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diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst index 7b143f6..94663c4 100644 --- a/docs/ReleaseNotes.rst +++ b/docs/ReleaseNotes.rst @@ -5,12 +5,6 @@ LLVM 3.4 Release Notes .. contents:: :local: -.. warning:: - These are in-progress notes for the upcoming LLVM 3.4 release. You may - prefer the `LLVM 3.3 Release Notes <http://llvm.org/releases/3.3/docs - /ReleaseNotes.html>`_. - - Introduction ============ @@ -34,12 +28,15 @@ page <http://llvm.org/releases/>`_. Non-comprehensive list of changes in this release ================================================= -.. NOTE - For small 1-3 sentence descriptions, just add an entry at the end of - this list. If your description won't fit comfortably in one bullet - point (e.g. maybe you would like to give an example of the - functionality, or simply have a lot to talk about), see the `NOTE` below - for adding a new subsection. +* This is expected to be the last release of LLVM which compiles using a C++98 + toolchain. We expect to start using some C++11 features in LLVM and other + sub-projects starting after this release. That said, we are committed to + supporting a reasonable set of modern C++ toolchains as the host compiler on + all of the platforms. This will at least include Visual Studio 2012 on + Windows, and Clang 3.1 or GCC 4.7.x on Mac and Linux. The final set of + compilers (and the C++11 features they support) is not set in stone, but we + wanted users of LLVM to have a heads up that the next release will involve + a substantial change in the host toolchain requirements. * The regression tests now fail if any command in a pipe fails. To disable it in a directory, just add ``config.pipefail = False`` to its ``lit.local.cfg``. @@ -50,9 +47,9 @@ Non-comprehensive list of changes in this release * The R600 backend is not marked experimental anymore and is built by default. -* APFloat::isNormal() was renamed to APFloat::isFiniteNonZero() and - APFloat::isIEEENormal() was renamed to APFloat::isNormal(). This ensures that - APFloat::isNormal() conforms to IEEE-754R-2008. +* ``APFloat::isNormal()`` was renamed to ``APFloat::isFiniteNonZero()`` and + ``APFloat::isIEEENormal()`` was renamed to ``APFloat::isNormal()``. This + ensures that ``APFloat::isNormal()`` conforms to IEEE-754R-2008. * The library call simplification pass has been removed. Its functionality has been integrated into the instruction combiner and function attribute @@ -62,26 +59,74 @@ Non-comprehensive list of changes in this release or later instead. For more information, see the `Getting Started using Visual Studio <GettingStartedVS.html>`_ page. -* The Loop Vectorizer that was previously enabled for -O3 is now enabled for - -Os and -O2. +* The Loop Vectorizer that was previously enabled for ``-O3`` is now enabled + for ``-Os`` and ``-O2``. * The new SLP Vectorizer is now enabled by default. -* llvm-ar now uses the new Object library and produces archives and +* ``llvm-ar`` now uses the new Object library and produces archives and symbol tables in the gnu format. -* ... next change ... +* FileCheck now allows specifing ``-check-prefix`` multiple times. This + helps reduce duplicate check lines when using multiple RUN lines. + +* The bitcast instruction no longer allows casting between pointers + with different address spaces. To achieve this, use the new addrspacecast + instruction. + +* Different sized pointers for different address spaces should now + generally work. This is primarily useful for GPU targets. + +* OCaml bindings have been significantly extended to cover almost all of the + LLVM libraries. + +Mips Target +----------- + +Support for the MIPS SIMD Architecture (MSA) has been added. MSA is supported +through inline assembly, intrinsics with the prefix '``__builtin_msa``', and +normal code generation. -.. NOTE - If you would like to document a larger change, then you can add a - subsection about it right here. You can copy the following boilerplate - and un-indent it (the indentation causes it to be inside this comment). +For more information on MSA (including documentation for the instruction set), +see the `MIPS SIMD page at Imagination Technologies +<http://imgtec.com/mips/mips-simd.asp>`_ - Special New Feature - ------------------- +PowerPC Target +-------------- - Makes programs 10x faster by doing Special New Thing. +Changes in the PowerPC backend include: +* fast-isel support (for faster ``-O0`` code generation) +* many improvements to the builtin assembler +* support for generating unaligned (Altivec) vector loads +* support for generating the fcpsgn instruction +* generate ``frin`` for ``round()`` (not ``nearbyint()`` and ``rint()``, which + had been done only in fast-math mode) +* improved instruction scheduling for embedded cores (such as the A2) +* improved prologue/epilogue generation (especially in 32-bit mode) +* support for dynamic stack alignment (and dynamic stack allocations with large alignments) +* improved generation of counter-register-based loops +* bug fixes + +SPARC