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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
48 major improvements from the previous release and significant known problems.
49 All LLVM releases may be downloaded from
50 the <a href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +000051
Chris Lattner7506b1d2004-12-07 08:04:13 +000052<p>For more information about LLVM, including information about the latest
Bill Wendling7b7fa742011-10-26 18:46:16 +000053 release, please check out the <a href="http://llvm.org/">main LLVM web
54 site</a>. If you have questions or comments,
55 the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM
56 Developer's Mailing List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +000057
Bill Wendling7b7fa742011-10-26 18:46:16 +000058<p>Note that if you are reading this file from a Subversion checkout or the main
59 LLVM web page, this document applies to the <i>next</i> release, not the
60 current one. To see the release notes for a specific release, please see the
61 <a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +000062
63</div>
Chris Lattner61358ab2009-10-13 17:48:04 +000064
Chris Lattnere4dc1962011-04-05 23:22:33 +000065<!-- Features that need text if they're finished for 3.1:
66 ARM EHABI
Chris Lattner914ce462010-04-22 06:28:20 +000067 combiner-aa?
Chris Lattner61358ab2009-10-13 17:48:04 +000068 strong phi elim
Chris Lattner61358ab2009-10-13 17:48:04 +000069 loop dependence analysis
Chris Lattnere07043c2010-09-29 05:30:03 +000070 CorrelatedValuePropagation
Chris Lattnere4dc1962011-04-05 23:22:33 +000071 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
Chris Lattneracce85d2008-02-10 07:46:44 +000072 -->
Chris Lattnere07043c2010-09-29 05:30:03 +000073
Chris Lattner96a445e2008-10-13 18:01:01 +000074<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000075<h2>
Chris Lattner96a445e2008-10-13 18:01:01 +000076 <a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000077</h2>
Chris Lattner96a445e2008-10-13 18:01:01 +000078<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +000079
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +000080<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +000081
82<p>The LLVM 3.0 distribution currently consists of code from the core LLVM
83 repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattnerc343e312011-11-10 20:15:40 +000084 supporting tools), and the Clang repository. In
Bill Wendling7b7fa742011-10-26 18:46:16 +000085 addition to this code, the LLVM Project includes other sub-projects that are
86 in development. Here we include updates on these subprojects.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +000087
Chris Lattner8348b472008-06-08 21:58:17 +000088<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000089<h3>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +000090<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +000091</h3>
Chris Lattner8348b472008-06-08 21:58:17 +000092
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +000093<div>
Chris Lattner8348b472008-06-08 21:58:17 +000094
Chris Lattner095539f2010-04-26 17:42:18 +000095<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
Bill Wendling7b7fa742011-10-26 18:46:16 +000096 C++, and Objective-C languages. Clang aims to provide a better user
97 experience through expressive diagnostics, a high level of conformance to
98 language standards, fast compilation, and low memory use. Like LLVM, Clang
99 provides a modular, library-based architecture that makes it suitable for
100 creating or integrating with other development tools. Clang is considered a
101 production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
102 (32- and 64-bit), and for darwin/arm targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000103
Chad Rosiere6291d02011-05-27 22:50:46 +0000104<p>In the LLVM 3.0 time-frame, the Clang team has made many improvements:</p>
Douglas Gregorba087df2011-10-15 00:48:01 +0000105
106<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000107 <li>Greatly improved support for building C++ applications, with greater
108 stability and better diagnostics.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000109
Bill Wendling7b7fa742011-10-26 18:46:16 +0000110 <li><a href="http://clang.llvm.org/cxx_status.html">Improved support</a> for
111 the <a href="http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=50372">C++
112 2011</a> standard, including implementations of non-static data member
113 initializers, alias templates, delegating constructors, the range-based
114 for loop, and implicitly-generated move constructors and move assignment
115 operators, among others.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000116
Bill Wendling7b7fa742011-10-26 18:46:16 +0000117 <li>Implemented support for some features of the upcoming C1x standard,
118 including static assertions and generic selections.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000119
Bill Wendling7b7fa742011-10-26 18:46:16 +0000120 <li>Better detection of include and linking paths for system headers and
121 libraries, especially for Linux distributions.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000122
Bill Wendling7b7fa742011-10-26 18:46:16 +0000123 <li>Implemented support
124 for <a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html">Automatic
125 Reference Counting</a> for Objective-C.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000126
Bill Wendling7b7fa742011-10-26 18:46:16 +0000127 <li>Implemented a number of optimizations in <tt>libclang</tt>, the Clang C
128 interface, to improve the performance of code completion and the mapping
129 from source locations to abstract syntax tree nodes.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000130</ul>
131
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000132
Duncan Sandsf3ba7af2011-04-06 08:07:40 +0000133<p>If Clang rejects your code but another compiler accepts it, please take a
Bill Wendling7b7fa742011-10-26 18:46:16 +0000134 look at the <a href="http://clang.llvm.org/compatibility.html">language
135 compatibility</a> guide to make sure this is not intentional or a known
136 issue.</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000137
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000138</div>
139
140<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000141<h3>
Duncan Sands528a5102011-04-04 11:09:08 +0000142<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000143</h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000144
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000145<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000146<p><a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
147 <a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
Duncan Sands77352c92011-11-10 18:44:29 +0000148 optimizers and code generators with LLVM's. It works with gcc-4.5 or gcc-4.6,
149 targets the x86-32 and x86-64 processor families, and has been successfully
150 used on the Darwin, FreeBSD, KFreeBSD, Linux and OpenBSD platforms. It fully
151 supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C
152 and Obj-C++.</p>
Duncan Sands749fd832010-04-02 09:23:15 +0000153
Bill Wendling7b7fa742011-10-26 18:46:16 +0000154<p>The 3.0 release has the following notable changes:</p>
155
Duncan Sands77352c92011-11-10 18:44:29 +0000156 <li>GCC version 4.6 is now fully supported.</li>
157
158 <li>Patching and building GCC is no longer required: the plugin should work
159 with your system GCC (version 4.5 or 4.6; on Debian/Ubuntu systems the
160 gcc-4.5-plugin-dev or gcc-4.6-plugin-dev package is also needed).</li>
161
162 <li>The <tt>-fplugin-arg-dragonegg-enable-gcc-optzns</tt> option, which runs
163 GCC's optimizers as well as LLVM's, now works much better. This is the
164 option to use if you want ultimate performance! It not yet completely
165 stable: it may cause the plugin to crash.</li>
166
167 <li>The type and constant conversion logic has been almost entirely rewritten,
168 fixing a multitude of obscure bugs.</li>
169
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000170<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000171<!--
172<li></li>
173-->
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000174</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000175
176</div>
177
Chris Lattner75547712010-10-03 23:49:06 +0000178<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000179<h3>
Chris Lattner75547712010-10-03 23:49:06 +0000180<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000181</h3>
Chris Lattner75547712010-10-03 23:49:06 +0000182
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000183<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000184
185<p>The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
186 is a simple library that provides an implementation of the low-level
187 target-specific hooks required by code generation and other runtime
188 components. For example, when compiling for a 32-bit target, converting a
189 double to a 64-bit unsigned integer is compiled into a runtime call to the
190 "__fixunsdfdi" function. The compiler-rt library provides highly optimized
191 implementations of this and other low-level routines (some are 3x faster than
192 the equivalent libgcc routines).</p>
Chris Lattner75547712010-10-03 23:49:06 +0000193
Chad Rosiere6291d02011-05-27 22:50:46 +0000194<p>In the LLVM 3.0 timeframe,</p>
Chris Lattner75547712010-10-03 23:49:06 +0000195
196</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000197
