<div>
<p>This document contains the release notes for the LLVM Compiler
-Infrastructure, release 3.0. Here we describe the status of LLVM, including
-major improvements from the previous release and significant known problems.
-All LLVM releases may be downloaded from the <a
-href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
+ Infrastructure, release 3.0. Here we describe the status of LLVM, including
+ major improvements from the previous release and significant known problems.
+ All LLVM releases may be downloaded from
+ the <a href="http://llvm.org/releases/">LLVM releases web site</a>.</p>
<p>For more information about LLVM, including information about the latest
-release, please check out the <a href="http://llvm.org/">main LLVM
-web site</a>. If you have questions or comments, the <a
-href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM Developer's
-Mailing List</a> is a good place to send them.</p>
+ release, please check out the <a href="http://llvm.org/">main LLVM web
+ site</a>. If you have questions or comments,
+ the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM
+ Developer's Mailing List</a> is a good place to send them.</p>
-<p>Note that if you are reading this file from a Subversion checkout or the
-main LLVM web page, this document applies to the <i>next</i> release, not the
-current one. To see the release notes for a specific release, please see the
-<a href="http://llvm.org/releases/">releases page</a>.</p>
+<p>Note that if you are reading this file from a Subversion checkout or the main
+ LLVM web page, this document applies to the <i>next</i> release, not the
+ current one. To see the release notes for a specific release, please see the
+
<a href="http://llvm.org/releases/">releases page</a>.</p>
</div>
<!-- *********************************************************************** -->
<div>
-<p>
-The LLVM 3.0 distribution currently consists of code from the core LLVM
-repository (which roughly includes the LLVM optimizers, code generators
-and supporting tools), the Clang repository and the llvm-gcc repository. In
-addition to this code, the LLVM Project includes other sub-projects that are in
-development. Here we include updates on these subprojects.
-</p>
+
+<p>The LLVM 3.0 distribution currently consists of code from the core LLVM
+ repository (which roughly includes the LLVM optimizers, code generators and
+ supporting tools), the Clang repository and the llvm-gcc repository. In
+ addition to this code, the LLVM Project includes other sub-projects that are
+ in development. Here we include updates on these subprojects.</p>
<!--=========================================================================-->
<h3>
<div>
<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
-C++, and Objective-C languages. Clang aims to provide a better user experience
-through expressive diagnostics, a high level of conformance to language
-standards, fast compilation, and low memory use. Like LLVM, Clang provides a
-modular, library-based architecture that makes it suitable for creating or
-integrating with other development tools. Clang is considered a
-production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
-(32- and 64-bit), and for darwin/arm targets.</p>
+ C++, and Objective-C languages. Clang aims to provide a better user
+ experience through expressive diagnostics, a high level of conformance to
+ language standards, fast compilation, and low memory use. Like LLVM, Clang
+ provides a modular, library-based architecture that makes it suitable for
+ creating or integrating with other development tools. Clang is considered a
+ production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
+ (32- and 64-bit), and for darwin/arm targets.</p>
<p>In the LLVM 3.0 time-frame, the Clang team has made many improvements:</p>
<ul>
- <li>Greatly improved support for building C++ applications, with greater stability and better diagnostics.</li>
+ <li>Greatly improved support for building C++ applications, with greater
+ stability and better diagnostics.</li>
- <li><a href="http://clang.llvm.org/cxx_status.html">Improved support</a> for the <a href="http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=50372 ">C++ 2011</a> standard, including implementations of non-static data member initializers, alias templates, delegating constructors, the range-based for loop, and implicitly-generated move constructors and move assignment operators, among others.</li>
-
- <li>Implemented support for some features of the upcoming C1x standard, including static assertions and generic selections.</li>
+ <li><a href="http://clang.llvm.org/cxx_status.html">Improved support</a> for
+ the <a href="http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=50372">C++
+ 2011</a> standard, including implementations of non-static data member
+ initializers, alias templates, delegating constructors, the range-based
+ for loop, and implicitly-generated move constructors and move assignment
+ operators, among others.</li>
+
+ <li>Implemented support for some features of the upcoming C1x standard,
+ including static assertions and generic selections.</li>
- <li>Better detection of include and linking paths for system headers and libraries, especially for Linux distributions.</li>
+ <li>Better detection of include and linking paths for system headers and
+ libraries, especially for Linux distributions.</li>
- <li>Implemented support for <a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html">Automatic Reference Counting</a> for Objective-C.</li>
+ <li>Implemented support
+ for <a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html">Automatic
+ Reference Counting</a> for Objective-C.</li>
- <li>Implemented a number of optimizations in <tt>libclang</tt>, the Clang C interface, to improve the performance of code completion and the mapping from source locations to abstract syntax tree nodes.</li>
+ <li>Implemented a number of optimizations in <tt>libclang</tt>, the Clang C
+ interface, to improve the performance of code completion and the mapping
+ from source locations to abstract syntax tree nodes.</li>
</ul>
<p>If Clang rejects your code but another compiler accepts it, please take a
-look at the <a href="http://clang.llvm.org/compatibility.html">language
-compatibility</a> guide to make sure this is not intentional or a known issue.
