The MPACT Project

Introduction

The MPACT project's main objective is to dramatically reduce the effort required to create highly optimizing HPC and ML compilers for a large class of architectures using LLVM and MLIR. We do this by providing a declarative language-based mechanism for collecting and expressing critical aspects of a target architecture in a way that can be reasoned about and leveraged by all passes in both MLIR and LLVM.

Building the MPACT compiler

To build and run the MPACT compiler from source (for developers), please follow the steps below.

Check out code and sync submodules

Use the following commands to clone the MPACT compiler repository.

git clone https://github.com/MPACT-ORG/mpact-compiler.git
cd mpact-compiler
git submodule update --init --recursive --progress

To always get updated submodules through git pull, set the following flag:

git config --global submodule.recurse true

NOTE: All following commands assume you remain in the mpact-compiler directory.

Setup Python virtual environment

The following commands initialize a virtual environment under bash/sh/etc. For other shells, see Note 1, below.

python3.11 -m venv mpact_venv   # one time set up
source mpact_venv/bin/activate  # MUST BE REPEATED FOR EVERY SESSION

Next, set the Python paths as follows; for shells not in the bash/sh family, see Note 2, below.

export PYTHONPATH=`pwd`/build/tools/mpact/python_packages/mpact

Install build requirements

Note that currently we rely on torch-mlir requirements defined in that submodule to ensure all the build requirements are consistent.

python -m pip install --upgrade pip
python -m pip install -r externals/torch-mlir/requirements.txt
python -m pip install -r externals/torch-mlir/torchvision-requirements.txt

For shells not in the bash/sh family, see Note 3, below.

Building the MPACT compiler in-tree

The following command generates configuration files to build the MPACT compiler project completely in-tree, which means that both LLVM as well as torch-mlir are built from source.

cmake -GNinja -Bbuild \
  -DCMAKE_BUILD_TYPE=Release \
  -DPython3_FIND_VIRTUALENV=ONLY \
  -DLLVM_ENABLE_PROJECTS=mlir \
  -DLLVM_EXTERNAL_PROJECTS="torch-mlir;mpact" \
  -DLLVM_EXTERNAL_TORCH_MLIR_SOURCE_DIR="${PWD}/externals/torch-mlir" \
  -DLLVM_EXTERNAL_MPACT_SOURCE_DIR="${PWD}" \
  -DLLVM_TARGETS_TO_BUILD=host \
  -DMLIR_ENABLE_BINDINGS_PYTHON=ON \
  externals/torch-mlir/externals/llvm-project/llvm

To speed up the build process, you can set up ccache and add the following flags to the command above:

-DCMAKE_C_COMPILER_LAUNCHER=ccache -DCMAKE_CXX_COMPILER_LAUNCHER=ccache

Run the following to ensure the MPACT compiler builds and runs correctly.

cmake --build build --target check-mpact

And the following to run all benchmarks (see Benchmarks for more details).

cmake --build build --target benchmark-mpact

Notes

1. Shells other than bash/sh/etc. require a different activate script, as shown. Because the python environment has to be set up for every session, we recommend putting it in your .*sh startup file.
   • For csh/tcsh/etc.:

         source `pwd`/mpact_venv/bin/activate.csh

   • For fish/etc.:

         source <path_to_mpact_compiler>/mpact_venv/bin/activate.fish

2. Shells other than bash/sh/etc. set their environment variables differently:
   • For csh/tcsh/etc.:

       setenv PYTHONPATH `pwd`/build/tools/mpact/python_packages/mpact

3. If using csh/tcsh/etc., run the following command before trying to build the compiler:

rehash