Re: [patch 14/44] generic hweight{64,32,16,8}()

Andi Kleen
2006-02-01T09:06:07Z

On Wednesday 01 February 2006 10:02, Akinobu Mita wrote:

> +static inline unsigned int hweight32(unsigned int w)
> +{
> + unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
> + res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
> + res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
> + res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
> + return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
> +}

How large are these functions on x86? Maybe it would be better to not inline them,
but put it into some C file out of line.

-Andi