-</p>
+
look at the <a href="http://clang.llvm.org/compatibility.html">language
+ compatibility</a> guide to make sure this is not intentional or a known
+ issue.</p>
</div>
</h3>
<div>
-<p>
-<a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
-<a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
-optimizers and code generators with LLVM's.
-Currently it requires a patched version of gcc-4.5.
-The plugin can target the x86-32 and x86-64 processor families and has been
-used successfully on the Darwin, FreeBSD and Linux platforms.
-The Ada, C, C++ and Fortran languages work well.
-The plugin is capable of compiling plenty of Obj-C, Obj-C++ and Java but it is
-not known whether the compiled code actually works or not!
-</p>
+<p><a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
+ <a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
+ optimizers and code generators with LLVM's. Currently it requires a patched
+ version of gcc-4.5. The plugin can target the x86-32 and x86-64 processor
+ families and has been used successfully on the Darwin, FreeBSD and Linux
+ platforms. The Ada, C, C++ and Fortran languages work well. The plugin is
+ capable of compiling plenty of Obj-C, Obj-C++ and Java but it is not known
+ whether the compiled code actually works or not!</p>
+
+<p>The 3.0 release has the following notable changes:</p>
-<p>
-The 3.0 release has the following notable changes:
<ul>
<!--
<li></li>
</h3>
<div>
-<p>
-The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
-is a simple library that provides an implementation of the low-level
-target-specific hooks required by code generation and other runtime components.
-For example, when compiling for a 32-bit target, converting a double to a 64-bit
-unsigned integer is compiled into a runtime call to the "__fixunsdfdi"
-function. The compiler-rt library provides highly optimized implementations of
-this and other low-level routines (some are 3x faster than the equivalent
-libgcc routines).</p>
+
+
<p>The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
+ is a simple library that provides an implementation of the low-level
+ target-specific hooks required by code generation and other runtime
+ components. For example, when compiling for a 32-bit target, converting a
+ double to a 64-bit unsigned integer is compiled into a runtime call to the
+ "__fixunsdfdi" function. The compiler-rt library provides highly optimized
+ implementations of this and other low-level routines (some are 3x faster than
+ the equivalent libgcc routines).</p>
<p>In the LLVM 3.0 timeframe,</p>
</h3>
<div>
-<p>
-<a href="http://lldb.llvm.org/">LLDB</a> is a brand new member of the LLVM
-umbrella of projects. LLDB is a next generation, high-performance debugger. It
-is built as a set of reusable components which highly leverage existing
-libraries in the larger LLVM Project, such as the Clang expression parser, the
-LLVM disassembler and the LLVM JIT.</p>
-<p>
-LLDB is has advanced by leaps and bounds in the 3.0 timeframe. It is
-dramatically more stable and useful, and includes both a new <a
-href="http://lldb.llvm.org/tutorial.html">tutorial</a> and a <a
-href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
-GDB</a>.</p>
+<p>LLDB has advanced by leaps and bounds in the 3.0 timeframe. It is
+ dramatically more stable and useful, and includes both a
+ new <a href="http://lldb.llvm.org/tutorial.html">tutorial</a> and
+ a <a href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with
+ GDB</a>.</p>
</div>
</h3>
<div>
-<p>
-<a href="http://libcxx.llvm.org/">libc++</a> is another new member of the LLVM
-family. It is an implementation of the C++ standard library, written from the
-ground up to specifically target the forthcoming C++'0X standard and focus on
-delivering great performance.</p>
-<p>
-In the LLVM 3.0 timeframe,</p>
-
-<p>
-Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
- licensed</a> under the MIT and UIUC license, allowing it to be used more
- permissively.
-</p>
+<p>Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
+ licensed</a> under the MIT and UIUC license, allowing it to be used more
+ permissively.</p>
</div>
</h3>
<div>
-<p>
-<a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
- LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
- module and displays its contents as an expandable tree view, facilitating an
- easy way to inspect types, functions, global variables, or metadata nodes. It
- is fully cross-platform, being based on the popular wxWidgets GUI toolkit.
-</p>
+
+<p><a href="http://llvm.org/svn/llvm-project/llbrowse/trunk/doc/LLBrowse.html">
+ LLBrowse</a> is an interactive viewer for LLVM modules. It can load any LLVM
+ module and displays its contents as an expandable tree view, facilitating an
+ easy way to inspect types, functions, global variables, or metadata nodes. It
+ is fully cross-platform, being based on the popular wxWidgets GUI
+ toolkit.</p>
+
</div>
<!--=========================================================================-->
</h3>
<div>
+
<p>The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation
- of a Java Virtual Machine (Java VM or JVM) that uses LLVM for static and
- just-in-time compilation. As of LLVM 3.0, VMKit now supports generational
- garbage collectors. The garbage collectors are provided by the MMTk framework,
- and VMKit can be configured to use one of the numerous implemented collectors
- of MMTk.
