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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 553284e69a08cc9177eff70815bc6d6681077711 / . / docs / ReleaseNotes.html
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Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]7 <title>LLVM 3.0 Release Notes</title>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]8</head>
9<body>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]10
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]11<h1>LLVM 3.0 Release Notes</h1>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]12
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]13<img align=right src="http://llvm.org/img/DragonSmall.png"
Gabor Greifee2187a2010-04-22 10:21:43 +0000[diff] [blame]14 width="136" height="136" alt="LLVM Dragon Logo">
Chris Lattner0e464a92010-03-17 04:02:39 +0000[diff] [blame]15
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]16<ol>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]17 <li><a href="#intro">Introduction</a></li>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]18 <li><a href="#subproj">Sub-project Status Update</a></li>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]19 <li><a href="#externalproj">External Projects Using LLVM 3.0</a></li>
20 <li><a href="#whatsnew">What's New in LLVM 3.0?</a></li>
Chris Lattner4b538b92004-04-30 22:17:12 +0000[diff] [blame]21 <li><a href="GettingStarted.html">Installation Instructions</a></li>
Dan Gohman44aa9212008-10-14 16:23:02 +0000[diff] [blame]22 <li><a href="#knownproblems">Known Problems</a></li>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]23 <li><a href="#additionalinfo">Additional Information</a></li>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]24</ol>
25
Chris Lattner7911ce22004-05-23 21:07:27 +0000[diff] [blame]26<div class="doc_author">
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]27 <p>Written by the <a href="http://llvm.org/">LLVM Team</a></p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]28</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]29
Chris Lattner49123fd2011-04-06 06:29:50 +0000[diff] [blame]30<!--
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]31<h1 style="color:red">These are in-progress notes for the upcoming LLVM 3.0
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]32release.<br>
33You may prefer the
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]34<a href="http://llvm.org/releases/2.9/docs/ReleaseNotes.html">LLVM 2.9
Dan Gohmanb44f6c62010-05-03 23:51:05 +0000[diff] [blame]35Release Notes</a>.</h1>
Chris Lattner49123fd2011-04-06 06:29:50 +0000[diff] [blame]36 -->
Jeffrey Yasskinbec48772010-01-28 01:14:43 +0000[diff] [blame]37
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]38<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]39<h2>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]40 <a name="intro">Introduction</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]41</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]42<!-- *********************************************************************** -->
43
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]44<div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]45
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]46<p>This document contains the release notes for the LLVM Compiler
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]47 Infrastructure, release 3.0. Here we describe the status of LLVM, including
48 major improvements from the previous release and significant known problems.
49 All LLVM releases may be downloaded from
50 the <a href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
Chris Lattner19092612003-10-02 16:38:05 +0000[diff] [blame]51
Chris Lattner7506b1d2004-12-07 08:04:13 +0000[diff] [blame]52<p>For more information about LLVM, including information about the latest
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]53 release, please check out the <a href="http://llvm.org/">main LLVM web
54 site</a>. If you have questions or comments,
55 the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM
56 Developer's Mailing List</a> is a good place to send them.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]57
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]58<p>Note that if you are reading this file from a Subversion checkout or the main
59 LLVM web page, this document applies to the <i>next</i> release, not the
60 current one. To see the release notes for a specific release, please see the
61 <a href="http://llvm.org/releases/">releases page</a>.</p>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]62
63</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]64
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame]65<!-- Features that need text if they're finished for 3.1:
66 ARM EHABI
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]67 combiner-aa?
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]68 strong phi elim
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]69 loop dependence analysis
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]70 CorrelatedValuePropagation
Chris Lattnere4dc1962011-04-05 23:22:33 +0000[diff] [blame]71 lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1.
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]72 -->
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]73
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]74<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]75<h2>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]76 <a name="subproj">Sub-project Status Update</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]77</h2>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]78<!-- *********************************************************************** -->
Chris Lattnerea34f642008-06-08 21:34:41 +0000[diff] [blame]79
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]80<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]81
82<p>The LLVM 3.0 distribution currently consists of code from the core LLVM
83 repository (which roughly includes the LLVM optimizers, code generators and
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]84 supporting tools), and the Clang repository. In
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]85 addition to this code, the LLVM Project includes other sub-projects that are
86 in development. Here we include updates on these subprojects.</p>
Chris Lattner96a445e2008-10-13 18:01:01 +0000[diff] [blame]87
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]88<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]89<h3>
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]90<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]91</h3>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]92
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]93<div>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]94
Chris Lattner095539f2010-04-26 17:42:18 +0000[diff] [blame]95<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]96 C++, and Objective-C languages. Clang aims to provide a better user
97 experience through expressive diagnostics, a high level of conformance to
98 language standards, fast compilation, and low memory use. Like LLVM, Clang
99 provides a modular, library-based architecture that makes it suitable for
100 creating or integrating with other development tools. Clang is considered a
101 production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
102 (32- and 64-bit), and for darwin/arm targets.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]103
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]104<p>In the LLVM 3.0 time-frame, the Clang team has made many improvements:</p>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]105
106<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]107 <li>Greatly improved support for building C++ applications, with greater
108 stability and better diagnostics.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]109
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]110 <li><a href="http://clang.llvm.org/cxx_status.html">Improved support</a> for
111 the <a href="http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=50372">C++
112 2011</a> standard, including implementations of non-static data member
113 initializers, alias templates, delegating constructors, the range-based
114 for loop, and implicitly-generated move constructors and move assignment
115 operators, among others.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]116
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]117 <li>Implemented support for some features of the upcoming C1x standard,
118 including static assertions and generic selections.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]119
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]120 <li>Better detection of include and linking paths for system headers and
121 libraries, especially for Linux distributions.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]122
David Chisnall553284e2011-11-26 10:56:17 +0000[diff] [blame^]123 <li>Several improvements to Objective-C support, including:
124
125 <ul>
126 <li><a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html">
127 Automatic Reference Counting</a> (ARC) and an improved memory model
128 cleanly separating object and C memory.</li>
129
130 <li>A migration tool for moving legacy code to ARC</li>
131
132 <li>Better support for data hiding, allowing instance variables to be
133 declared in implementation contexts or class extensions</li>
134 <li>Weak linking for classes</li>
135 <li>Improved static type checking by inferring the return type of methods
136 such as +alloc and -init.</li>
137 </ul>
138
139 Some new features require either the Mac OS X 10.7 / iOS 5 Objective-C
140 runtime, or version 1.6 or later of the GNUstep Objective-C runtime
141 version.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]142
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]143 <li>Implemented a number of optimizations in <tt>libclang</tt>, the Clang C
144 interface, to improve the performance of code completion and the mapping
145 from source locations to abstract syntax tree nodes.</li>
Douglas Gregorba087df2011-10-15 00:48:01 +0000[diff] [blame]146</ul>
147
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]148
Duncan Sandsf3ba7af2011-04-06 08:07:40 +0000[diff] [blame]149<p>If Clang rejects your code but another compiler accepts it, please take a
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]150 look at the <a href="http://clang.llvm.org/compatibility.html">language
151 compatibility</a> guide to make sure this is not intentional or a known
152 issue.</p>
Bill Wendling741748a2008-10-27 09:27:33 +0000[diff] [blame]153
Chris Lattnerfb97b2d2008-10-13 18:11:54 +0000[diff] [blame]154</div>
155
156<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]157<h3>
Duncan Sands528a5102011-04-04 11:09:08 +0000[diff] [blame]158<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]159</h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]160
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]161<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]162<p><a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
163 <a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
Duncan Sands77352c92011-11-10 18:44:29 +0000[diff] [blame]164 optimizers and code generators with LLVM's. It works with gcc-4.5 or gcc-4.6,
165 targets the x86-32 and x86-64 processor families, and has been successfully
166 used on the Darwin, FreeBSD, KFreeBSD, Linux and OpenBSD platforms. It fully
167 supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C
168 and Obj-C++.</p>
Duncan Sands749fd832010-04-02 09:23:15 +0000[diff] [blame]169
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]170<p>The 3.0 release has the following notable changes:</p>
171
Duncan Sands77352c92011-11-10 18:44:29 +0000[diff] [blame]172 <li>GCC version 4.6 is now fully supported.</li>
173
174 <li>Patching and building GCC is no longer required: the plugin should work
175 with your system GCC (version 4.5 or 4.6; on Debian/Ubuntu systems the
176 gcc-4.5-plugin-dev or gcc-4.6-plugin-dev package is also needed).</li>
177
178 <li>The <tt>-fplugin-arg-dragonegg-enable-gcc-optzns</tt> option, which runs
179 GCC's optimizers as well as LLVM's, now works much better. This is the
180 option to use if you want ultimate performance! It not yet completely
181 stable: it may cause the plugin to crash.</li>
182
183 <li>The type and constant conversion logic has been almost entirely rewritten,
184 fixing a multitude of obscure bugs.</li>
185
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]186<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]187<!--
188<li></li>
189-->
Duncan Sands4b1da2b2010-09-30 17:37:34 +0000[diff] [blame]190</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]191
192</div>
193
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]194<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]195<h3>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]196<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]197</h3>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]198