198<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000199<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000200<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000201</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000202
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000203<div>
Chris Lattnere07043c2010-09-29 05:30:03 +0000204
Bill Wendling7b7fa742011-10-26 18:46:16 +0000205<p>LLDB has advanced by leaps and bounds in the 3.0 timeframe. It is
206 dramatically more stable and useful, and includes both a
207 new <a href="http://lldb.llvm.org/tutorial.html">tutorial</a> and
208 a <a href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
209 GDB</a>.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000210
211</div>
212
213<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000214<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000215<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000216</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000217
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000218<div>
Chris Lattnere07043c2010-09-29 05:30:03 +0000219
Bill Wendling7b7fa742011-10-26 18:46:16 +0000220<p>Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
221 licensed</a> under the MIT and UIUC license, allowing it to be used more
222 permissively.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000223
224</div>
225
Chris Lattner61358ab2009-10-13 17:48:04 +0000226
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000227<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000228<h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000229<a name="LLBrowse">LLBrowse: IR Browser</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000230</h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000231
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000232<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000233
234<p><a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
235 LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
236 module and displays its contents as an expandable tree view, facilitating an
237 easy way to inspect types, functions, global variables, or metadata nodes. It
238 is fully cross-platform, being based on the popular wxWidgets GUI
239 toolkit.</p>
240
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000241</div>
242
243<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000244<h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000245<a name="vmkit">VMKit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000246</h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000247
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000248<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000249
Nicolas Geoffray54d5df92011-11-10 23:37:56 +0000250 <p>The <a href="http://vmkit.llvm.org/">VMKit project</a> is an
251 implementation of a Java Virtual Machine (Java VM or JVM) that uses LLVM for
252 static and just-in-time compilation.
253
254 <p>In the LLVM 3.0 time-frame, VMKit has had significant improvements on both
255 runtime and startup performance:</p>
256
257 <ul>
258 <li>Precompilation: by compiling ahead of time a small subset of Java's core
259 library, the startup performance have been highly optimized to the point that
260 running a 'Hello World' program takes less than 30 milliseconds.</li>
261
262 <li>Customization: by customizing virtual methods for individual classes,
263 the VM can statically determine the target of a virtual call, and decide to
264 inline it.</li>
265
266 <li>Inlining: the VM does more inlining than it did before, by allowing more
267 bytecode instructions to be inlined, and thanks to customization. It also
268 inlines GC barriers, and object allocations.</li>
269
270 <li>New exception model: the generated code for a method that does not do
271 any try/catch is not penalized anymore by the eventuality of calling a
272 method that throws an exception. Instead, the method that throws the
273 exception jumps directly to the method that could catch it.</li>
274 </ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000275
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000276</div>
277
278
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000279<!--=========================================================================-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000280<!--
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000281<h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000282<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000283</h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000284
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000285<div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000286<p>
287<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
288programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
289through the application and records state transitions that lead to fault
290states. This allows it to construct testcases that lead to faults and can even
291be used to verify some algorithms.
292</p>
293
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000294<p>UPDATE!</p>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000295</div>-->
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000296
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000297</div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000298
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000299<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000300<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000301 <a name="externalproj">External Open Source Projects Using LLVM 3.0</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000302</h2>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000303<!-- *********************************************************************** -->
304
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000305<div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000306
307<p>An exciting aspect of LLVM is that it is used as an enabling technology for
308 a lot of other language and tools projects. This section lists some of the
Chad Rosiere6291d02011-05-27 22:50:46 +0000309 projects that have already been updated to work with LLVM 3.0.</p>
Chris Lattner75547712010-10-03 23:49:06 +0000310
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000311<!--=========================================================================-->
Bill Wendling7be6bc52011-10-26 00:17:54 +0000312<h3>AddressSanitizer</h3>
313
314<div>
315
316<p><a href="http://code.google.com/p/address-sanitizer/">AddressSanitizer</a>
317 uses compiler instrumentation and a specialized malloc library to find C/C++
318 bugs such as use-after-free and out-of-bound accesses to heap, stack, and
319 globals. The key feature of the tool is speed: the average slowdown
320 introduced by AddressSanitizer is less than 2x.</p>
321
322</div>
323
324<!--=========================================================================-->
Bill Wendling29817ea2011-10-26 00:14:36 +0000325<h3>ClamAV</h3>
326
327<div>
Bill Wendlingf2a78332011-10-25 01:01:42 +0000328
Bill Wendling29817ea2011-10-26 00:14:36 +0000329<p><a href="http://www.clamav.net">Clam AntiVirus</a> is an open source (GPL)
330 anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
331 gateways.</p>
332
333<p>Since version 0.96 it
334 has <a href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
335 signatures</a> that allow writing detections for complex malware.</p>
336
337<p>It uses LLVM's JIT to speed up the execution of bytecode on X86, X86-64,
338 PPC32/64, falling back to its own interpreter otherwise. The git version was
339 updated to work with LLVM 3.0.</p>
340
341</div>
342
343<!--=========================================================================-->
Bill Wendling65d1f412011-10-26 18:23:06 +0000344<h3>clReflect</h3>
345
346<div>
347
348<p><a href="https://bitbucket.org/dwilliamson/clreflect">clReflect</a> is a C++
349 parser that uses clang/LLVM to derive a light-weight reflection database
350 suitable for use in game development. It comes with a very simple runtime
351 library for loading and querying the database, requiring no external
352 dependencies (including CRT), and an additional utility library for object
353 management and serialisation.</p>
354
355</div>
356
357<!--=========================================================================-->
Bill Wendling63507d12011-10-29 01:10:01 +0000358<h3>Cling C++ Interpreter</h3>
359
360<div>
361
362<p><a href="http://cern.ch/cling">Cling</a> is an interactive compiler interface
363 (aka C++ interpreter). It uses LLVM's JIT and clang; it currently supports
364 C++ and C. It has a prompt interface, runs source files, calls into shared
365 libraries, prints the value of expressions, even does runtime lookup of
366 identifiers (dynamic scopes). And it just behaves like one would expect from
367 an interpreter.</p>
368
369</div>
370
371<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000372<h3>Crack Programming Language</h3>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000373
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000374<div>
Bill Wendling55d6e672011-11-03 20:10:01 +0000375
376<p><a href="http://code.google.com/p/crack-language/">Crack</a> aims to provide
377 the ease of development of a scripting language with the performance of a
378 compiled language. The language derives concepts from C++, Java and Python,
379 incorporating object-oriented programming, operator overloading and strong
380 typing.</p>
381
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000382</div>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000383
