diff options
| author | Chris Lattner <sabre@nondot.org> | 2011-12-13 17:55:30 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2011-12-13 17:55:30 +0000 |
| commit | 21e1b7a13c0b1201b51304c9801a66a9f7dd7871 (patch) | |
| tree | ba18904b622e4010933c0c161d415f2aa048c7b4 /docs | |
| parent | 5bd83345c7ba2c15a062495a0267d1dc1d478aac (diff) | |
Rip llvm 3.0 out of the release notes, making room for LLVM 3.1
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146493 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/ReleaseNotes.html | 1022 |
1 files changed, 39 insertions, 983 deletions
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index 1ac15688a3..c20cf74f34 100644 --- a/docs/ReleaseNotes.html +++ b/docs/ReleaseNotes.html @@ -4,11 +4,11 @@ <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> <div> <img style="float:right" src="http://llvm.org/img/DragonSmall.png" @@ -18,8 +18,8 @@ <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> @@ -29,13 +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> @@ -46,7 +44,7 @@ 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 + 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 @@ -74,7 +72,7 @@ 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), and the Clang repository. In addition to this code, the LLVM Project includes other sub-projects that are @@ -96,49 +94,12 @@ Release Notes</a>.</h1> 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> +<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 (aka "C++'0x"), including implementations of non-static data member - initializers, alias templates, delegating constructors, range-based - for loops, 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>Several improvements to Objective-C support, including: - - <ul> - <li><a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html"> - Automatic Reference Counting</a> (ARC) and an improved memory model - cleanly separating object and C memory.</li> - - <li>A migration tool for moving manual retain/release code to ARC</li> - - <li>Better support for data hiding, allowing instance variables to be - declared in implementation contexts or class extensions</li> - <li>Weak linking support for Objective-C classes</li> - <li>Improved static type checking by inferring the return type of methods - such as +alloc and -init.</li> - </ul> - - Some new Objective-C features require either the Mac OS X 10.7 / iOS 5 - Objective-C runtime, or version 1.6 or later of the GNUstep Objective-C - runtime version.</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 + + <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> @@ -164,24 +125,11 @@ Release Notes</a>.</h1> 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>GCC version 4.6 is now fully supported.</li> - - <li>Patching and building GCC is no longer required: the plugin should work - with your system GCC (version 4.5 or 4.6; on Debian/Ubuntu systems the - gcc-4.5-plugin-dev or gcc-4.6-plugin-dev package is also needed).</li> - <li>The <tt>-fplugin-arg-dragonegg-enable-gcc-optzns</tt> option, which runs - GCC's optimizers as well as LLVM's, now works much better. This is the - option to use if you want ultimate performance! It is still experimental - though: it may cause the plugin to crash. Setting the optimization level - to <tt>-O4</tt> when using this option will optimize even harder, though - this usually doesn't result in any improvement over <tt>-O3</tt>.</li> - - <li>The type and constant conversion logic has been almost entirely rewritten, - fixing a multitude of obscure bugs.</li> + <li>...</li> </ul> @@ -203,9 +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, the target specific ARM code has converted to - "unified" assembly syntax, and several new functions have been added to the - library.</p> +<p>....</p> </div> @@ -221,11 +167,7 @@ Release Notes</a>.</h1> Clang parser to provide high-fidelity expression parsing (particularly for C++) and uses the LLVM JIT for target support.</p> -<p>LLDB has advanced by leaps and bounds in the 3.0 timeframe. It is - dramatically more stable and useful, and includes both a - new <a href="http://lldb.llvm.org/tutorial.html">tutorial</a> and - a <a href="http://lldb.llvm.org/lldb-gdb.html">side-by-side comparison with - GDB</a>.</p> +<p>...</p> </div> @@ -240,8 +182,7 @@ Release Notes</a>.</h1> licensed</a> under the MIT and UIUC license, allowing it to be used more permissively.