-</p>
+ of a Java Virtual Machine (Java VM or JVM) that uses LLVM for static and
+ just-in-time compilation. As of LLVM 3.0, VMKit now supports generational
+ garbage collectors. The garbage collectors are provided by the MMTk
+ framework, and VMKit can be configured to use one of the numerous implemented
+ collectors of MMTk.</p>
+
</div>
projects that have already been updated to work with LLVM 3.0.</p>
<!--=========================================================================-->
+<h3>AddressSanitizer</h3>
+
+<div>
+
+<p><a href="http://code.google.com/p/address-sanitizer/">AddressSanitizer</a>
+ uses compiler instrumentation and a specialized malloc library to find C/C++
+ bugs such as use-after-free and out-of-bound accesses to heap, stack, and
+ globals. The key feature of the tool is speed: the average slowdown
+ introduced by AddressSanitizer is less than 2x.</p>
+
+</div>
+
+<!--=========================================================================-->
+<h3>ClamAV</h3>
+
+<div>
+
+<p><a href="http://www.clamav.net">Clam AntiVirus</a> is an open source (GPL)
+ anti-virus toolkit for UNIX, designed especially for e-mail scanning on mail
+ gateways.</p>
+
+<p>Since version 0.96 it
+ has <a href="http://vrt-sourcefire.blogspot.com/2010/09/introduction-to-clamavs-low-level.html">bytecode
+ signatures</a> that allow writing detections for complex malware.</p>
+
+<p>It uses LLVM's JIT to speed up the execution of bytecode on X86, X86-64,
+ PPC32/64, falling back to its own interpreter otherwise. The git version was
+ updated to work with LLVM 3.0.</p>
+
+</div>
+
+<!--=========================================================================-->
+<h3>clReflect</h3>
+<div>
+
+<p><a href="https://bitbucket.org/dwilliamson/clreflect">clReflect</a> is a C++
+ parser that uses clang/LLVM to derive a light-weight reflection database
+ suitable for use in game development. It comes with a very simple runtime
+ library for loading and querying the database, requiring no external
+ dependencies (including CRT), and an additional utility library for object
+ management and serialisation.</p>
+
+</div>
+
+<!--=========================================================================-->
<!-- FIXME: Comment out
<h3>Crack Programming Language</h3>
<div>
<p><a href="http://botwars.tk/gwscript/">gwXscript</a> is an object oriented,
- aspect orientied programing language which can create both, executables (ELF,
+ aspect oriented programming language which can create both executables (ELF,
EXE) and shared libraries (DLL, SO, DYNLIB). The compiler is implemented in
its own language and translates scripts into LLVM-IR which can be optimized
and translated into native code by the LLVM framework. Source code in
</div>
+<!--=========================================================================-->
+<h3>include-what-you-use</h3>
+
+<div>
+
+<p><a href="http://code.google.com/p/include-what-you-use">include-what-you-use</a>
+ is a tool to ensure that a file directly <code>#include</code>s
+ all <code>.h</code> files that provide a symbol that the file uses. It also
+ removes superfluous <code>#include</code>s from source files.</p>
+
+</div>
+
+<!--=========================================================================-->
+<h3>LanguageKit and Pragmatic Smalltalk</h3>
+
+<div>
+
+<p><a href="http://etoileos.com/etoile/features/languagekit/">LanguageKit</a> is
+ a framework for implementing dynamic languages sharing an object model with
+ Objective-C. It provides static and JIT compilation using LLVM along with
+ its own interpreter. Pragmatic Smalltalk is a dialect of Smalltalk, built on
+ top of LanguageKit, that interfaces directly with Objective-C, sharing the
+ same object representation and message sending behaviour. These projects are
+ developed as part of the Étoié desktop environment.</p>
+
+</div>
+
+<!--=========================================================================-->
+<h3>Mono</h3>
+
+<div>
+
+<p>An open source, cross-platform implementation of C# and the CLR that is
+ binary compatible with Microsoft.NET. Has an optional, dynamically-loaded
+ LLVM code generation backend in Mini, the JIT compiler.</p>
+
+<p>Note that we use a Git mirror of LLVM with some patches. See:
+ https://github.com/mono/llvm</p>
+
+</div>
+
<!--=========================================================================-->
<h3>Portable OpenCL (pocl)</h3>
</div>
+<!--=========================================================================-->
+<h3>Renderscript</h3>
+
+<div>
+
+<p><a href="http://developer.android.com/guide/topics/renderscript/index.html">Renderscript</a>
+ is Android's advanced 3D graphics rendering and compute API. It provides a
+ portable C99-based language with extensions to facilitate common use cases
+ for enhancing graphics and thread level parallelism. The Renderscript
+ compiler frontend is based on Clang/LLVM. It emits a portable bitcode format
+ for the actual compiled script code, as well as reflects a Java interface for
+ developers to control the execution of the compiled bitcode. Executable
+ machine code is then generated from this bitcode by an LLVM backend on the
+ device. Renderscript is thus able to provide a mechanism by which Android
+ developers can improve performance of their applications while retaining
+ portability.</p>
+
+</div>
+
<!--=========================================================================-->