384<!--=========================================================================-->
Bill Wendlingb99486f2011-11-08 05:22:54 +0000385<h3>Eero</h3>
386
387<div>
388
389<p><a href="http://eerolanguage.org/">Eero</a> is a fully
390 header-and-binary-compatible dialect of Objective-C 2.0, implemented with a
391 patched version of the Clang/LLVM compiler. It features a streamlined syntax,
392 Python-like indentation, and new operators, for improved readability and
393 reduced code clutter. It also has new features such as limited forms of
394 operator overloading and namespaces, and strict (type-and-operator-safe)
395 enumerations. It is inspired by languages such as Smalltalk, Python, and
396 Ruby.</p>
397
398</div>
399
400<!--=========================================================================-->
Bill Wendlingf9778192011-10-26 00:09:55 +0000401<h3>Glasgow Haskell Compiler (GHC)</h3>
402
403<div>
404
405<p>GHC is an open source, state-of-the-art programming suite for Haskell, a
406 standard lazy functional programming language. It includes an optimizing
407 static compiler generating good code for a variety of platforms, together
408 with an interactive system for convenient, quick development.</p>
409
410<p>GHC 7.0 and onwards include an LLVM code generator, supporting LLVM 2.8 and
411 later. Since LLVM 2.9, GHC now includes experimental support for the ARM
412 platform with LLVM 3.0.</p>
413
414</div>
415
416<!--=========================================================================-->
Bill Wendlingf62333d2011-10-25 20:35:31 +0000417<h3>gwXscript</h3>
418
419<div>
420
421<p><a href="http://botwars.tk/gwscript/">gwXscript</a> is an object oriented,
Bill Wendling7c38de22011-10-26 04:24:15 +0000422 aspect oriented programming language which can create both executables (ELF,
Bill Wendlingf62333d2011-10-25 20:35:31 +0000423 EXE) and shared libraries (DLL, SO, DYNLIB). The compiler is implemented in
424 its own language and translates scripts into LLVM-IR which can be optimized
425 and translated into native code by the LLVM framework. Source code in
426 gwScript contains definitions that expand the namespaces. So you can build
427 your project and simply 'plug out' features by removing a file. The remaining
428 project does not leave scars since you directly separate concerns by the
429 'template' feature of gwX. It is also possible to add new features to a
430 project by just adding files and without editing the original project. This
431 language is used for example to create games or content management systems
432 that should be extendable.</p>
433
434<p>gwXscript is strongly typed and offers comfort with its native types string,
435 hash and array. You can easily write new libraries in gwXscript or native
436 code. gwXscript is type safe and users should not be able to crash your
437 program or execute malicious code except code that is eating CPU time.</p>
438
439</div>
440
441<!--=========================================================================-->
Bill Wendling50cacc82011-10-26 22:55:18 +0000442<h3>include-what-you-use</h3>
443
444<div>
445
446<p><a href="http://code.google.com/p/include-what-you-use">include-what-you-use</a>
447 is a tool to ensure that a file directly <code>#include</code>s
448 all <code>.h</code> files that provide a symbol that the file uses. It also
449 removes superfluous <code>#include</code>s from source files.</p>
450
451</div>
452
453<!--=========================================================================-->
Bill Wendling32dc4d92011-11-07 22:05:17 +0000454<h3>ispc: The Intel SPMD Program Compiler</h3>
455
456<div>
457
458<p><a href="http://ispc.github.com">ispc</a> is a compiler for "single program,
459 multiple data" (SPMD) programs. It compiles a C-based SPMD programming
460 language to run on the SIMD units of CPUs; it often delivers 5-6x speedups on
461 a single core of a CPU with an 8-wide SIMD unit compared to serial code,
462 while still providing a clean and easy-to-understand programming model. For
463 an introduction to the language and its performance,
Chris Lattnerc343e312011-11-10 20:15:40 +0000464 see <a href="http://ispc.github.com/example.html">the walkthrough</a> of a short
Bill Wendling32dc4d92011-11-07 22:05:17 +0000465 example program. ispc is licensed under the BSD license.</p>
466
467</div>
468
469<!--=========================================================================-->
Bill Wendling57fd8762011-10-26 18:20:54 +0000470<h3>LanguageKit and Pragmatic Smalltalk</h3>
471
472<div>
473
474<p><a href="http://etoileos.com/etoile/features/languagekit/">LanguageKit</a> is
475 a framework for implementing dynamic languages sharing an object model with
476 Objective-C. It provides static and JIT compilation using LLVM along with
477 its own interpreter. Pragmatic Smalltalk is a dialect of Smalltalk, built on
478 top of LanguageKit, that interfaces directly with Objective-C, sharing the
479 same object representation and message sending behaviour. These projects are
480 developed as part of the &Eacute;toi&eacute; desktop environment.</p>
481
482</div>
483
484<!--=========================================================================-->
Bill Wendling03250532011-11-01 04:08:23 +0000485<h3>LuaAV</h3>
486
487<div>
488
489<p><a href="http://lua-av.mat.ucsb.edu/blog/">LuaAV</a> is a real-time
490 audiovisual scripting environment based around the Lua language and a
491 collection of libraries for sound, graphics, and other media protocols. LuaAV
492 uses LLVM and Clang to JIT compile efficient user-defined audio synthesis
493 routines specified in a declarative syntax.</p>
494
495</div>
496
497<!--=========================================================================-->
Bill Wendlingd4821b82011-10-26 00:16:17 +0000498<h3>Mono</h3>
499
500<div>
501
502<p>An open source, cross-platform implementation of C# and the CLR that is
503 binary compatible with Microsoft.NET. Has an optional, dynamically-loaded
504 LLVM code generation backend in Mini, the JIT compiler.</p>
505
506<p>Note that we use a Git mirror of LLVM with some patches. See:
507 https://github.com/mono/llvm</p>
508
509</div>
510
511<!--=========================================================================-->
Bill Wendlingba226272011-10-25 20:37:45 +0000512<h3>Portable OpenCL (pocl)</h3>
513
514<div>
515
516<p>Portable OpenCL is an open source implementation of the OpenCL standard which
517 can be easily adapted for new targets. One of the goals of the project is
518 improving performance portability of OpenCL programs, avoiding the need for
519 target-dependent manual optimizations. A "native" target is included, which
520 allows running OpenCL kernels on the host (CPU).</p>
521
522</div>
523
524<!--=========================================================================-->
Bill Wendling0bad98c2011-10-25 20:39:06 +0000525<h3>Pure</h3>
526
527<div>
528<p><a href="http://pure-lang.googlecode.com/">Pure</a> is an
529 algebraic/functional programming language based on term rewriting. Programs
530 are collections of equations which are used to evaluate expressions in a
531 symbolic fashion. The interpreter uses LLVM as a backend to JIT-compile Pure
532 programs to fast native code. Pure offers dynamic typing, eager and lazy
533 evaluation, lexical closures, a hygienic macro system (also based on term
534 rewriting), built-in list and matrix support (including list and matrix
535 comprehensions) and an easy-to-use interface to C and other programming
536 languages (including the ability to load LLVM bitcode modules, and inline C,
537 C++, Fortran and Faust code in Pure programs if the corresponding LLVM-enabled
538 compilers are installed).</p>
539
540<p>Pure version 0.48 has been tested and is known to work with LLVM 3.0
541 (and continues to work with older LLVM releases &gt;= 2.5).</p>
542
543</div>
544
545<!--=========================================================================-->
Bill Wendling537d85b2011-10-26 00:12:04 +0000546<h3>Renderscript</h3>
547
548<div>
549
550<p><a href="http://developer.android.com/guide/topics/renderscript/index.html">Renderscript</a>
551 is Android's advanced 3D graphics rendering and compute API. It provides a
552 portable C99-based language with extensions to facilitate common use cases
553 for enhancing graphics and thread level parallelism. The Renderscript
554 compiler frontend is based on Clang/LLVM. It emits a portable bitcode format
555 for the actual compiled script code, as well as reflects a Java interface for
556 developers to control the execution of the compiled bitcode. Executable
557 machine code is then generated from this bitcode by an LLVM backend on the
558 device. Renderscript is thus able to provide a mechanism by which Android
559 developers can improve performance of their applications while retaining
560 portability.</p>
561
562</div>
563
564<!--=========================================================================-->
Bill Wendling7d5b6212011-10-25 20:40:26 +0000565<h3>SAFECode</h3>
566
567<div>
568
569<p><a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C/C++
570 compiler built using LLVM. It takes standard, unannotated C/C++ code,
571 analyzes the code to ensure that memory accesses and array indexing
572 operations are safe, and instruments the code with run-time checks when
573 safety cannot be proven statically. SAFECode can be used as a debugging aid
574 (like Valgrind) to find and repair memory safety bugs. It can also be used
575 to protect code from security attacks at run-time.</p>
576
577</div>
578
579<!--=========================================================================-->
