. It uses an advanced, mathematical
577 model to calculate detailed data dependency information which it uses to
578 optimize the loop structure of a program. Polly can speed up sequential code
579 by improving memory locality and consequently the cache use. Furthermore,
580 Polly is able to expose different kind of parallelism which it exploits by
581 introducing (basic) OpenMP and SIMD code. A mid-term goal of Polly is to
582 automatically create optimized GPU code.</p>
583
584</div>
585
586<!--=========================================================================-->
Bill Wendlingba226272011-10-25 20:37:45 +0000587<h3>Portable OpenCL (pocl)</h3>
588
589<div>
590
591<p>Portable OpenCL is an open source implementation of the OpenCL standard which
592 can be easily adapted for new targets. One of the goals of the project is
593 improving performance portability of OpenCL programs, avoiding the need for
594 target-dependent manual optimizations. A "native" target is included, which
595 allows running OpenCL kernels on the host (CPU).</p>
596
597</div>
598
599<!--=========================================================================-->
Bill Wendling0bad98c2011-10-25 20:39:06 +0000600<h3>Pure</h3>
601
602<div>
603<p><a href="http://pure-lang.googlecode.com/">Pure</a> is an
604 algebraic/functional programming language based on term rewriting. Programs
605 are collections of equations which are used to evaluate expressions in a
606 symbolic fashion. The interpreter uses LLVM as a backend to JIT-compile Pure
607 programs to fast native code. Pure offers dynamic typing, eager and lazy
608 evaluation, lexical closures, a hygienic macro system (also based on term
609 rewriting), built-in list and matrix support (including list and matrix
610 comprehensions) and an easy-to-use interface to C and other programming
611 languages (including the ability to load LLVM bitcode modules, and inline C,
612 C++, Fortran and Faust code in Pure programs if the corresponding LLVM-enabled
613 compilers are installed).</p>
614
615<p>Pure version 0.48 has been tested and is known to work with LLVM 3.0
616 (and continues to work with older LLVM releases &gt;= 2.5).</p>
617
618</div>
619
620<!--=========================================================================-->
Bill Wendling537d85b2011-10-26 00:12:04 +0000621<h3>Renderscript</h3>
622
623<div>
624
625<p><a href="http://developer.android.com/guide/topics/renderscript/index.html">Renderscript</a>
626 is Android's advanced 3D graphics rendering and compute API. It provides a
627 portable C99-based language with extensions to facilitate common use cases
628 for enhancing graphics and thread level parallelism. The Renderscript
629 compiler frontend is based on Clang/LLVM. It emits a portable bitcode format
630 for the actual compiled script code, as well as reflects a Java interface for
631 developers to control the execution of the compiled bitcode. Executable
632 machine code is then generated from this bitcode by an LLVM backend on the
633 device. Renderscript is thus able to provide a mechanism by which Android
634 developers can improve performance of their applications while retaining
635 portability.</p>
636
637</div>
638
639<!--=========================================================================-->
Bill Wendling7d5b6212011-10-25 20:40:26 +0000640<h3>SAFECode</h3>
641
642<div>
643
644<p><a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C/C++
645 compiler built using LLVM. It takes standard, unannotated C/C++ code,
646 analyzes the code to ensure that memory accesses and array indexing
647 operations are safe, and instruments the code with run-time checks when
648 safety cannot be proven statically. SAFECode can be used as a debugging aid
649 (like Valgrind) to find and repair memory safety bugs. It can also be used
650 to protect code from security attacks at run-time.</p>
651
652</div>
653
654<!--=========================================================================-->
Bill Wendling02b77b72011-10-26 07:38:19 +0000655<h3>The Stupid D Compiler (SDC)</h3>
656
657<div>
658
659<p><a href="https://github.com/bhelyer/SDC">The Stupid D Compiler</a> is a
660 project seeking to write a self-hosting compiler for the D programming
661 language without using the frontend of the reference compiler (DMD).</p>
662
663</div>
664
665<!--=========================================================================-->
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000666<h3>TTA-based Co-design Environment (TCE)</h3>
667
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000668<div>
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000669
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000670<p>TCE is a toolset for designing application-specific processors (ASP) based on
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000671 the Transport triggered architecture (TTA). The toolset provides a complete
672 co-design flow from C/C++ programs down to synthesizable VHDL and parallel
673 program binaries. Processor customization points include the register files,
674 function units, supported operations, and the interconnection network.</p>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000675
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000676<p>TCE uses Clang and LLVM for C/C++ language support, target independent
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000677 optimizations and also for parts of code generation. It generates new
Bill Wendling7b7fa742011-10-26 18:46:16 +0000678 LLVM-based code generators "on the fly" for the designed TTA processors and
679 loads them in to the compiler backend as runtime libraries to avoid
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000680 per-target recompilation of larger parts of the compiler chain.</p>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000681
Bill Wendling7b7fa742011-10-26 18:46:16 +0000682</div>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000683
684<!--=========================================================================-->
Bill Wendling628c2662011-10-25 20:27:37 +0000685<h3>Tart Programming Language</h3>
686
687<div>
688
689<p><a href="http://code.google.com/p/tart/">Tart</a> is a general-purpose,
690 strongly typed programming language designed for application
691 developers. Strongly inspired by Python and C#, Tart focuses on practical
692 solutions for the professional software developer, while avoiding the clutter
693 and boilerplate of legacy languages like Java and C++. Although Tart is still
694 in development, the current implementation supports many features expected of
695 a modern programming language, such as garbage collection, powerful
696 bidirectional type inference, a greatly simplified syntax for template
697 metaprogramming, closures and function literals, reflection, operator
698 overloading, explicit mutability and immutability, and much more. Tart is
699 flexible enough to accommodate a broad range of programming styles and
700 philosophies, while maintaining a strong commitment to simplicity, minimalism
701 and elegance in design.</p>
702
703</div>
704
705<!--=========================================================================-->
Bill Wendling644ce532011-10-26 09:25:01 +0000706<h3>ThreadSanitizer</h3>
707
708<div>
709
710<p><a href="http://code.google.com/p/data-race-test/">ThreadSanitizer</a> is a
711 data race detector for (mostly) C and C++ code, available for Linux, Mac OS
712 and Windows. On different systems, we use binary instrumentation frameworks
Bill Wendlingae8538e2011-10-29 01:11:15 +0000713 (Valgrind and Pin) as frontends that generate the program events for the race
714 detection algorithm. On Linux, there's an option of using LLVM-based
715 compile-time instrumentation.</p>
Bill Wendling644ce532011-10-26 09:25:01 +0000716
717</div>
718
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000719</div>
720
Chris Lattner8348b472008-06-08 21:58:17 +0000721<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000722<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000723 <a name="whatsnew">What's New in LLVM 3.0?</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000724</h2>
Chris Lattner8348b472008-06-08 21:58:17 +0000725<!-- *********************************************************************** -->
726
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000727<div>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000728
Chris Lattner61358ab2009-10-13 17:48:04 +0000729<p>This release includes a huge number of bug fixes, performance tweaks and
Bill Wendling7b7fa742011-10-26 18:46:16 +0000730 minor improvements. Some of the major improvements and new features are
731 listed in this section.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000732
Chris Lattner914ce462010-04-22 06:28:20 +0000733<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000734<h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000735<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000736</h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000737
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000738<div>
Chris Lattner252b83d2008-02-06 18:00:06 +0000739
Chris Lattner1ab8ce92011-11-27 18:47:37 +0000740 <!-- Features that need text if they're finished for 3.1:
741 ARM EHABI
742 combiner-aa?