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]199<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]200
201<p>The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
202 is a simple library that provides an implementation of the low-level
203 target-specific hooks required by code generation and other runtime
204 components. For example, when compiling for a 32-bit target, converting a
205 double to a 64-bit unsigned integer is compiled into a runtime call to the
206 "__fixunsdfdi" function. The compiler-rt library provides highly optimized
207 implementations of this and other low-level routines (some are 3x faster than
208 the equivalent libgcc routines).</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]209
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]210<p>In the LLVM 3.0 timeframe,</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]211
212</div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]213
214<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]215<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]216<a name="lldb">LLDB: Low Level Debugger</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]217</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]218
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]219<div>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]220
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]221<p>LLDB has advanced by leaps and bounds in the 3.0 timeframe. It is
222 dramatically more stable and useful, and includes both a
223 new <a href="http://lldb.llvm.org/tutorial.html">tutorial</a> and
224 a <a href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
225 GDB</a>.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]226
227</div>
228
229<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]230<h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]231<a name="libc++">libc++: C++ Standard Library</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]232</h3>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]233
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]234<div>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]235
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]236<p>Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
237 licensed</a> under the MIT and UIUC license, allowing it to be used more
238 permissively.</p>
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]239
David Chisnall553284e2011-11-26 10:56:17 +0000[diff] [blame^]240<p>Libc++ has been ported to FreeBSD and imported into the base system. It is
241 planned to be the default STL implementation for FreeBSD 10.</p>
242
Chris Lattnere07043c2010-09-29 05:30:03 +0000[diff] [blame]243</div>
244
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]245
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]246<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]247<h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]248<a name="LLBrowse">LLBrowse: IR Browser</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]249</h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]250
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]251<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]252
253<p><a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
254 LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
255 module and displays its contents as an expandable tree view, facilitating an
256 easy way to inspect types, functions, global variables, or metadata nodes. It
257 is fully cross-platform, being based on the popular wxWidgets GUI
258 toolkit.</p>
259
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]260</div>
261
262<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]263<h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]264<a name="vmkit">VMKit</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]265</h3>
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]266
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]267<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]268
Nicolas Geoffray54d5df92011-11-10 23:37:56 +0000[diff] [blame]269 <p>The <a href="http://vmkit.llvm.org/">VMKit project</a> is an
270 implementation of a Java Virtual Machine (Java VM or JVM) that uses LLVM for
271 static and just-in-time compilation.
272
273 <p>In the LLVM 3.0 time-frame, VMKit has had significant improvements on both
274 runtime and startup performance:</p>
275
276 <ul>
277 <li>Precompilation: by compiling ahead of time a small subset of Java's core
278 library, the startup performance have been highly optimized to the point that
279 running a 'Hello World' program takes less than 30 milliseconds.</li>
280
281 <li>Customization: by customizing virtual methods for individual classes,
282 the VM can statically determine the target of a virtual call, and decide to
283 inline it.</li>
284
285 <li>Inlining: the VM does more inlining than it did before, by allowing more
286 bytecode instructions to be inlined, and thanks to customization. It also
287 inlines GC barriers, and object allocations.</li>
288
289 <li>New exception model: the generated code for a method that does not do
290 any try/catch is not penalized anymore by the eventuality of calling a
291 method that throws an exception. Instead, the method that throws the
292 exception jumps directly to the method that could catch it.</li>
293 </ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]294
Chris Lattner3d6a80a2011-04-07 03:08:22 +0000[diff] [blame]295</div>
296
297
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]298<!--=========================================================================-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]299<!--
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]300<h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]301<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]302</h3>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]303
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]304<div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]305<p>
306<a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for
307programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths
308through the application and records state transitions that lead to fault
309states. This allows it to construct testcases that lead to faults and can even
310be used to verify some algorithms.
311</p>
312
Chris Lattnerbe2e1b52011-03-10 07:43:44 +0000[diff] [blame]313<p>UPDATE!</p>
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]314</div>-->
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]315
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]316</div>
Daniel Dunbar97b01a82010-10-04 17:39:47 +0000[diff] [blame]317
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]318<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]319<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]320 <a name="externalproj">External Open Source Projects Using LLVM 3.0</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]321</h2>
Chris Lattnerab68e9e2009-02-26 22:33:38 +0000[diff] [blame]322<!-- *********************************************************************** -->
323
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]324<div>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]325
326<p>An exciting aspect of LLVM is that it is used as an enabling technology for
327 a lot of other language and tools projects. This section lists some of the
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]328 projects that have already been updated to work with LLVM 3.0.</p>
Chris Lattner75547712010-10-03 23:49:06 +0000[diff] [blame]329
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]330<!--=========================================================================-->
Bill Wendling7be6bc52011-10-26 00:17:54 +0000[diff] [blame]331<h3>AddressSanitizer</h3>
332
333<div>
334
335<p><a href="http://code.google.com/p/address-sanitizer/">AddressSanitizer</a>
336 uses compiler instrumentation and a specialized malloc library to find C/C++
337 bugs such as use-after-free and out-of-bound accesses to heap, stack, and
338 globals. The key feature of the tool is speed: the average slowdown
339 introduced by AddressSanitizer is less than 2x.</p>
340
341</div>
342
343<!--=========================================================================-->
Bill Wendling29817ea2011-10-26 00:14:36 +0000[diff] [blame]344<h3>ClamAV</h3>
345
346<div>
Bill Wendlingf2a78332011-10-25 01:01:42 +0000[diff] [blame]347
Bill Wendling29817ea2011-10-26 00:14:36 +0000[diff] [blame]348<p><a href="http://www.clamav.net">Clam AntiVirus</a> is an open source (GPL)
349 anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
350 gateways.</p>
351
352<p>Since version 0.96 it
353 has <a href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
354 signatures</a> that allow writing detections for complex malware.</p>
355
356<p>It uses LLVM's JIT to speed up the execution of bytecode on X86, X86-64,
357 PPC32/64, falling back to its own interpreter otherwise. The git version was
358 updated to work with LLVM 3.0.</p>
359
360</div>
361
362<!--=========================================================================-->
Tobias Grosserae5a6fd2011-11-14 09:09:26 +0000[diff] [blame]363<h3>clang_complete for VIM</h3>
364
365<div>
366
367<p><a href="https://github.com/Rip-Rip/clang_complete">clang_complete</a> is a
368 VIM plugin, that provides accurate C/C++ autocompletion using the clang front
369 end. The development version of clang complete, can directly use libclang
370 which can maintain a cache to speed up auto completion.</p>
371
372</div>
373
374<!--=========================================================================-->
Bill Wendling65d1f412011-10-26 18:23:06 +0000[diff] [blame]375<h3>clReflect</h3>
376
377<div>
378
379<p><a href="https://bitbucket.org/dwilliamson/clreflect">clReflect</a> is a C++
380 parser that uses clang/LLVM to derive a light-weight reflection database
381 suitable for use in game development. It comes with a very simple runtime
382 library for loading and querying the database, requiring no external
383 dependencies (including CRT), and an additional utility library for object
384 management and serialisation.</p>
385
386</div>
387
388<!--=========================================================================-->
Bill Wendling63507d12011-10-29 01:10:01 +0000[diff] [blame]389<h3>Cling C++ Interpreter</h3>
390
391<div>
392
393<p><a href="http://cern.ch/cling">Cling</a> is an interactive compiler interface
394 (aka C++ interpreter). It uses LLVM's JIT and clang; it currently supports
395 C++ and C. It has a prompt interface, runs source files, calls into shared
396 libraries, prints the value of expressions, even does runtime lookup of
397 identifiers (dynamic scopes). And it just behaves like one would expect from
398 an interpreter.</p>
399
400</div>
401
402<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]403<h3>Crack Programming Language</h3>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]404
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]405<div>
Bill Wendling55d6e672011-11-03 20:10:01 +0000[diff] [blame]406
407<p><a href="http://code.google.com/p/crack-language/">Crack</a> aims to provide
408 the ease of development of a scripting language with the performance of a
409 compiled language. The language derives concepts from C++, Java and Python,
410 incorporating object-oriented programming, operator overloading and strong
411 typing.</p>
412
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]413</div>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]414
415<!--=========================================================================-->
Bill Wendlingb99486f2011-11-08 05:22:54 +0000[diff] [blame]416<h3>Eero</h3>
417
418<div>
419
420<p><a href="http://eerolanguage.org/">Eero</a> is a fully
421 header-and-binary-compatible dialect of Objective-C 2.0, implemented with a
422 patched version of the Clang/LLVM compiler. It features a streamlined syntax,
423 Python-like indentation, and new operators, for improved readability and
424 reduced code clutter. It also has new features such as limited forms of
425 operator overloading and namespaces, and strict (type-and-operator-safe)
426 enumerations. It is inspired by languages such as Smalltalk, Python, and
427 Ruby.</p>
428
429</div>
430
431<!--=========================================================================-->
Chris Lattneradb417a2011-11-25 20:28:16 +0000[diff] [blame]432<h3>FAUST Real-Time Audio Signal Processing Language</h3>
433
434<div>
435
436<p><a href="http://faust.grame.fr/">FAUST</a> is a compiled language for
437 real-time audio signal processing. The name FAUST stands for Functional
438 AUdio STream. Its programming model combines two approaches: functional
439 programming and block diagram composition. In addition with the C, C++, Java
440 output formats, the Faust compiler can now generate LLVM bitcode, and works
441 with LLVM 2.7-3.0.