Bill Wendling02b77b72011-10-26 07:38:19 +0000580<h3>The Stupid D Compiler (SDC)</h3>
581
582<div>
583
584<p><a href="https://github.com/bhelyer/SDC">The Stupid D Compiler</a> is a
585 project seeking to write a self-hosting compiler for the D programming
586 language without using the frontend of the reference compiler (DMD).</p>
587
588</div>
589
590<!--=========================================================================-->
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000591<h3>TTA-based Co-design Environment (TCE)</h3>
592
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000593<div>
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000594
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000595<p>TCE is a toolset for designing application-specific processors (ASP) based on
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000596 the Transport triggered architecture (TTA). The toolset provides a complete
597 co-design flow from C/C++ programs down to synthesizable VHDL and parallel
598 program binaries. Processor customization points include the register files,
599 function units, supported operations, and the interconnection network.</p>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000600
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000601<p>TCE uses Clang and LLVM for C/C++ language support, target independent
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000602 optimizations and also for parts of code generation. It generates new
Bill Wendling7b7fa742011-10-26 18:46:16 +0000603 LLVM-based code generators "on the fly" for the designed TTA processors and
604 loads them in to the compiler backend as runtime libraries to avoid
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000605 per-target recompilation of larger parts of the compiler chain.</p>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000606
Bill Wendling7b7fa742011-10-26 18:46:16 +0000607</div>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000608
609<!--=========================================================================-->
Bill Wendling628c2662011-10-25 20:27:37 +0000610<h3>Tart Programming Language</h3>
611
612<div>
613
614<p><a href="http://code.google.com/p/tart/">Tart</a> is a general-purpose,
615 strongly typed programming language designed for application
616 developers. Strongly inspired by Python and C#, Tart focuses on practical
617 solutions for the professional software developer, while avoiding the clutter
618 and boilerplate of legacy languages like Java and C++. Although Tart is still
619 in development, the current implementation supports many features expected of
620 a modern programming language, such as garbage collection, powerful
621 bidirectional type inference, a greatly simplified syntax for template
622 metaprogramming, closures and function literals, reflection, operator
623 overloading, explicit mutability and immutability, and much more. Tart is
624 flexible enough to accommodate a broad range of programming styles and
625 philosophies, while maintaining a strong commitment to simplicity, minimalism
626 and elegance in design.</p>
627
628</div>
629
630<!--=========================================================================-->
Bill Wendling644ce532011-10-26 09:25:01 +0000631<h3>ThreadSanitizer</h3>
632
633<div>
634
635<p><a href="http://code.google.com/p/data-race-test/">ThreadSanitizer</a> is a
636 data race detector for (mostly) C and C++ code, available for Linux, Mac OS
637 and Windows. On different systems, we use binary instrumentation frameworks
Bill Wendlingae8538e2011-10-29 01:11:15 +0000638 (Valgrind and Pin) as frontends that generate the program events for the race
639 detection algorithm. On Linux, there's an option of using LLVM-based
640 compile-time instrumentation.</p>
Bill Wendling644ce532011-10-26 09:25:01 +0000641
642</div>
643
644<!--=========================================================================-->
Bill Wendling8a924c62011-10-26 07:42:45 +0000645<h3>The ZooLib C++ Cross-Platform Application Framework</h3>
646
647<div>
648
649<p><a href="http://www.zoolib.org/">ZooLib</a> is Open Source under the MIT
650 License. It provides GUI, filesystem access, TCP networking, thread-safe
651 memory management, threading and locking for Mac OS X, Classic Mac OS,
652 Microsoft Windows, POSIX operating systems with X11, BeOS, Haiku, Apple's iOS
653 and Research in Motion's BlackBerry.</p>
654
655<p>My current work is to use CLang's static analyzer to improve ZooLib's code
656 quality. I also plan to set up LLVM compiles of the demo programs and test
657 programs using CLang and LLVM on all the platforms that CLang, LLVM and
658 ZooLib all support.</p>
659
660</div>
Chris Lattnera844a3e2011-04-07 03:09:21 +0000661
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000662</div>
663
Chris Lattner8348b472008-06-08 21:58:17 +0000664<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000665<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000666 <a name="whatsnew">What's New in LLVM 3.0?</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000667</h2>
Chris Lattner8348b472008-06-08 21:58:17 +0000668<!-- *********************************************************************** -->
669
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000670<div>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000671
Chris Lattner61358ab2009-10-13 17:48:04 +0000672<p>This release includes a huge number of bug fixes, performance tweaks and
Bill Wendling7b7fa742011-10-26 18:46:16 +0000673 minor improvements. Some of the major improvements and new features are
674 listed in this section.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000675
Chris Lattner914ce462010-04-22 06:28:20 +0000676<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000677<h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000678<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000679</h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000680
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000681<div>
Chris Lattner252b83d2008-02-06 18:00:06 +0000682
Chris Lattnerc343e312011-11-10 20:15:40 +0000683<p><b>llvm-gcc is gone</b></p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000684
Chris Lattnerc343e312011-11-10 20:15:40 +0000685<p>LLVM 3.0 includes several major new capabilities:</p>
686
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000687<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000688
Chad Rosiere6291d02011-05-27 22:50:46 +0000689<!--
690<li></li>
691-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000692
Chris Lattner8170c102008-02-10 08:18:42 +0000693</ul>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000694
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000695</div>
696
Chris Lattner84977642007-09-21 03:54:09 +0000697<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000698<h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000699<a name="coreimprovements">LLVM IR and Core Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000700</h3>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000701
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000702<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000703
Chris Lattner61358ab2009-10-13 17:48:04 +0000704<p>LLVM IR has several new features for better support of new targets and that
Bill Wendling7b7fa742011-10-26 18:46:16 +0000705 expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000706
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000707<p>One of the biggest changes is that 3.0 has a new exception handling
708 system. The old system used LLVM intrinsics to convey the exception handling
709 information to the code generator. It worked in most cases, but not
710 all. Inlining was especially difficult to get right. Also, the intrinsics
711 could be moved away from the <code>invoke</code> instruction, making it hard
712 to recover that information.</p>
713
714<p>The new EH system makes exception handling a first-class member of the IR. It
715 adds two new instructions:</p>
716
Chris Lattner791f77b2008-06-05 06:25:56 +0000717<ul>
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000718 <li><a href="LangRef.html#i_landingpad"><code>landingpad</code></a> &mdash;
719 this instruction defines a landing pad basic block. It contains all of the
720 information that's needed by the code generator. It's also required to be
721 the first non-PHI instruction in the landing pad. In addition, a landing
722 pad may be jumped to only by the unwind edge of an <code>invoke</code>
723 instruction.</li>
724
725 <li><a href="LangRef.html#i_resume"><code>resume</code></a> &mdash; this
726 instruction causes the current exception to resume traveling up the
727 stack. It replaces the <code>@llvm.eh.resume</code> intrinsic.</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000728</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000729
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000730<p>Converting from the old EH API to the new EH API is rather simple, because a
731 lot of complexity has been removed. The two intrinsics,
732 <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code> have been
733 superceded by the <code>landingpad</code> instruction. Instead of generating
734 a call to <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code>:
735
736<div class="doc_code">
737<pre>
738Function *ExcIntr = Intrinsic::getDeclaration(TheModule,
739 Intrinsic::eh_exception);
740Function *SlctrIntr = Intrinsic::getDeclaration(TheModule,
741 Intrinsic::eh_selector);
742
743// The exception pointer.
