On Fri, Oct 16, 2009 at 8:53 PM, Pauli Virtanen <pav...@iki.fi> wrote: > Fri, 16 Oct 2009 12:07:10 +0200, Francesc Alted wrote: > [clip] >> 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.
I wonder whether we could switch at runtime (import time) - it could be useful for testing. That being said, I agree that the cpu checks should be done at compile time - we had quite a few problems with cpuinfo in the past with new cpu/unhandled cpu, I think a compilation-based method is much more robust (and simpler) here. There are things where C is just much easier than python :) David _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