743 strong phi elim
744 loop dependence analysis
745 CorrelatedValuePropagation
746 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
747 -->
748
Chris Lattner5a1731d2011-11-27 08:32:32 +0000749<p><b>llvm-gcc is gone</b>. LLVM's configure script doesn't depend on llvm-gcc anymore, clean layering.</p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000750
Chris Lattnerc343e312011-11-10 20:15:40 +0000751<p>LLVM 3.0 includes several major new capabilities:</p>
752
Chris Lattnerdec23b62011-11-15 22:13:27 +0000753<!-- Near dead:
754 Analysis/RegionInfo.h + Dom Frontiers
755 SparseBitVector: used in LiveVar.
Chris Lattner5a1731d2011-11-27 08:32:32 +0000756 llvm/lib/Archive - replace with lib object?
Chris Lattnerdec23b62011-11-15 22:13:27 +0000757 -->
758
759<!--
Chris Lattner5130d4e2011-11-27 05:47:57 +0000760 Type system rewrite: http://blog.llvm.org/2011/11/llvm-30-type-system-rewrite.html
Chris Lattnerdec23b62011-11-15 22:13:27 +0000761 Better performance for Neon code in clang due to SRoA improvements.
762 New regalloc on by default. Lin scan going away in 3.1
763 PGO / builtin_expect improvements (summary needed)
764 Big EH rewrite.
765 AVX support, assembler, compiler and disassembler.
766 IndVar improvements: andy
767 PTX backend improvements: Justin
768 llvm-rtdyld & MC JIT: JimG
769 InstAliases now automatically used in the asmprinter where they are shorter.
770 Integrated assembler on by default for arm/thumb?
771 PostOrder Dominator frontiers were removed.
772 Line Profiling / gcov support
773 EH and debug information produced with CFI directives, yielding smaller executables: http://blog.mozilla.com/respindola/2011/05/12/cfi-directives/
774 X86-64 generates smaller and faster code at -O0 (fast isel improvements)
775 Better code generation for Cortex-A9
776 Many APIs take ArrayRef's now.
777 Pass manager extension API.
Chris Lattner5130d4e2011-11-27 05:47:57 +0000778 ARM inline asm constraints implemented.
779 LangRef.html#fnattrs uwtable attribute for asynch unwind tables.
780 better performance for indirect gotos.
781 llvm.prefetch now takes a 4th argument that specifies whether the prefetch happens to the icache or dcache.
782 New PackedVector, TinyPtrVector class (see Programmer's Manual)
783 New nonlazybind function attribute.
784 ARC language specific optimizer (Transforms/ObjCARC) a decent example of language-specific transformation.
Chris Lattnerfbe910e2011-11-27 06:56:53 +0000785 LLVM 3.0 removes support for reading LLVM 2.8 and earlier files. Aim to maintain compatibility all the way back to 3.0 "forever".
Chris Lattner6a007d12011-11-25 20:33:27 +0000786
Chris Lattner5130d4e2011-11-27 05:47:57 +0000787 New llvm.expect intrinsic.
788 Table generated MC expansion logic for pseudo instructions that expand to multiple MC instructions through the PseudoInstExpansion class. (JimG)
789 New llvm.fma intrinsic.
790
791 Euro dev meeting and main one too.
Chris Lattnerf51572a2011-11-27 07:37:53 +0000792 New atomics instructions, "#i_fence" instruction, cmpxchg, atomicrmw too. What target support (X86/ARM)? Also 'atomic load/store'. See Atomics.html
Chris Lattner5130d4e2011-11-27 05:47:57 +0000793 X86: inline assembler supports .code32 and .code64.
Chris Lattner8ddff912011-11-27 06:24:49 +0000794 Exception handling rewrite: new landingpad and resume instruction. Unwind gone.
795 LowerSetJmp pass removed, unused.
Chris Lattner5a1731d2011-11-27 08:32:32 +0000796 llvm-objdump / dwarf parser library / llvm-dwarfdump (d0k)
797 object file parsing stuff and llvm-size (mspencer)
798 llvm-cov (devang)
Chris Lattner8ddff912011-11-27 06:24:49 +0000799 Old arm disassembler replaced with a new one based on autogenerated encoding information from ARM .td files.
