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| |
| <h1>LLVM 3.0 Release Notes</h1> |
| |
| <img align=right src="http://llvm.org/img/DragonSmall.png" |
| width="136" height="136" alt="LLVM Dragon Logo"> |
| |
| <ol> |
| <li><a href="#intro">Introduction</a></li> |
| <li><a href="#subproj">Sub-project Status Update</a></li> |
| <li><a href="#externalproj">External Projects Using LLVM 3.0</a></li> |
| <li><a href="#whatsnew">What's New in LLVM 3.0?</a></li> |
| <li><a href="GettingStarted.html">Installation Instructions</a></li> |
| <li><a href="#knownproblems">Known Problems</a></li> |
| <li><a href="#additionalinfo">Additional Information</a></li> |
| </ol> |
| |
| <div class="doc_author"> |
| <p>Written by the <a href="http://llvm.org/">LLVM Team</a></p> |
| </div> |
| |
| <!-- |
| <h1 style="color:red">These are in-progress notes for the upcoming LLVM 3.0 |
| release.<br> |
| You may prefer the |
| <a href="http://llvm.org/releases/2.9/docs/ReleaseNotes.html">LLVM 2.9 |
| Release Notes</a>.</h1> |
| --> |
| |
| <!-- *********************************************************************** --> |
| <h2> |
| <a name="intro">Introduction</a> |
| </h2> |
| <!-- *********************************************************************** --> |
| |
| <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> |
| |
| <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> |
| |
| <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> |
| |
| <!-- Features that need text if they're finished for 3.1: |
| ARM EHABI |
| combiner-aa? |
| strong phi elim |
| loop dependence analysis |
| CorrelatedValuePropagation |
| lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.1. |
| --> |
| |
| <!-- *********************************************************************** --> |
| <h2> |
| <a name="subproj">Sub-project Status Update</a> |
| </h2> |
| <!-- *********************************************************************** --> |
| |
| <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> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a> |
| </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> |
| |
| <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><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>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> |
| </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> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a> |
| </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>The 3.0 release has the following notable changes:</p> |
| |
| <ul> |
| <!-- |
| <li></li> |
| --> |
| </ul> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="compiler-rt">compiler-rt: Compiler Runtime Library</a> |
| </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>In the LLVM 3.0 timeframe,</p> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="lldb">LLDB: Low Level Debugger</a> |
| </h3> |
| |
| <div> |
| |
| <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> |
| <a name="libc++">libc++: C++ Standard Library</a> |
| </h3> |
| |
| <div> |
| |
| <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> |
| <a name="LLBrowse">LLBrowse: IR Browser</a> |
| </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> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="vmkit">VMKit</a> |
| </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> |
| |
| </div> |
| |
| |
| <!--=========================================================================--> |
| <!-- |
| <h3> |
| <a name="klee">KLEE: A Symbolic Execution Virtual Machine</a> |
| </h3> |
| |
| <div> |
| <p> |
| <a href="http://klee.llvm.org/">KLEE</a> is a symbolic execution framework for |
| programs in LLVM bitcode form. KLEE tries to symbolically evaluate "all" paths |
| through the application and records state transitions that lead to fault |
| states. This allows it to construct testcases that lead to faults and can even |
| be used to verify some algorithms. |
| </p> |
| |
| <p>UPDATE!</p> |
| </div>--> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <h2> |
| <a name="externalproj">External Open Source Projects Using LLVM 3.0</a> |
| </h2> |
| <!-- *********************************************************************** --> |
| |
| <div> |
| |
| <p>An exciting aspect of LLVM is that it is used as an enabling technology for |
| a lot of other language and tools projects. This section lists some of the |
| 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> |
| |
| <!--=========================================================================--> |
| <h3>Cling C++ Interpreter</h3> |
| |
| <div> |
| |
| <p><a href="http://cern.ch/cling">Cling</a> is an interactive compiler interface |
| (aka C++ interpreter). It uses LLVM's JIT and clang; it currently supports |
| C++ and C. It has a prompt interface, runs source files, calls into shared |
| libraries, prints the value of expressions, even does runtime lookup of |