744Value *ExnPtr = Builder.CreateCall(ExcIntr, "exc_ptr");
745
746std::vector&lt;Value*&gt; Args;
747Args.push_back(ExnPtr);
748Args.push_back(Builder.CreateBitCast(Personality,
749 Type::getInt8PtrTy(Context)));
750
751<i>// Add selector clauses to Args.</i>
752
753// The selector call.
754Builder.CreateCall(SlctrIntr, Args, "exc_sel");
755</pre>
756</div>
757
758<p>You should instead generate a <code>landingpad</code> instruction, that
759 returns an exception object and selector value:</p>
760
761<div class="doc_code">
762<pre>
763LandingPadInst *LPadInst =
764 Builder.CreateLandingPad(StructType::get(Int8PtrTy, Int32Ty, NULL),
765 Personality, 0);
766
767Value *LPadExn = Builder.CreateExtractValue(LPadInst, 0);
768Builder.CreateStore(LPadExn, getExceptionSlot());
769
770Value *LPadSel = Builder.CreateExtractValue(LPadInst, 1);
771Builder.CreateStore(LPadSel, getEHSelectorSlot());
772</pre>
773</div>
774
775<p>It's now trivial to add the individual clauses to the <code>landingpad</code>
776 instruction.</p>
777
778<div class="doc_code">
779<pre>
780<i><b>// Adding a catch clause</b></i>
781Constant *TypeInfo = getTypeInfo();
782LPadInst-&gt;addClause(TypeInfo);
783
784<i><b>// Adding a C++ catch-all</b></i>
785LPadInst-&gt;addClause(Constant::getNullValue(Builder.getInt8PtrTy()));
786
787<i><b>// Adding a cleanup</b></i>
788LPadInst-&gt;setCleanup(true);
789
790<i><b>// Adding a filter clause</b></i>
791std::vector&lt;Constant*&gt; TypeInfos;
792Constant *TypeInfo = getFilterTypeInfo();
793TypeInfos.push_back(Builder.CreateBitCast(TypeInfo, Builder.getInt8PtrTy()));
794
795ArrayType *FilterTy = ArrayType::get(Int8PtrTy, TypeInfos.size());
796LPadInst-&gt;addClause(ConstantArray::get(FilterTy, TypeInfos));
797</pre>
798</div>
799
800<p>Converting from using the <code>@llvm.eh.resume</code> intrinsic to
801 the <code>resume</code> instruction is trivial. It takes the exception
802 pointer and exception selector values returned by
803 the <code>landingpad</code> instruction:</p>
804
805<div class="doc_code">
806<pre>
807Type *UnwindDataTy = StructType::get(Builder.getInt8PtrTy(),
808 Builder.getInt32Ty(), NULL);
809Value *UnwindData = UndefValue::get(UnwindDataTy);
810Value *ExcPtr = Builder.CreateLoad(getExceptionObjSlot());
811Value *ExcSel = Builder.CreateLoad(getExceptionSelSlot());
812UnwindData = Builder.CreateInsertValue(UnwindData, ExcPtr, 0, "exc_ptr");
813UnwindData = Builder.CreateInsertValue(UnwindData, ExcSel, 1, "exc_sel");
814Builder.CreateResume(UnwindData);
815</pre>
816</div>
817
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000818</div>
819
820<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000821<h3>
Andrew Trick5aab6382011-11-06 17:59:24 +0000822<a name="loopoptimization">Loop Optimization Improvements</a>
823</h3>
824
825<div>
826<p>The induction variable simplification pass in 3.0 only modifies
827 induction variables when profitable. Sign and zero extension
828 elimination, linear function test replacement, loop unrolling, and
829 other simplifications that require induction variable analysis have
830 been generalized so they no longer require loops to be rewritten in a
831 typically suboptimal form prior to optimization. This new design
832 preserves more IR level information, avoids undoing earlier loop
833 optimizations (particularly hand-optimized loops), and no longer
834 strongly depends on the code generator rewriting loops a second time
835 in a now optimal form--an intractable problem.</p>
836
837<p>The original behavior can be restored with -mllvm -enable-iv-rewrite;
838 however, support for this mode will be short lived. As such, bug
839 reports should be filed for any significant performance regressions
840 when moving from -mllvm -enable-iv-rewrite to the 3.0 default mode.</p>
841</div>
842
843<!--=========================================================================-->
844<h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000845<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000846</h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000847
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000848<div>
Chris Lattneracce85d2008-02-10 07:46:44 +0000849
Chris Lattner61358ab2009-10-13 17:48:04 +0000850<p>In addition to a large array of minor performance tweaks and bug fixes, this
Bill Wendling7b7fa742011-10-26 18:46:16 +0000851 release includes a few major enhancements and additions to the
852 optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000853
854<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000855<!--
856<li></li>
857-->
Chris Lattnerc5ac61d2011-04-06 05:50:04 +0000858</li>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000859
Chris Lattner11b66112010-10-04 02:42:39 +0000860</ul>
861
Chris Lattner61358ab2009-10-13 17:48:04 +0000862</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000863
Chris Lattner0b832202008-06-08 02:45:07 +0000864<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000865<h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000866<a name="mc">MC Level Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000867</h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000868
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000869<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000870
871<p>The LLVM Machine Code (aka MC) subsystem was created to solve a number of
872 problems in the realm of assembly, disassembly, object file format handling,
873 and a number of other related areas that CPU instruction-set level tools work
874 in.</p>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000875
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000876<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000877<!--
878<li></li>
879-->
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000880</ul>
881
Bill Wendling7b7fa742011-10-26 18:46:16 +0000882<p>For more information, please see
883 the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro
884 to the LLVM MC Project Blog Post</a>.</p>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000885
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000886</div>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000887
Chris Lattner4ba2b652010-09-30 16:31:33 +0000888<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000889<h3>
Chris Lattner511433e2009-03-02 03:24:11 +0000890<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000891</h3>
Chris Lattner0b832202008-06-08 02:45:07 +0000892
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000893<div>
Chris Lattner0b832202008-06-08 02:45:07 +0000894
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000895<p>We have put a significant amount of work into the code generator
Bill Wendling7b7fa742011-10-26 18:46:16 +0000896 infrastructure, which allows us to implement more aggressive algorithms and
897 make it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000898
899<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000900<!--
901<li></li>
902-->
Chris Lattner84977642007-09-21 03:54:09 +0000903</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000904</div>
905
Chris Lattner917cc712009-03-02 02:37:32 +0000906<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000907<h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000908<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000909</h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000910
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000911<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000912
913<p>New features and major changes in the X86 target include:</p>
Chris Lattner917cc712009-03-02 02:37:32 +0000914
915<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000916
917 <li>The CRC32 intrinsics have been renamed. The intrinsics were previously
918 <code>@llvm.x86.sse42.crc32.[8|16|32]</code>
919 and <code>@llvm.x86.sse42.crc64.[8|64]</code>. They have been renamed to
920 <code>@llvm.x86.sse42.crc32.32.[8|16|32]</code> and
921 <code>@llvm.x86.sse42.crc32.64.[8|64]</code>.</li>
Chad Rosierf94c9c12011-05-27 20:13:10 +0000922
Chris Lattner917cc712009-03-02 02:37:32 +0000923</ul>
924
Chris Lattner917cc712009-03-02 02:37:32 +0000925</div>
Chris Lattner84977642007-09-21 03:54:09 +0000926
927<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000928<h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000929<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000930</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000931
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000932<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000933
934<p>New features of the ARM target include:</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000935
936<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000937<!--
938<li></li>
939-->
Bob Wilsone8472772010-09-13 17:39:35 +0000940</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000941</div>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000942
943<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000944<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000945<a name="OtherTS">Other Target Specific Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000946</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000947
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000948<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000949
Chris Lattnerc343e312011-11-10 20:15:40 +0000950 <p>PPC32/ELF va_arg was implemented.</p>
951 <p>PPC32 initial support for .o file writing was implemented.</p>
952
Chris Lattner1efe27e2011-04-06 00:45:11 +0000953<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000954<!--
955<li></li>
956-->
Chris Lattner1efe27e2011-04-06 00:45:11 +0000957</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000958
Chris Lattner1efe27e2011-04-06 00:45:11 +0000959</div>
Chris Lattner77d29b12008-06-05 08:02:49 +0000960
961<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000962<h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000963<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000964</h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000965
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000966<div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000967
Bill Wendling2626dba2011-08-03 22:18:20 +0000968<p>If you're already an LLVM user or developer with out-of-tree changes based on
969 LLVM 2.9, this section lists some "gotchas" that you may run into upgrading
970 from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000971
972<ul>
Eric Christopher90d6ec52011-09-28 19:47:28 +0000973 <li>The <code>LLVMC</code> front end code was removed while separating
974 out language independence.</li>
Jay Foadf42e9b22011-08-04 10:43:43 +0000975 <li>The <code>LowerSetJmp</code> pass wasn't used effectively by any
976 target and has been removed.</li>
Rafael Espindolaf940a1a2011-08-30 23:03:45 +0000977 <li>The old <code>TailDup</code> pass was not used in the standard pipeline
978 and was unable to update ssa form, so it has been removed.
Eli Friedmanf03bb262011-08-12 22:50:01 +0000979 <li>The syntax of volatile loads and stores in IR has been changed to
980 "<code>load volatile</code>"/"<code>store volatile</code>". The old
981 syntax ("<code>volatile load</code>"/"<code>volatile store</code>")
982 is still accepted, but is now considered deprecated.</li>
Eli Friedman526e1bb2011-10-26 00:55:23 +0000983 <li>The old atomic intrinscs (<code>llvm.memory.barrier</code> and
984 <code>llvm.atomic.*</code>) are now gone. Please use the new atomic
985 instructions, described in the <a href="Atomics.html">atomics guide</a>.
Devang Patelb34dd132008-10-14 20:03:43 +0000986</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000987
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000988<h4>Windows (32-bit)</h4>
989<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000990
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000991<ul>
992 <li>On Win32(MinGW32 and MSVC), Windows 2000 will not be supported.