</p> -<p>Libc++ has been ported to FreeBSD and imported into the base system. It is - planned to be the default STL implementation for FreeBSD 10.</p> +<p>...</p> </div> @@ -256,71 +197,20 @@ Release Notes</a>.</h1> implementation of a Java Virtual Machine (Java VM or JVM) that uses LLVM for static and just-in-time compilation. - <p>In the LLVM 3.0 time-frame, VMKit has had significant improvements on both + <p>In the LLVM 3.1 time-frame, VMKit has had significant improvements on both runtime and startup performance:</p> <ul> - <li>Precompilation: by compiling ahead of time a small subset of Java's core - library, the startup performance have been highly optimized to the point that - running a 'Hello World' program takes less than 30 milliseconds.</li> - - <li>Customization: by customizing virtual methods for individual classes, - the VM can statically determine the target of a virtual call, and decide to - inline it.</li> - - <li>Inlining: the VM does more inlining than it did before, by allowing more - bytecode instructions to be inlined, and thanks to customization. It also - inlines GC barriers, and object allocations.</li> - - <li>New exception model: the generated code for a method that does not do - any try/catch is not penalized anymore by the eventuality of calling a - method that throws an exception. Instead, the method that throws the - exception jumps directly to the method that could catch it.</li> + <li>...</li> </ul> </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="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> + <a name="externalproj">External Open Source Projects Using LLVM 3.1</a> </h2> <!-- *********************************************************************** --> @@ -328,404 +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. - 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>clang_complete for VIM</h3> - -<div> - -<p><a href="https://github.com/Rip-Rip/clang_complete">clang_complete</a> is a - VIM plugin, that provides accurate C/C++ autocompletion using the clang front - end. The development version of clang complete, can directly use libclang - which can maintain a cache to speed up auto completion.</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 supports C++ and C, and uses LLVM's JIT and the - Clang parser. 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>Eero</h3> - -<div> - -<p><a href="http://eerolanguage.org/">Eero</a> is a fully - header-and-binary-compatible dialect of Objective-C 2.0, implemented with a - patched version of the Clang/LLVM compiler. It features a streamlined syntax, - Python-like indentation, and new operators, for improved readability and - reduced code clutter. It also has new features such as limited forms of - operator overloading and namespaces, and strict (type-and-operator-safe) - enumerations. It is inspired by languages such as Smalltalk, Python, and - Ruby.</p> - -</div> - -<!--=========================================================================--> -<h3>FAUST Real-Time Audio Signal Processing Language</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> - -<!--=========================================================================--> -<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>ispc: The Intel SPMD Program Compiler</h3> - -<div> - -<p><a href="http://ispc.github.com">ispc</a> is a compiler for "single program, - multiple data" (SPMD) programs. It compiles a C-based SPMD programming - language to run on the SIMD units of CPUs; it often delivers 5-6x speedups on - a single core of a CPU with an 8-wide SIMD unit compared to serial code, - while still providing a clean and easy-to-understand programming model. For - an introduction to the language and its performance, - see <a href="http://ispc.github.com/example.html">the walkthrough</a> of a short - example program. ispc is licensed under the BSD license.</p> - -</div> - -<!--=========================================================================--> -<h3>The Julia Programming Language</h3> - -<div> - -<p><a href="http://github.com/JuliaLang/julia">Julia</a> is a high-level, - high-performance dynamic language for technical - computing. It provides a sophisticated compiler, distributed parallel - execution, numerical accuracy, and an extensive mathematical function - library. The compiler uses type inference to generate fast code - without any type declarations, and uses LLVM's optimization passes and - JIT compiler. The language is designed around multiple dispatch, - giving programs a large degree of flexibility. It is ready for use on many - kinds of problems.