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-<html>
-<head>
- <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
- <link rel="stylesheet" href="_static/llvm.css" type="text/css">
- <title>LLVM 3.2 Release Notes</title>
-</head>
-<body>
-
-<h1>LLVM 3.2 Release Notes</h1>
-
-<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 3.2</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>
-</ol>
-
-<div class="doc_author">
- <p>Written by the <a href="http://llvm.org/">LLVM Team</a></p>
-</div>
-
-<h1 style="color:red">These are in-progress notes for the upcoming LLVM 3.2
-release.<br>
-You may prefer the
-<a href="http://llvm.org/releases/3.1/docs/ReleaseNotes.html">LLVM 3.1
-Release Notes</a>.</h1>
-
-<!-- *********************************************************************** -->
-<h2>
- <a name="intro">Introduction</a>
-</h2>
-<!-- *********************************************************************** -->
-
-<div>
-
-<p>This document contains the release notes for the LLVM Compiler
- Infrastructure, release 3.2. 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>
-
-<p>For more information about LLVM, including information about the latest
- release, please check out the <a href="http://llvm.org/">main LLVM web
- site</a>. If you have questions or comments,
- the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">LLVM
- Developer's Mailing List</a> is a good place to send them.</p>
-
-<p>Note that if you are reading this file from a Subversion checkout or the main
- LLVM web page, this document applies to the <i>next</i> release, not the
- current one. To see the release notes for a specific release, please see the
- <a href="http://llvm.org/releases/">releases page</a>.</p>
-
-</div>
-
-
-<!-- *********************************************************************** -->
-<h2>
- <a name="subproj">Sub-project Status Update</a>
-</h2>
-<!-- *********************************************************************** -->
-
-<div>
-
-<p>The LLVM 3.2 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 in development. Here we
- include updates on these subprojects.</p>
-
-<!--=========================================================================-->
-<h3>
-<a name="clang">Clang: C/C++/Objective-C Frontend Toolkit</a>
-</h3>
-
-<div>
-
-<p><a href="http://clang.llvm.org/">Clang</a> is an LLVM front end for the C,
- C++, and Objective-C languages. Clang aims to provide a better user
- experience through expressive diagnostics, a high level of conformance to
- language standards, fast compilation, and low memory use. Like LLVM, Clang
- provides a modular, library-based architecture that makes it suitable for
- creating or integrating with other development tools. Clang is considered a
- production-quality compiler for C, Objective-C, C++ and Objective-C++ on x86
- (32- and 64-bit), and for Darwin/ARM targets.</p>
-
-<p>In the LLVM 3.2 time-frame, the Clang team has made many improvements.
- Highlights include:</p>
-<ul>
- <li>...</li>
-</ul>
-
-<p>For more details about the changes to Clang since the 3.1 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
- issue.</p>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="dragonegg">DragonEgg: GCC front-ends, LLVM back-end</a>
-</h3>
-
-<div>
-
-<p><a href="http://dragonegg.llvm.org/">DragonEgg</a> is a
- <a href="http://gcc.gnu.org/wiki/plugins">gcc plugin</a> that replaces GCC's
- optimizers and code generators with LLVM's. It works with gcc-4.5 and gcc-4.6
- (and partially with gcc-4.7), can target the x86-32/x86-64 and ARM 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 3.2 release has the following notable changes:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="compiler-rt">compiler-rt: Compiler Runtime Library</a>
-</h3>
-
-<div>
-
-<p>The new LLVM <a href="http://compiler-rt.llvm.org/">compiler-rt project</a>
- is a simple library that provides an implementation of the low-level
- target-specific hooks required by code generation and other runtime
- components. For example, when compiling for a 32-bit target, converting a
- double to a 64-bit unsigned integer is compiled into a runtime call to the
- <code>__fixunsdfdi</code> function. The compiler-rt library provides highly
- optimized implementations of this and other low-level routines (some are 3x
- faster than the equivalent libgcc routines).</p>
-
-<p>The 3.2 release has the following notable changes:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="lldb">LLDB: Low Level Debugger</a>
-</h3>
-
-<div>
-
-<p><a href="http://lldb.llvm.org">LLDB</a> 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>The 3.2 release has the following notable changes:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="libc++">libc++: C++ Standard Library</a>
-</h3>
-
-<div>
-
-<p>Like compiler_rt, libc++ is now <a href="DeveloperPolicy.html#license">dual
- licensed</a> under the MIT and UIUC license, allowing it to be used more
- permissively.</p>
-
-<p>Within the LLVM 3.2 time-frame there were the following highlights:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="vmkit">VMKit</a>
