[Numpy-discussion] Openmp support (was numpy's future (1.1 and beyond): which direction(s) ?)

David Cournapeau david@ar.media.kyoto-u.ac...
Sun Mar 23 01:21:26 CDT 2008

Charles R Harris wrote:
> Yep, but I expect the compilers to take care of alignment, say by 
> inserting a few single ops when needed.

The other solution would be to have aligned allocators (it won't solve 
all cases, of course). Because the compilers will never be able to take 
care of the cases where you call external libraries (fftw, where we 
could have between 50 % and more than 100 % speed increase if we had 
aligned data buffers by default).

> So I would just as soon leave vectorization to the compilers and wait 
> until they get that good. The only thing needed then is contiguous data.

For non contiguous data, things will be extremely slow anyway, so I 
don't think those need a lot of attention. If you care about 
performances, you should not use non contiguous data.



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