442 </p>
443
444</div>
445
446<!--=========================================================================-->
Bill Wendlingf9778192011-10-26 00:09:55 +0000[diff] [blame]447<h3>Glasgow Haskell Compiler (GHC)</h3>
448
449<div>
450
451<p>GHC is an open source, state-of-the-art programming suite for Haskell, a
452 standard lazy functional programming language. It includes an optimizing
453 static compiler generating good code for a variety of platforms, together
454 with an interactive system for convenient, quick development.</p>
455
456<p>GHC 7.0 and onwards include an LLVM code generator, supporting LLVM 2.8 and
457 later. Since LLVM 2.9, GHC now includes experimental support for the ARM
458 platform with LLVM 3.0.</p>
459
460</div>
461
462<!--=========================================================================-->
Bill Wendlingf62333d2011-10-25 20:35:31 +0000[diff] [blame]463<h3>gwXscript</h3>
464
465<div>
466
467<p><a href="http://botwars.tk/gwscript/">gwXscript</a> is an object oriented,
Bill Wendling7c38de22011-10-26 04:24:15 +0000[diff] [blame]468 aspect oriented programming language which can create both executables (ELF,
Bill Wendlingf62333d2011-10-25 20:35:31 +0000[diff] [blame]469 EXE) and shared libraries (DLL, SO, DYNLIB). The compiler is implemented in
470 its own language and translates scripts into LLVM-IR which can be optimized
471 and translated into native code by the LLVM framework. Source code in
472 gwScript contains definitions that expand the namespaces. So you can build
473 your project and simply 'plug out' features by removing a file. The remaining
474 project does not leave scars since you directly separate concerns by the
475 'template' feature of gwX. It is also possible to add new features to a
476 project by just adding files and without editing the original project. This
477 language is used for example to create games or content management systems
478 that should be extendable.</p>
479
480<p>gwXscript is strongly typed and offers comfort with its native types string,
481 hash and array. You can easily write new libraries in gwXscript or native
482 code. gwXscript is type safe and users should not be able to crash your
483 program or execute malicious code except code that is eating CPU time.</p>
484
485</div>
486
487<!--=========================================================================-->
Bill Wendling50cacc82011-10-26 22:55:18 +0000[diff] [blame]488<h3>include-what-you-use</h3>
489
490<div>
491
492<p><a href="http://code.google.com/p/include-what-you-use">include-what-you-use</a>
493 is a tool to ensure that a file directly <code>#include</code>s
494 all <code>.h</code> files that provide a symbol that the file uses. It also
495 removes superfluous <code>#include</code>s from source files.</p>
496
497</div>
498
499<!--=========================================================================-->
Bill Wendling32dc4d92011-11-07 22:05:17 +0000[diff] [blame]500<h3>ispc: The Intel SPMD Program Compiler</h3>
501
502<div>
503
504<p><a href="http://ispc.github.com">ispc</a> is a compiler for "single program,
505 multiple data" (SPMD) programs. It compiles a C-based SPMD programming
506 language to run on the SIMD units of CPUs; it often delivers 5-6x speedups on
507 a single core of a CPU with an 8-wide SIMD unit compared to serial code,
508 while still providing a clean and easy-to-understand programming model. For
509 an introduction to the language and its performance,
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]510 see <a href="http://ispc.github.com/example.html">the walkthrough</a> of a short
Bill Wendling32dc4d92011-11-07 22:05:17 +0000[diff] [blame]511 example program. ispc is licensed under the BSD license.</p>
512
513</div>
Chris Lattnercc089772011-11-25 20:36:17 +0000[diff] [blame]514
515<!--=========================================================================-->
516<h3>The Julia Programming Language</h3>
517
518<div>
519
520<p><a href="http://github.com/JuliaLang/julia">Julia</a> is a high-level,
521 high-performance dynamic language for technical
522 computing. It provides a sophisticated compiler, distributed parallel
523 execution, numerical accuracy, and an extensive mathematical function
524 library. The compiler uses type inference to generate fast code
525 without any type declarations, and uses LLVM's optimization passes and
526 JIT compiler. The language is designed around multiple dispatch,
527 giving programs a large degree of flexibility. It is ready for use on many
528 kinds of problems.</p>
529</div>
Bill Wendling32dc4d92011-11-07 22:05:17 +0000[diff] [blame]530
531<!--=========================================================================-->
Bill Wendling57fd8762011-10-26 18:20:54 +0000[diff] [blame]532<h3>LanguageKit and Pragmatic Smalltalk</h3>
533
534<div>
535
536<p><a href="http://etoileos.com/etoile/features/languagekit/">LanguageKit</a> is
537 a framework for implementing dynamic languages sharing an object model with
538 Objective-C. It provides static and JIT compilation using LLVM along with
539 its own interpreter. Pragmatic Smalltalk is a dialect of Smalltalk, built on
540 top of LanguageKit, that interfaces directly with Objective-C, sharing the
541 same object representation and message sending behaviour. These projects are
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000[diff] [blame]542 developed as part of the &Eacute;toil&eacute; desktop environment.</p>
Bill Wendling57fd8762011-10-26 18:20:54 +0000[diff] [blame]543
544</div>
545
546<!--=========================================================================-->
Bill Wendling03250532011-11-01 04:08:23 +0000[diff] [blame]547<h3>LuaAV</h3>
548
549<div>
550
551<p><a href="http://lua-av.mat.ucsb.edu/blog/">LuaAV</a> is a real-time
552 audiovisual scripting environment based around the Lua language and a
553 collection of libraries for sound, graphics, and other media protocols. LuaAV
554 uses LLVM and Clang to JIT compile efficient user-defined audio synthesis
555 routines specified in a declarative syntax.</p>
556
557</div>
558
559<!--=========================================================================-->
Bill Wendlingd4821b82011-10-26 00:16:17 +0000[diff] [blame]560<h3>Mono</h3>
561
562<div>
563
564<p>An open source, cross-platform implementation of C# and the CLR that is
565 binary compatible with Microsoft.NET. Has an optional, dynamically-loaded
566 LLVM code generation backend in Mini, the JIT compiler.</p>
567
568<p>Note that we use a Git mirror of LLVM with some patches. See:
569 https://github.com/mono/llvm</p>
570
571</div>
572
573<!--=========================================================================-->
Tobias Grosser093cb7e2011-11-14 09:09:23 +0000[diff] [blame]574<h3>Polly</h3>
575
576<div>
577
578<p><a href="http://polly.grosser.es">Polly</a> is an advanced data-locality
579 optimizer and automatic parallelizer. It uses an advanced, mathematical
580 model to calculate detailed data dependency information which it uses to
581 optimize the loop structure of a program. Polly can speed up sequential code
582 by improving memory locality and consequently the cache use. Furthermore,
583 Polly is able to expose different kind of parallelism which it exploits by
584 introducing (basic) OpenMP and SIMD code. A mid-term goal of Polly is to
585 automatically create optimized GPU code.</p>
586
587</div>
588
589<!--=========================================================================-->
Bill Wendlingba226272011-10-25 20:37:45 +0000[diff] [blame]590<h3>Portable OpenCL (pocl)</h3>
591
592<div>
593
594<p>Portable OpenCL is an open source implementation of the OpenCL standard which
595 can be easily adapted for new targets. One of the goals of the project is
596 improving performance portability of OpenCL programs, avoiding the need for
597 target-dependent manual optimizations. A "native" target is included, which
598 allows running OpenCL kernels on the host (CPU).</p>
599
600</div>
601
602<!--=========================================================================-->
Bill Wendling0bad98c2011-10-25 20:39:06 +0000[diff] [blame]603<h3>Pure</h3>
604
605<div>
606<p><a href="http://pure-lang.googlecode.com/">Pure</a> is an
607 algebraic/functional programming language based on term rewriting. Programs