-</h3>
-
-<div>
-
-<p>The <a href="http://vmkit.llvm.org/">VMKit project</a> is an implementation
- of a Java Virtual Machine (Java VM or JVM) that uses LLVM for static and
- just-in-time compilation.</p>
-
-<p>The 3.2 release has the following notable changes:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-
-<!--=========================================================================-->
-<h3>
-<a name="Polly">Polly: Polyhedral Optimizer</a>
-</h3>
-
-<div>
-
-<p><a href="http://polly.llvm.org/">Polly</a> is an <em>experimental</em>
- optimizer for data locality and parallelism. It provides high-level
- loop optimizations and automatic parallelisation.</p>
-
-<p>Within the LLVM 3.2 time-frame there were the following highlights:</p>
-
-<ul>
- <li>isl, the integer set library used by Polly, was relicensed to the MIT
-license</li>
- <li>isl based code generation<br />
- <ul>
-<li>MIT licensed replacement for CLooG (LGPLv2) </li>
-<li>Fine grained option handling (separation of
-core and border computations, control overhead vs. code size) </li>
-</li>
-</ul>
-<li>Support for FORTRAN and dragonegg</li>
-<li>OpenMP code generation fixes</li>
-</ul>
-
-
-</div>
-
-</div>
-
-<!-- *********************************************************************** -->
-<h2>
- <a name="externalproj">External Open Source Projects Using LLVM 3.2</a>
-</h2>
-<!-- *********************************************************************** -->
-
-<div>
-
-<p>An exciting aspect of LLVM is that it is used as an enabling technology for
- a lot of other language and tools projects. This section lists some of the
- projects that have already been updated to work with LLVM 3.2.</p>
-
-<h3>Crack</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>FAUST</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,
- JavaScript output formats, the Faust compiler can generate LLVM bitcode, and
- works with LLVM 2.7-3.1.</p>
-
-</div>
-
-<h3>Glasgow Haskell Compiler (GHC)</h3>
-
-<div>
-
-<p><a href="http://www.haskell.org/ghc/">GHC</a> is an open source compiler and
- programming suite for Haskell, a 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.</p>
-
-</div>
-
-<h3>Julia</h3>
-
-<div>
-
-<p><a href="https://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
- <a href="http://julialang.org/"> Julia Language</a> 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>LLVM D Compiler</h3>
-
-<div>
-
-<p><a href="https://github.com/ldc-developers/ldc">LLVM D Compiler</a> (LDC) is
- a compiler for the D programming Language. It is based on the DMD frontend
- and uses LLVM as backend.</p>
-
-</div>
-
-<h3>Open Shading Language</h3>
-
-<div>
-
-<p><a href="https://github.com/imageworks/OpenShadingLanguage/">Open Shading
- Language (OSL)</a> is a small but rich language for programmable shading in
- advanced global illumination renderers and other applications, ideal for
- describing materials, lights, displacement, and pattern generation. It uses
- LLVM to JIT complex shader networks to x86 code at runtime.</p>
-
-<p>OSL was developed by Sony Pictures Imageworks for use in its in-house
- renderer used for feature film animation and visual effects, and is
- distributed as open source software with the "New BSD" license.</p>
-
-</div>
-
-<h3>Portable OpenCL (pocl)</h3>
-
-<div>
-
-<p>In addition to producing an easily portable open source OpenCL
- implementation, another major goal of <a href="http://pocl.sourceforge.net/">
- pocl</a> is improving performance portability of OpenCL programs with
- compiler optimizations, reducing the need for target-dependent manual
- optimizations. An important part of pocl is a set of LLVM passes used to
- statically parallelize multiple work-items with the kernel compiler, even in
- the presence of work-group barriers. This enables static parallelization of
- the fine-grained static concurrency in the work groups in multiple ways
- (SIMD, VLIW, superscalar,...).</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 0.54 has been tested and is known to work with LLVM 3.1 (and
- continues to work with older LLVM releases >= 2.5).</p>
-
-</div>
-
-<h3>TTA-based Co-design Environment (TCE)</h3>
-
-<div>
-
-<p><a href="http://tce.cs.tut.fi/">TCE</a> 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/Verilog 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>
-
-</div>
-
-<!-- *********************************************************************** -->
-<h2>
- <a name="whatsnew">What's New in LLVM 3.2?</a>
-</h2>
-<!-- *********************************************************************** -->
-
-<div>
-
-<p>This release includes a huge number of bug fixes, performance tweaks and
- minor improvements. Some of the major improvements and new features are
- listed in this section.</p>
-
-<!--=========================================================================-->
-<h3>
-<a name="majorfeatures">Major New Features</a>
-</h3>
-
-<div>
-
- <!-- Features that need text if they're finished for 3.2:
- ARM EHABI
- combiner-aa?