| identifiers (dynamic scopes). And it just behaves like one would expect from |
| an interpreter.</p> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3>Crack Programming Language</h3> |
| |
| <div> |
| |
| <p><a href="http://code.google.com/p/crack-language/">Crack</a> aims to provide |
| the ease of development of a scripting language with the performance of a |
| compiled language. The language derives concepts from C++, Java and Python, |
| incorporating object-oriented programming, operator overloading and strong |
| typing.</p> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3>Glasgow Haskell Compiler (GHC)</h3> |
| |
| <div> |
| |
| <p>GHC is an open source, state-of-the-art programming suite for Haskell, a |
| standard lazy functional programming language. It includes an optimizing |
| static compiler generating good code for a variety of platforms, together |
| with an interactive system for convenient, quick development.</p> |
| |
| <p>GHC 7.0 and onwards include an LLVM code generator, supporting LLVM 2.8 and |
| later. Since LLVM 2.9, GHC now includes experimental support for the ARM |
| platform with LLVM 3.0.</p> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3>gwXscript</h3> |
| |
| <div> |
| |
| <p><a href="http://botwars.tk/gwscript/">gwXscript</a> is an object oriented, |
| 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 |
| gwScript contains definitions that expand the namespaces. So you can build |
| your project and simply 'plug out' features by removing a file. The remaining |
| project does not leave scars since you directly separate concerns by the |
| 'template' feature of gwX. It is also possible to add new features to a |
| project by just adding files and without editing the original project. This |
| language is used for example to create games or content management systems |
| that should be extendable.</p> |
| |
| <p>gwXscript is strongly typed and offers comfort with its native types string, |
| hash and array. You can easily write new libraries in gwXscript or native |
| code. gwXscript is type safe and users should not be able to crash your |
| program or execute malicious code except code that is eating CPU time.</p> |
| |
| </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>LuaAV</h3> |
| |
| <div> |
| |
| <p><a href="http://lua-av.mat.ucsb.edu/blog/">LuaAV</a> is a real-time |
| audiovisual scripting environment based around the Lua language and a |
| collection of libraries for sound, graphics, and other media protocols. LuaAV |
| uses LLVM and Clang to JIT compile efficient user-defined audio synthesis |
| routines specified in a declarative syntax.</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> |
| |
| <p>Portable OpenCL is an open source implementation of the OpenCL standard which |
| can be easily adapted for new targets. One of the goals of the project is |
| improving performance portability of OpenCL programs, avoiding the need for |
| target-dependent manual optimizations. A "native" target is included, which |
| allows running OpenCL kernels on the host (CPU).</p> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3>Pure</h3> |
| |
| <div> |
| <p><a href="http://pure-lang.googlecode.com/">Pure</a> is an |
| algebraic/functional programming language based on term rewriting. Programs |
| are collections of equations which are used to evaluate expressions in a |
| symbolic fashion. The interpreter uses LLVM as a backend to JIT-compile Pure |
| programs to fast native code. Pure offers dynamic typing, eager and lazy |
| evaluation, lexical closures, a hygienic macro system (also based on term |
| rewriting), built-in list and matrix support (including list and matrix |
| comprehensions) and an easy-to-use interface to C and other programming |
| languages (including the ability to load LLVM bitcode modules, and inline C, |
| C++, Fortran and Faust code in Pure programs if the corresponding LLVM-enabled |
| compilers are installed).</p> |
| |
| <p>Pure version 0.48 has been tested and is known to work with LLVM 3.0 |
| (and continues to work with older LLVM releases >= 2.5).</p> |
| |
| </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> |
| |
| <p><a href="http://safecode.cs.illinois.edu">SAFECode</a> is a memory safe C/C++ |
| compiler built using LLVM. It takes standard, unannotated C/C++ code, |
| analyzes the code to ensure that memory accesses and array indexing |
| operations are safe, and instruments the code with run-time checks when |
| safety cannot be proven statically. SAFECode can be used as a debugging aid |
| (like Valgrind) to find and repair memory safety bugs. It can also be used |
| to protect code from security attacks at run-time.</p> |
| |
| </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> |
| |
| <div> |
| |
