95800da914
This patch adds more instructions to the Uniforms list, for example certain intrinsics that are uniform by definition or whose operands are loop invariant. This list includes: 1. The intrinsics 'experimental.noalias.scope.decl' and 'sideeffect', which are always uniform by definition. 2. If intrinsics 'lifetime.start', 'lifetime.end' and 'assume' have loop invariant input operands then these are also uniform too. Also, in VPRecipeBuilder::handleReplication we check if an instruction is uniform based purely on whether or not the instruction lives in the Uniforms list. However, there are certain cases where calls to some intrinsics can be effectively treated as uniform too. Therefore, we now also treat the following cases as uniform for scalable vectors: 1. If the 'assume' intrinsic's operand is not loop invariant, then we are free to treat this as uniform anyway since it's only a performance hint. We will get the benefit for the first lane. 2. When the input pointers for 'lifetime.start' and 'lifetime.end' are loop variant then for scalable vectors we assume these still ultimately come from the broadcast of an alloca. We do not support scalable vectorisation of loops containing alloca instructions, hence the alloca itself would be invariant. If the pointer does not come from an alloca then the intrinsic itself has no effect. I have updated the assume test for fixed width, since we now treat it as uniform: Transforms/LoopVectorize/assume.ll I've also added new scalable vectorisation tests for other intriniscs: Transforms/LoopVectorize/scalable-assume.ll Transforms/LoopVectorize/scalable-lifetime.ll Transforms/LoopVectorize/scalable-noalias-scope-decl.ll Differential Revision: https://reviews.llvm.org/D107284
The LLVM Compiler Infrastructure
This directory and its sub-directories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The README briefly describes how to get started with building LLVM. For more information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Getting Started with the LLVM System
Taken from https://llvm.org/docs/GettingStarted.html.
Overview
Welcome to the LLVM project!
The LLVM project has multiple components. The core of the project is itself called "LLVM". This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer. It also contains basic regression tests.
C-like languages use the Clang front end. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Getting the Source Code and Building LLVM
The LLVM Getting Started documentation may be out of date. The Clang Getting Started page might have more accurate information.
This is an example work-flow and configuration to get and build the LLVM source:
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Checkout LLVM (including related sub-projects like Clang):
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git clone https://github.com/llvm/llvm-project.git -
Or, on windows,
git clone --config core.autocrlf=false https://github.com/llvm/llvm-project.git
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Configure and build LLVM and Clang:
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cd llvm-project -
cmake -S llvm -B build -G <generator> [options]Some common build system generators are:
Ninja--- for generating Ninja build files. Most llvm developers use Ninja.Unix Makefiles--- for generating make-compatible parallel makefiles.Visual Studio--- for generating Visual Studio projects and solutions.Xcode--- for generating Xcode projects.
Some Common options:
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-DLLVM_ENABLE_PROJECTS='...'--- semicolon-separated list of the LLVM sub-projects you'd like to additionally build. Can include any of: clang, clang-tools-extra, libcxx, libcxxabi, libunwind, lldb, compiler-rt, lld, polly, or cross-project-tests.For example, to build LLVM, Clang, libcxx, and libcxxabi, use
-DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi". -
-DCMAKE_INSTALL_PREFIX=directory--- Specify for directory the full path name of where you want the LLVM tools and libraries to be installed (default/usr/local). -
-DCMAKE_BUILD_TYPE=type--- Valid options for type are Debug, Release, RelWithDebInfo, and MinSizeRel. Default is Debug. -
-DLLVM_ENABLE_ASSERTIONS=On--- Compile with assertion checks enabled (default is Yes for Debug builds, No for all other build types).
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cmake --build build [-- [options] <target>]or your build system specified above directly.-
The default target (i.e.
ninjaormake) will build all of LLVM. -
The
check-alltarget (i.e.ninja check-all) will run the regression tests to ensure everything is in working order. -
CMake will generate targets for each tool and library, and most LLVM sub-projects generate their own
check-<project>target. -
Running a serial build will be slow. To improve speed, try running a parallel build. That's done by default in Ninja; for
make, use the option-j NNN, whereNNNis the number of parallel jobs, e.g. the number of CPUs you have.
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For more information see CMake
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Consult the Getting Started with LLVM page for detailed information on configuring and compiling LLVM. You can visit Directory Layout to learn about the layout of the source code tree.