993 Windows XP or higher is required.</li>
994</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000995
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000996</div>
997
Chris Lattnerf6662f92008-10-13 17:57:36 +0000998</div>
999
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001000<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001001<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +00001002<a name="api_changes">Internal API Changes</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001003</h3>
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001004
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001005<div>
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001006
Chris Lattner1efe27e2011-04-06 00:45:11 +00001007<p>In addition, many APIs have changed in this release. Some of the major
Bill Wendling16005252011-08-02 06:20:17 +00001008 LLVM API changes are:</p>
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001009
1010<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001011 <li>The biggest and most pervasive change is that llvm::Type's are no longer
1012 returned or accepted as 'const' values. Instead, just pass around
1013 non-const Type's.</li>
Chris Lattnerd1324302011-07-18 04:56:02 +00001014
Bill Wendling7b7fa742011-10-26 18:46:16 +00001015 <li><code>PHINode::reserveOperandSpace</code> has been removed. Instead, you
1016 must specify how many operands to reserve space for when you create the
1017 PHINode, by passing an extra argument
1018 into <code>PHINode::Create</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +00001019
Bill Wendling7b7fa742011-10-26 18:46:16 +00001020 <li>PHINodes no longer store their incoming BasicBlocks as operands. Instead,
1021 the list of incoming BasicBlocks is stored separately, and can be accessed
1022 with new functions <code>PHINode::block_begin</code>
1023 and <code>PHINode::block_end</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +00001024
Bill Wendling7b7fa742011-10-26 18:46:16 +00001025 <li>Various functions now take an <code>ArrayRef</code> instead of either a
1026 pair of pointers (or iterators) to the beginning and end of a range, or a
1027 pointer and a length. Others now return an <code>ArrayRef</code> instead
1028 of a reference to a <code>SmallVector</code>
1029 or <code>std::vector</code>. These include:
Jay Foad558d3762011-07-14 09:19:05 +00001030<ul>
1031<!-- Please keep this list sorted. -->
Jay Foada3efbb12011-07-15 08:37:34 +00001032<li><code>CallInst::Create</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001033<li><code>ComputeLinearIndex</code> (in <code>llvm/CodeGen/Analysis.h</code>)</li>
1034<li><code>ConstantArray::get</code></li>
1035<li><code>ConstantExpr::getExtractElement</code></li>
Jay Foaddab3d292011-07-21 14:31:17 +00001036<li><code>ConstantExpr::getGetElementPtr</code></li>
1037<li><code>ConstantExpr::getInBoundsGetElementPtr</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001038<li><code>ConstantExpr::getIndices</code></li>
1039<li><code>ConstantExpr::getInsertElement</code></li>
1040<li><code>ConstantExpr::getWithOperands</code></li>
Jay Foad1d2f5692011-07-19 13:32:40 +00001041<li><code>ConstantFoldCall</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
1042<li><code>ConstantFoldInstOperands</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
Jay Foad558d3762011-07-14 09:19:05 +00001043<li><code>ConstantVector::get</code></li>
1044<li><code>DIBuilder::createComplexVariable</code></li>
1045<li><code>DIBuilder::getOrCreateArray</code></li>
1046<li><code>ExtractValueInst::Create</code></li>
1047<li><code>ExtractValueInst::getIndexedType</code></li>
1048<li><code>ExtractValueInst::getIndices</code></li>
1049<li><code>FindInsertedValue</code> (in <code>llvm/Analysis/ValueTracking.h</code>)</li>
Jay Foadca12a212011-07-19 14:42:50 +00001050<li><code>gep_type_begin</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
1051<li><code>gep_type_end</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
Jay Foada9203102011-07-25 09:48:08 +00001052<li><code>GetElementPtrInst::Create</code></li>
1053<li><code>GetElementPtrInst::CreateInBounds</code></li>
1054<li><code>GetElementPtrInst::getIndexedType</code></li>
Jay Foadb60e8512011-07-21 14:42:51 +00001055<li><code>InsertValueInst::Create</code></li>
1056<li><code>InsertValueInst::getIndices</code></li>
1057<li><code>InvokeInst::Create</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +00001058<li><code>IRBuilder::CreateCall</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001059<li><code>IRBuilder::CreateExtractValue</code></li>
Jay Foad0a2a60a2011-07-22 08:16:57 +00001060<li><code>IRBuilder::CreateGEP</code></li>
1061<li><code>IRBuilder::CreateInBoundsGEP</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001062<li><code>IRBuilder::CreateInsertValue</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +00001063<li><code>IRBuilder::CreateInvoke</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001064<li><code>MDNode::get</code></li>
1065<li><code>MDNode::getIfExists</code></li>
1066<li><code>MDNode::getTemporary</code></li>
1067<li><code>MDNode::getWhenValsUnresolved</code></li>
Jay Foadb9b54eb2011-07-19 15:07:52 +00001068<li><code>SimplifyGEPInst</code> (in <code>llvm/Analysis/InstructionSimplify.h</code>)</li>
Jay Foad8fbbb392011-07-19 14:01:37 +00001069<li><code>TargetData::getIndexedOffset</code></li>
Jay Foad558d3762011-07-14 09:19:05 +00001070</ul></li>
1071
Bill Wendling7b7fa742011-10-26 18:46:16 +00001072 <li>All forms of <code>StringMap::getOrCreateValue</code> have been remove
1073 except for the one which takes a <code>StringRef</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +00001074
Bill Wendling7b7fa742011-10-26 18:46:16 +00001075 <li>The <code>LLVMBuildUnwind</code> function from the C API was removed. The
1076 LLVM <code>unwind</code> instruction has been deprecated for a long time
1077 and isn't used by the current front-ends. So this was removed during the
1078 exception handling rewrite.</li>
Bill Wendling16005252011-08-02 06:20:17 +00001079
