[Numpy-discussion] object array alignment issues

Pauli Virtanen pav+sp@iki...
Fri Oct 16 06:53:45 CDT 2009

Fri, 16 Oct 2009 12:07:10 +0200, Francesc Alted wrote:
> IMO, NumPy can be improved for unaligned data handling.  For example,
> Numexpr is using this small snippet:
> from cpuinfo import cpu
> if cpu.is_AMD() or cpu.is_Intel():
>     is_cpu_amd_intel = True
> else:
>     is_cpu_amd_intel = False
> for detecting AMD/Intel architectures and allowing the code to avoid
> memcpy() calls for the unaligned arrays.
> The above code uses the excellent ``cpuinfo.py`` module from Pearu
> Peterson, which is distributed under NumPy, so it should not be too
> difficult to take advantage of this for avoiding unnecessary copies in
> this scenario.

I suppose this kind of check is easiest to do at compile-time, and 
defining a -DFORCE_ALIGNED? This wouldn't cause performance penalties for 
those architectures for which they are not necessary.

Pauli Virtanen

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