- strong phi elim
- loop dependence analysis
- CorrelatedValuePropagation
- lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.2.
- Integrated assembler on by default for arm/thumb?
-
- -->
-
- <!-- Near dead:
- Analysis/RegionInfo.h + Dom Frontiers
- SparseBitVector: used in LiveVar.
- llvm/lib/Archive - replace with lib object?
- -->
-
-<p>LLVM 3.2 includes several major changes and big features:</p>
-
-<ul>
- <li>...</li>
- <li>New NVPTX back-end (replacing existing PTX back-end) based on NVIDIA
- sources</li>
-</ul>
-
-</div>
-
-
-<!--=========================================================================-->
-<h3>
-<a name="coreimprovements">LLVM IR and Core Improvements</a>
-</h3>
-
-<div>
-
-<p>LLVM IR has several new features for better support of new targets and that
- expose new optimization opportunities:</p>
-
-<ul>
- <li>Thread local variables may have a specified TLS model. See the
- <a href="LangRef.html#globalvars">Language Reference Manual</a>.</li>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="optimizer">Optimizer Improvements</a>
-</h3>
-
-<div>
-
-<p>In addition to many minor performance tweaks and bug fixes, this release
- includes a few major enhancements and additions to the optimizers:</p>
-
-<p> Loop Vectorizer - We've added a loop vectorizer and we are now able to
- vectorize small loops. The loop vectorizer is disabled by default and
- can be enabled using the <b>-mllvm -vectorize-loops</b> flag.
- The SIMD vector width can be specified using the flag
- <b>-mllvm -force-vector-width=4</b>.
- The default value is <b>0</b> which means auto-select.
- <br/>
- We can now vectorize this function:
-
- <pre class="doc_code">
- unsigned sum_arrays(int *A, int *B, int start, int end) {
- unsigned sum = 0;
- for (int i = start; i < end; ++i)
- sum += A[i] + B[i] + i;
-
- return sum;
- }
- </pre>
-
- We vectorize under the following loops:
- <ul>
- <li>The inner most loops must have a single basic block.</li>
- <li>The number of iterations are known before the loop starts to execute.</li>
- <li>The loop counter needs to be incremented by one.</li>
- <li>The loop trip count <b>can</b> be a variable.</li>
- <li>Loops do <b>not</b> need to start at zero.</li>
- <li>The induction variable can be used inside the loop.</li>
- <li>Loop reductions are supported.</li>
- <li>Arrays with affine access pattern do <b>not</b> need to be marked as 'noalias' and are checked at runtime.</li>
- <li>...</li>
- </ul>
-
-</p>
-
-<p>SROA - We've re-written SROA to be significantly more powerful.
-<!-- FIXME: Add more text here... --></p>
-
-<ul>
- <li>Branch weight metadata is preseved through more of the optimizer.</li>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="mc">MC Level Improvements</a>
-</h3>
-
-<div>
-
-<p>The LLVM Machine Code (aka MC) subsystem was created to solve a number of
- problems in the realm of assembly, disassembly, object file format handling,
- and a number of other related areas that CPU instruction-set level tools work
- in. 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>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="codegen">Target Independent Code Generator Improvements</a>
-</h3>
-
-<div>
-
-<p>Stack Coloring - We have implemented a new optimization pass
- to merge stack objects which are used in disjoin areas of the code.
- This optimization reduces the required stack space significantly, in cases
- where it is clear to the optimizer that the stack slot is not shared.