Chris Lattnerf51572a2011-11-27 07:37:53 +0000800 Frontend tests removed from llvm/test/Frontend* (was this completed for 3.0?)
801 Segmented stack support (X86 only?) Rafael and Sanjoy Das: docs/SegmentedStacks.html should be in CodeGen.html status table?
802 X86 backend support for NaCl (David Meyer / Nick L)
803 Codegen now supports vector "select" operations on vector comparisons, turning
804 them into various optimized code sequences (e.g. using the SSE4/AVX "blend"
805 instructions).
Chris Lattner5a1731d2011-11-27 08:32:32 +0000806 #line directives in integrated assembler
807 SSE domain fixing code enabled for AVX (Bruno/Jakob). Domain fixing pass is
808 now target independent (ExecutionDepsFix pass). (Jakob)
809 X86 backend synthesizes horizontal add/sub instructions from generic code.
810 returns_twice attribute (rafael)
811 Tablegen has been split into a library, clang tblgen pieces now live in clang.
812 The llvm version is now named llvm-tblgen instead of tblgen.
813 X86: Tons of encoding improvements and new instructions (e.g. Atom, Ivy Bridge,
814 and BMI instructions)
815 added to assembler and disassembler (Craig Topper)
816 data layout string can encode the natural alignment of the target's stack for better optimization (LangRef.html#datalayout)
Chris Lattnerdec23b62011-11-15 22:13:27 +0000817 -->
818
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000819<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000820
Chad Rosiere6291d02011-05-27 22:50:46 +0000821<!--
822<li></li>
823-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000824
Chris Lattner8170c102008-02-10 08:18:42 +0000825</ul>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000826
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000827</div>
828
Chris Lattner84977642007-09-21 03:54:09 +0000829<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000830<h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000831<a name="coreimprovements">LLVM IR and Core Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000832</h3>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000833
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000834<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000835
Chris Lattner61358ab2009-10-13 17:48:04 +0000836<p>LLVM IR has several new features for better support of new targets and that
Bill Wendling7b7fa742011-10-26 18:46:16 +0000837 expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000838
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000839<p>One of the biggest changes is that 3.0 has a new exception handling
840 system. The old system used LLVM intrinsics to convey the exception handling
841 information to the code generator. It worked in most cases, but not
842 all. Inlining was especially difficult to get right. Also, the intrinsics
843 could be moved away from the <code>invoke</code> instruction, making it hard
844 to recover that information.</p>
845
846<p>The new EH system makes exception handling a first-class member of the IR. It
847 adds two new instructions:</p>
848
Chris Lattner791f77b2008-06-05 06:25:56 +0000849<ul>
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000850 <li><a href="LangRef.html#i_landingpad"><code>landingpad</code></a> &mdash;
851 this instruction defines a landing pad basic block. It contains all of the
852 information that's needed by the code generator. It's also required to be
853 the first non-PHI instruction in the landing pad. In addition, a landing
854 pad may be jumped to only by the unwind edge of an <code>invoke</code>
855 instruction.</li>
856
857 <li><a href="LangRef.html#i_resume"><code>resume</code></a> &mdash; this
858 instruction causes the current exception to resume traveling up the
859 stack. It replaces the <code>@llvm.eh.resume</code> intrinsic.</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000860</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000861
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000862<p>Converting from the old EH API to the new EH API is rather simple, because a
863 lot of complexity has been removed. The two intrinsics,
864 <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code> have been
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000865 superseded by the <code>landingpad</code> instruction. Instead of generating
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000866 a call to <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code>:
867
868<div class="doc_code">
869<pre>
870Function *ExcIntr = Intrinsic::getDeclaration(TheModule,
871 Intrinsic::eh_exception);
872Function *SlctrIntr = Intrinsic::getDeclaration(TheModule,
873 Intrinsic::eh_selector);
874
875// The exception pointer.
876Value *ExnPtr = Builder.CreateCall(ExcIntr, "exc_ptr");
877
878std::vector&lt;Value*&gt; Args;
879Args.push_back(ExnPtr);
880Args.push_back(Builder.CreateBitCast(Personality,
881 Type::getInt8PtrTy(Context)));
882
883<i>// Add selector clauses to Args.</i>
884
885// The selector call.