<h3>SAFECode</h3>
</div>
+<!--=========================================================================-->
+<h3>The Stupid D Compiler (SDC)</h3>
+
+<div>
+
+<p><a href="https://github.com/bhelyer/SDC">The Stupid D Compiler</a> is a
+ project seeking to write a self-hosting compiler for the D programming
+ language without using the frontend of the reference compiler (DMD).</p>
+
+</div>
+
<!--=========================================================================-->
<h3>TTA-based Co-design Environment (TCE)</h3>
co-design flow from C/C++ programs down to synthesizable VHDL and parallel
program binaries. Processor customization points include the register files,
function units, supported operations, and the interconnection network.</p>
-
+
<p>TCE uses Clang and LLVM for C/C++ language support, target independent
optimizations and also for parts of code generation. It generates new
- LLVM-based code generators <i>on the fly</i> for the designed TTA processors
- and loads them in to the compiler backend as runtime libraries to avoid
+ LLVM-based code generators "on the fly" for the designed TTA processors and
+ loads them in to the compiler backend as runtime libraries to avoid
per-target recompilation of larger parts of the compiler chain.</p>
-</div>
+</div>
<!--=========================================================================-->
<h3>Tart Programming Language</h3>
</div>
+<!--=========================================================================-->
+<h3>ThreadSanitizer</h3>
+
+<div>
+
+<p><a href="http://code.google.com/p/data-race-test/">ThreadSanitizer</a> is a
+ data race detector for (mostly) C and C++ code, available for Linux, Mac OS
+ and Windows. On different systems, we use binary instrumentation frameworks
+ (Valgrind, Pin and DynamoRio) as frontends that generate the program events
+ for the race detection algorithm. On Linux, there's an option of using
+ LLVM-based compile-time instrumentation.</p>
+
+</div>
+
+<!--=========================================================================-->
+<h3>The ZooLib C++ Cross-Platform Application Framework</h3>
+
+<div>
+
+<p><a href="http://www.zoolib.org/">ZooLib</a> is Open Source under the MIT
+ License. It provides GUI, filesystem access, TCP networking, thread-safe
+ memory management, threading and locking for Mac OS X, Classic Mac OS,
+ Microsoft Windows, POSIX operating systems with X11, BeOS, Haiku, Apple's iOS
+ and Research in Motion's BlackBerry.</p>
+
+<p>My current work is to use CLang's static analyzer to improve ZooLib's code
+ quality. I also plan to set up LLVM compiles of the demo programs and test
+ programs using CLang and LLVM on all the platforms that CLang, LLVM and
+ ZooLib all support.</p>
+
+</div>
+
<!--=========================================================================-->
<!--
<h3>PinaVM</h3>
<div>
<p>This release includes a huge number of bug fixes, performance tweaks and
-minor improvements. Some of the major improvements and new features are listed
-in this section.
-</p>
+ minor improvements. Some of the major improvements and new features are
+ listed in this section.</p>
<!--=========================================================================-->
<h3>
</h3>
<div>
+
<p>LLVM IR has several new features for better support of new targets and that
-expose new optimization opportunities:</p>
+ expose new optimization opportunities:</p>
+
+<p>One of the biggest changes is that 3.0 has a new exception handling
+ system. The old system used LLVM intrinsics to convey the exception handling
+ information to the code generator. It worked in most cases, but not
+ all. Inlining was especially difficult to get right. Also, the intrinsics
+ could be moved away from the <code>invoke</code> instruction, making it hard
+ to recover that information.</p>
+
+<p>The new EH system makes exception handling a first-class member of the IR. It
+ adds two new instructions:</p>
<ul>
-<!--
-<li></li>
--->
+ <li><a href="LangRef.html#i_landingpad"><code>landingpad</code></a> —
+ this instruction defines a landing pad basic block. It contains all of the
+ information that's needed by the code generator. It's also required to be
+ the first non-PHI instruction in the landing pad. In addition, a landing
+ pad may be jumped to only by the unwind edge of an <code>invoke</code>
+ instruction.</li>
+
+ <li><a href="LangRef.html#i_resume"><code>resume</code></a> — this
+ instruction causes the current exception to resume traveling up the
+ stack. It replaces the <code>@llvm.eh.resume</code> intrinsic.</li>
</ul>
+<p>Converting from the old EH API to the new EH API is rather simple, because a
+ lot of complexity has been removed. The two intrinsics,
+ <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code> have been
+ superceded by the <code>landingpad</code> instruction. Instead of generating
+ a call to <code>@llvm.eh.exception</code> and <code>@llvm.eh.selector</code>:
+
+<div class="doc_code">
+<pre>
+Function *ExcIntr = Intrinsic::getDeclaration(TheModule,
+ Intrinsic::eh_exception);
+Function *SlctrIntr = Intrinsic::getDeclaration(TheModule,
+ Intrinsic::eh_selector);
+
+// The exception pointer.
+Value *ExnPtr = Builder.CreateCall(ExcIntr, "exc_ptr");
+
+std::vector<Value*> Args;
+Args.push_back(ExnPtr);
+Args.push_back(Builder.CreateBitCast(Personality,
+ Type::getInt8PtrTy(Context)));
+
+<i>// Add selector clauses to Args.</i>
+
+// The selector call.