608 are collections of equations which are used to evaluate expressions in a
609 symbolic fashion. The interpreter uses LLVM as a backend to JIT-compile Pure
610 programs to fast native code. Pure offers dynamic typing, eager and lazy
611 evaluation, lexical closures, a hygienic macro system (also based on term
612 rewriting), built-in list and matrix support (including list and matrix
613 comprehensions) and an easy-to-use interface to C and other programming
614 languages (including the ability to load LLVM bitcode modules, and inline C,
615 C++, Fortran and Faust code in Pure programs if the corresponding LLVM-enabled
616 compilers are installed).</p>
617
618<p>Pure version 0.48 has been tested and is known to work with LLVM 3.0
619 (and continues to work with older LLVM releases &gt;= 2.5).</p>
620
621</div>
622
623<!--=========================================================================-->
Bill Wendling537d85b2011-10-26 00:12:04 +0000[diff] [blame]624<h3>Renderscript</h3>
625
626<div>
627
628<p><a href="http://developer.android.com/guide/topics/renderscript/index.html">Renderscript</a>
629 is Android's advanced 3D graphics rendering and compute API. It provides a
630 portable C99-based language with extensions to facilitate common use cases
631 for enhancing graphics and thread level parallelism. The Renderscript
632 compiler frontend is based on Clang/LLVM. It emits a portable bitcode format
633 for the actual compiled script code, as well as reflects a Java interface for
634 developers to control the execution of the compiled bitcode. Executable
635 machine code is then generated from this bitcode by an LLVM backend on the
636 device. Renderscript is thus able to provide a mechanism by which Android
637 developers can improve performance of their applications while retaining
638 portability.</p>
639
640</div>
641
642<!--=========================================================================-->
Bill Wendling7d5b6212011-10-25 20:40:26 +0000[diff] [blame]643<h3>SAFECode</h3>
644
645<div>
646
647<p><a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C/C++
648 compiler built using LLVM. It takes standard, unannotated C/C++ code,
649 analyzes the code to ensure that memory accesses and array indexing
650 operations are safe, and instruments the code with run-time checks when
651 safety cannot be proven statically. SAFECode can be used as a debugging aid
652 (like Valgrind) to find and repair memory safety bugs. It can also be used
653 to protect code from security attacks at run-time.</p>
654
655</div>
656
657<!--=========================================================================-->
Bill Wendling02b77b72011-10-26 07:38:19 +0000[diff] [blame]658<h3>The Stupid D Compiler (SDC)</h3>
659
660<div>
661
662<p><a href="https://github.com/bhelyer/SDC">The Stupid D Compiler</a> is a
663 project seeking to write a self-hosting compiler for the D programming
664 language without using the frontend of the reference compiler (DMD).</p>
665
666</div>
667
668<!--=========================================================================-->
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]669<h3>TTA-based Co-design Environment (TCE)</h3>
670
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]671<div>
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]672
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]673<p>TCE is a toolset for designing application-specific processors (ASP) based on
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]674 the Transport triggered architecture (TTA). The toolset provides a complete
675 co-design flow from C/C++ programs down to synthesizable VHDL and parallel
676 program binaries. Processor customization points include the register files,
677 function units, supported operations, and the interconnection network.</p>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]678
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]679<p>TCE uses Clang and LLVM for C/C++ language support, target independent
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]680 optimizations and also for parts of code generation. It generates new
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]681 LLVM-based code generators "on the fly" for the designed TTA processors and
682 loads them in to the compiler backend as runtime libraries to avoid
Bill Wendling2d7b4af2011-10-25 20:24:32 +0000[diff] [blame]683 per-target recompilation of larger parts of the compiler chain.</p>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]684
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]685</div>
Chris Lattner3bfe57e2011-04-06 01:13:49 +0000[diff] [blame]686
687<!--=========================================================================-->
Bill Wendling628c2662011-10-25 20:27:37 +0000[diff] [blame]688<h3>Tart Programming Language</h3>
689
690<div>
691
692<p><a href="http://code.google.com/p/tart/">Tart</a> is a general-purpose,
693 strongly typed programming language designed for application
694 developers. Strongly inspired by Python and C#, Tart focuses on practical
695 solutions for the professional software developer, while avoiding the clutter
696 and boilerplate of legacy languages like Java and C++. Although Tart is still
697 in development, the current implementation supports many features expected of
698 a modern programming language, such as garbage collection, powerful
699 bidirectional type inference, a greatly simplified syntax for template
700 metaprogramming, closures and function literals, reflection, operator
701 overloading, explicit mutability and immutability, and much more. Tart is
702 flexible enough to accommodate a broad range of programming styles and
703 philosophies, while maintaining a strong commitment to simplicity, minimalism
704 and elegance in design.</p>
705
706</div>
707
708<!--=========================================================================-->
Bill Wendling644ce532011-10-26 09:25:01 +0000[diff] [blame]709<h3>ThreadSanitizer</h3>
710
711<div>
712
713<p><a href="http://code.google.com/p/data-race-test/">ThreadSanitizer</a> is a
714 data race detector for (mostly) C and C++ code, available for Linux, Mac OS
715 and Windows. On different systems, we use binary instrumentation frameworks
Bill Wendlingae8538e2011-10-29 01:11:15 +0000[diff] [blame]716 (Valgrind and Pin) as frontends that generate the program events for the race
717 detection algorithm. On Linux, there's an option of using LLVM-based
718 compile-time instrumentation.</p>
Bill Wendling644ce532011-10-26 09:25:01 +0000[diff] [blame]719
720</div>
721
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]722</div>
723
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]724<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]725<h2>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]726 <a name="whatsnew">What's New in LLVM 3.0?</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]727</h2>
Chris Lattner8348b472008-06-08 21:58:17 +0000[diff] [blame]728<!-- *********************************************************************** -->
729
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]730<div>
Chris Lattnerf8e0b4e2008-06-08 22:59:35 +0000[diff] [blame]731
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]732<p>This release includes a huge number of bug fixes, performance tweaks and
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]733 minor improvements. Some of the major improvements and new features are
734 listed in this section.</p>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]735
Chris Lattner914ce462010-04-22 06:28:20 +0000[diff] [blame]736<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]737<h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]738<a name="majorfeatures">Major New Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]739</h3>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]740
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]741<div>
Chris Lattner252b83d2008-02-06 18:00:06 +0000[diff] [blame]742
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]743<p><b>llvm-gcc is gone</b></p>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]744
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]745<p>LLVM 3.0 includes several major new capabilities:</p>
746
Chris Lattnerdec23b62011-11-15 22:13:27 +0000[diff] [blame]747<!-- Near dead:
