Exporting LLVM IR from xDSL

xDSL is a compiler toolkit optimised for accessibility and low iteration time during experimentation and development. Since the beginning, users have been able to design their own abstractions and rewrites on them, but getting an executable required going via mlir-translate, still requiring users to download and install MLIR. We recently bridged this gap, allowing users to emit LLVM directly in xDSL. We leverage llvmlite, a package developed by the Numba team, to convert xDSL modules in the llvm dialect to llvmlite modules. Users of the Python API can do this with the convert_module function, and the llvm IR can be printed via the command line with --target llvm. This functionality allows users to more easily produce LLVM IR files when prototyping, and unlocks JIT functionality which will describe in a future post.

Please find a detailed user guide on the documentation page.

We did a quick comparison of disk usage of xDSL + llvmlite and a full MLIR installation using Homebrew on MacOS ARM64.

# xdsl + llvmlite
uv venv /tmp/lite
uv pip install --python /tmp/lite/bin/python "xdsl[llvm]"
du -sh /tmp/lite                                     # 127M - total venv
du -sh /tmp/lite/lib/python*/site-packages/xdsl      # 5.5M - xdsl
du -sh /tmp/lite/lib/python*/site-packages/llvmlite  # 112M - llvmlite

# mlir-translate
brew install llvm
ls -lh /opt/homebrew/opt/llvm/bin/mlir-translate  # 34K  - binary
du -sh /opt/homebrew/opt/llvm/lib/libMLIR.dylib   # 149M - dependency
du -sh /opt/homebrew/opt/llvm/lib/libLLVM.dylib   # 156M - dependency
du -sh /opt/homebrew/Cellar/llvm                  # 1.7G - full keg

The actual mlir-translate binary is just 34 KB but it’s linked against two very large dylibs at around 305 MB that aren’t split by Homebrew, forcing you to download the entire ~2 GB keg. The optional llvmlite dependency with xDSL on the other hand is around 13x smaller and can be omitted from your build image.

We hope you find this functionality useful. Happy hacking!