+Builder.CreateCall(SlctrIntr, Args, "exc_sel");
+</pre>
+</div>
+
+<p>You should instead generate a <code>landingpad</code> instruction, that
+ returns an exception object and selector value:</p>
+
+<div class="doc_code">
+<pre>
+LandingPadInst *LPadInst =
+ Builder.CreateLandingPad(StructType::get(Int8PtrTy, Int32Ty, NULL),
+ Personality, 0);
+
+Value *LPadExn = Builder.CreateExtractValue(LPadInst, 0);
+Builder.CreateStore(LPadExn, getExceptionSlot());
+
+Value *LPadSel = Builder.CreateExtractValue(LPadInst, 1);
+Builder.CreateStore(LPadSel, getEHSelectorSlot());
+</pre>
+</div>
+
+<p>It's now trivial to add the individual clauses to the <code>landingpad</code>
+ instruction.</p>
+
+<div class="doc_code">
+<pre>
+<i><b>// Adding a catch clause</b></i>
+Constant *TypeInfo = getTypeInfo();
+LPadInst->addClause(TypeInfo);
+
+<i><b>// Adding a C++ catch-all</b></i>
+LPadInst->addClause(Constant::getNullValue(Builder.getInt8PtrTy()));
+
+<i><b>// Adding a cleanup</b></i>
+LPadInst->setCleanup(true);
+
+<i><b>// Adding a filter clause</b></i>
+std::vector<Constant*> TypeInfos;
+Constant *TypeInfo = getFilterTypeInfo();
+TypeInfos.push_back(Builder.CreateBitCast(TypeInfo, Builder.getInt8PtrTy()));
+
+ArrayType *FilterTy = ArrayType::get(Int8PtrTy, TypeInfos.size());
+LPadInst->addClause(ConstantArray::get(FilterTy, TypeInfos));
+</pre>
+</div>
+
+<p>Converting from using the <code>@llvm.eh.resume</code> intrinsic to
+ the <code>resume</code> instruction is trivial. It takes the exception
+ pointer and exception selector values returned by
+ the <code>landingpad</code> instruction:</p>
+
+<div class="doc_code">
+<pre>
+Type *UnwindDataTy = StructType::get(Builder.getInt8PtrTy(),
+ Builder.getInt32Ty(), NULL);
+Value *UnwindData = UndefValue::get(UnwindDataTy);
+Value *ExcPtr = Builder.CreateLoad(getExceptionObjSlot());
+Value *ExcSel = Builder.CreateLoad(getExceptionSelSlot());
+UnwindData = Builder.CreateInsertValue(UnwindData, ExcPtr, 0, "exc_ptr");
+UnwindData = Builder.CreateInsertValue(UnwindData, ExcSel, 1, "exc_sel");
+Builder.CreateResume(UnwindData);
+</pre>
+</div>
+
</div>
<!--=========================================================================-->
<div>
<p>In addition to a large array of minor performance tweaks and bug fixes, this
-release includes a few major enhancements and additions to the optimizers:</p>
+ release includes a few major enhancements and additions to the
+ optimizers:</p>
<ul>
<!--
</h3>
<div>
-<p>
-The LLVM Machine Code (aka MC) subsystem was created to solve a number
-of problems in the realm of assembly, disassembly, object file format handling,
-and a number of other related areas that CPU instruction-set level tools work
-in.</p>
+
+<p>The LLVM Machine Code (aka MC) subsystem was created to solve a number of
+ problems in the realm of assembly, disassembly, object file format handling,
+ and a number of other related areas that CPU instruction-set level tools work
+ in.</p>
<ul>
<!--
-->
</ul>
-<p>For more information, please see the <a
-href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro to the
-LLVM MC Project Blog Post</a>.
-</p>
+<p>For more information, please see
+ the <a href="http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html">Intro
+ to the LLVM MC Project Blog Post</a>.</p>
</div>
<div>
<p>We have put a significant amount of work into the code generator
-infrastructure, which allows us to implement more aggressive algorithms and make
-it run faster:</p>
+ infrastructure, which allows us to implement more aggressive algorithms and
+ make it run faster:</p>
<ul>
<!--
</h3>
<div>
-<p>New features and major changes in the X86 target include:
-</p>
+
+<p>New features and major changes in the X86 target include:</p>
<ul>
-<li>The CRC32 intrinsics have been renamed. The intrinsics were previously
- @llvm.x86.sse42.crc32.[8|16|32] and @llvm.x86.sse42.crc64.[8|64]. They have
- been renamed to @llvm.x86.sse42.crc32.32.[8|16|32] and
- @llvm.x86.sse42.crc32.64.[8|64].</li>
+
+ <li>The CRC32 intrinsics have been renamed. The intrinsics were previously
+ <code>@llvm.x86.sse42.crc32.[8|16|32]</code>
+ and <code>@llvm.x86.sse42.crc64.[8|64]</code>. They have been renamed to
+ <code>@llvm.x86.sse42.crc32.32.[8|16|32]</code> and
+ <code>@llvm.x86.sse42.crc32.64.[8|64]</code>.</li>
</ul>
</h3>
<div>
-<p>New features of the ARM target include:
-</p>
+
+<p>New features of the ARM target include:</p>
<ul>
<!--
</h3>
<div>
+
<ul>
<!--
<li></li>
-->
</ul>
+
</div>
<!--=========================================================================-->
"<code>load volatile</code>"/"<code>store volatile</code>". The old
syntax ("<code>volatile load</code>"/"<code>volatile store</code>")
is still accepted, but is now considered deprecated.</li>
+ <li>The old atomic intrinscs (<code>llvm.memory.barrier</code> and
+ <code>llvm.atomic.*</code>) are now gone. Please use the new atomic
+ instructions, described in the <a href="Atomics.html">atomics guide</a>.