886Builder.CreateCall(SlctrIntr, Args, "exc_sel");
887</pre>
888</div>
889
890<p>You should instead generate a <code>landingpad</code> instruction, that
891 returns an exception object and selector value:</p>
892
893<div class="doc_code">
894<pre>
895LandingPadInst *LPadInst =
896 Builder.CreateLandingPad(StructType::get(Int8PtrTy, Int32Ty, NULL),
897 Personality, 0);
898
899Value *LPadExn = Builder.CreateExtractValue(LPadInst, 0);
900Builder.CreateStore(LPadExn, getExceptionSlot());
901
902Value *LPadSel = Builder.CreateExtractValue(LPadInst, 1);
903Builder.CreateStore(LPadSel, getEHSelectorSlot());
904</pre>
905</div>
906
907<p>It's now trivial to add the individual clauses to the <code>landingpad</code>
908 instruction.</p>
909
910<div class="doc_code">
911<pre>
912<i><b>// Adding a catch clause</b></i>
913Constant *TypeInfo = getTypeInfo();
914LPadInst-&gt;addClause(TypeInfo);
915
916<i><b>// Adding a C++ catch-all</b></i>
917LPadInst-&gt;addClause(Constant::getNullValue(Builder.getInt8PtrTy()));
918
919<i><b>// Adding a cleanup</b></i>
920LPadInst-&gt;setCleanup(true);
921
922<i><b>// Adding a filter clause</b></i>
923std::vector&lt;Constant*&gt; TypeInfos;
924Constant *TypeInfo = getFilterTypeInfo();
925TypeInfos.push_back(Builder.CreateBitCast(TypeInfo, Builder.getInt8PtrTy()));
926
927ArrayType *FilterTy = ArrayType::get(Int8PtrTy, TypeInfos.size());
928LPadInst-&gt;addClause(ConstantArray::get(FilterTy, TypeInfos));
929</pre>
930</div>
931
932<p>Converting from using the <code>@llvm.eh.resume</code> intrinsic to
933 the <code>resume</code> instruction is trivial. It takes the exception
934 pointer and exception selector values returned by
935 the <code>landingpad</code> instruction:</p>
936
937<div class="doc_code">
938<pre>
939Type *UnwindDataTy = StructType::get(Builder.getInt8PtrTy(),
940 Builder.getInt32Ty(), NULL);
941Value *UnwindData = UndefValue::get(UnwindDataTy);
942Value *ExcPtr = Builder.CreateLoad(getExceptionObjSlot());
943Value *ExcSel = Builder.CreateLoad(getExceptionSelSlot());
944UnwindData = Builder.CreateInsertValue(UnwindData, ExcPtr, 0, "exc_ptr");
945UnwindData = Builder.CreateInsertValue(UnwindData, ExcSel, 1, "exc_sel");
946Builder.CreateResume(UnwindData);
947</pre>
948</div>
949
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000950</div>
951
952<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000953<h3>
Andrew Trick5aab6382011-11-06 17:59:24 +0000954<a name="loopoptimization">Loop Optimization Improvements</a>
955</h3>
956
957<div>
958<p>The induction variable simplification pass in 3.0 only modifies
959 induction variables when profitable. Sign and zero extension
960 elimination, linear function test replacement, loop unrolling, and
961 other simplifications that require induction variable analysis have
962 been generalized so they no longer require loops to be rewritten in a
963 typically suboptimal form prior to optimization. This new design
964 preserves more IR level information, avoids undoing earlier loop
965 optimizations (particularly hand-optimized loops), and no longer
966 strongly depends on the code generator rewriting loops a second time
967 in a now optimal form--an intractable problem.</p>
968
969<p>The original behavior can be restored with -mllvm -enable-iv-rewrite;
970 however, support for this mode will be short lived. As such, bug
971 reports should be filed for any significant performance regressions
972 when moving from -mllvm -enable-iv-rewrite to the 3.0 default mode.</p>
973</div>
974
975<!--=========================================================================-->
976<h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000977<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000978</h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000979
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000980<div>
Chris Lattneracce85d2008-02-10 07:46:44 +0000981
Chris Lattner61358ab2009-10-13 17:48:04 +0000982<p>In addition to a large array of minor performance tweaks and bug fixes, this
Bill Wendling7b7fa742011-10-26 18:46:16 +0000983 release includes a few major enhancements and additions to the
984 optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000985
986<ul>
Benjamin Kramer933a78c2011-11-26 11:14:54 +0000987<li>Information about <a href="BranchWeightMetadata.html">branch probability</a>
988 and basic block frequency is now available within LLVM, based on a
989 combination of static branch prediction heuristics and
990 <code>__builtin_expect</code> calls. That information is currently used for
991 register spill placement and if-conversion, with additional optimizations
992 planned for future releases. The same framework is intended for eventual
993 use with profile-guided optimization.</li>
Chris Lattnerc5ac61d2011-04-06 05:50:04 +0000994</li>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000995
Chris Lattner11b66112010-10-04 02:42:39 +0000996</ul>
997
Chris Lattner61358ab2009-10-13 17:48:04 +0000998</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000999
Chris Lattner0b832202008-06-08 02:45:07 +00001000<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001001<h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +00001002<a name="mc">MC Level Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001003</h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +00001004
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001005<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001006
1007<p>The LLVM Machine Code (aka MC) subsystem was created to solve a number of
1008 problems in the realm of assembly, disassembly, object file format handling,
1009 and a number of other related areas that CPU instruction-set level tools work
1010 in.</p>
Chris Lattner7d9b6b42010-10-02 21:59:30 +00001011
Chris Lattner7d9b6b42010-10-02 21:59:30 +00001012<ul>
Jim Grosbach2552de02011-11-24 00:49:21 +00001013 <li>The ELF object streamers are much more full featured.</li>
1014 <li>Target dependent relocation handling has been refactored into the Targets.</li>
1015 <li>Early stage MC-JIT infrastructure has been implemented.</li>
Chris Lattner7d9b6b42010-10-02 21:59:30 +00001016</ul>
1017
Jim Grosbach2552de02011-11-24 00:49:21 +00001018<p>The MC-JIT is a major new feature for MC, and will eventually grow to replace
1019the current JIT implementation. It emits object files direct to memory and
1020uses a runtime dynamic linker to resolve references and drive lazy compilation.
1021The MC-JIT enables much greater code reuse between the JIT and the static
1022compiler and provides better integration with the platform ABI as a result.</p>
1023
Bill Wendling7b7fa742011-10-26 18:46:16 +00001024<p>For more information, please see
1025 the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro
1026 to the LLVM MC Project Blog Post</a>.</p>
Chris Lattner4ba2b652010-09-30 16:31:33 +00001027
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +00001028</div>
Chris Lattner4ba2b652010-09-30 16:31:33 +00001029
Chris Lattner4ba2b652010-09-30 16:31:33 +00001030<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001031<h3>
Chris Lattner511433e2009-03-02 03:24:11 +00001032<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001033</h3>
Chris Lattner0b832202008-06-08 02:45:07 +00001034
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001035<div>
Chris Lattner0b832202008-06-08 02:45:07 +00001036
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +00001037<p>We have put a significant amount of work into the code generator
Bill Wendling7b7fa742011-10-26 18:46:16 +00001038 infrastructure, which allows us to implement more aggressive algorithms and
1039 make it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +00001040
1041<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +00001042<!--
1043<li></li>
1044-->
Chris Lattner84977642007-09-21 03:54:09 +00001045</ul>
Chris Lattner84977642007-09-21 03:54:09 +00001046</div>
1047
Chris Lattner917cc712009-03-02 02:37:32 +00001048<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001049<h3>
Chris Lattner917cc712009-03-02 02:37:32 +00001050<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001051</h3>
Chris Lattner917cc712009-03-02 02:37:32 +00001052
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001053<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001054
1055<p>New features and major changes in the X86 target include:</p>
Chris Lattner917cc712009-03-02 02:37:32 +00001056
1057<ul>
Benjamin Kramer933a78c2011-11-26 11:14:54 +00001058 <li>The X86 backend, assembler and disassembler now completely support AVX.