| <p>TCE is a toolset for designing application-specific processors (ASP) based on |
| the Transport triggered architecture (TTA). The toolset provides a complete |
| 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 "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> |
| |
| <!--=========================================================================--> |
| <h3>Tart Programming Language</h3> |
| |
| <div> |
| |
| <p><a href="http://code.google.com/p/tart/">Tart</a> is a general-purpose, |
| strongly typed programming language designed for application |
| developers. Strongly inspired by Python and C#, Tart focuses on practical |
| solutions for the professional software developer, while avoiding the clutter |
| and boilerplate of legacy languages like Java and C++. Although Tart is still |
| in development, the current implementation supports many features expected of |
| a modern programming language, such as garbage collection, powerful |
| bidirectional type inference, a greatly simplified syntax for template |
| metaprogramming, closures and function literals, reflection, operator |
| overloading, explicit mutability and immutability, and much more. Tart is |
| flexible enough to accommodate a broad range of programming styles and |
| philosophies, while maintaining a strong commitment to simplicity, minimalism |
| and elegance in design.</p> |
| |
| </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 and Pin) 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><a href="http://gitorious.org/pinavm/pages/Home">PinaVM</a> is an open |
| source, <a href="http://www.systemc.org/">SystemC</a> front-end. Unlike many |
| other front-ends, PinaVM actually executes the elaboration of the |
| program analyzed using LLVM's JIT infrastructure. It later enriches the |
| bitcode with SystemC-specific information.</p> |
| </div> |
| --> |
| |
| |
| <!--=========================================================================--> |
| <!-- |
| <h3 id="icedtea">IcedTea Java Virtual Machine Implementation</h3> |
| |
| <div> |
| <p> |
| <a href="http://icedtea.classpath.org/wiki/Main_Page">IcedTea</a> provides a |
| harness to build OpenJDK using only free software build tools and to provide |
| replacements for the not-yet free parts of OpenJDK. One of the extensions that |
| IcedTea provides is a new JIT compiler named <a |
| href="http://icedtea.classpath.org/wiki/ZeroSharkFaq">Shark</a> which uses LLVM |
| to provide native code generation without introducing processor-dependent |
| code. |
| </p> |
| |
| <p> OpenJDK 7 b112, IcedTea6 1.9 and IcedTea7 1.13 and later have been tested |
| and are known to work with LLVM 3.0 (and continue to work with older LLVM |
| releases >= 2.6 as well).</p> |
| </div> |
| --> |
| |
| <!--=========================================================================--> |
| <!-- |
| <h3>Polly - Polyhedral optimizations for LLVM</h3> |
| |
| <div> |
| <p>Polly is a project that aims to provide advanced memory access optimizations |
| to better take advantage of SIMD units, cache hierarchies, multiple cores or |
| even vector accelerators for LLVM. Built around an abstract mathematical |
| description based on Z-polyhedra, it provides the infrastructure to develop |
| advanced optimizations in LLVM and to connect complex external optimizers. In |
| its first year of existence Polly already provides an exact value-based |
| dependency analysis as well as basic SIMD and OpenMP code generation support. |
| Furthermore, Polly can use PoCC(Pluto) an advanced optimizer for data-locality |
| and parallelism.</p> |
| </div> |
| --> |
| |
| <!--=========================================================================--> |
| <!-- |
| <h3>Rubinius</h3> |
| |
| <div> |
| <p><a href="http://github.com/evanphx/rubinius">Rubinius</a> is an environment |
| for running Ruby code which strives to write as much of the implementation in |
| Ruby as possible. Combined with a bytecode interpreting VM, it uses LLVM to |
| optimize and compile ruby code down to machine code. Techniques such as type |
| feedback, method inlining, and deoptimization are all used to remove dynamism |
| from ruby execution and increase performance.</p> |
| </div> |
| --> |
| |
| <!--=========================================================================--> |
| <!-- |
| <h3> |
| <a name="FAUST">FAUST Real-Time Audio Signal Processing Language</a> |
| </h3> |
| |
| <div> |
| <p> |
| <a href="http://faust.grame.fr">FAUST</a> is a compiled language for real-time |
| audio signal processing. The name FAUST stands for Functional AUdio STream. Its |
| programming model combines two approaches: functional programming and block |
| diagram composition. In addition with the C, C++, JAVA output formats, the |
| Faust compiler can now generate LLVM bitcode, and works with LLVM 2.7-3.0.</p> |
| |
| </div> |
| --> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <h2> |