- We use the lifetime markers to tell the codegen that a certain alloca
- is used within a region.</p>
-
-<p> We now merge consecutive loads and stores. </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>
-</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>
-
-<p> We have added a new target independent VLIW packetizer based on the
- DFA infrastructure to group machine instructions into bundles.</p>
-
-</div>
-
-<h4>
-<a name="blockplacement">Basic Block Placement</a>
-</h4>
-
-<div>
-
-<p>A probability based block placement and code layout algorithm was added to
- LLVM's code generator. This layout pass supports probabilities derived from
- static heuristics as well as source code annotations such as
- <code>__builtin_expect</code>.</p>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="x86">X86-32 and X86-64 Target Improvements</a>
-</h3>
-
-<div>
-
-<p>New features and major changes in the X86 target include:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="ARM">ARM Target Improvements</a>
-</h3>
-
-<div>
-
-<p>New features of the ARM target include:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-<!--_________________________________________________________________________-->
-
-<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>
-
-<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="MIPS">MIPS Target Improvements</a>
-</h3>
-
-<div>
-
-<p>New features and major changes in the MIPS target include:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="PowerPC">PowerPC Target Improvements</a>
-</h3>
-
-<div>
-
-<ul>
-<p>Many fixes and changes across LLVM (and Clang) for better compliance with
- the 64-bit PowerPC ELF Application Binary Interface, interoperability with
- GCC, and overall 64-bit PowerPC support. Some highlights include:</p>
-<ul>
- <li> MCJIT support added.</li>
- <li> PPC64 relocation support and (small code model) TOC handling
- added.</li>
- <li> Parameter passing and return value fixes (alignment issues,
- padding, varargs support, proper register usage, odd-sized
- structure support, float support, extension of return values
- for i32 return values).</li>
- <li> Fixes in spill and reload code for vector registers.</li>
- <li> C++ exception handling enabled.</li>
- <li> Changes to remediate double-rounding compatibility issues with
- respect to GCC behavior.</li>
- <li> Refactoring to disentangle ppc64-elf-linux ABI from Darwin
- ppc64 ABI support.</li>
- <li> Assorted new test cases and test case fixes (endian and word
- size issues).</li>
- <li> Fixes for big-endian codegen bugs, instruction encodings, and
- instruction constraints.</li>
- <li> Implemented -integrated-as support.</li>
- <li> Additional support for Altivec compare operations.</li>
- <li> IBM long double support.</li>
-</ul>
-<p>There have also been code generation improvements for both 32- and 64-bit
- code. Instruction scheduling support for the Freescale e500mc and e5500
- cores has been added.</p>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="NVPTX">PTX/NVPTX Target Improvements</a>
-</h3>
-
-<div>
-
-<p>The PTX back-end has been replaced by the NVPTX back-end, which is based on
- the LLVM back-end used by NVIDIA in their CUDA (nvcc) and OpenCL compiler.
- Some highlights include:</p>
-<ul>
- <li>Compatibility with PTX 3.1 and SM 3.5</li>
- <li>Support for NVVM intrinsics as defined in the NVIDIA Compiler SDK</li>
- <li>Full compatibility with old PTX back-end, with much greater coverage of
- LLVM IR</li>
-</ul>
-
-<p>Please submit any back-end bugs to the LLVM Bugzilla site.</p>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="OtherTS">Other Target Specific Improvements</a>
-</h3>
-
-<div>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="changes">Major Changes and Removed Features</a>
-</h3>
-
-<div>
-
-<p>If you're already an LLVM user or developer with out-of-tree changes based on
- LLVM 3.2, this section lists some "gotchas" that you may run into upgrading
- from the previous release.</p>
-
-<ul>
- <li>The CellSPU port has been removed. It can still be found in older
- versions.</li>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="api_changes">Internal API Changes</a>
-</h3>
-
-<div>
-
-<p>In addition, many APIs have changed in this release. Some of the major
- LLVM API changes are:</p>
-
-<p> We've added a new interface for allowing IR-level passes to access
- target-specific information. A new IR-level pass, called
- "TargetTransformInfo" provides a number of low-level interfaces.