1059 To enable it pass <code>-mavx</code> to the compiler.</li>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001060
Chris Lattner62f009a2011-11-15 22:48:24 +00001061 <li>The X86 backend now supports
1062 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
1063 floating point stack</a>.</li>
1064
Bill Wendling7b7fa742011-10-26 18:46:16 +00001065 <li>The CRC32 intrinsics have been renamed. The intrinsics were previously
1066 <code>@llvm.x86.sse42.crc32.[8|16|32]</code>
1067 and <code>@llvm.x86.sse42.crc64.[8|64]</code>. They have been renamed to
1068 <code>@llvm.x86.sse42.crc32.32.[8|16|32]</code> and
1069 <code>@llvm.x86.sse42.crc32.64.[8|64]</code>.</li>
Chad Rosierf94c9c12011-05-27 20:13:10 +00001070
Chris Lattner917cc712009-03-02 02:37:32 +00001071</ul>
1072
Chris Lattner917cc712009-03-02 02:37:32 +00001073</div>
Chris Lattner84977642007-09-21 03:54:09 +00001074
1075<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001076<h3>
Chris Lattner61358ab2009-10-13 17:48:04 +00001077<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001078</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +00001079
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001080<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001081
1082<p>New features of the ARM target include:</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +00001083
1084<ul>
Jim Grosbach2552de02011-11-24 00:49:21 +00001085 <li>Reworked Set Jump Long Jump EH Lowering,</li>
1086 <li>improved support for Cortex-M series processors, and</li>
1087 <li>beta quality integrated assembler support.</li>
Bob Wilsone8472772010-09-13 17:39:35 +00001088</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +00001089</div>
Chris Lattner7b95c382011-11-15 22:23:46 +00001090
Chris Lattner1efe27e2011-04-06 00:45:11 +00001091
1092<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001093<h3>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +00001094<a name="MIPS">MIPS Target Improvements</a>
1095</h3>
1096
1097<div>
1098
1099<p>New features and major changes in the MIPS target include:</p>
1100
1101<ul>
1102 <li>Most MIPS32r1 and r2 instructions are now supported.</li>
1103 <li>LE/BE MIPS32r1/r2 has been tested extensively.</li>
1104 <li>O32 ABI has been fully tested.</li>
1105 <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>
1106 <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>
1107 <li>Support for old-style JIT is complete.</li>
1108 <li>Support for old architectures (MIPS1 and MIPS2) has been removed.</li>
1109 <li>Initial support for MIPS64 has been added.</li>
1110</ul>
1111</div>
Chris Lattner7b95c382011-11-15 22:23:46 +00001112
1113<!--=========================================================================-->
1114<h3>
1115 <a name="PTX">PTX Target Improvements</a>
1116</h3>
1117
1118<div>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +00001119
Chris Lattner7b95c382011-11-15 22:23:46 +00001120 <p>
1121 The PTX back-end is still experimental, but is fairly usable for compute kernels
1122 in LLVM 3.0. Most scalar arithmetic is implemented, as well as intrinsics to
1123 access the special PTX registers and sync instructions. The major missing
1124 pieces are texture/sampler support and some vector operations.</p>
1125
1126 <p>That said, the backend is already being used for domain-specific languages
1127 and works well with the <a href="http://www.pcc.me.uk/~peter/libclc/">libclc
1128 library</a> to supply OpenCL built-ins. With it, you can use Clang to compile
1129 OpenCL code into PTX and execute it by loading the resulting PTX as a binary
1130 blob using the nVidia OpenCL library. It has been tested with several OpenCL
1131 programs, including some from the nVidia GPU Computing SDK, and the performance
1132 is on par with the nVidia compiler.</p>
1133
1134</div>
1135
Akira Hatanaka5381cbf2011-11-15 21:33:05 +00001136<!--=========================================================================-->
1137<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +00001138<a name="OtherTS">Other Target Specific Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001139</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +00001140
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001141<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001142
Chris Lattnerc343e312011-11-10 20:15:40 +00001143 <p>PPC32/ELF va_arg was implemented.</p>
1144 <p>PPC32 initial support for .o file writing was implemented.</p>
Wesley Peck3ff16db2011-11-14 18:56:41 +00001145 <p>MicroBlaze scheduling itineraries were added that model the
1146 3-stage and the 5-stage pipeline architectures. The 3-stage
1147 pipeline model can be selected with <code>-mcpu=mblaze3</code>
1148 and the 5-stage pipeline model can be selected with
1149 <code>-mcpu=mblaze5</code>.</p>
Chris Lattnerc343e312011-11-10 20:15:40 +00001150
Chris Lattner1efe27e2011-04-06 00:45:11 +00001151<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +00001152<!--
1153<li></li>
1154-->
Chris Lattner1efe27e2011-04-06 00:45:11 +00001155</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001156
Chris Lattner1efe27e2011-04-06 00:45:11 +00001157</div>
Chris Lattner77d29b12008-06-05 08:02:49 +00001158
1159<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001160<h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +00001161<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001162</h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +00001163
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001164<div>
Chris Lattnerf6662f92008-10-13 17:57:36 +00001165
Bill Wendling2626dba2011-08-03 22:18:20 +00001166<p>If you're already an LLVM user or developer with out-of-tree changes based on
1167 LLVM 2.9, this section lists some "gotchas" that you may run into upgrading
1168 from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +00001169
1170<ul>
Chris Lattner5a1731d2011-11-27 08:32:32 +00001171 <li>The <code>LLVMC</code> meta compiler driver was removed.</li>
Jay Foadf42e9b22011-08-04 10:43:43 +00001172 <li>The <code>LowerSetJmp</code> pass wasn't used effectively by any
1173 target and has been removed.</li>
Rafael Espindolaf940a1a2011-08-30 23:03:45 +00001174 <li>The old <code>TailDup</code> pass was not used in the standard pipeline
1175 and was unable to update ssa form, so it has been removed.