</ul>
<h4>Windows (32-bit)</h4>
<div>
+
<ul>
<li>On Win32(MinGW32 and MSVC), Windows 2000 will not be supported.
Windows XP or higher is required.</li>
</ul>
+
</div>
</div>
LLVM API changes are:</p>
<ul>
-<li>The biggest and most pervasive change is that llvm::Type's are no longer
- returned or accepted as 'const' values. Instead, just pass around non-const
- Type's.</li>
+ <li>The biggest and most pervasive change is that llvm::Type's are no longer
+ returned or accepted as 'const' values. Instead, just pass around
+ non-const Type's.</li>
-<li><code>PHINode::reserveOperandSpace</code> has been removed. Instead, you
- must specify how many operands to reserve space for when you create the
- PHINode, by passing an extra argument into <code>PHINode::Create</code>.</li>
-
-<li>PHINodes no longer store their incoming BasicBlocks as operands. Instead,
- the list of incoming BasicBlocks is stored separately, and can be accessed
- with new functions <code>PHINode::block_begin</code>
- and <code>PHINode::block_end</code>.</li>
-
-<li>Various functions now take an <code>ArrayRef</code> instead of either a pair
- of pointers (or iterators) to the beginning and end of a range, or a pointer
- and a length. Others now return an <code>ArrayRef</code> instead of a
- reference to a <code>SmallVector</code> or <code>std::vector</code>. These
- include:
+ <li><code>PHINode::reserveOperandSpace</code> has been removed. Instead, you
+ must specify how many operands to reserve space for when you create the
+ PHINode, by passing an extra argument
+ into <code>PHINode::Create</code>.</li>
+
+ <li>PHINodes no longer store their incoming BasicBlocks as operands. Instead,
+ the list of incoming BasicBlocks is stored separately, and can be accessed
+ with new functions <code>PHINode::block_begin</code>
+ and <code>PHINode::block_end</code>.</li>
+
+ <li>Various functions now take an <code>ArrayRef</code> instead of either a
+ pair of pointers (or iterators) to the beginning and end of a range, or a
+ pointer and a length. Others now return an <code>ArrayRef</code> instead
+ of a reference to a <code>SmallVector</code>
+ or <code>std::vector</code>. These include:
<ul>
<!-- Please keep this list sorted. -->
<li><code>CallInst::Create</code></li>
<li><code>TargetData::getIndexedOffset</code></li>
</ul></li>
-<li>All forms of <code>StringMap::getOrCreateValue</code> have been remove
- except for the one which takes a <code>StringRef</code>.</li>
-
-<li>The <code>LLVMBuildUnwind</code> function from the C API was removed. The
- LLVM <code>unwind</code> instruction has been deprecated for a long time and
- isn't used by the current front-ends. So this was removed during the
- exception handling rewrite.</li>
-
-<li>The <code>LLVMAddLowerSetJmpPass</code> function from the C API was removed
- because the <code>LowerSetJmp</code> pass was removed.</li>
-
-<li>The <code>DIBuilder</code> interface used by front ends to encode debugging
- information in the LLVM IR now expects clients to use <code>DIBuilder::finalize()</code>
- at the end of translation unit to complete debugging information encoding.</li>
-
-<li>The way the type system works has been rewritten: <code>PATypeHolder</code>
-and <code>OpaqueType</code> are gone, and all APIs deal with <code>Type*</code>
-instead of <code>const Type*</code>.
-If you need to create recursive structures, then create a named structure,
-and use <code>setBody()</code> when all its elements are built.
-Type merging and refining is gone too: named structures are not
-merged with other structures, even if their layout is identical.
-(of course anonymous structures are still uniqued by layout).