748 Analysis/RegionInfo.h + Dom Frontiers
749 SparseBitVector: used in LiveVar.
750
751 -->
752
753<!--
754 Type system rewrite.
755 Better performance for Neon code in clang due to SRoA improvements.
756 New regalloc on by default. Lin scan going away in 3.1
757 PGO / builtin_expect improvements (summary needed)
758 Big EH rewrite.
759 AVX support, assembler, compiler and disassembler.
760 IndVar improvements: andy
761 PTX backend improvements: Justin
762 llvm-rtdyld & MC JIT: JimG
763 InstAliases now automatically used in the asmprinter where they are shorter.
764 Integrated assembler on by default for arm/thumb?
765 PostOrder Dominator frontiers were removed.
766 Line Profiling / gcov support
767 EH and debug information produced with CFI directives, yielding smaller executables: http://blog.mozilla.com/respindola/2011/05/12/cfi-directives/
768 X86-64 generates smaller and faster code at -O0 (fast isel improvements)
769 Better code generation for Cortex-A9
770 Many APIs take ArrayRef's now.
771 Pass manager extension API.
Chris Lattner6a007d12011-11-25 20:33:27 +0000[diff] [blame]772
773
774Information about branch probability and basic block frequency is now available within LLVM based on a combination of static branch prediction heuristics and __builtin_expect calls. That information is currently used for register spill placement and if-conversion, with additional optimizations planned for future releases. The same frameworks are intended for eventual use with profile-guided optimization, but that is not yet implemented.
Chris Lattnerdec23b62011-11-15 22:13:27 +0000[diff] [blame]775
776 -->
777
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]778<ul>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]779
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]780<!--
781<li></li>
782-->
Chris Lattner7a8e6c52011-04-05 18:38:45 +0000[diff] [blame]783
Chris Lattner8170c102008-02-10 08:18:42 +0000[diff] [blame]784</ul>
Chris Lattner0a6f6d52011-04-05 07:19:28 +0000[diff] [blame]785
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]786</div>
787
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]788<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]789<h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]790<a name="coreimprovements">LLVM IR and Core Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]791</h3>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]792
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]793<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]794
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]795<p>LLVM IR has several new features for better support of new targets and that
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]796 expose new optimization opportunities:</p>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]797
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]798<p>One of the biggest changes is that 3.0 has a new exception handling
799 system. The old system used LLVM intrinsics to convey the exception handling
800 information to the code generator. It worked in most cases, but not
801 all. Inlining was especially difficult to get right. Also, the intrinsics
802 could be moved away from the <code>invoke</code> instruction, making it hard
803 to recover that information.</p>
804
805<p>The new EH system makes exception handling a first-class member of the IR. It
806 adds two new instructions:</p>
807
Chris Lattner791f77b2008-06-05 06:25:56 +0000[diff] [blame]808<ul>
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]809 <li><a href="LangRef.html#i_landingpad"><code>landingpad</code></a> &mdash;
810 this instruction defines a landing pad basic block. It contains all of the
811 information that's needed by the code generator. It's also required to be
812 the first non-PHI instruction in the landing pad. In addition, a landing
813 pad may be jumped to only by the unwind edge of an <code>invoke</code>
814 instruction.</li>
815
816 <li><a href="LangRef.html#i_resume"><code>resume</code></a> &mdash; this
817 instruction causes the current exception to resume traveling up the
818 stack. It replaces the <code>@llvm.eh.resume</code> intrinsic.</li>
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]819</ul>
Mikhail Glushenkovea65d7d2008-10-13 02:08:34 +0000[diff] [blame]820
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]821<p>Converting from the old EH API to the new EH API is rather simple, because a
822 lot of complexity has been removed. The two intrinsics,
823 <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code> have been
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000[diff] [blame]824 superseded by the <code>landingpad</code> instruction. Instead of generating
Bill Wendlingbc5f6dd2011-10-26 18:33:01 +0000[diff] [blame]825 a call to <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code>:
826
827<div class="doc_code">
828<pre>
829Function *ExcIntr = Intrinsic::getDeclaration(TheModule,
830 Intrinsic::eh_exception);
831Function *SlctrIntr = Intrinsic::getDeclaration(TheModule,
832 Intrinsic::eh_selector);
833
834// The exception pointer.
835Value *ExnPtr = Builder.CreateCall(ExcIntr, "exc_ptr");
836
837std::vector&lt;Value*&gt; Args;
838Args.push_back(ExnPtr);
839Args.push_back(Builder.CreateBitCast(Personality,
840 Type::getInt8PtrTy(Context)));
841
842<i>// Add selector clauses to Args.</i>
843
844// The selector call.
845Builder.CreateCall(SlctrIntr, Args, "exc_sel");
846</pre>
847</div>
848
849<p>You should instead generate a <code>landingpad</code> instruction, that
850 returns an exception object and selector value:</p>
851
852<div class="doc_code">
853<pre>
854LandingPadInst *LPadInst =
855 Builder.CreateLandingPad(StructType::get(Int8PtrTy, Int32Ty, NULL),
856 Personality, 0);
857
858Value *LPadExn = Builder.CreateExtractValue(LPadInst, 0);
859Builder.CreateStore(LPadExn, getExceptionSlot());
860
861Value *LPadSel = Builder.CreateExtractValue(LPadInst, 1);
862Builder.CreateStore(LPadSel, getEHSelectorSlot());
863</pre>
864</div>
865
866<p>It's now trivial to add the individual clauses to the <code>landingpad</code>
867 instruction.</p>
868
869<div class="doc_code">
870<pre>
871<i><b>// Adding a catch clause</b></i>
872Constant *TypeInfo = getTypeInfo();
873LPadInst-&gt;addClause(TypeInfo);
874
875<i><b>// Adding a C++ catch-all</b></i>
876LPadInst-&gt;addClause(Constant::getNullValue(Builder.getInt8PtrTy()));
877
878<i><b>// Adding a cleanup</b></i>
879LPadInst-&gt;setCleanup(true);
880
881<i><b>// Adding a filter clause</b></i>
882std::vector&lt;Constant*&gt; TypeInfos;
883Constant *TypeInfo = getFilterTypeInfo();
884TypeInfos.push_back(Builder.CreateBitCast(TypeInfo, Builder.getInt8PtrTy()));
885
886ArrayType *FilterTy = ArrayType::get(Int8PtrTy, TypeInfos.size());
887LPadInst-&gt;addClause(ConstantArray::get(FilterTy, TypeInfos));
888</pre>
889</div>
890
891<p>Converting from using the <code>@llvm.eh.resume</code> intrinsic to
892 the <code>resume</code> instruction is trivial. It takes the exception
893 pointer and exception selector values returned by
894 the <code>landingpad</code> instruction:</p>
895
896<div class="doc_code">
897<pre>
898Type *UnwindDataTy = StructType::get(Builder.getInt8PtrTy(),
899 Builder.getInt32Ty(), NULL);
900Value *UnwindData = UndefValue::get(UnwindDataTy);
901Value *ExcPtr = Builder.CreateLoad(getExceptionObjSlot());
902Value *ExcSel = Builder.CreateLoad(getExceptionSelSlot());
903UnwindData = Builder.CreateInsertValue(UnwindData, ExcPtr, 0, "exc_ptr");
904UnwindData = Builder.CreateInsertValue(UnwindData, ExcSel, 1, "exc_sel");
905Builder.CreateResume(UnwindData);
906</pre>
907</div>
908
Chris Lattnerf304ffc2008-02-10 08:17:19 +0000[diff] [blame]909</div>
910
911<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]912<h3>
Andrew Trick5aab6382011-11-06 17:59:24 +0000[diff] [blame]913<a name="loopoptimization">Loop Optimization Improvements</a>
914</h3>
915
916<div>
917<p>The induction variable simplification pass in 3.0 only modifies
918 induction variables when profitable. Sign and zero extension
919 elimination, linear function test replacement, loop unrolling, and
920 other simplifications that require induction variable analysis have
921 been generalized so they no longer require loops to be rewritten in a
922 typically suboptimal form prior to optimization. This new design
923 preserves more IR level information, avoids undoing earlier loop
924 optimizations (particularly hand-optimized loops), and no longer
925 strongly depends on the code generator rewriting loops a second time
926 in a now optimal form--an intractable problem.</p>
927
928<p>The original behavior can be restored with -mllvm -enable-iv-rewrite;
929 however, support for this mode will be short lived. As such, bug
930 reports should be filed for any significant performance regressions
931 when moving from -mllvm -enable-iv-rewrite to the 3.0 default mode.</p>
932</div>
933
934<!--=========================================================================-->
935<h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]936<a name="optimizer">Optimizer Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]937</h3>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]938
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]939<div>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]940
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]941<p>In addition to a large array of minor performance tweaks and bug fixes, this
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]942 release includes a few major enhancements and additions to the
943 optimizers:</p>
Chris Lattneracce85d2008-02-10 07:46:44 +0000[diff] [blame]944
945<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]946<!--
947<li></li>
948-->
Chris Lattnerc5ac61d2011-04-06 05:50:04 +0000[diff] [blame]949</li>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]950
Chris Lattner11b66112010-10-04 02:42:39 +0000[diff] [blame]951</ul>
952
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]953</div>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]954
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]955<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]956<h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]957<a name="mc">MC Level Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]958</h3>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]959
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]960<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]961
962<p>The LLVM Machine Code (aka MC) subsystem was created to solve a number of
963 problems in the realm of assembly, disassembly, object file format handling,
964 and a number of other related areas that CPU instruction-set level tools work
965 in.</p>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]966
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]967<ul>
Jim Grosbach2552de02011-11-24 00:49:21 +0000[diff] [blame]968 <li>The ELF object streamers are much more full featured.</li>
969 <li>Target dependent relocation handling has been refactored into the Targets.</li>
970 <li>Early stage MC-JIT infrastructure has been implemented.</li>
Chris Lattner7d9b6b42010-10-02 21:59:30 +0000[diff] [blame]971</ul>
972
Jim Grosbach2552de02011-11-24 00:49:21 +0000[diff] [blame]973<p>The MC-JIT is a major new feature for MC, and will eventually grow to replace
974the current JIT implementation. It emits object files direct to memory and
975uses a runtime dynamic linker to resolve references and drive lazy compilation.