Eli Friedmanf03bb262011-08-12 22:50:01 +00001176 <li>The syntax of volatile loads and stores in IR has been changed to
1177 "<code>load volatile</code>"/"<code>store volatile</code>". The old
1178 syntax ("<code>volatile load</code>"/"<code>volatile store</code>")
1179 is still accepted, but is now considered deprecated.</li>
Benjamin Kramer7c5025b2011-11-25 21:26:00 +00001180 <li>The old atomic intrinsics (<code>llvm.memory.barrier</code> and
Eli Friedman526e1bb2011-10-26 00:55:23 +00001181 <code>llvm.atomic.*</code>) are now gone. Please use the new atomic
1182 instructions, described in the <a href="Atomics.html">atomics guide</a>.
Devang Patelb34dd132008-10-14 20:03:43 +00001183</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +00001184
NAKAMURA Takumi2026de22011-08-22 23:22:05 +00001185<h4>Windows (32-bit)</h4>
1186<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001187
NAKAMURA Takumi2026de22011-08-22 23:22:05 +00001188<ul>
1189 <li>On Win32(MinGW32 and MSVC), Windows 2000 will not be supported.
1190 Windows XP or higher is required.</li>
1191</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001192
NAKAMURA Takumi2026de22011-08-22 23:22:05 +00001193</div>
1194
Chris Lattnerf6662f92008-10-13 17:57:36 +00001195</div>
1196
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001197<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001198<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +00001199<a name="api_changes">Internal API Changes</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001200</h3>
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001201
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001202<div>
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001203
Chris Lattner1efe27e2011-04-06 00:45:11 +00001204<p>In addition, many APIs have changed in this release. Some of the major
Bill Wendling16005252011-08-02 06:20:17 +00001205 LLVM API changes are:</p>
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001206
1207<ul>
Benjamin Kramer7c5025b2011-11-25 21:26:00 +00001208 <li>The biggest and most pervasive change is that llvm::Types are no longer
Bill Wendling7b7fa742011-10-26 18:46:16 +00001209 returned or accepted as 'const' values. Instead, just pass around
Benjamin Kramer7c5025b2011-11-25 21:26:00 +00001210 non-const Types.</li>
Chris Lattnerd1324302011-07-18 04:56:02 +00001211
Bill Wendling7b7fa742011-10-26 18:46:16 +00001212 <li><code>PHINode::reserveOperandSpace</code> has been removed. Instead, you
1213 must specify how many operands to reserve space for when you create the
1214 PHINode, by passing an extra argument
1215 into <code>PHINode::Create</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +00001216
Bill Wendling7b7fa742011-10-26 18:46:16 +00001217 <li>PHINodes no longer store their incoming BasicBlocks as operands. Instead,
1218 the list of incoming BasicBlocks is stored separately, and can be accessed
1219 with new functions <code>PHINode::block_begin</code>
1220 and <code>PHINode::block_end</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +00001221
Bill Wendling7b7fa742011-10-26 18:46:16 +00001222 <li>Various functions now take an <code>ArrayRef</code> instead of either a
1223 pair of pointers (or iterators) to the beginning and end of a range, or a
1224 pointer and a length. Others now return an <code>ArrayRef</code> instead
1225 of a reference to a <code>SmallVector</code>
1226 or <code>std::vector</code>. These include:
Jay Foad558d3762011-07-14 09:19:05 +00001227<ul>
1228<!-- Please keep this list sorted. -->
Jay Foada3efbb12011-07-15 08:37:34 +00001229<li><code>CallInst::Create</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001230<li><code>ComputeLinearIndex</code> (in <code>llvm/CodeGen/Analysis.h</code>)</li>
1231<li><code>ConstantArray::get</code></li>
1232<li><code>ConstantExpr::getExtractElement</code></li>
Jay Foaddab3d292011-07-21 14:31:17 +00001233<li><code>ConstantExpr::getGetElementPtr</code></li>
1234<li><code>ConstantExpr::getInBoundsGetElementPtr</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001235<li><code>ConstantExpr::getIndices</code></li>
1236<li><code>ConstantExpr::getInsertElement</code></li>
1237<li><code>ConstantExpr::getWithOperands</code></li>
Jay Foad1d2f5692011-07-19 13:32:40 +00001238<li><code>ConstantFoldCall</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
1239<li><code>ConstantFoldInstOperands</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
Jay Foad558d3762011-07-14 09:19:05 +00001240<li><code>ConstantVector::get</code></li>
1241<li><code>DIBuilder::createComplexVariable</code></li>
1242<li><code>DIBuilder::getOrCreateArray</code></li>
1243<li><code>ExtractValueInst::Create</code></li>
1244<li><code>ExtractValueInst::getIndexedType</code></li>
1245<li><code>ExtractValueInst::getIndices</code></li>
1246<li><code>FindInsertedValue</code> (in <code>llvm/Analysis/ValueTracking.h</code>)</li>
Jay Foadca12a212011-07-19 14:42:50 +00001247<li><code>gep_type_begin</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
1248<li><code>gep_type_end</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
Jay Foada9203102011-07-25 09:48:08 +00001249<li><code>GetElementPtrInst::Create</code></li>
1250<li><code>GetElementPtrInst::CreateInBounds</code></li>
1251<li><code>GetElementPtrInst::getIndexedType</code></li>
Jay Foadb60e8512011-07-21 14:42:51 +00001252<li><code>InsertValueInst::Create</code></li>
1253<li><code>InsertValueInst::getIndices</code></li>
1254<li><code>InvokeInst::Create</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +00001255<li><code>IRBuilder::CreateCall</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001256<li><code>IRBuilder::CreateExtractValue</code></li>
Jay Foad0a2a60a2011-07-22 08:16:57 +00001257<li><code>IRBuilder::CreateGEP</code></li>
1258<li><code>IRBuilder::CreateInBoundsGEP</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001259<li><code>IRBuilder::CreateInsertValue</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +00001260<li><code>IRBuilder::CreateInvoke</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001261<li><code>MDNode::get</code></li>
1262<li><code>MDNode::getIfExists</code></li>
1263<li><code>MDNode::getTemporary</code></li>
1264<li><code>MDNode::getWhenValsUnresolved</code></li>
Jay Foadb9b54eb2011-07-19 15:07:52 +00001265<li><code>SimplifyGEPInst</code> (in <code>llvm/Analysis/InstructionSimplify.h</code>)</li>
Jay Foad8fbbb392011-07-19 14:01:37 +00001266<li><code>TargetData::getIndexedOffset</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001267</ul></li>
1268
