Minimal MLIR

This repo demos a slightly unconventional way to bootstrap an MLIR project:

1. It relies on https://makslevental.github.io/wheels for the upstream distribution of MLIR
2. It smashes all the include headers into a single header include/MinimalDialect.h and all the tablegen into a single include/MinimalDialect.td and also emits all the tablegen into the source tree itself;
   1. I think seeing the emitted tablegen is useful for demystifying how MLIR works
3. It smashes all the implementation into a single src/MinimalDialect.cpp
4. Python bindings @ python/mmlir/dialects are arranged to have generated artifacts to be dumped in place.

It is primarily meant to be used as a learning aid (e.g., for understanding which parts of the upstream CMake are essential and which aren't) and not as a germ/seed/cookiecutter for a production quality project.

Building and exercising

You can either use CMake to build and run lit tests or you can pip install and run test/python/smoketest.py. Note, pip install -r requirements.txt is required either way and pip download mlir -f https://makslevental.github.io/wheels in order to get the mlir distribution package.

A minimal CMake might look like:

pip install -r requirements.txt
pip download mlir -f https://makslevental.github.io/wheels
unzip mlir-*.whl

cmake -G Ninja \
  -DCMAKE_BUILD_TYPE=Release \
  -DPython3_EXECUTABLE=$(which python) \
  -DCMAKE_PREFIX_PATH=$PWD/mlir \
  -DLLVM_EXTERNAL_LIT=$(which lit) \
  -B build \
  -S $PWD

and then just do pushd build && ninja check-minimal && popd.

Alternatively you can pip install, e.g., pip install . -v --no-build-isolation and then pushd test/python && pthon smoketest.py && popd.

If something isn't working you're probably missing ninja or CMake or you haven't done pip install -r requirements.txt. My recommendation is to go to the tests/GitHub actions and see how they're run since they run consistently.