Target +------------ + +The SPARC backend got many improvements, namely + +* experimental SPARC V9 backend +* JIT support for SPARC +* fp128 support +* exception handling +* TLS support +* leaf functions optimization +* bug fixes + +SystemZ/s390x Backend +--------------------- + +LLVM and clang can now optimize for zEnterprise z196 and zEnterprise EC12 +targets. In clang these targets are selected using ``-march=z196`` and +``-march=zEC12`` respectively. External Open Source Projects Using LLVM 3.4 ============================================ @@ -90,6 +135,105 @@ 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 3.4. +DXR +--- + +`DXR <https://wiki.mozilla.org/DXR>`_ is Mozilla's code search and navigation +tool, aimed at making sense of large projects like Firefox. It supports +full-text and regex searches as well as structural queries like "Find all the +callers of this function." Behind the scenes, it uses a custom trigram index, +the re2 library, and structural data collected by a clang compiler plugin. + +LDC - the LLVM-based D compiler +------------------------------- + +`D <http://dlang.org>`_ is a language with C-like syntax and static typing. It +pragmatically combines efficiency, control, and modeling power, with safety and +programmer productivity. D supports powerful concepts like Compile-Time Function +Execution (CTFE) and Template Meta-Programming, provides an innovative approach +to concurrency and offers many classical paradigms. + +`LDC <http://wiki.dlang.org/LDC>`_ uses the frontend from the reference compiler +combined with LLVM as backend to produce efficient native code. LDC targets +x86/x86_64 systems like Linux, OS X, FreeBSD and Windows and also Linux/PPC64. +Ports to other architectures like ARM and AArch64 are underway. + +LibBeauty +--------- + +The `LibBeauty <http://www.libbeauty.com>`_ decompiler and reverse +engineering tool currently utilises the LLVM disassembler and the LLVM IR +Builder. The current aim of the project is to take a x86_64 binary ``.o`` file +as input, and produce an equivalent LLVM IR ``.bc`` or ``.ll`` file as +output. Support for ARM binary ``.o`` file as input will be added later. + +Likely +------ + +`Likely <http://www.liblikely.org/>`_ is an open source domain specific +language for image recognition. Algorithms are just-in-time compiled using +LLVM's MCJIT infrastructure to execute on single or multi-threaded CPUs as well +as OpenCL SPIR or CUDA enabled GPUs. Likely exploits the observation that while +image processing and statistical learning kernels must be written generically +to handle any matrix datatype, at runtime they tend to be executed repeatedly +on the same type. + +Portable Computing Language (pocl) +---------------------------------- + +In addition to producing an easily portable open source OpenCL +implementation, another major goal of `pocl <http://portablecl.org/>`_ +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. + +Portable Native Client (PNaCl) +------------------------------ + +`Portable Native Client (PNaCl) <http://www.chromium.org/nativeclient/pnacl>`_ +is a Chrome initiative to bring the performance and low-level control of native +code to modern web browsers, without sacrificing the security benefits and +portability of web applications. PNaCl works by compiling native C and C++ code +to an intermediate representation using the LLVM clang compiler. This +intermediate representation is a subset of LLVM bytecode that is wrapped into a +portable executable, which can be hosted on a web server like any other website +asset. When the site is accessed, Chrome fetches and translates the portable +executable into an architecture-specific machine code optimized directly for +the underlying device. PNaCl lets developers compile their code once to run on +any hardware platform and embed their PNaCl application in any website, +enabling developers to directly leverage the power of the underlying CPU and +GPU. + +TTA-based Co-design Environment (TCE) +------------------------------------- + +`TCE <http://tce.cs.tut.fi/>`_ is a toolset for designing new +exposed datapath processors 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++/OpenCL 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 processors and +loads them in to the compiler backend as runtime libraries to avoid +per-target recompilation of larger parts of the compiler chain. + +WebCL Validator +--------------- + +`WebCL Validator <https://github.com/KhronosGroup/webcl-validator>`_ implements +validation for WebCL C language which is a subset of OpenCL ES 1.1. Validator +checks the correctness of WebCL C, and implements memory protection for it as a +source-2-source transformation. The transformation converts WebCL to memory +protected OpenCL. The protected OpenCL cannot access any memory ranges which +were not allocated for it, and its memory is always initialized to prevent +information leakage from other programs. + Additional Information ====================== @@ -103,4 +247,3 @@ 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>`_. - |