MLIR Backend

mlir-backend is an MLIR based backend for the Remora programming language.

Building and testing

With nix

nix develop
build

The shell also includes scripts to compile programs (run) and clean up the build (clean).

Pins latest release of LLVM 22 that's available in nixpkgs-unstable.

Test cases are Futhark -- input/-- output blocks in mlir-backend/tests/. Run them (via the IREE pipeline) from the repo root:

run-tests              # all annotated tests
run-tests FILE.fut     # one file

Verify test specifications using Futhark's C backend:

futhark-test

Without nix

Build LLVM 22.x from source:

cd llvm
mkdir build
cd build
cmake -G "Ninja" -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLLVM_ENABLE_ASSERTIONS=ON -DLLVM_ENABLE_PROJECTS="clang;mlir" -DLLVM_TARGETS_TO_BUILD="Native;X86;NVPTX;AMDGPU" -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../llvm
ninja

The compiler is currently based on LLVM commit cd70e2d8367493785f1591045db2151540b14b91.

Install Antlr4

Install vcpkg:

git clone https://github.com/microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.sh

Install antlr:

vcpkg install antlr4

Clone the repository

git clone --recursive https://gitlab.draper.com/mocha/mocha-working.git

Generate build files

cd mlir-backend
cmake -S . -G "Ninja" -DLLVM_DIR=[LLVM_DIR] -DMLIR_DIR=[MLIR_DIR] -DCMAKE_TOOLCHAIN_FILE=[VCPKG_ROOT] -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=RelWithDebInfo -B build

Example invocation:

cmake -S . -G "Ninja" -DLLVM_DIR=../llvm-project/build/lib/cmake/llvm -DMLIR_DIR=../llvm-project/build/lib/cmake/mlir -DCMAKE_TOOLCHAIN_FILE=../vcpkg/scripts/buildsystems/vcpkg.cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=RelWithDebInfo -B build

Build the solution

To build from the commandline:

cd build
ninja

Running

To compile a futhark IR file to MLIR:

mlir-backend [FUTHARK_FILE_PATH]