MLIR For Beginners
This is the code repository for a series of articles on the MLIR framework for building compilers.
Articles
- Build System (Getting Started)
- Running and Testing a Lowering
- Writing Our First Pass
- Using Tablegen for Passes
- Defining a New Dialect
- Using Traits
- Folders and Constant Propagation
- Verifiers
- Canonicalizers and Declarative Rewrite Patterns
- Dialect Conversion
- Lowering through LLVM
- A Global Optimization and Dataflow Analysis
Bazel build
Bazel is one of two supported build systems for this tutorial. The other is CMake. If you're unfamiliar with Bazel, you can read the tutorials at https://bazel.build/start. Familiarity with Bazel is not required to build or test, but it is required to follow the articles in the tutorial series and explained in the first article, Build System (Getting Started). The CMake build is maintained, but was added at article 10 (Dialect Conversion) and will not be explained in the articles.
Prerequisites
Install Bazelisk via instructions at
https://github.com/bazelbuild/bazelisk#installation.
This should create the bazel command on your system.
You should also have a modern C++ compiler on your system, either gcc or
clang, which Bazel will detect.
Build and test
Run
bazel build ...:all
bazel test ...:allCMake build
CMake is one of two supported build systems for this tutorial. The other is Bazel. If you're unfamiliar with CMake, you can read the tutorials at https://cmake.org/getting-started/. The CMake build is maintained, but was added at article 10 (Dialect Conversion) and will not be explained in the articles.
Prerequisites
- Make sure you have installed everything needed to build LLVM https://llvm.org/docs/GettingStarted.html#software
- For this recipe Ninja is used so be sure to have it as well installed https://github.com/ninja-build/ninja/wiki/Pre-built-Ninja-packages
Checking out the code
Checkout the tutorial including the LLVM dependency (submodules):
git clone --recurse-submodules https://github.com/j2kun/mlir-tutorial.git
cd mlir-tutorialBuilding dependencies
Note: The following steps are suitable for macOs and use ninja as building system, they should not be hard to adapt for your environment.
Build LLVM/MLIR
#!/bin/sh
BUILD_SYSTEM=Ninja
BUILD_TAG=ninja
THIRDPARTY_LLVM_DIR=$PWD/externals/llvm-project
BUILD_DIR=$THIRDPARTY_LLVM_DIR/build
INSTALL_DIR=$THIRDPARTY_LLVM_DIR/install
mkdir -p $BUILD_DIR
mkdir -p $INSTALL_DIR
pushd $BUILD_DIR
cmake ../llvm -G $BUILD_SYSTEM \
-DCMAKE_CXX_COMPILER="$(xcrun --find clang++)" \
-DCMAKE_C_COMPILER="$(xcrun --find clang)" \
-DCMAKE_INSTALL_PREFIX=$INSTALL_DIR \
-DLLVM_LOCAL_RPATH=$INSTALL_DIR/lib \
-DLLVM_PARALLEL_COMPILE_JOBS=7 \
-DLLVM_PARALLEL_LINK_JOBS=1 \
-DLLVM_BUILD_EXAMPLES=OFF \
-DLLVM_INSTALL_UTILS=ON \
-DCMAKE_OSX_ARCHITECTURES="$(uname -m)" \
-DCMAKE_BUILD_TYPE=Release \
-DLLVM_ENABLE_ASSERTIONS=ON \
-DLLVM_CCACHE_BUILD=ON \
-DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
-DLLVM_ENABLE_PROJECTS='mlir' \
-DDEFAULT_SYSROOT="$(xcrun --show-sdk-path)" \
-DCMAKE_OSX_SYSROOT="$(xcrun --show-sdk-path)"
cmake --build . --target check-mlir
popdBuild and test
#!/bin/sh
BUILD_SYSTEM="Ninja"
BUILD_DIR=./build-`echo ${BUILD_SYSTEM}| tr '[:upper:]' '[:lower:]'`
rm -rf $BUILD_DIR
mkdir $BUILD_DIR
pushd $BUILD_DIR
LLVM_BUILD_DIR=externals/llvm-project/build
cmake -G $BUILD_SYSTEM .. \
-DLLVM_DIR="$LLVM_BUILD_DIR/lib/cmake/llvm" \
-DMLIR_DIR="$LLVM_BUILD_DIR/lib/cmake/mlir" \
-DBUILD_DEPS="ON" \
-DBUILD_SHARED_LIBS="OFF" \
-DCMAKE_BUILD_TYPE=Debug
popd
cmake --build $BUILD_DIR --target MLIRAffineFullUnrollPasses
cmake --build $BUILD_DIR --target MLIRMulToAddPasses
cmake --build $BUILD_DIR --target MLIRNoisyPasses
cmake --build $BUILD_DIR --target mlir-headers
cmake --build $BUILD_DIR --target mlir-doc
cmake --build $BUILD_DIR --target tutorial-opt
cmake --build $BUILD_DIR --target check-mlir-tutorial