Performance issue ...

[kif]

Hi, I am looking for a fast and portable CRC implementation for Python ... but I think I found a performance bug:

import numpy,zlib,fastcrc
a = numpy.random.random((2048,2048))
%timeit zlib.crc32(a)
26.4 ms ± 29 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)
%timeit fastcrc.crc32.aixm(a.tobytes())
83.9 ms ± 8.78 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)
%timeit pyFAI.ext.fastcrc.crc32(a)
7.59 ms ± 2.07 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

The implementation from pyFAI relies on the SSE4 instruction, thus not portable.