Bill Wendling7b7fa742011-10-26 18:46:16 +00001080 <li>The <code>LLVMAddLowerSetJmpPass</code> function from the C API was
1081 removed because the <code>LowerSetJmp</code> pass was removed.</li>
Bill Wendling2626dba2011-08-03 22:18:20 +00001082
Bill Wendling7b7fa742011-10-26 18:46:16 +00001083 <li>The <code>DIBuilder</code> interface used by front ends to encode
1084 debugging information in the LLVM IR now expects clients to
1085 use <code>DIBuilder::finalize()</code> at the end of translation unit to
1086 complete debugging information encoding.</li>
Devang Patel6326a422011-08-15 23:00:00 +00001087
Bill Wendling7b7fa742011-10-26 18:46:16 +00001088 <li>The way the type system works has been
1089 rewritten: <code>PATypeHolder</code> and <code>OpaqueType</code> are gone,
1090 and all APIs deal with <code>Type*</code> instead of <code>const
1091 Type*</code>. If you need to create recursive structures, then create a
1092 named structure, and use <code>setBody()</code> when all its elements are
1093 built. Type merging and refining is gone too: named structures are not
1094 merged with other structures, even if their layout is identical. (of
1095 course anonymous structures are still uniqued by layout).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +00001096
Bill Wendling7b7fa742011-10-26 18:46:16 +00001097 <li>TargetSelect.h moved to Support/ from Target/</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +00001098
Bill Wendling7b7fa742011-10-26 18:46:16 +00001099 <li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls (for
1100 example <code>llvm.memset.i32</code>).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +00001101
Bill Wendling7b7fa742011-10-26 18:46:16 +00001102 <li>It is mandatory to initialize all out-of-tree passes too and their dependencies now with
1103 <code>INITIALIZE_PASS{BEGIN,END,}</code>
1104 and <code>INITIALIZE_{PASS,AG}_DEPENDENCY</code>.</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +00001105
Bill Wendling7b7fa742011-10-26 18:46:16 +00001106 <li>The interface for MemDepResult in MemoryDependenceAnalysis has been
1107 enhanced with new return types Unknown and NonFuncLocal, in addition to
1108 the existing types Clobber, Def, and NonLocal.</li>
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001109</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001110
Daniel Dunbarf0233c62010-10-04 20:11:41 +00001111</div>
Chris Lattnerf6662f92008-10-13 17:57:36 +00001112
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001113</div>
1114
Chris Lattner79c3fe12003-10-02 04:57:28 +00001115<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001116<h2>
Misha Brukman500bc302003-11-22 00:38:41 +00001117 <a name="knownproblems">Known Problems</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001118</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001119<!-- *********************************************************************** -->
1120
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001121<div>
Misha Brukman500bc302003-11-22 00:38:41 +00001122
Bill Wendling7b7fa742011-10-26 18:46:16 +00001123<p>This section contains significant known problems with the LLVM system, listed
1124 by component. If you run into a problem, please check
1125 the <a href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
1126 there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001127
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001128<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001129<h3>
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001130 <a name="experimental">Experimental features included with this release</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001131</h3>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001132
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001133<div>
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001134
Misha Brukman6df9e2c2004-05-12 21:46:05 +00001135<p>The following components of this LLVM release are either untested, known to
Bill Wendling7b7fa742011-10-26 18:46:16 +00001136 be broken or unreliable, or are in early development. These components
1137 should not be relied on, and bugs should not be filed against them, but they
1138 may be useful to some people. In particular, if you would like to work on
1139 one of these components, please contact us on
1140 the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev
1141 list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001142
1143<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001144 <li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ and
1145 XCore backends are experimental.</li>
1146
1147 <li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets other
1148 than darwin and ELF X86 systems.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +00001149</ul>
1150
1151</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001152
Misha Brukman500bc302003-11-22 00:38:41 +00001153<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001154<h3>
Chris Lattner26299222006-11-18 07:51:14 +00001155 <a name="x86-be">Known problems with the X86 back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001156</h3>
John Criswellc0c186d2005-11-08 21:11:33 +00001157
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001158<div>
John Criswellc0c186d2005-11-08 21:11:33 +00001159
1160<ul>
Anton Korobeynikova6094be2008-06-08 10:24:13 +00001161 <li>The X86 backend does not yet support
Bill Wendling7b7fa742011-10-26 18:46:16 +00001162 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
1163 floating point stack</a>. It supports the 'f' and 't' constraints, but
1164 not 'u'.</li>
1165
Dan Gohman8207ba92008-06-08 23:05:11 +00001166 <li>The X86-64 backend does not yet support the LLVM IR instruction
Bill Wendling7b7fa742011-10-26 18:46:16 +00001167 <tt>va_arg</tt>. Currently, front-ends support variadic argument
1168 constructs on X86-64 by lowering them manually.</li>
1169
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +00001170 <li>Windows x64 (aka Win64) code generator has a few issues.
