[Theory] How to speed up python code execution / pypy vs GPU

[Christian Gollwitzer]

Am 08.11.16 um 02:23 schrieb Steve D'Aprano:
> But as far as I know, they [NVidia] 're not the only manufacturer of GPUs, and they
> are the only ones who support IEEE 754. So this is *exactly* the situation
> I feared: incompatible GPUs with varying support for IEEE 754 making it
> difficult or impossible to write correct numeric code across GPU platforms.
>

I don't agree. Exact IEEE 754 conforming rounding could guarantee that 
you get bit-identical results. However, if the results of your 
computation depends on the exact rounding rules, i.e. differs by more 
than a minor value, then your algorithm is numerically unstable and you 
there is no way to decide which of both results is correct - most 
probably both are wrong.

	Christian