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llvmlite
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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.
.. _llvmpy: https://github.com/llvmpy/llvmpy
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.
Key Benefits
- 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
The llvmlite.llvmpy namespace provides a minimal llvmpy compatibility
layer.
Compatibility
llvmlite works with Python 2.7 and Python 3.4 or greater.
As of version 0.29.0, llvmlite requires LLVM 7.0.x or later
Historical compatibility table:
================= ========================
llvmlite versions compatible LLVM versions
================= ========================
0.29.0 - ... 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
================= ========================
Documentation
You'll find the documentation at http://llvmlite.pydata.org
Pre-built binaries
We recommend you use the binaries provided by the Numba_ team for
the Conda_ package manager. You can find them in Numba's anaconda.org channel <https://anaconda.org/numba>_. For example::
$ conda install --channel=numba llvmlite
(or, simply, the official llvmlite package provided in the Anaconda_
distribution)
.. _Numba: http://numba.pydata.org/
.. _Conda: http://conda.pydata.org/
.. _Anaconda: http://docs.continuum.io/anaconda/index.html
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