1171 <ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001172 <li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt> due
1173 to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
1174 It is fixed
1175 in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
1176
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +00001177 <li>Miss-aligned MOVDQA might crash your program. It is due to
Bill Wendling7b7fa742011-10-26 18:46:16 +00001178 <a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>, lack
1179 of handling aligned internal globals.</li>
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +00001180 </ul>
1181 </li>
1182
Chris Lattner26299222006-11-18 07:51:14 +00001183</ul>
1184
1185</div>
1186
1187<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001188<h3>
Chris Lattner26299222006-11-18 07:51:14 +00001189 <a name="ppc-be">Known problems with the PowerPC back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001190</h3>
Chris Lattner26299222006-11-18 07:51:14 +00001191
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001192<div>
Chris Lattner26299222006-11-18 07:51:14 +00001193
1194<ul>
Roman Divacky223764c2011-10-30 07:49:04 +00001195 <li>The PPC32/ELF support lacks PIC support.</li>
Chris Lattner26299222006-11-18 07:51:14 +00001196</ul>
1197
1198</div>
1199
1200<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001201<h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001202 <a name="arm-be">Known problems with the ARM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001203</h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001204
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001205<div>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001206
1207<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001208 <li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
1209 processors, thumb programs can crash or produce wrong results
1210 (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
1211
1212 <li>Compilation for ARM Linux OABI (old ABI) is supported but not fully
1213 tested.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001214</ul>
1215
1216</div>
1217
1218<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001219<h3>
Chris Lattner26299222006-11-18 07:51:14 +00001220 <a name="sparc-be">Known problems with the SPARC back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001221</h3>
Chris Lattner26299222006-11-18 07:51:14 +00001222
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001223<div>
Chris Lattner26299222006-11-18 07:51:14 +00001224
1225<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001226 <li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
1227 support the 64-bit SPARC ABI (-m64).</li>
Chris Lattner26299222006-11-18 07:51:14 +00001228</ul>
1229
1230</div>
1231
1232<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001233<h3>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +00001234 <a name="mips-be">Known problems with the MIPS back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001235</h3>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +00001236
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001237<div>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +00001238
1239<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001240 <li>64-bit MIPS targets are not supported yet.</li>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +00001241</ul>
1242
1243</div>
1244
1245<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001246<h3>
Chris Lattner26299222006-11-18 07:51:14 +00001247 <a name="alpha-be">Known problems with the Alpha back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001248</h3>
Chris Lattner26299222006-11-18 07:51:14 +00001249
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001250<div>
Chris Lattner26299222006-11-18 07:51:14 +00001251
1252<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001253 <li>On 21164s, some rare FP arithmetic sequences which may trap do not have
1254 the appropriate nops inserted to ensure restartability.</li>
John Criswellc0c186d2005-11-08 21:11:33 +00001255</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001256
John Criswellc0c186d2005-11-08 21:11:33 +00001257</div>
1258
Chris Lattner26299222006-11-18 07:51:14 +00001259<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001260<h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +00001261 <a name="c-be">Known problems with the C back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001262</h3>
Chris Lattner26299222006-11-18 07:51:14 +00001263
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001264<div>
Chris Lattner26299222006-11-18 07:51:14 +00001265
Chris Lattner3016ee92010-09-29 05:34:42 +00001266<p>The C backend has numerous problems and is not being actively maintained.
Bill Wendling7b7fa742011-10-26 18:46:16 +00001267 Depending on it for anything serious is not advised.</p>
Chris Lattner3016ee92010-09-29 05:34:42 +00001268
Chris Lattner26299222006-11-18 07:51:14 +00001269<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +00001270 <li><a href="http://llvm.org/PR802">The C backend has only basic support for
1271 inline assembly code</a>.</li>
1272
1273 <li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
1274 C++ programs</a>, preventing intermixing between C++ compiled by the CBE
1275 and C++ code compiled with <tt>llc</tt> or native compilers.</li>
1276
1277 <li>The C backend does not support all exception handling constructs.</li>
1278
1279 <li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +00001280</ul>
1281
1282</div>
John Criswellc0c186d2005-11-08 21:11:33 +00001283
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001284</div>
1285
Chris Lattner79c3fe12003-10-02 04:57:28 +00001286<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001287<h2>
Misha Brukman500bc302003-11-22 00:38:41 +00001288 <a name="additionalinfo">Additional Information</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +00001289</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001290<!-- *********************************************************************** -->
1291
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +00001292<div>
Misha Brukman500bc302003-11-22 00:38:41 +00001293
Bill Wendling7b7fa742011-10-26 18:46:16 +00001294<p>A wide variety of additional information is available on
1295 the <a href="http://llvm.org/">LLVM web page</a>, in particular in
1296 the <a href="http://llvm.org/docs/">documentation</a> section. The web page
1297 also contains versions of the API documentation which is up-to-date with the
1298 Subversion version of the source code. You can access versions of these
1299 documents specific to this release by going into the "<tt>llvm/doc/</tt>"
1300 directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001301
Misha Brukman500bc302003-11-22 00:38:41 +00001302<p>If you have any questions or comments about LLVM, please feel free to contact
Bill Wendling7b7fa742011-10-26 18:46:16 +00001303 us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001304
Misha Brukman500bc302003-11-22 00:38:41 +00001305</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +00001306
1307<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +00001308
Misha Brukman500bc302003-11-22 00:38:41 +00001309<hr>
Misha Brukman2061e892003-11-22 01:23:39 +00001310<address>
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Misha Brukman2061e892003-11-22 01:23:39 +00001315
Chris Lattnerb4b0ce72007-05-18 00:44:29 +00001316 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +00001317 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +00001318</address>
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