| <a name="whatsnew">What's New in LLVM 3.0?</a> |
| </h2> |
| <!-- *********************************************************************** --> |
| |
| <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> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="majorfeatures">Major New Features</a> |
| </h3> |
| |
| <div> |
| |
| <p>LLVM 3.0 includes several major new capabilities:</p> |
| |
| <ul> |
| |
| <!-- |
| <li></li> |
| --> |
| |
| </ul> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="coreimprovements">LLVM IR and Core Improvements</a> |
| </h3> |
| |
| <div> |
| |
| <p>LLVM IR has several new features for better support of new targets and that |
| 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><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> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="optimizer">Optimizer Improvements</a> |
| </h3> |
| |
| <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> |
| |
| <ul> |
| <!-- |
| <li></li> |
| --> |
| </li> |
| |
| </ul> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="mc">MC Level Improvements</a> |
| </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> |
| |
| <ul> |
| <!-- |
| <li></li> |
| --> |
| </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> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="codegen">Target Independent Code Generator Improvements</a> |
| </h3> |
| |
| <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> |
| |
| <ul> |
| <!-- |
| <li></li> |
| --> |
| </ul> |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="x86">X86-32 and X86-64 Target Improvements</a> |
| </h3> |
| |
| <div> |
| |
| <p>New features and major changes in the X86 target include:</p> |
| |
| <ul> |
| |
| <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> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="ARM">ARM Target Improvements</a> |
| </h3> |
| |
| <div> |
| |
| <p>New features of the ARM target include:</p> |
| |
| <ul> |
| <!-- |
| <li></li> |
| --> |
| </ul> |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="OtherTS">Other Target Specific Improvements</a> |
| </h3> |
| |
| <p>PPC32/ELF va_arg was implemented.</p> |
| <p>PPC32 initial support for .o file writing was implemented.</p> |
| |
| <div> |
| |
| <ul> |
| <!-- |
| <li></li> |
| --> |
| </ul> |
| |
| </div> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="changes">Major Changes and Removed Features</a> |
| </h3> |
| |
| <div> |
| |
| <p>If you're already an LLVM user or developer with out-of-tree changes based on |
| LLVM 2.9, this section lists some "gotchas" that you may run into upgrading |
| from the previous release.</p> |
| |
| <ul> |
| <li>The <code>LLVMC</code> front end code was removed while separating |
| out language independence.</li> |
| <li>The <code>LowerSetJmp</code> pass wasn't used effectively by any |
| target and has been removed.</li> |
| <li>The old <code>TailDup</code> pass was not used in the standard pipeline |
| and was unable to update ssa form, so it has been removed. |
| <li>The syntax of volatile loads and stores in IR has been changed to |
| "<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> |
| |
| <!--=========================================================================--> |
| <h3> |
| <a name="api_changes">Internal API Changes</a> |
| </h3> |
| |
| <div> |
| |
| <p>In addition, many APIs have changed in this release. Some of the major |
| 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><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>ComputeLinearIndex</code> (in <code>llvm/CodeGen/Analysis.h</code>)</li> |
| <li><code>ConstantArray::get</code></li> |
| <li><code>ConstantExpr::getExtractElement</code></li> |
| <li><code>ConstantExpr::getGetElementPtr</code></li> |
| <li><code>ConstantExpr::getInBoundsGetElementPtr</code></li> |
| <li><code>ConstantExpr::getIndices</code></li> |
| <li><code>ConstantExpr::getInsertElement</code></li> |
| <li><code>ConstantExpr::getWithOperands</code></li> |
| <li><code>ConstantFoldCall</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li> |
| <li><code>ConstantFoldInstOperands</code> (in <code>llvm/Analysis/ConstantFolding.h</code>)</li> |
| <li><code>ConstantVector::get</code></li> |
| <li><code>DIBuilder::createComplexVariable</code></li> |
| <li><code>DIBuilder::getOrCreateArray</code></li> |
| <li><code>ExtractValueInst::Create</code></li> |
| <li><code>ExtractValueInst::getIndexedType</code></li> |
| <li><code>ExtractValueInst::getIndices</code></li> |
| <li><code>FindInsertedValue</code> (in <code>llvm/Analysis/ValueTracking.h</code>)</li> |
| <li><code>gep_type_begin</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li> |
| <li><code>gep_type_end</code> (in <code>llvm/Support/GetElementPtrTypeIterator.h</code>)</li> |
| <li><code>GetElementPtrInst::Create</code></li> |