- LSR and LowerInvoke already use the new interface. </p>
-
-<p> The TargetData structure has been renamed to DataLayout and moved to VMCore
-to remove a dependency on Target. </p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-<!--=========================================================================-->
-<h3>
-<a name="tools_changes">Tools Changes</a>
-</h3>
-
-<div>
-
-<p>In addition, some tools have changed in this release. Some of the changes
- are:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-
-<!--=========================================================================-->
-<h3>
-<a name="python">Python Bindings</a>
-</h3>
-
-<div>
-
-<p>Officially supported Python bindings have been added! Feature support is far
- from complete. The current bindings support interfaces to:</p>
-
-<ul>
- <li>...</li>
-</ul>
-
-</div>
-
-</div>
-
-<!-- *********************************************************************** -->
-<h2>
- <a name="knownproblems">Known Problems</a>
-</h2>
-<!-- *********************************************************************** -->
-
-<div>
-
-<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>Known problem areas include:</p>
-
-<ul>
- <li>The CellSPU, MSP430, and XCore backends are experimental.</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>
-</ul>
-
-</div>
-
-<!-- *********************************************************************** -->
-<h2>
- <a name="additionalinfo">Additional Information</a>
-</h2>
-<!-- *********************************************************************** -->
-
-<div>
-
-<p>A wide variety of additional information is available on
- the <a href="http://llvm.org/">LLVM web page</a>, in particular in
- the <a href="http://llvm.org/docs/">documentation</a> section. The web page
- also contains versions of the API documentation which is up-to-date with the
- Subversion version of the source code. You can access versions of these
- documents specific to this release by going into the "<tt>llvm/doc/</tt>"
- directory in the LLVM tree.</p>
-
-<p>If you have any questions or comments about LLVM, please feel free to contact
- us via the <a href="http://llvm.org/docs/#maillist"> mailing lists</a>.</p>
-
-</div>
-
-<!-- *********************************************************************** -->
-
-<hr>
-<address>
- <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
- src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
- <a href="http://validator.w3.org/check/referer"><img
- 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: $Date$
-</address>
-
-</body>
-</html>
--- /dev/null
+.. raw:: html
+
+ <style> .red {color:red} </style>
+
+.. role:: red
+
+======================
+LLVM 3.2 Release Notes
+======================
+
+.. contents::
+ :local:
+
+Written by the `LLVM Team <http://llvm.org/>`_
+
+:red:`These are in-progress notes for the upcoming LLVM 3.2 release. You may
+prefer the` `LLVM 3.1 Release Notes <http://llvm.org/releases/3.1/docs
+/ReleaseNotes.html>`_.
+
+Introduction
+============
+
+This document contains the release notes for the LLVM Compiler Infrastructure,
+release 3.2. 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 `LLVM releases web site <http://llvm.org/releases/>`_.
+
+For more information about LLVM, including information about the latest
+release, please check out the `main LLVM web site <http://llvm.org/>`_. If you
+have questions or comments, the `LLVM Developer's Mailing List
+<http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev>`_ is a good place to send
+them.
+
+Note that if you are reading this file from a Subversion checkout or the main
+LLVM web page, this document applies to the *next* release, not the current
+one. To see the release notes for a specific release, please see the `releases
+page <http://llvm.org/releases/>`_.
+
+Sub-project Status Update
+=========================
+
+The LLVM 3.2 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 in development. Here we include
+updates on these subprojects.
+
+Clang: C/C++/Objective-C Frontend Toolkit
+-----------------------------------------
+
+`Clang <http://clang.llvm.org/>`_ is an LLVM front end for the C, C++, and
+Objective-C languages. Clang aims to provide a better user experience through
+expressive diagnostics, a high level of conformance to language standards, fast
+compilation, and low memory use. Like LLVM, Clang provides a modular,
+library-based architecture that makes it suitable for creating or integrating
+with other development tools. Clang is considered a production-quality
+compiler for C, Objective-C, C++ and Objective-C++ on x86 (32- and 64-bit), and
+for Darwin/ARM targets.
+
+In the LLVM 3.2 time-frame, the Clang team has made many improvements.
+Highlights include:
+
+#. ...
+
+For more details about the changes to Clang since the 3.1 release, see the
+`Clang release notes. <http://clang.llvm.org/docs/ReleaseNotes.html>`_
+
+If Clang rejects your code but another compiler accepts it, please take a look
+at the `language compatibility <http://clang.llvm.org/compatibility.html>`_
+guide to make sure this is not intentional or a known issue.
+
+DragonEgg: GCC front-ends, LLVM back-end
+----------------------------------------
+
+`DragonEgg <http://dragonegg.llvm.org/>`_ is a `gcc plugin
+<http://gcc.gnu.org/wiki/plugins>`_ that replaces GCC's optimizers and code
+generators with LLVM's. It works with gcc-4.5 and gcc-4.6 (and partially with
+gcc-4.7), can target the x86-32/x86-64 and ARM 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++.
+
+The 3.2 release has the following notable changes:
+
+#. ...
+
+compiler-rt: Compiler Runtime Library
+-------------------------------------
+
+The new LLVM `compiler-rt project <http://compiler-rt.llvm.org/>`_ is a simple
+library that provides an implementation of the low-level target-specific hooks
+required by code generation and other runtime components. For example, when
+compiling for a 32-bit target, converting a double to a 64-bit unsigned integer
+is compiled into a runtime call to the ``__fixunsdfdi`` function. The
+``compiler-rt`` library provides highly optimized implementations of this and
+other low-level routines (some are 3x faster than the equivalent libgcc
+routines).
