[PATCH] Use x86 bsr instruction in Log2 functions

Michel Dänzer michel at tungstengraphics.com
Tue Sep 18 02:27:37 PDT 2007

On Mon, 2007-09-17 at 15:37 -0400, Matt Turner wrote:
> This patch edits RADEONLog2 and ATILog2 to use the x86 bsr instruction
> instread of looping through bits. It should provide a somewhat of a
> speed increase in this function on x86 and AMD64 architectures.

Have you seen any profiles where these were anywhere near the top
though? Not sure it's worth bothering otherwise.

P.S. There's a xorg-driver-ati list dedicated to xf86-video-ati

Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer

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