976The MC-JIT enables much greater code reuse between the JIT and the static
977compiler and provides better integration with the platform ABI as a result.</p>
978
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]979<p>For more information, please see
980 the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro
981 to the LLVM MC Project Blog Post</a>.</p>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]982
NAKAMURA Takumi45c435a2011-04-05 08:24:22 +0000[diff] [blame]983</div>
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]984
Chris Lattner4ba2b652010-09-30 16:31:33 +0000[diff] [blame]985<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]986<h3>
Chris Lattner511433e2009-03-02 03:24:11 +0000[diff] [blame]987<a name="codegen">Target Independent Code Generator Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]988</h3>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]989
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]990<div>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]991
Mikhail Glushenkovf795ef02009-03-01 18:09:47 +0000[diff] [blame]992<p>We have put a significant amount of work into the code generator
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]993 infrastructure, which allows us to implement more aggressive algorithms and
994 make it run faster:</p>
Chris Lattner0b832202008-06-08 02:45:07 +0000[diff] [blame]995
996<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]997<!--
998<li></li>
999-->
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]1000</ul>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]1001</div>
1002
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]1003<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1004<h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]1005<a name="x86">X86-32 and X86-64 Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1006</h3>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]1007
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1008<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1009
1010<p>New features and major changes in the X86 target include:</p>
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]1011
1012<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1013
Chris Lattner62f009a2011-11-15 22:48:24 +0000[diff] [blame]1014 <li>The X86 backend now supports
1015 all <a href="http://llvm.org/PR879">inline assembly that uses the X86
1016 floating point stack</a>.</li>
1017
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1018 <li>The CRC32 intrinsics have been renamed. The intrinsics were previously
1019 <code>@llvm.x86.sse42.crc32.[8|16|32]</code>
1020 and <code>@llvm.x86.sse42.crc64.[8|64]</code>. They have been renamed to
1021 <code>@llvm.x86.sse42.crc32.32.[8|16|32]</code> and
1022 <code>@llvm.x86.sse42.crc32.64.[8|64]</code>.</li>
Chad Rosierf94c9c12011-05-27 20:13:10 +0000[diff] [blame]1023
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]1024</ul>
1025
Chris Lattner917cc712009-03-02 02:37:32 +0000[diff] [blame]1026</div>
Chris Lattner84977642007-09-21 03:54:09 +0000[diff] [blame]1027
1028<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1029<h3>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]1030<a name="ARM">ARM Target Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1031</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1032
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1033<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1034
1035<p>New features of the ARM target include:</p>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1036
1037<ul>
Jim Grosbach2552de02011-11-24 00:49:21 +0000[diff] [blame]1038 <li>Reworked Set Jump Long Jump EH Lowering,</li>
1039 <li>improved support for Cortex-M series processors, and</li>
1040 <li>beta quality integrated assembler support.</li>
Bob Wilsone8472772010-09-13 17:39:35 +0000[diff] [blame]1041</ul>
Chris Lattner61358ab2009-10-13 17:48:04 +0000[diff] [blame]1042</div>
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1043
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1044
1045<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1046<h3>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1047<a name="MIPS">MIPS Target Improvements</a>
1048</h3>
1049
1050<div>
1051
1052<p>New features and major changes in the MIPS target include:</p>
1053
1054<ul>
1055 <li>Most MIPS32r1 and r2 instructions are now supported.</li>
1056 <li>LE/BE MIPS32r1/r2 has been tested extensively.</li>
1057 <li>O32 ABI has been fully tested.</li>
1058 <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>
1059 <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>
1060 <li>Support for old-style JIT is complete.</li>
1061 <li>Support for old architectures (MIPS1 and MIPS2) has been removed.</li>
1062 <li>Initial support for MIPS64 has been added.</li>
1063</ul>
1064</div>
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1065
1066<!--=========================================================================-->
1067<h3>
1068 <a name="PTX">PTX Target Improvements</a>
1069</h3>
1070
1071<div>
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1072
Chris Lattner7b95c382011-11-15 22:23:46 +0000[diff] [blame]1073 <p>
1074 The PTX back-end is still experimental, but is fairly usable for compute kernels
1075 in LLVM 3.0. Most scalar arithmetic is implemented, as well as intrinsics to
1076 access the special PTX registers and sync instructions. The major missing
1077 pieces are texture/sampler support and some vector operations.</p>
1078
1079 <p>That said, the backend is already being used for domain-specific languages
1080 and works well with the <a href="http://www.pcc.me.uk/~peter/libclc/">libclc
1081 library</a> to supply OpenCL built-ins. With it, you can use Clang to compile
1082 OpenCL code into PTX and execute it by loading the resulting PTX as a binary
1083 blob using the nVidia OpenCL library. It has been tested with several OpenCL
1084 programs, including some from the nVidia GPU Computing SDK, and the performance
1085 is on par with the nVidia compiler.</p>
1086
1087</div>
1088
Akira Hatanaka5381cbf2011-11-15 21:33:05 +0000[diff] [blame]1089<!--=========================================================================-->
1090<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1091<a name="OtherTS">Other Target Specific Improvements</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1092</h3>
Chris Lattnerc441fb82009-03-01 02:30:21 +0000[diff] [blame]1093
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1094<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1095
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]1096 <p>PPC32/ELF va_arg was implemented.</p>
1097 <p>PPC32 initial support for .o file writing was implemented.</p>
Wesley Peck3ff16db2011-11-14 18:56:41 +0000[diff] [blame]1098 <p>MicroBlaze scheduling itineraries were added that model the
1099 3-stage and the 5-stage pipeline architectures. The 3-stage
1100 pipeline model can be selected with <code>-mcpu=mblaze3</code>
1101 and the 5-stage pipeline model can be selected with
1102 <code>-mcpu=mblaze5</code>.</p>
Chris Lattnerc343e312011-11-10 20:15:40 +0000[diff] [blame]1103
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1104<ul>
Chad Rosiere6291d02011-05-27 22:50:46 +0000[diff] [blame]1105<!--
1106<li></li>
1107-->
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1108</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1109
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1110</div>
Chris Lattner77d29b12008-06-05 08:02:49 +0000[diff] [blame]1111
1112<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1113<h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1114<a name="changes">Major Changes and Removed Features</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1115</h3>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1116
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1117<div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1118
Bill Wendling2626dba2011-08-03 22:18:20 +0000[diff] [blame]1119<p>If you're already an LLVM user or developer with out-of-tree changes based on
1120 LLVM 2.9, this section lists some "gotchas" that you may run into upgrading
1121 from the previous release.</p>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1122
1123<ul>
Eric Christopher90d6ec52011-09-28 19:47:28 +0000[diff] [blame]1124 <li>The <code>LLVMC</code> front end code was removed while separating
1125 out language independence.</li>
Jay Foadf42e9b22011-08-04 10:43:43 +0000[diff] [blame]1126 <li>The <code>LowerSetJmp</code> pass wasn't used effectively by any
1127 target and has been removed.</li>
Rafael Espindolaf940a1a2011-08-30 23:03:45 +0000[diff] [blame]1128 <li>The old <code>TailDup</code> pass was not used in the standard pipeline
1129 and was unable to update ssa form, so it has been removed.