</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 Étoilé desktop environment.</p> - -</div> - -<!--=========================================================================--> -<h3>LuaAV</h3> + projects that have already been updated to work with LLVM 3.1.</p> -<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 <a - href="https://github.com/mono/llvm">with some patches</a>.</p> - -</div> - -<!--=========================================================================--> -<h3>Polly</h3> - -<div> - -<p><a href="http://polly.grosser.es">Polly</a> is an advanced data-locality - optimizer and automatic parallelizer. It uses an advanced, mathematical - model to calculate detailed data dependency information which it uses to - optimize the loop structure of a program. Polly can speed up sequential code - by improving memory locality and consequently the cache use. Furthermore, - Polly is able to expose different kind of parallelism which it exploits by - introducing (basic) OpenMP and SIMD code. A mid-term goal of Polly is to - automatically create optimized GPU code.</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> + ... to be filled in right before the release ... </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> <!-- *********************************************************************** --> @@ -759,49 +260,10 @@ be used to verify some algorithms. llvm/lib/Archive - replace with lib object? --> -<p>LLVM 3.0 includes several major changes and big features:</p> +<p>LLVM 3.1 includes several major changes and big features:</p> <ul> -<li>llvm-gcc is no longer supported, and not included in the release. We - recommend switching to <a - href="http://clang.llvm.org/">Clang</a> or <a - href="http://dragonegg.llvm.org/">DragonEgg</a>.</li> - -<li>The linear scan register allocator has been replaced with a new "greedy" - register allocator, enabling live range splitting and many other - optimizations that lead to better code quality. Please see its <a - href="http://blog.llvm.org/2011/09/greedy-register-allocation-in-llvm-30.html">blog post</a> or its talk at the <a - href="http://llvm.org/devmtg/2011-11/">Developer Meeting</a> - for more information.</li> -<li>LLVM IR now includes full support for <a href="Atomics.html">atomics - memory operations</a> intended to support the C++'11 and C'1x memory models. - This includes <a href="LangRef.html#memoryops">atomic load and store, - compare and exchange, and read/modify/write instructions</a> as well as a - full set of <a href="LangRef.html#ordering">memory ordering constraints</a>. - Please see the <a href="Atomics.html">Atomics Guide</a> for more - information. -</li> -<li>The LLVM IR exception handling representation has been redesigned and - reimplemented, making it more elegant, fixing a huge number of bugs, and - enabling inlining and other optimizations. Please see its <a href= - "http://blog.llvm.org/2011/11/llvm-30-exception-handling-redesign.html">blog - post</a> and the <a href="ExceptionHandling.html">Exception Handling - documentation</a> for more information.</li> -<li>The LLVM IR Type system has been redesigned and reimplemented, making it - faster and solving some long-standing problems. - Please see its <a - href="http://blog.llvm.org/2011/11/llvm-30-type-system-rewrite.html">blog - post</a> for more information.</li> - -<li>The MIPS backend has made major leaps in this release, going from an - experimental target to being virtually production quality and supporting a - wide variety of MIPS subtargets. See the <a href="#MIPS">MIPS section</a> - below for more information.</li> - -<li>The optimizer and code generator now supports gprof and gcov-style coverage - and profiling information, and includes a new llvm-cov tool (but also works - with gcov). Clang exposes coverage and profiling through GCC-compatible - command line options.</li> + <li>....</li> </ul> </div> @@ -818,27 +280,7 @@ be used to verify some algorithms. expose new optimization opportunities:</p> <ul> - <li><a href="Atomics.html">Atomic memory accesses and memory ordering</a> are - now directly expressible in the IR.