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diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index 56d0eb9..bcac293 100644 --- a/docs/ReleaseNotes.html +++ b/docs/ReleaseNotes.html @@ -4,20 +4,22 @@ <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <link rel="stylesheet" href="llvm.css" type="text/css"> - <title>LLVM 3.0 Release Notes</title> + <title>LLVM 3.1 Release Notes</title> </head> <body> -<h1>LLVM 3.0 Release Notes</h1> +<h1>LLVM 3.1 Release Notes</h1> -<img align=right src="http://llvm.org/img/DragonSmall.png" - width="136" height="136" alt="LLVM Dragon Logo"> +<div> +<img style="float:right" src="http://llvm.org/img/DragonSmall.png" + width="136" height="136" alt="LLVM Dragon Logo"> +</div> <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="#externalproj">External Projects Using LLVM 3.1</a></li> + <li><a href="#whatsnew">What's New in LLVM?</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> @@ -27,13 +29,11 @@ <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 +<h1 style="color:red">These are in-progress notes for the upcoming LLVM 3.1 release.<br> You may prefer the -<a href="http://llvm.org/releases/2.9/docs/ReleaseNotes.html">LLVM 2.9 +<a href="http://llvm.org/releases/3.0/docs/ReleaseNotes.html">LLVM 3.0 Release Notes</a>.</h1> - --> <!-- *********************************************************************** --> <h2> @@ -44,8 +44,9 @@ Release Notes</a>.</h1> <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. + Infrastructure, release 3.1. Here we describe the status of LLVM, including + major improvements from the previous release, improvements in various + subprojects of LLVM, and some of the current users of the code. All LLVM releases may be downloaded from the <a href="http://llvm.org/releases/">LLVM releases web site</a>.</p> @@ -61,16 +62,8 @@ Release Notes</a>.</h1> <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> @@ -79,9 +72,9 @@ Release Notes</a>.</h1> <div> -<p>The LLVM 3.0 distribution currently consists of code from the core LLVM +<p>The LLVM 3.1 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 + supporting tools), and the Clang 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> @@ -99,37 +92,18 @@ Release Notes</a>.</h1> 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> + (32- and 64-bit), and for Darwin/ARM targets.</p> +<p>In the LLVM 3.1 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> + <li>...</li> </ul> - + <p>For more details about the changes to Clang since the 2.9 release, see the +<a href="http://clang.llvm.org/docs/ReleaseNotes.html">Clang release notes</a> +</p> + + <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 @@ -145,19 +119,18 @@ Release Notes</a>.</h1> <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> + optimizers and code generators with LLVM's. It works with gcc-4.5 or gcc-4.6, + targets the x86-32 and x86-64 processor families, and has been successfully + used on the Darwin, FreeBSD, KFreeBSD, Linux and OpenBSD platforms. It fully + supports Ada, C, C++ and Fortran. It has partial support for Go, Java, Obj-C + and Obj-C++.</p> -<p>The 3.0 release has the following notable changes:</p> +<p>The 3.1 release has the following notable changes:</p> + + <ul> + + <li>...</li> -<ul> -<!-- -<li></li> ---> </ul> </div> @@ -178,7 +151,7 @@ Release Notes</a>.</h1> 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> +<p>....</p> </div> @@ -189,11 +162,12 @@ Release Notes</a>.</h1> <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> +<p>LLDB is a ground-up implementation of a command line debugger, as well as a + debugger API that can be used from other applications. LLDB makes use of the + Clang parser to provide high-fidelity expression parsing (particularly for + C++) and uses the LLVM JIT for target support.</p> + +<p>...</p> </div> @@ -208,22 +182,7 @@ Release Notes</a>.</h1> 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> +<p>...</p> </div> @@ -234,39 +193,24 @@ Release Notes</a>.</h1> <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> + <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. -</div> - - -<!--=========================================================================--> -<!-- -<h3> -<a name="klee">KLEE: A Symbolic Execution Virtual Machine</a> -</h3> + <p>In the LLVM 3.1 time-frame, VMKit has had significant improvements on both + runtime and startup performance:</p> -<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> + <ul> + <li>...</li> + </ul> -<p>UPDATE!</p> -</div>--> +</div> </div> <!-- *********************************************************************** --> <h2> - <a name="externalproj">External Open Source Projects Using LLVM 3.0</a> + <a name="externalproj">External Open Source Projects Using LLVM 3.1</a> </h2> <!-- *********************************************************************** --> @@ -274,415 +218,15 @@ be used to verify some algorithms. <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> - -<!--=========================================================================--> -<!-- FIXME: Comment out -<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> + projects that have already been updated to work with LLVM 3.1.</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> + ... to be filled in right before the release ... -<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> + <a name="whatsnew">What's New in LLVM 3.1?</a> </h2> <!-- *********************************************************************** --> @@ -699,18 +243,38 @@ Faust compiler can now generate LLVM bitcode, and works with LLVM 2.7-3.0.</p> <div> -<p>LLVM 3.0 includes several major new capabilities:</p> + <!-- 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. + Integrated assembler on by default for arm/thumb? -<ul> + --> + + <!