Eli Friedmanf03bb262011-08-12 22:50:01 +0000[diff] [blame]1130 <li>The syntax of volatile loads and stores in IR has been changed to
1131 "<code>load volatile</code>"/"<code>store volatile</code>". The old
1132 syntax ("<code>volatile load</code>"/"<code>volatile store</code>")
1133 is still accepted, but is now considered deprecated.</li>
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000[diff] [blame]1134 <li>The old atomic intrinsics (<code>llvm.memory.barrier</code> and
Eli Friedman526e1bb2011-10-26 00:55:23 +0000[diff] [blame]1135 <code>llvm.atomic.*</code>) are now gone. Please use the new atomic
1136 instructions, described in the <a href="Atomics.html">atomics guide</a>.
Devang Patelb34dd132008-10-14 20:03:43 +0000[diff] [blame]1137</ul>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1138
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1139<h4>Windows (32-bit)</h4>
1140<div>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1141
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1142<ul>
1143 <li>On Win32(MinGW32 and MSVC), Windows 2000 will not be supported.
1144 Windows XP or higher is required.</li>
1145</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1146
NAKAMURA Takumi2026de22011-08-22 23:22:05 +0000[diff] [blame]1147</div>
1148
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1149</div>
1150
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1151<!--=========================================================================-->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1152<h3>
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1153<a name="api_changes">Internal API Changes</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1154</h3>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1155
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1156<div>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1157
Chris Lattner1efe27e2011-04-06 00:45:11 +0000[diff] [blame]1158<p>In addition, many APIs have changed in this release. Some of the major
Bill Wendling16005252011-08-02 06:20:17 +0000[diff] [blame]1159 LLVM API changes are:</p>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1160
1161<ul>
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000[diff] [blame]1162 <li>The biggest and most pervasive change is that llvm::Types are no longer
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1163 returned or accepted as 'const' values. Instead, just pass around
Benjamin Kramer7c5025b2011-11-25 21:26:00 +0000[diff] [blame]1164 non-const Types.</li>
Chris Lattnerd1324302011-07-18 04:56:02 +0000[diff] [blame]1165
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1166 <li><code>PHINode::reserveOperandSpace</code> has been removed. Instead, you
1167 must specify how many operands to reserve space for when you create the
1168 PHINode, by passing an extra argument
1169 into <code>PHINode::Create</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1170
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1171 <li>PHINodes no longer store their incoming BasicBlocks as operands. Instead,
1172 the list of incoming BasicBlocks is stored separately, and can be accessed
1173 with new functions <code>PHINode::block_begin</code>
1174 and <code>PHINode::block_end</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1175
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1176 <li>Various functions now take an <code>ArrayRef</code> instead of either a
1177 pair of pointers (or iterators) to the beginning and end of a range, or a
1178 pointer and a length. Others now return an <code>ArrayRef</code> instead
1179 of a reference to a <code>SmallVector</code>
1180 or <code>std::vector</code>. These include:
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1181<ul>
1182<!-- Please keep this list sorted. -->
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1183<li><code>CallInst::Create</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1184<li><code>ComputeLinearIndex</code> (in <code>llvm/CodeGen/Analysis.h</code>)</li>
1185<li><code>ConstantArray::get</code></li>
1186<li><code>ConstantExpr::getExtractElement</code></li>
Jay Foaddab3d292011-07-21 14:31:17 +0000[diff] [blame]1187<li><code>ConstantExpr::getGetElementPtr</code></li>
1188<li><code>ConstantExpr::getInBoundsGetElementPtr</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1189<li><code>ConstantExpr::getIndices</code></li>
1190<li><code>ConstantExpr::getInsertElement</code></li>
1191<li><code>ConstantExpr::getWithOperands</code></li>
Jay Foad1d2f5692011-07-19 13:32:40 +0000[diff] [blame]1192<li><code>ConstantFoldCall</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
1193<li><code>ConstantFoldInstOperands</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1194<li><code>ConstantVector::get</code></li>
1195<li><code>DIBuilder::createComplexVariable</code></li>
1196<li><code>DIBuilder::getOrCreateArray</code></li>
1197<li><code>ExtractValueInst::Create</code></li>
1198<li><code>ExtractValueInst::getIndexedType</code></li>
1199<li><code>ExtractValueInst::getIndices</code></li>
1200<li><code>FindInsertedValue</code> (in <code>llvm/Analysis/ValueTracking.h</code>)</li>
Jay Foadca12a212011-07-19 14:42:50 +0000[diff] [blame]1201<li><code>gep_type_begin</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
1202<li><code>gep_type_end</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li>
Jay Foada9203102011-07-25 09:48:08 +0000[diff] [blame]1203<li><code>GetElementPtrInst::Create</code></li>
1204<li><code>GetElementPtrInst::CreateInBounds</code></li>
1205<li><code>GetElementPtrInst::getIndexedType</code></li>
Jay Foadb60e8512011-07-21 14:42:51 +0000[diff] [blame]1206<li><code>InsertValueInst::Create</code></li>
1207<li><code>InsertValueInst::getIndices</code></li>
1208<li><code>InvokeInst::Create</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1209<li><code>IRBuilder::CreateCall</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1210<li><code>IRBuilder::CreateExtractValue</code></li>
Jay Foad0a2a60a2011-07-22 08:16:57 +0000[diff] [blame]1211<li><code>IRBuilder::CreateGEP</code></li>
1212<li><code>IRBuilder::CreateInBoundsGEP</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1213<li><code>IRBuilder::CreateInsertValue</code></li>
Jay Foada3efbb12011-07-15 08:37:34 +0000[diff] [blame]1214<li><code>IRBuilder::CreateInvoke</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1215<li><code>MDNode::get</code></li>
1216<li><code>MDNode::getIfExists</code></li>
1217<li><code>MDNode::getTemporary</code></li>
1218<li><code>MDNode::getWhenValsUnresolved</code></li>
Jay Foadb9b54eb2011-07-19 15:07:52 +0000[diff] [blame]1219<li><code>SimplifyGEPInst</code> (in <code>llvm/Analysis/InstructionSimplify.h</code>)</li>
Jay Foad8fbbb392011-07-19 14:01:37 +0000[diff] [blame]1220<li><code>TargetData::getIndexedOffset</code></li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1221</ul></li>
1222
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1223 <li>All forms of <code>StringMap::getOrCreateValue</code> have been remove
1224 except for the one which takes a <code>StringRef</code>.</li>
Jay Foad558d3762011-07-14 09:19:05 +0000[diff] [blame]1225
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1226 <li>The <code>LLVMBuildUnwind</code> function from the C API was removed. The
1227 LLVM <code>unwind</code> instruction has been deprecated for a long time
1228 and isn't used by the current front-ends. So this was removed during the
1229 exception handling rewrite.</li>
Bill Wendling16005252011-08-02 06:20:17 +0000[diff] [blame]1230
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1231 <li>The <code>LLVMAddLowerSetJmpPass</code> function from the C API was
1232 removed because the <code>LowerSetJmp</code> pass was removed.</li>
Bill Wendling2626dba2011-08-03 22:18:20 +0000[diff] [blame]1233
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1234 <li>The <code>DIBuilder</code> interface used by front ends to encode
1235 debugging information in the LLVM IR now expects clients to
1236 use <code>DIBuilder::finalize()</code> at the end of translation unit to
1237 complete debugging information encoding.</li>
Devang Patel6326a422011-08-15 23:00:00 +0000[diff] [blame]1238
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1239 <li>The way the type system works has been
1240 rewritten: <code>PATypeHolder</code> and <code>OpaqueType</code> are gone,
1241 and all APIs deal with <code>Type*</code> instead of <code>const
1242 Type*</code>. If you need to create recursive structures, then create a
1243 named structure, and use <code>setBody()</code> when all its elements are
1244 built. Type merging and refining is gone too: named structures are not
1245 merged with other structures, even if their layout is identical. (of
1246 course anonymous structures are still uniqued by layout).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1247
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1248 <li>TargetSelect.h moved to Support/ from Target/</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1249
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1250 <li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls (for
1251 example <code>llvm.memset.i32</code>).</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1252
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1253 <li>It is mandatory to initialize all out-of-tree passes too and their dependencies now with
1254 <code>INITIALIZE_PASS{BEGIN,END,}</code>
1255 and <code>INITIALIZE_{PASS,AG}_DEPENDENCY</code>.</li>
Torok Edwinf16e2d42011-09-30 13:07:52 +0000[diff] [blame]1256
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1257 <li>The interface for MemDepResult in MemoryDependenceAnalysis has been
1258 enhanced with new return types Unknown and NonFuncLocal, in addition to
1259 the existing types Clobber, Def, and NonLocal.</li>
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1260</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1261
Daniel Dunbarf0233c62010-10-04 20:11:41 +0000[diff] [blame]1262</div>
Chris Lattnerf6662f92008-10-13 17:57:36 +0000[diff] [blame]1263
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1264</div>
1265
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1266<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1267<h2>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1268 <a name="knownproblems">Known Problems</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1269</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1270<!-- *********************************************************************** -->
1271