Bill Wendling7b7fa742011-10-26 18:46:16 +00001269 <li>All forms of <code>StringMap::getOrCreateValue</code> have been remove
1270 except for the one which takes a <code>StringRef</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +00001271
Bill Wendling7b7fa742011-10-26 18:46:16 +00001272 <li>The <code>LLVMBuildUnwind</code> function from the C API was removed. The
1273 LLVM <code>unwind</code> instruction has been deprecated for a long time
1274 and isn't used by the current front-ends. So this was removed during the
1275 exception handling rewrite.</li>
Bill Wendling16005252011-08-02 06:20:17 +00001276
Bill Wendling7b7fa742011-10-26 18:46:16 +00001277 <li>The <code>LLVMAddLowerSetJmpPass</code> function from the C API was
1278 removed because the <code>LowerSetJmp</code> pass was removed.</li>
Bill Wendling2626dba2011-08-03 22:18:20 +00001279
Bill Wendling7b7fa742011-10-26 18:46:16 +00001280 <li>The <code>DIBuilder</code> interface used by front ends to encode
1281 debugging information in the LLVM IR now expects clients to
1282 use <code>DIBuilder::finalize()</code> at the end of translation unit to
1283 complete debugging information encoding.</li>
Devang Patel6326a422011-08-15 23:00:00 +00001284
Bill Wendling7b7fa742011-10-26 18:46:16 +00001285 <li>The way the type system works has been
1286 rewritten: <code>PATypeHolder</code> and <code>OpaqueType</code> are gone,
1287 and all APIs deal with <code>Type*</code> instead of <code>const
1288 Type*</code>. If you need to create recursive structures, then create a
1289 named structure, and use <code>setBody()</code> when all its elements are
1290 built. Type merging and refining is gone too: named structures are not
1291 merged with other structures, even if their layout is identical. (of
1292 course anonymous structures are still uniqued by layout).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +00001293
Bill Wendling7b7fa742011-10-26 18:46:16 +00001294 <li>TargetSelect.h moved to Support/ from Target/</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +00001295
Bill Wendling7b7fa742011-10-26 18:46:16 +00001296 <li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls (for
1297 example <code>llvm.memset.i32</code>).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +00001298
Bill Wendling7b7fa742011-10-26 18:46:16 +00001299 <li>It is mandatory to initialize all out-of-tree passes too and their dependencies now with
1300 <code>INITIALIZE_PASS{BEGIN,END,}</code>
1301 and <code>INITIALIZE_{PASS,AG}_DEPENDENCY</code>.</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +00001302
Bill Wendling7b7fa742011-10-26 18:46:16 +00001303 <li>The interface for MemDepResult in MemoryDependenceAnalysis has been
1304 enhanced with new return types Unknown and NonFuncLocal, in addition to
1305 the existing types Clobber, Def, and NonLocal.</li>
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001306</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001307
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001308</div>
Chris Lattnerf6662f92008-10-13 17:57:36 +00001309
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001310</div>
1311
Chris Lattner79c3fe12003-10-02 04:57:28 +00001312<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001313<h2>
Misha Brukman500bc302003-11-22 00:38:41 +00001314 <a name="knownproblems">Known Problems</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001315</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001316<!-- *********************************************************************** -->
1317
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001318<div>
Misha Brukman500bc302003-11-22 00:38:41 +00001319
Bill Wendling7b7fa742011-10-26 18:46:16 +00001320<p>This section contains significant known problems with the LLVM system, listed
1321 by component. If you run into a problem, please check
1322 the <a href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
1323 there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001324
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001325<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001326<h3>
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001327 <a name="experimental">Experimental features included with this release</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001328</h3>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001329
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001330<div>
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001331
Misha Brukman6df9e2c2004-05-12 21:46:05 +00001332<p>The following components of this LLVM release are either untested, known to
Bill Wendling7b7fa742011-10-26 18:46:16 +00001333 be broken or unreliable, or are in early development. These components
1334 should not be relied on, and bugs should not be filed against them, but they
1335 may be useful to some people. In particular, if you would like to work on
1336 one of these components, please contact us on
1337 the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev
1338 list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001339
1340<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001341 <li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ and
1342 XCore backends are experimental.</li>
1343
1344 <li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets other
1345 than darwin and ELF X86 systems.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001346</ul>
1347
1348</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001349
Misha Brukman500bc302003-11-22 00:38:41 +00001350<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001351<h3>
Chris Lattner26299222006-11-18 07:51:14 +00001352 <a name="x86-be">Known problems with the X86 back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001353</h3>
John Criswellc0c186d2005-11-08 21:11:33 +00001354
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001355<div>
John Criswellc0c186d2005-11-08 21:11:33 +00001356
1357<ul>
Chris Lattnerc78daaf2011-11-17 01:42:23 +00001358 <li>The X86-64 backend <a href="http://llvm.org/PR1740">does not yet support
1359 the <tt>va_arg</tt> LLVM IR instruction</a>. Currently, front-ends support
1360 variadic argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +00001361</ul>
1362
1363</div>
1364
1365<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001366<h3>
Chris Lattner26299222006-11-18 07:51:14 +00001367 <a name="ppc-be">Known problems with the PowerPC back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001368</h3>
Chris Lattner26299222006-11-18 07:51:14 +00001369
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001370<div>