-- Near dead: + Analysis/RegionInfo.h + Dom Frontiers + SparseBitVector: used in LiveVar. + llvm/lib/Archive - replace with lib object? + --> + +<p>LLVM 3.1 includes several major changes and big features:</p> -<!-- -<li></li> ---> - +<ul> + <li><a href="../tools/clang/docs/AddressSanitizer.html">AddressSanitizer</a>, + a fast memory error detector.</li> + <li><a href="CodeGenerator.html#machineinstrbundle">MachineInstr Bundles</a>, + Support to model instruction bundling / packing.</li> + <li><a href="#armintegratedassembler">ARM Integrated Assembler</a>, + A full featured assembler and direct-to-object support for ARM.</li> + <li>....</li> </ul> - + </div> + <!--=========================================================================--> <h3> <a name="coreimprovements">LLVM IR and Core Improvements</a> @@ -721,117 +285,15 @@ Faust compiler can now generate LLVM bitcode, and works with LLVM 2.7-3.0.</p> <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> - + <ul> + <li>IR support for half float</li> + <li>IR support for vectors of pointers, including vector GEPs.</li> + <li>Module flags have been introduced. They convey information about the + module as a whole to LLVM subsystems.</li> + <li>Loads can now have range metadata attached to them to describe the + possible values being loaded.</li> + <li>....</li> + </ul> </div> <!--=========================================================================--> @@ -841,16 +303,12 @@ Builder.CreateResume(UnwindData); <div> -<p>In addition to a large array of minor performance tweaks and bug fixes, this +<p>In addition to many minor performance tweaks and bug fixes, this release includes a few major enhancements and additions to the optimizers:</p> <ul> -<!-- -<li></li> ---> -</li> - + <li>....</li> </ul> </div> @@ -865,18 +323,14 @@ Builder.CreateResume(UnwindData); <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> + in. 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> <ul> -<!-- -<li></li> ---> + <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> <!--=========================================================================--> @@ -886,15 +340,39 @@ Builder.CreateResume(UnwindData); <div> +<p>We have changed the way that the Type Legalizer legalizes vectors. The type + legalizer now attempts to promote integer elements. This enabled the + implementation of vector-select. Additionally, we see a performance boost on + workloads which use vectors of chars and shorts, since they are now promoted + to 32-bit types, which are better supported by the SIMD instruction set. + Floating point types are still widened as before.</p> + + <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> ---> + <li>TableGen can now synthesize register classes that are only needed to + represent combinations of constraints from instructions and sub-registers. + The synthetic register classes inherit most of their properties form their + closest user-defined super-class.</li> + <li><code>MachineRegisterInfo</code> now allows the reserved registers to be + frozen when register allocation starts. Target hooks should use the + <code>MRI->canReserveReg(FramePtr)</code> method to avoid accidentally + disabling frame pointer elimination during register allocation.</li> + <li>A new kind of <code>MachineOperand</code> provides a compact + representation of large clobber lists on call instructions. The register + mask operand references a bit mask of preserved registers. Everything else + is clobbered.</li> </ul> + +<p> We added new TableGen infrastructure to support bundling for + Very Long Instruction Word (VLIW) architectures. TableGen can now + automatically generate a deterministic finite automaton from a VLIW + target's schedule description which can be queried to determine + legal groupings of instructions in a bundle.</p> + </div> <!--=========================================================================--> @@ -907,13 +385,12 @@ Builder.CreateResume(UnwindData); <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> - + <li>Bug fixes and improved support for AVX1</li> + <li>Support for AVX2 (still incomplete at this point)</li> + <li>Call instructions use the new register mask operands for faster compile + times and better support for different calling conventions. The old WINCALL + instructions are no longer needed.</li> + <li>DW2 Exception Handling is enabled on Cygwin and MinGW.</li> </ul> </div> @@ -928,386 +405,188 @@ Builder.CreateResume(UnwindData); <p>New features of the ARM target include:</p> <ul> -<!-- -<li></li> ---> + <li>The constant island pass now supports basic block and constant pool entry + alignments greater than 4 bytes.</li> + <li>On Darwin, the ARM target now has a full-featured integrated assembler. + </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> +<h4> +<a name="armintegratedassembler">ARM Integrated Assembler</a> +</h4> <div> +<p>The ARM target now includes a full featured macro assembler, including +direct-to-object module support for clang. The assembler is currently enabled +by default for Darwin only pending testing and any additional necessary +platform specific support for Linux.</p> -<ul> -<!-- -<li></li> ---> -</ul> +<p>Full support is included for Thumb1, Thumb2 and ARM modes, along with +subtarget and CPU specific extensions for VFP2, VFP3 and NEON.</p> +<p>The assembler is Unified Syntax only (see ARM Architecural Reference Manual +for details). While there is some, and growing, support for pre-unfied (divided) +syntax, there are still significant gaps in that support.</p> </div> +</div> <!--=========================================================================--> <h3> -<a name="changes">Major Changes and Removed Features</a> +<a name="MIPS">MIPS Target Improvements</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> +<p>This release has seen major new work on just about every aspect of the MIPS + backend. Some of the major new features include:</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>. + <li>....