+
+The 3.2 release has the following notable changes:
+
+#. ...
+
+LLDB: Low Level Debugger
+------------------------
+
+`LLDB <http://lldb.llvm.org>`_ 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.
+
+The 3.2 release has the following notable changes:
+
+#. ...
+
+libc++: C++ Standard Library
+----------------------------
+
+Like compiler_rt, libc++ is now :ref:`dual licensed
+<copyright-license-patents>` under the MIT and UIUC license, allowing it to be
+used more permissively.
+
+Within the LLVM 3.2 time-frame there were the following highlights:
+
+#. ...
+
+VMKit
+-----
+
+The `VMKit project <http://vmkit.llvm.org/>`_ is an implementation of a Java
+Virtual Machine (Java VM or JVM) that uses LLVM for static and just-in-time
+compilation.
+
+The 3.2 release has the following notable changes:
+
+#. ...
+
+Polly: Polyhedral Optimizer
+---------------------------
+
+`Polly <http://polly.llvm.org/>`_ is an *experimental* optimizer for data
+locality and parallelism. It provides high-level loop optimizations and
+automatic parallelisation.
+
+Within the LLVM 3.2 time-frame there were the following highlights:
+
+#. isl, the integer set library used by Polly, was relicensed to the MIT license
+#. isl based code generation
+#. MIT licensed replacement for CLooG (LGPLv2)
+#. Fine grained option handling (separation of core and border computations,
+ control overhead vs. code size)
+#. Support for FORTRAN and dragonegg
+#. OpenMP code generation fixes
+
+External Open Source Projects Using LLVM 3.2
+============================================
+
+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 3.2.
+
+Crack
+-----
+
+`Crack <http://code.google.com/p/crack-language/>`_ 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.
+
+FAUST
+-----
+
+`FAUST <http://faust.grame.fr/>`_ 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, JavaScript output
+formats, the Faust compiler can generate LLVM bitcode, and works with LLVM
+2.7-3.1.
+
+Glasgow Haskell Compiler (GHC)
+------------------------------
+
+`GHC <http://www.haskell.org/ghc/>`_ is an open source compiler and programming
+suite for Haskell, a 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.
+
+GHC 7.0 and onwards include an LLVM code generator, supporting LLVM 2.8 and
+later.
+
+Julia
+-----
+
+`Julia <https://github.com/JuliaLang/julia>`_ 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 `Julia Language <http://julialang.org/>`_ is designed
+around multiple dispatch, giving programs a large degree of flexibility. It is
+ready for use on many kinds of problems.
+
+LLVM D Compiler
+---------------
+
+`LLVM D Compiler <https://github.com/ldc-developers/ldc>`_ (LDC) is a compiler
+for the D programming Language. It is based on the DMD frontend and uses LLVM
+as backend.
+
+Open Shading Language
+---------------------
+
+`Open Shading Language (OSL)
+<https://github.com/imageworks/OpenShadingLanguage/>`_ is a small but rich
+language for programmable shading in advanced global illumination renderers and
+other applications, ideal for describing materials, lights, displacement, and
+pattern generation. It uses LLVM to JIT complex shader networks to x86 code at
+runtime.
+
+OSL was developed by Sony Pictures Imageworks for use in its in-house renderer
+used for feature film animation and visual effects, and is distributed as open
+source software with the "New BSD" license.
+
+Portable OpenCL (pocl)
+----------------------
+
+In addition to producing an easily portable open source OpenCL implementation,
+another major goal of `pocl <http://pocl.sourceforge.net/>`_ is improving
+performance portability of OpenCL programs with compiler optimizations,
+reducing the need for target-dependent manual optimizations. An important part
+of pocl is a set of LLVM passes used to statically parallelize multiple
+work-items with the kernel compiler, even in the presence of work-group
+barriers. This enables static parallelization of the fine-grained static
+concurrency in the work groups in multiple ways (SIMD, VLIW, superscalar, ...).
+
+Pure
+----
+
+`Pure <http://pure-lang.googlecode.com/>`_ 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).
+
+Pure version 0.54 has been tested and is known to work with LLVM 3.1 (and
+continues to work with older LLVM releases >= 2.5).