</li> - <li>A new <a href="LangRef.html#int_fma">llvm.fma intrinsic</a> directly - represents floating point multiply accumulate operations without an - intermediate rounding stage.</li> - <li>A new <a href="LangRef.html#int_expect">llvm.expect intrinsic</a> allows a - frontend to express expected control flow (and the - <a href="BranchWeightMetadata.html#builtin_expect"> - <code>__builtin_expect</code></a> from GNU C).</li> - <li>The <a href="LangRef.html#int_prefetch">llvm.prefetch intrinsic</a> now - takes a 4th argument that specifies whether the prefetch happens from the - icache or dcache.</li> - <li>The new <a href="LangRef.html#uwtable">uwtable function attribute</a> - allows a frontend to control emission of unwind tables.</li> - <li>The new <a href="LangRef.html#fnattrs">nonlazybind function - attribute</a> allow optimization of Global Offset Table (GOT) accesses.</li> - <li>The new <a href="LangRef.html#returns_twice">returns_twice attribute</a> - allows better modeling of functions like setjmp.</li> - <li>The <a href="LangRef.html#datalayout">target datalayout</a> string can now - encode the natural alignment of the target's stack for better optimization. - </li> + <li>....</li> </ul> </div> @@ -854,35 +296,7 @@ be used to verify some algorithms. optimizers:</p> <ul> -<li>The pass manager now has an extension API that allows front-ends and plugins - to insert their own optimizations in the well-known places in the standard - pass optimization pipeline.</li> - -<li>Information about <a href="BranchWeightMetadata.html">branch probability</a> - and basic block frequency is now available within LLVM, based on a - combination of static branch prediction heuristics and - <code>__builtin_expect</code> calls. That information is currently used for - register spill placement and if-conversion, with additional optimizations - planned for future releases. The same framework is intended for eventual - use with profile-guided optimization.</li> - -<li>The "-indvars" induction variable simplification pass only modifies - induction variables when profitable. Sign and zero extension - elimination, linear function test replacement, loop unrolling, and - other simplifications that require induction variable analysis have - been generalized so they no longer require loops to be rewritten into - canonical form prior to optimization. This new design - preserves more IR level information, avoids undoing earlier loop - optimizations (particularly hand-optimized loops), and no longer - requires the code generator to reconstruct loops into an optimal form - - an intractable problem.</li> - -<li>LLVM now includes a pass to optimize retain/release calls for the - <a href="http://clang.llvm.org/docs/AutomaticReferenceCounting.html">Automatic - Reference Counting</a> (ARC) Objective-C language feature (in - lib/Transforms/Scalar/ObjCARC.cpp). It is a decent example of implementing - a source-language-specific optimization in LLVM.</li> - + <li>....</li> </ul> </div> @@ -902,30 +316,7 @@ be used to verify some algorithms. to the LLVM MC Project Blog Post</a>.</p> <ul> - <li>The MC layer has undergone significant refactoring to eliminate layering - violations that caused it to pull in the LLVM compiler backend code.</li> - <li>The ELF object file writers are much more full featured.</li> - <li>The integrated assembler now supports #line directives.</li> - <li>An early implementation of a JIT built on top of the MC framework (known - as MC-JIT) has been implemented and will eventually replace the old JIT. - It emits object files direct to memory and uses a runtime dynamic linker to - resolve references and drive lazy compilation. The MC-JIT enables much - greater code reuse between the JIT and the static compiler and provides - better integration with the platform ABI as a result. - </li> - <li>The assembly printer now makes uses of assemblers instruction aliases - (InstAliases) to print simplified mneumonics when possible.</li> - <li>TableGen can now autogenerate MC expansion logic for pseudo - instructions that expand to multiple MC instructions (through the - PseudoInstExpansion class).</li> - <li>A new llvm-dwarfdump tool provides a start of a drop-in - replacement for the corresponding tool that use LLVM libraries. As part of - this, LLVM has the beginnings of a dwarf parsing library.