Chris Lattner26299222006-11-18 07:51:14 +00001371
1372<ul>
Roman Divacky223764c2011-10-30 07:49:04 +00001373 <li>The PPC32/ELF support lacks PIC support.</li>
Chris Lattner26299222006-11-18 07:51:14 +00001374</ul>
1375
1376</div>
1377
1378<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001379<h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001380 <a name="arm-be">Known problems with the ARM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001381</h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001382
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001383<div>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001384
1385<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001386 <li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
1387 processors, thumb programs can crash or produce wrong results
1388 (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
1389
1390 <li>Compilation for ARM Linux OABI (old ABI) is supported but not fully
1391 tested.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001392</ul>
1393
1394</div>
1395
1396<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001397<h3>
Chris Lattner26299222006-11-18 07:51:14 +00001398 <a name="sparc-be">Known problems with the SPARC back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001399</h3>
Chris Lattner26299222006-11-18 07:51:14 +00001400
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001401<div>
Chris Lattner26299222006-11-18 07:51:14 +00001402
1403<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001404 <li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
1405 support the 64-bit SPARC ABI (-m64).</li>
Chris Lattner26299222006-11-18 07:51:14 +00001406</ul>
1407
1408</div>
1409
1410<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001411<h3>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +00001412 <a name="mips-be">Known problems with the MIPS back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001413</h3>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +00001414
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001415<div>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +00001416
1417<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001418 <li>64-bit MIPS targets are not supported yet.</li>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +00001419</ul>
1420
1421</div>
1422
1423<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001424<h3>
Chris Lattner26299222006-11-18 07:51:14 +00001425 <a name="alpha-be">Known problems with the Alpha back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001426</h3>
Chris Lattner26299222006-11-18 07:51:14 +00001427
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001428<div>
Chris Lattner26299222006-11-18 07:51:14 +00001429
1430<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001431 <li>On 21164s, some rare FP arithmetic sequences which may trap do not have
1432 the appropriate nops inserted to ensure restartability.</li>
John Criswellc0c186d2005-11-08 21:11:33 +00001433</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001434
John Criswellc0c186d2005-11-08 21:11:33 +00001435</div>
1436
Chris Lattner26299222006-11-18 07:51:14 +00001437<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001438<h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001439 <a name="c-be">Known problems with the C back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001440</h3>
Chris Lattner26299222006-11-18 07:51:14 +00001441
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001442<div>
Chris Lattner26299222006-11-18 07:51:14 +00001443
Chris Lattner3016ee92010-09-29 05:34:42 +00001444<p>The C backend has numerous problems and is not being actively maintained.
Bill Wendling7b7fa742011-10-26 18:46:16 +00001445 Depending on it for anything serious is not advised.</p>
Chris Lattner3016ee92010-09-29 05:34:42 +00001446
Chris Lattner26299222006-11-18 07:51:14 +00001447<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001448 <li><a href="http://llvm.org/PR802">The C backend has only basic support for
1449 inline assembly code</a>.</li>
1450
1451 <li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
1452 C++ programs</a>, preventing intermixing between C++ compiled by the CBE
1453 and C++ code compiled with <tt>llc</tt> or native compilers.</li>
1454
1455 <li>The C backend does not support all exception handling constructs.</li>
1456
1457 <li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +00001458</ul>
1459
1460</div>
John Criswellc0c186d2005-11-08 21:11:33 +00001461
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001462</div>
1463
Chris Lattner79c3fe12003-10-02 04:57:28 +00001464<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001465<h2>
Misha Brukman500bc302003-11-22 00:38:41 +00001466 <a name="additionalinfo">Additional Information</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001467</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001468<!-- *********************************************************************** -->
1469
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001470<div>
Misha Brukman500bc302003-11-22 00:38:41 +00001471
Bill Wendling7b7fa742011-10-26 18:46:16 +00001472<p>A wide variety of additional information is available on
1473 the <a href="http://llvm.org/">LLVM web page</a>, in particular in
1474 the <a href="http://llvm.org/docs/">documentation</a> section. The web page
1475 also contains versions of the API documentation which is up-to-date with the
1476 Subversion version of the source code. You can access versions of these
1477 documents specific to this release by going into the "<tt>llvm/doc/</tt>"
1478 directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001479
Misha Brukman500bc302003-11-22 00:38:41 +00001480<p>If you have any questions or comments about LLVM, please feel free to contact
Bill Wendling7b7fa742011-10-26 18:46:16 +00001481 us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001482
Misha Brukman500bc302003-11-22 00:38:41 +00001483</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001484
1485<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +00001486
Misha Brukman500bc302003-11-22 00:38:41 +00001487<hr>
Misha Brukman2061e892003-11-22 01:23:39 +00001488<address>
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Misha Brukman2061e892003-11-22 01:23:39 +00001493
Chris Lattnerb4b0ce72007-05-18 00:44:29 +00001494 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +00001495 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +00001496</address>
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1499</html>