+
+TTA-based Co-design Environment (TCE)
+-------------------------------------
+
+`TCE <http://tce.cs.tut.fi/>`_ 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/Verilog and parallel program binaries. Processor
+customization points include the register files, function units, supported
+operations, and the interconnection network.
+
+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.
+
+Installation Instructions
+=========================
+
+See :doc:`GettingStarted`.
+
+What's New in LLVM 3.2?
+=======================
+
+This release includes a huge number of bug fixes, performance tweaks and minor
+improvements. Some of the major improvements and new features are listed in
+this section.
+
+Major New Features
+------------------
+
+..
+
+ Features that need text if they're finished for 3.2:
+ ARM EHABI
+ combiner-aa?
+ strong phi elim
+ loop dependence analysis
+ CorrelatedValuePropagation
+ lib/Transforms/IPO/MergeFunctions.cpp => consider for 3.2.
+ Integrated assembler on by default for arm/thumb?
+
+ Near dead:
+ Analysis/RegionInfo.h + Dom Frontiers
+ SparseBitVector: used in LiveVar.
+ llvm/lib/Archive - replace with lib object?
+
+
+LLVM 3.2 includes several major changes and big features:
+
+#. New NVPTX back-end (replacing existing PTX back-end) based on NVIDIA sources
+#. ...
+
+LLVM IR and Core Improvements
+-----------------------------
+
+LLVM IR has several new features for better support of new targets and that
+expose new optimization opportunities:
+
+#. Thread local variables may have a specified TLS model. See the :ref:`Language
+ Reference Manual <globalvars>`.
+#. ...
+
+Optimizer Improvements
+----------------------
+
+In addition to many minor performance tweaks and bug fixes, this release
+includes a few major enhancements and additions to the optimizers:
+
+Loop Vectorizer - We've added a loop vectorizer and we are now able to
+vectorize small loops. The loop vectorizer is disabled by default and can be
+enabled using the ``-mllvm -vectorize-loops`` flag. The SIMD vector width can
+be specified using the flag ``-mllvm -force-vector-width=4``. The default
+value is ``0`` which means auto-select.
+
+We can now vectorize this function:
+
+.. code-block:: c++
+
+ unsigned sum_arrays(int *A, int *B, int start, int end) {
+ unsigned sum = 0;
+ for (int i = start; i < end; ++i)
+ sum += A[i] + B[i] + i;
+ return sum;
+ }
+
+We vectorize under the following loops:
+
+#. The inner most loops must have a single basic block.
+#. The number of iterations are known before the loop starts to execute.
+#. The loop counter needs to be incremented by one.
+#. The loop trip count **can** be a variable.
+#. Loops do **not** need to start at zero.
+#. The induction variable can be used inside the loop.
+#. Loop reductions are supported.
+#. Arrays with affine access pattern do **not** need to be marked as
+ '``noalias``' and are checked at runtime.
+#. ...
+
+SROA - We've re-written SROA to be significantly more powerful.
+
+#. Branch weight metadata is preseved through more of the optimizer.
+#. ...
+
+MC Level Improvements
+---------------------
+
+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. For more information, please see the `Intro to the LLVM MC Project Blog
+Post <http://blog.llvm.org/2010/04/intro-to-llvm-mc-project.html>`_.
+
+#. ...
+
+.. _codegen:
+
+Target Independent Code Generator Improvements
+----------------------------------------------
+
+Stack Coloring - We have implemented a new optimization pass to merge stack
+objects which are used in disjoin areas of the code. This optimization reduces
+the required stack space significantly, in cases where it is clear to the
+optimizer that the stack slot is not shared. We use the lifetime markers to
+tell the codegen that a certain alloca is used within a region.
+
+We now merge consecutive loads and stores.
+
+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:
+
+#. ...
+
+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.
+
+We have added a new target independent VLIW packetizer based on the DFA
+infrastructure to group machine instructions into bundles.
+
+Basic Block Placement
+^^^^^^^^^^^^^^^^^^^^^
+
+A probability based block placement and code layout algorithm was added to
+LLVM's code generator. This layout pass supports probabilities derived from
+static heuristics as well as source code annotations such as
+``__builtin_expect``.
+
+X86-32 and X86-64 Target Improvements
+-------------------------------------
+
+New features and major changes in the X86 target include:
+
+#. ...
+
+.. _ARM:
+
+ARM Target Improvements
+-----------------------
+
+New features of the ARM target include:
+
+#. ...