</li> - <li>llvm-objdump has more output including, symbol by symbol disassembly, - inline relocations, section headers, symbol tables, and section contents. - Support for archive files has also been added.</li> - <li>llvm-nm has gained support for archives of binary files.</li> - <li>llvm-size has been added. This tool prints out section sizes.</li> + <li>....</li> </ul> </div> @@ -942,30 +333,7 @@ be used to verify some algorithms. make it run faster:</p> <ul> -<li>LLVM can now produce code that works with libgcc - to <a href="SegmentedStacks.html">dynamically allocate stack - segments</a>, as opposed to allocating a worst-case chunk of - virtual memory for each thread.</li> -<li>LLVM generates substantially better code for indirect gotos due to a new - tail duplication pass, which can be a substantial performance win for - interpreter loops that use them.</li> -<li>Exception handling and debug frame information is now emitted with CFI - directives. This lets the assembler produce more compact info as it knows - the final offsets, yielding <a href="http://blog.mozilla.com/respindola/2011/05/12/cfi-directives/">much smaller executables</a> for some C++ applications. - If the system assembler doesn't support it, MC exands the directives when - the integrated assembler is not used. -</li> - -<li>The code generator now supports vector "select" operations on vector - comparisons, turning them into various optimized code sequences (e.g. - using the SSE4/AVX "blend" instructions).</li> -<li>The SSE execution domain fix pass and the ARM NEON move fix pass have been - merged to a target independent execution dependency fix pass. This pass is - used to select alternative equivalent opcodes in a way that minimizes - execution domain crossings. Closely connected instructions are moved to - the same execution domain when possible. Targets can override the - <code>getExecutionDomain</code> and <code>setExecutionDomain</code> hooks - to use the pass.</li> + <li>....</li> </ul> </div> @@ -979,30 +347,7 @@ be used to verify some algorithms. <p>New features and major changes in the X86 target include:</p> <ul> -<li>The X86 backend, assembler and disassembler now have full support for AVX 1. - To enable it pass <code>-mavx</code> to the compiler. AVX2 implementation is - underway on mainline.</li> -<li>The integrated assembler and disassembler now support a broad range of new - instructions including Atom, Ivy Bridge, <a - href="http://en.wikipedia.org/wiki/SSE4a">SSE4a/BMI</a> instructions, <a - href="http://en.wikipedia.org/wiki/RdRand">rdrand</a> and many others.</li> -<li>The X86 backend now fully supports the <a href="http://llvm.org/PR879">X87 - floating point stack inline assembly constraints</a>.</li> -<li>The integrated assembler now supports the <tt>.code32</tt> and - <tt>.code64</tt> directives to switch between 32-bit and 64-bit - instructions.</li> -<li>The X86 backend now synthesizes horizontal add/sub instructions from generic - vector code when the appropriate instructions are enabled.</li> -<li>The X86-64 backend generates smaller and faster code at -O0 due to - improvements in fast instruction selection.</li> -<li><a href="http://code.google.com/p/nativeclient/">Native Client</a> - subtarget support has been added.</li> - -<li>The CRC32 intrinsics have been renamed. The intrinsics were previously - <code>@llvm.x86.sse42.crc32.[8|16|32]</code> - and <code>@llvm.x86.sse42.crc64.[8|64]</code>. They have been renamed to - <code>@llvm.x86.sse42.crc32.32.[8|16|32]</code> and - <code>@llvm.x86.sse42.crc32.64.[8|64]</code>.</li> + <li>....</li> </ul> </div> @@ -1017,15 +362,7 @@ be used to verify some algorithms. <p>New features of the ARM target include:</p> <ul> -<li>The ARM backend generates much faster code for Cortex-A9 chips.</li> -<li>The ARM backend has improved support for Cortex-M series processors.</li> -<li>The ARM inline assembly constraints have been implemented and are now fully - supported.</li> -<li>NEON code produced by Clang often runs much faster due to improvements in - the Scalar Replacement of Aggregates pass.</li> -<li>The old ARM disassembler is replaced with a new one based on autogenerated - encoding information from ARM .td files.</li> -<li>The integrated assembler has made major leaps forward, but is still beta quality in LLVM 3.0.</li> + <li>....</li> </ul> </div> @@ -1041,53 +378,20 @@ be used to verify some algorithms. backend. Some of the major new features include:</p> <ul> - <li>Most MIPS32r1 and r2 instructions are now supported.