[PATCH] normal_distribution<double> performance improvement with SSE

[Paolo Carlini]

Hi,

On 09/26/2012 01:16 PM, Ulrich Drepper wrote:
> Here is a patch to accelerate the __generate function for the
> normal_distribution<double> class.  The speed-up is quite significant,
> the amount depending on which random number engine is used.
>
> mt19937        +20%
>
> mt19937_64     +30%
>
> sfmt19937      +30%
>
> sfmt19937_64   +30%
>
>
> This patch introduces a header with optimizations for <random>.  No
> changes to existing code needed, this is a straight-forward
> specialization.  Tested on x86_64-linux.  More optimizations follow,
> there is still quite a bit of inefficiency in the existing interfaces.
>   OK to commit?
Looks fine to me. I suppose you want _Power_of_2 inline?

Paolo.