| <li><code>GetElementPtrInst::CreateInBounds</code></li> |
| <li><code>GetElementPtrInst::getIndexedType</code></li> |
| <li><code>InsertValueInst::Create</code></li> |
| <li><code>InsertValueInst::getIndices</code></li> |
| <li><code>InvokeInst::Create</code></li> |
| <li><code>IRBuilder::CreateCall</code></li> |
| <li><code>IRBuilder::CreateExtractValue</code></li> |
| <li><code>IRBuilder::CreateGEP</code></li> |
| <li><code>IRBuilder::CreateInBoundsGEP</code></li> |
| <li><code>IRBuilder::CreateInsertValue</code></li> |
| <li><code>IRBuilder::CreateInvoke</code></li> |
| <li><code>MDNode::get</code></li> |
| <li><code>MDNode::getIfExists</code></li> |
| <li><code>MDNode::getTemporary</code></li> |
| <li><code>MDNode::getWhenValsUnresolved</code></li> |
| <li><code>SimplifyGEPInst</code> (in <code>llvm/Analysis/InstructionSimplify.h</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>TargetSelect.h moved to Support/ from Target/</li> |
| |
| <li>UpgradeIntrinsicCall no longer upgrades pre-2.9 intrinsic calls (for |
| example <code>llvm.memset.i32</code>).</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> |
| |
| <!-- *********************************************************************** --> |
| <h2> |
| <a name="knownproblems">Known Problems</a> |
| </h2> |
| <!-- *********************************************************************** --> |
| |
| <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> |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="experimental">Experimental features included with this release</a> |
| </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> |
| |
| <ul> |
| <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> |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="x86-be">Known problems with the X86 back-end</a> |
| </h3> |
| |
| <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> |
| |
| <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> |
| |
| <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>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> |
| </ul> |
| </li> |
| |
| </ul> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="ppc-be">Known problems with the PowerPC back-end</a> |
| </h3> |
| |
| <div> |
| |
| <ul> |
| <li>The PPC32/ELF support lacks PIC support.</li> |
| </ul> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="arm-be">Known problems with the ARM back-end</a> |
| </h3> |
| |
| <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> |
| </ul> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="sparc-be">Known problems with the SPARC back-end</a> |
| </h3> |
| |
| <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> |
| </ul> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="mips-be">Known problems with the MIPS back-end</a> |
| </h3> |
| |
| <div> |
| |
| <ul> |
| <li>64-bit MIPS targets are not supported yet.</li> |
| </ul> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="alpha-be">Known problems with the Alpha back-end</a> |
| </h3> |
| |
| <div> |
| |
| <ul> |
| <li>On 21164s, some rare FP arithmetic sequences which may trap do not have |
| the appropriate nops inserted to ensure restartability.</li> |
| </ul> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="c-be">Known problems with the C back-end</a> |
| </h3> |
| |
| <div> |
| |
| <p>The C backend has numerous problems and is not being actively maintained. |
| 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> |
| </ul> |
| |
| </div> |
| |
| |
| <!-- ======================================================================= --> |
| <h3> |
| <a name="llvm-gcc">Known problems with the llvm-gcc front-end</a> |
| </h3> |
| |
| <div> |
| |
| <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 |
| <tt>__builtin_apply</tt> family of builtins. However, some extensions |
| are only supported on some targets. For example, trampolines are only |
| supported on some targets (these are used when you take the address of a |
| nested function).</p> |
| |
| <p>Fortran support generally works, but there are still several unresolved bugs |
| in <a href="http://llvm.org/bugs/">Bugzilla</a>. Please see the |
| tools/gfortran component for details. Note that llvm-gcc is missing major |
| Fortran performance work in the frontend and library that went into GCC after |
| 4.2. If you are interested in Fortran, we recommend that you consider using |
| <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> |
| |
| </div> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <h2> |
| <a name="additionalinfo">Additional Information</a> |
| </h2> |
| <!-- *********************************************************************** --> |
| |
| <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>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> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
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