</li> - <li>LE/BE MIPS32r1/r2 has been tested extensively.</li> - <li>O32 ABI has been fully tested.</li> - <li>MIPS backend has migrated to using the MC infrastructure for assembly printing. Initial support for direct object code emission has been implemented too.</li> - <li>Delay slot filler has been updated. Now it tries to fill delay slots with useful instructions instead of always filling them with NOPs.</li> - <li>Support for old-style JIT is complete.</li> - <li>Support for old architectures (MIPS1 and MIPS2) has been removed.</li> - <li>Initial support for MIPS64 has been added.</li> + <li>....</li> </ul> </div> <!--=========================================================================--> <h3> - <a name="PTX">PTX Target Improvements</a> -</h3> - -<div> - - <p> - The PTX back-end is still experimental, but is fairly usable for compute kernels - in LLVM 3.0. Most scalar arithmetic is implemented, as well as intrinsics to - access the special PTX registers and sync instructions. The major missing - pieces are texture/sampler support and some vector operations.</p> - - <p>That said, the backend is already being used for domain-specific languages - and can be used by Clang to - <a href="http://clang.llvm.org/docs/ReleaseNotes.html#opencl">compile OpenCL - C code</a> into PTX.</p> - -</div> - -<!--=========================================================================--> -<h3> <a name="OtherTS">Other Target Specific Improvements</a> </h3> <div> <ul> -<li>Many PowerPC improvements have been implemented for ELF targets, including - support for varargs and initial support for direct .o file emission.</li> + <li>....</li> -<li>MicroBlaze scheduling itineraries were added that model the - 3-stage and the 5-stage pipeline architectures. The 3-stage - pipeline model can be selected with <code>-mcpu=mblaze3</code> - and the 5-stage pipeline model can be selected with - <code>-mcpu=mblaze5</code>.</li> </ul> @@ -1101,49 +405,18 @@ be used to verify some algorithms. <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 + LLVM 3.1, this section lists some "gotchas" that you may run into upgrading from the previous release.</p> <ul> -<li>LLVM 3.0 removes support for reading LLVM 2.8 and earlier files, and LLVM - 3.1 will eliminate support for reading LLVM 2.9 files. Going forward, we - aim for all future versions of LLVM to read bitcode files and .ll files - produced by LLVM 3.0.</li> -<li>Tablegen has been split into a library, allowing the clang tblgen pieces - to now live in the clang tree. The llvm version has been renamed to - llvm-tblgen instead of tblgen.</li> - <li>The <code>LLVMC</code> meta compiler driver was removed.</li> - <li>The unused PostOrder Dominator Frontiers and LowerSetJmp passes were 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 and will be removed in - 3.1.</li> - <li>llvm-gcc's frontend tests have been removed from llvm/test/Frontend*, sunk - into the clang and dragonegg testsuites.</li> - <li>The old atomic intrinsics (<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>LLVM's configure script doesn't depend on llvm-gcc anymore, eliminating a - strange circular dependence between projects.</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> +<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 .ll files + produced by LLVM 3.0 and later.</li> + <li>....</li> </ul> </div> -</div> - <!--=========================================================================--> <h3> <a name="api_changes">Internal API Changes</a> @@ -1155,100 +428,7 @@ be used to verify some algorithms. LLVM API changes are:</p> <ul> - <li>The biggest and most pervasive change is that the type system 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><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>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> + <li>....</li> </ul> </div> @@ -1312,130 +492,6 @@ be used to verify some algorithms. </div> -<!--=========================================================================--> - -<!-- EH details: to be moved to a blog post: - - - - -<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 - superseded 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> - - - - - --> - - <!-- *********************************************************************** --> <hr> |