</li> </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> +<a name="OtherTS">Other Target Specific Improvements</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>....</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> +<a name="changes">Major Changes and Removed Features</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> +<p>If you're already an LLVM user or developer with out-of-tree changes based on + LLVM 3.1, this section lists some "gotchas" that you may run into upgrading + from the previous release.</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> + <li>LLVM 3.1 removes support for reading LLVM 2.9 bitcode files. Going + forward, we aim for all future versions of LLVM to read bitcode files and + <tt>.ll</tt> files produced by LLVM 3.0 and later.</li> + <li>The <tt>unwind</tt> instruction is now gone. With the introduction of the + new exception handling system in LLVM 3.0, the <tt>unwind</tt> instruction + became obsolete.</li> + <li>....</li> </ul> </div> -<!-- ======================================================================= --> +<!--=========================================================================--> <h3> - <a name="x86-be">Known problems with the X86 back-end</a> +<a name="api_changes">Internal API Changes</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> +<p>In addition, many APIs have changed in this release. Some of the major + LLVM API changes are:</p> <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> - + <li>Target specific options have been moved from global variables to members + on the new <code>TargetOptions</code> class, which is local to each + <code>TargetMachine</code>. As a consequence, the associated flags will + no longer be accepted by <tt>clang -mllvm</tt>. This includes: <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><code>llvm::PrintMachineCode</code></li> +<li><code>llvm::NoFramePointerElim</code></li> +<li><code>llvm::NoFramePointerElimNonLeaf</code></li> +<li><code>llvm::DisableFramePointerElim(const MachineFunction &)</code></li> +<li><code>llvm::LessPreciseFPMADOption</code></li> +<li><code>llvm::LessPrecideFPMAD()</code></li> +<li><code>llvm::NoExcessFPPrecision</code></li> +<li><code>llvm::UnsafeFPMath</code></li> +<li><code>llvm::NoInfsFPMath</code></li> +<li><code>llvm::NoNaNsFPMath</code></li> +<li><code>llvm::HonorSignDependentRoundingFPMathOption</code></li> +<li><code>llvm::HonorSignDependentRoundingFPMath()</code></li> +<li><code>llvm::UseSoftFloat</code></li> +<li><code>llvm::FloatABIType</code></li> +<li><code>llvm::NoZerosInBSS</code></li> +<li><code>llvm::JITExceptionHandling</code></li> +<li><code>llvm::JITEmitDebugInfo</code></li> +<li><code>llvm::JITEmitDebugInfoToDisk</code></li> +<li><code>llvm::GuaranteedTailCallOpt</code></li> +<li><code>llvm::StackAlignmentOverride</code></li> +<li><code>llvm::RealignStack</code></li> +<li><code>llvm::DisableJumpTables</code></li> +<li><code>llvm::EnableFastISel</code></li> +<li><code>llvm::getTrapFunctionName()</code></li> +<li><code>llvm::EnableSegmentedStacks</code></li> +</ul></li> + <li>....</li> </ul> </div> -<!-- ======================================================================= --> +<!--=========================================================================--> <h3> - <a name="sparc-be">Known problems with the SPARC back-end</a> +<a name="tools_changes">Tools Changes</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> +<p>In addition, some tools have changed in this release. Some of the changes + are:</p> -</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> + <li>llvm-stress is a command line tool for generating random .ll files to fuzz + different LLVM components. </li> + <li>....</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> + <li>....</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> +<!-- *********************************************************************** --> +<h2> + <a name="knownproblems">Known Problems</a> +</h2> +<!-- *********************************************************************** --> <div> -<p><b>LLVM 2.9 was the last release of llvm-gcc.</b></p> +<p>LLVM is generally a production quality compiler, and is used by a broad range + of applications and shipping in many products. That said, not every + subsystem is as mature as the aggregate, particularly the more obscure + targets. 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 or ask on the <a + href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVMdev + list</a>.</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>Known problem areas include:</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> +<ul> + <li>The Alpha, Blackfin, CellSPU, MSP430, PTX, SystemZ and + XCore backends are experimental, and the Alpha, Blackfin and SystemZ + targets have already been removed from mainline.</li> + + <li>The integrated assembler, disassembler, and JIT is not supported by + several targets. If an integrated assembler is not supported, then a + system assembler is required. For more details, see the <a + href="CodeGenerator.html#targetfeatures">Target Features Matrix</a>. + </li> -</div> + <li>The C backend has numerous problems and is not being actively maintained. + Depending on it for anything serious is not advised.</li> +</ul> </div> @@ -1342,7 +621,7 @@ Builder.CreateResume(UnwindData); src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a> <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br> - Last modified: $Date: 2011-11-01 05:51:35 +0100 (Tue, 01 Nov 2011) $ + Last modified: $Date: 2012-04-12 17:17:35 +0200 (Thu, 12 Apr 2012) $ </address> </body> |