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1272<div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1273
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1274<p>This section contains significant known problems with the LLVM system, listed
1275 by component. If you run into a problem, please check
1276 the <a href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
1277 there isn't already one.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1278
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1279<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1280<h3>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1281 <a name="experimental">Experimental features included with this release</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1282</h3>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1283
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1284<div>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1285
Misha Brukman6df9e2c2004-05-12 21:46:05 +0000[diff] [blame]1286<p>The following components of this LLVM release are either untested, known to
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1287 be broken or unreliable, or are in early development. These components
1288 should not be relied on, and bugs should not be filed against them, but they
1289 may be useful to some people. In particular, if you would like to work on
1290 one of these components, please contact us on
1291 the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev
1292 list</a>.</p>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1293
1294<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1295 <li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ and
1296 XCore backends are experimental.</li>
1297
1298 <li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets other
1299 than darwin and ELF X86 systems.</li>
Chris Lattnerf5ee1702004-03-14 02:03:02 +0000[diff] [blame]1300</ul>
1301
1302</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1303
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1304<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1305<h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1306 <a name="x86-be">Known problems with the X86 back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1307</h3>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1308
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1309<div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1310
1311<ul>
Chris Lattnerc78daaf2011-11-17 01:42:23 +0000[diff] [blame]1312 <li>The X86-64 backend <a href="http://llvm.org/PR1740">does not yet support
1313 the <tt>va_arg</tt> LLVM IR instruction</a>. Currently, front-ends support
1314 variadic argument constructs on X86-64 by lowering them manually.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1315</ul>
1316
1317</div>
1318
1319<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1320<h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1321 <a name="ppc-be">Known problems with the PowerPC back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1322</h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1323
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1324<div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1325
1326<ul>
Roman Divacky223764c2011-10-30 07:49:04 +0000[diff] [blame]1327 <li>The PPC32/ELF support lacks PIC support.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1328</ul>
1329
1330</div>
1331
1332<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1333<h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1334 <a name="arm-be">Known problems with the ARM back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1335</h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1336
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1337<div>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1338
1339<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1340 <li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
1341 processors, thumb programs can crash or produce wrong results
1342 (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
1343
1344 <li>Compilation for ARM Linux OABI (old ABI) is supported but not fully
1345 tested.</li>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1346</ul>
1347
1348</div>
1349
1350<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1351<h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1352 <a name="sparc-be">Known problems with the SPARC back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1353</h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1354
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1355<div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1356
1357<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1358 <li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
1359 support the 64-bit SPARC ABI (-m64).</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1360</ul>
1361
1362</div>
1363
1364<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1365<h3>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]1366 <a name="mips-be">Known problems with the MIPS back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1367</h3>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]1368
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1369<div>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]1370
1371<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1372 <li>64-bit MIPS targets are not supported yet.</li>
Bruno Cardoso Lopesb7e1a4f2008-10-25 14:56:26 +0000[diff] [blame]1373</ul>
1374
1375</div>
1376
1377<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1378<h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1379 <a name="alpha-be">Known problems with the Alpha back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1380</h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1381
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1382<div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1383
1384<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1385 <li>On 21164s, some rare FP arithmetic sequences which may trap do not have
1386 the appropriate nops inserted to ensure restartability.</li>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1387</ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1388
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1389</div>
1390
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1391<!-- ======================================================================= -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1392<h3>
Chris Lattnerf3e5bc62007-05-14 06:56:09 +0000[diff] [blame]1393 <a name="c-be">Known problems with the C back-end</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1394</h3>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1395
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1396<div>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1397
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]1398<p>The C backend has numerous problems and is not being actively maintained.
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1399 Depending on it for anything serious is not advised.</p>
Chris Lattner3016ee92010-09-29 05:34:42 +0000[diff] [blame]1400
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1401<ul>
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1402 <li><a href="http://llvm.org/PR802">The C backend has only basic support for
1403 inline assembly code</a>.</li>
1404
1405 <li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
1406 C++ programs</a>, preventing intermixing between C++ compiled by the CBE
1407 and C++ code compiled with <tt>llc</tt> or native compilers.</li>
1408
1409 <li>The C backend does not support all exception handling constructs.</li>
1410
1411 <li>The C backend does not support arbitrary precision integers.</li>
Chris Lattner26299222006-11-18 07:51:14 +0000[diff] [blame]1412</ul>
1413
1414</div>
John Criswellc0c186d2005-11-08 21:11:33 +0000[diff] [blame]1415
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1416</div>
1417
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1418<!-- *********************************************************************** -->
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1419<h2>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1420 <a name="additionalinfo">Additional Information</a>
NAKAMURA Takumi06c6d9a2011-04-18 01:17:51 +0000[diff] [blame]1421</h2>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1422<!-- *********************************************************************** -->
1423
NAKAMURA Takumi074eeaa2011-04-21 01:52:00 +0000[diff] [blame]1424<div>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1425
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1426<p>A wide variety of additional information is available on
1427 the <a href="http://llvm.org/">LLVM web page</a>, in particular in
1428 the <a href="http://llvm.org/docs/">documentation</a> section. The web page
1429 also contains versions of the API documentation which is up-to-date with the
1430 Subversion version of the source code. You can access versions of these
1431 documents specific to this release by going into the "<tt>llvm/doc/</tt>"
1432 directory in the LLVM tree.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1433
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1434<p>If you have any questions or comments about LLVM, please feel free to contact
Bill Wendling7b7fa742011-10-26 18:46:16 +0000[diff] [blame]1435 us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1436
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1437</div>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1438
1439<!-- *********************************************************************** -->
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1440
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1441<hr>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1442<address>
Misha Brukman38847d52003-12-21 22:53:21 +0000[diff] [blame]1443 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]1444 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1445 <a href="http://validator.w3.org/check/referer"><img
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Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1447
Chris Lattnerb4b0ce72007-05-18 00:44:29 +0000[diff] [blame]1448 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1449 Last modified: $Date$
Misha Brukman2061e892003-11-22 01:23:39 +0000[diff] [blame]1450</address>
Chris Lattner79c3fe12003-10-02 04:57:28 +0000[diff] [blame]1451
Misha Brukman500bc302003-11-22 00:38:41 +0000[diff] [blame]1452</body>
1453</html>