-</li>
+ <li>All forms of <code>StringMap::getOrCreateValue</code> have been remove
+ except for the one which takes a <code>StringRef</code>.</li>
+
+ <li>The <code>LLVMBuildUnwind</code> function from the C API was removed. The
+ LLVM <code>unwind</code> instruction has been deprecated for a long time
+ and isn't used by the current front-ends. So this was removed during the
+ exception handling rewrite.</li>
+
+ <li>The <code>LLVMAddLowerSetJmpPass</code> function from the C API was
+ removed because the <code>LowerSetJmp</code> pass was removed.</li>
+
+ <li>The <code>DIBuilder</code> interface used by front ends to encode
+ debugging information in the LLVM IR now expects clients to
+ use <code>DIBuilder::finalize()</code> at the end of translation unit to
+ complete debugging information encoding.</li>
-<li>TargetSelect.h moved to Support/ from Target/</li>
+ <li>The way the type system works has been
+ rewritten: <code>PATypeHolder</code> and <code>OpaqueType</code> are gone,
+ and all APIs deal with <code>Type*</code> instead of <code>const
+ Type*</code>. If you need to create recursive structures, then create a
+ named structure, and use <code>setBody()</code> when all its elements are
+ built. Type merging and refining is gone too: named structures are not
+ merged with other structures, even if their layout is identical. (of
+ course anonymous structures are still uniqued by layout).</li>
-<li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls
-(for example <code>llvm.memset.i32</code>).</li>
+ <li>TargetSelect.h moved to Support/ from Target/</li>
-<li>It is mandatory to initialize all out-of-tree passes too and their dependencies now with
-<code>INITIALIZE_PASS{BEGIN,END,}</code> and <code>INITIALIZE_{PASS,AG}_DEPENDENCY</code>.</li>
+ <li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls (for
+ example <code>llvm.memset.i32</code>).</li>
-<li>The interface for MemDepResult in MemoryDependenceAnalysis has been enhanced
- with new return types Unknown and NonFuncLocal, in addition to the existing
- types Clobber, Def, and NonLocal.</li>
+ <li>It is mandatory to initialize all out-of-tree passes too and their dependencies now with
+ <code>INITIALIZE_PASS{BEGIN,END,}</code>
+ and <code>INITIALIZE_{PASS,AG}_DEPENDENCY</code>.</li>
+ <li>The interface for MemDepResult in MemoryDependenceAnalysis has been
+ enhanced with new return types Unknown and NonFuncLocal, in addition to
+ the existing types Clobber, Def, and NonLocal.</li>
</ul>
+
</div>
</div>
<div>
-<p>This section contains significant known problems with the LLVM system,
-listed by component. If you run into a problem, please check the <a
-href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
-there isn't already one.</p>
+<p>This section contains significant known problems with the LLVM system, listed
+ by component. If you run into a problem, please check
+ the <a href="http://llvm.org/bugs/">LLVM bug database</a> and submit a bug if
+ there isn't already one.</p>
<!-- ======================================================================= -->
<h3>
<div>
<p>The following components of this LLVM release are either untested, known to
-be broken or unreliable, or are in early development. These components should
-not be relied on, and bugs should not be filed against them, but they may be
-useful to some people. In particular, if you would like to work on one of these
-components, please contact us on the <a
-href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev list</a>.</p>
+ be broken or unreliable, or are in early development. These components
+ should not be relied on, and bugs should not be filed against them, but they
+ may be useful to some people. In particular, if you would like to work on
+ one of these components, please contact us on
+ the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev
+ list</a>.</p>
<ul>
-<li>The Alpha, CellSPU, MicroBlaze, MSP430, MIPS, PTX,
- and XCore backends are experimental.</li>
-<li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets
- other than darwin and ELF X86 systems.</li>
-
+ <li>The Alpha, Blackfin, CellSPU, MicroBlaze, MSP430, MIPS, PTX, SystemZ and
+ XCore backends are experimental.</li>
+
+ <li><tt>llc</tt> "<tt>-filetype=obj</tt>" is experimental on all targets other
+ than darwin and ELF X86 systems.</li>
</ul>
</div>
<ul>
<li>The X86 backend does not yet support
- all <a href="http://llvm.org/PR879">inline assembly that uses the X86
- floating point stack</a>. It supports the 'f' and 't' constraints, but not
- 'u'.</li>
+ all <a href="http://llvm.org/PR879">inline assembly that uses the X86
+ floating point stack</a>. It supports the 'f' and 't' constraints, but
+ not 'u'.</li>
+
<li>The X86-64 backend does not yet support the LLVM IR instruction
- <tt>va_arg</tt>. Currently, front-ends support variadic
- argument constructs on X86-64 by lowering them manually.</li>
+ <tt>va_arg</tt>. Currently, front-ends support variadic argument
+ constructs on X86-64 by lowering them manually.</li>
+
<li>Windows x64 (aka Win64) code generator has a few issues.
<ul>
- <li>llvm-gcc cannot build the mingw-w64 runtime currently
- due to lack of support for the 'u' inline assembly
- constraint and for X87 floating point inline assembly.</li>
- <li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt>
- due to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
- It is fixed in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
+ <li>llvm-gcc cannot build the mingw-w64 runtime currently due to lack of
+ support for the 'u' inline assembly constraint and for X87 floating
+ point inline assembly.</li>
+
+ <li>On mingw-w64, you will see unresolved symbol <tt>__chkstk</tt> due
+ to <a href="http://llvm.org/bugs/show_bug.cgi?id=8919">Bug 8919</a>.