+
+.. _armintegratedassembler:
+
+ARM Integrated Assembler
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+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.
+
+Full support is included for Thumb1, Thumb2 and ARM modes, along with subtarget
+and CPU specific extensions for VFP2, VFP3 and NEON.
+
+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.
+
+MIPS Target Improvements
+------------------------
+
+New features and major changes in the MIPS target include:
+
+#. ...
+
+PowerPC Target Improvements
+---------------------------
+
+Many fixes and changes across LLVM (and Clang) for better compliance with the
+64-bit PowerPC ELF Application Binary Interface, interoperability with GCC, and
+overall 64-bit PowerPC support. Some highlights include:
+
+#. MCJIT support added.
+#. PPC64 relocation support and (small code model) TOC handling added.
+#. Parameter passing and return value fixes (alignment issues, padding, varargs
+ support, proper register usage, odd-sized structure support, float support,
+ extension of return values for i32 return values).
+#. Fixes in spill and reload code for vector registers.
+#. C++ exception handling enabled.
+#. Changes to remediate double-rounding compatibility issues with respect to
+ GCC behavior.
+#. Refactoring to disentangle ``ppc64-elf-linux`` ABI from Darwin ppc64 ABI
+ support.
+#. Assorted new test cases and test case fixes (endian and word size issues).
+#. Fixes for big-endian codegen bugs, instruction encodings, and instruction
+ constraints.
+#. Implemented ``-integrated-as`` support.
+#. Additional support for Altivec compare operations.
+#. IBM long double support.
+
+There have also been code generation improvements for both 32- and 64-bit code.
+Instruction scheduling support for the Freescale e500mc and e5500 cores has
+been added.
+
+PTX/NVPTX Target Improvements
+-----------------------------
+
+The PTX back-end has been replaced by the NVPTX back-end, which is based on the
+LLVM back-end used by NVIDIA in their CUDA (nvcc) and OpenCL compiler. Some
+highlights include:
+
+#. Compatibility with PTX 3.1 and SM 3.5.
+#. Support for NVVM intrinsics as defined in the NVIDIA Compiler SDK.
+#. Full compatibility with old PTX back-end, with much greater coverage of LLVM
+ SIR.
+
+Please submit any back-end bugs to the LLVM Bugzilla site.
+
+Other Target Specific Improvements
+----------------------------------
+
+#. ...
+
+Major Changes and Removed Features
+----------------------------------
+
+If you're already an LLVM user or developer with out-of-tree changes based on
+LLVM 3.2, this section lists some "gotchas" that you may run into upgrading
+from the previous release.
+
+#. The CellSPU port has been removed. It can still be found in older versions.
+#. ...
+
+Internal API Changes
+--------------------
+
+In addition, many APIs have changed in this release. Some of the major LLVM
+API changes are:
+
+We've added a new interface for allowing IR-level passes to access
+target-specific information. A new IR-level pass, called
+``TargetTransformInfo`` provides a number of low-level interfaces. LSR and
+LowerInvoke already use the new interface.
+
+The ``TargetData`` structure has been renamed to ``DataLayout`` and moved to
+``VMCore`` to remove a dependency on ``Target``.
+
+#. ...
+
+Tools Changes
+-------------
+
+In addition, some tools have changed in this release. Some of the changes are:
+
+#. ...
+
+Python Bindings
+---------------
+
+Officially supported Python bindings have been added! Feature support is far
+from complete. The current bindings support interfaces to:
+
+#. ...
+
+Known Problems
+==============
+
+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 obscure1 targets. If you
+run into a problem, please check the `LLVM bug database
+<http://llvm.org/bugs/>`_ and submit a bug if there isn't already one or ask on
+the `LLVMdev list <http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev>`_.
+
+Known problem areas include:
+
+#. The CellSPU, MSP430, and XCore backends are experimental.
+
+#. 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
+ :ref:`target-feature-matrix`.
+
+Additional Information
+======================
+
+A wide variety of additional information is available on the `LLVM web page
+<http://llvm.org/>`_, in particular in the `documentation
+<http://llvm.org/docs/>`_ section. The web page also contains versions of the
+API documentation which is up-to-date with the Subversion version of the source
+code. You can access versions of these documents specific to this release by
+going into the ``llvm/docs/`` directory in the LLVM tree.
+
+If you have any questions or comments about LLVM, please feel free to contact
+us via the `mailing lists <http://llvm.org/docs/#maillist>`_.
+
projects / platform / upstream / llvm.git / commitdiff