A lightweight LLVM python binding for writing JIT compilers
The old llvmpy binding exposes a lot of LLVM APIs but the mapping of C++-style memory management to Python is error prone. Numba and many JIT compilers do not need a full LLVM API. Only the IR builder, optimizer, and JIT compiler APIs are necessary.
llvmlite is a project originally tailored for Numba's needs, using the following approach:
- A small C wrapper around the parts of the LLVM C++ API we need that are not already exposed by the LLVM C API.
- A ctypes Python wrapper around the C API.
- A pure Python implementation of the subset of the LLVM IR builder that we need for Numba.
- The IR builder is pure Python code and decoupled from LLVM's frequently-changing C++ APIs.
- Materializing a LLVM module calls LLVM's IR parser which provides better error messages than step-by-step IR building through the C++ API (no more segfaults or process aborts).
- Most of llvmlite uses the LLVM C API which is small but very stable (low maintenance when changing LLVM version).
- The binding is not a Python C-extension, but a plain DLL accessed using ctypes (no need to wrestle with Python's compiler requirements and C++ 11 compatibility).
- The Python binding layer has sane memory management.
- llvmlite is quite faster than llvmpy's thanks to a much simpler architeture (the Numba test suite is twice faster than it was).
llvmpy Compatibility Layer
llvmlite.llvmpy namespace provides a minimal llvmpy compatibility
llvmlite works with Python 3.6 and greater.
As of version 0.33.0, llvmlite requires LLVM 9.0.x.
Historical compatibility table:
|llvmlite versions||compatible LLVM versions|
|0.33.0 - ...||9.0.x|
|0.29.0 - 0.32.0||7.0.x, 7.1.x, 8.0.x|
|0.27.0 - 0.28.0||7.0.x|
|0.23.0 - 0.26.0||6.0.x|
|0.21.0 - 0.22.0||5.0.x|
|0.17.0 - 0.20.0||4.0.x|
|0.16.0 - 0.17.0||3.9.x|
|0.13.0 - 0.15.0||3.8.x|
|0.9.0 - 0.12.1||3.7.x|
|0.6.0 - 0.8.0||3.6.x|
|0.1.0 - 0.5.1||3.5.x|
You'll find the documentation at http://llvmlite.pydata.org
$ conda install --channel=numba llvmlite
(or, simply, the official llvmlite package provided in the Anaconda distribution)
Other build methods
If you don't want to use our pre-built packages, you can compile and install llvmlite yourself. The documentation will teach you how: http://llvmlite.pydata.org/en/latest/install/index.html