+ It is fixed
+ in <a href="http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20110321/118499.html">r128206</a>.</li>
+
<li>Miss-aligned MOVDQA might crash your program. It is due to
- <a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>,
- lack of handling aligned internal globals.</li>
+ <a href="http://llvm.org/bugs/show_bug.cgi?id=9483">Bug 9483</a>, lack
+ of handling aligned internal globals.</li>
</ul>
</li>
<div>
<ul>
-<li>The Linux PPC32/ABI support needs testing for the interpreter and static
-compilation, and lacks support for debug information.</li>
+ <li>The Linux PPC32/ABI support needs testing for the interpreter and static
+ compilation, and lacks support for debug information.</li>
</ul>
</div>
<div>
<ul>
-<li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
-processors, thumb programs can crash or produce wrong
-results (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
-<li>Compilation for ARM Linux OABI (old ABI) is supported but not fully tested.
-</li>
+ <li>Thumb mode works only on ARMv6 or higher processors. On sub-ARMv6
+ processors, thumb programs can crash or produce wrong results
+ (<a href="http://llvm.org/PR1388">PR1388</a>).</li>
+
+ <li>Compilation for ARM Linux OABI (old ABI) is supported but not fully
+ tested.</li>
</ul>
</div>
<div>
<ul>
-<li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
- support the 64-bit SPARC ABI (-m64).</li>
+ <li>The SPARC backend only supports the 32-bit SPARC ABI (-m32); it does not
+ support the 64-bit SPARC ABI (-m64).</li>
</ul>
</div>
<div>
<ul>
-<li>64-bit MIPS targets are not supported yet.</li>
+ <li>64-bit MIPS targets are not supported yet.</li>
</ul>
</div>
<div>
<ul>
-
-<li>On 21164s, some rare FP arithmetic sequences which may trap do not have the
-appropriate nops inserted to ensure restartability.</li>
-
+ <li>On 21164s, some rare FP arithmetic sequences which may trap do not have
+ the appropriate nops inserted to ensure restartability.</li>
</ul>
+
</div>
<!-- ======================================================================= -->
<div>
<p>The C backend has numerous problems and is not being actively maintained.
-Depending on it for anything serious is not advised.</p>
+ Depending on it for anything serious is not advised.</p>
<ul>
-<li><a href="http://llvm.org/PR802">The C backend has only basic support for
- inline assembly code</a>.</li>
-<li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
- C++ programs</a>, preventing intermixing between C++ compiled by the CBE and
- C++ code compiled with <tt>llc</tt> or native compilers.</li>
-<li>The C backend does not support all exception handling constructs.</li>
-<li>The C backend does not support arbitrary precision integers.</li>
+ <li><a href="http://llvm.org/PR802">The C backend has only basic support for
+ inline assembly code</a>.</li>
+
+ <li><a href="http://llvm.org/PR1658">The C backend violates the ABI of common
+ C++ programs</a>, preventing intermixing between C++ compiled by the CBE
+ and C++ code compiled with <tt>llc</tt> or native compilers.</li>
+
+ <li>The C backend does not support all exception handling constructs.</li>
+
+ <li>The C backend does not support arbitrary precision integers.</li>
</ul>
</div>
<div>
-<p><b>LLVM 3.0 will be the last release of llvm-gcc.</b></p>
+<p><b>LLVM 2.9 was the last release of llvm-gcc.</b></p>
<p>llvm-gcc is generally very stable for the C family of languages. The only
major language feature of GCC not supported by llvm-gcc is the
<a href="#dragonegg">dragonegg</a> instead.</p>
<p>The llvm-gcc 4.2 Ada compiler has basic functionality, but is no longer being
-actively maintained. If you are interested in Ada, we recommend that you
-consider using <a href="#dragonegg">dragonegg</a> instead.</p>
+ actively maintained. If you are interested in Ada, we recommend that you
+ consider using <a href="#dragonegg">dragonegg</a> instead.</p>
+
</div>
</div>
<div>
-<p>A wide variety of additional information is available on the <a
-href="http://llvm.org/">LLVM web page</a>, in particular in the <a
-href="http://llvm.org/docs/">documentation</a> section. The web page also
-contains versions of the API documentation which is up-to-date with the
-Subversion version of the source code.
-You can access versions of these documents specific to this release by going
-into the "<tt>llvm/doc/</tt>" directory in the LLVM tree.</p>
+<p>A wide variety of additional information is available on
+ the <a href="http://llvm.org/">LLVM web page</a>, in particular in
+ the <a href="http://llvm.org/docs/">documentation</a> section. The web page
+ also contains versions of the API documentation which is up-to-date with the
+ Subversion version of the source code. You can access versions of these
+ documents specific to this release by going into the "<tt>llvm/doc/</tt>"
+ directory in the LLVM tree.</p>
<p>If you have any questions or comments about LLVM, please feel free to contact
-us via the <a href="http://llvm.org/docs/#maillist"> mailing
-lists</a>.</p>
+ us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p>
</div>
projects / oota-llvm.git / blobdiff