I've written a few simple cython routines for assisting in creating byte-aligned numpy arrays. The point being for the arrays to work with SSE/AVX code. https://github.com/hgomersall/pyFFTW/blob/master/pyfftw/utils.pxi The change recently has been to add a check on the CPU as to what flags are supported (though it's not complete, I should make the default return 0 or something). It occurred to me that this is something that (a) other people almost certainly need and are solving themselves and (b) I lack the necessary platforms to test all the possible CPU/OS combinations to make sure something sensible happens in all cases. Is this something that can be rolled into Numpy (the feature, not my particular implementation or interface - though I'd be happy for it to be so)? Regarding (b), I've written a test case that works for Linux on x86-64 with GCC (my platform!). I can test it on 32-bit windows, but that's it. Is ARM supported by Numpy? Neon would be great to include as well. What other platforms might need this? Cheers, Henry