[haiku-development] Re: Optimizing Painter::_DrawBitmapBilinearCopy32 (was: Re: ShowImage patch)
- From: Stephen Deken <stephen.deken@xxxxxxxxx>
- To: haiku-development@xxxxxxxxxxxxx
- Date: Wed, 11 Mar 2009 15:25:33 -0500
On Wed, Mar 11, 2009 at 11:59 AM, Christian Packmann <
Christian.Packmann@xxxxxx> wrote:
> So we can do
> (component_value * 129) >> 23
> to approximate the division by 65025.
>
I'll prefix this by saying I know only slightly more than nothing about MMX
and SSE. But I do notice:
(x * 129) >> 23 == (x >> 16) + (x >> 23)
That's just by definition, of course. Is that faster at all? (One more bit
of accuracy could be eked out by adding x >> 31, but that's probably
overkill.)
--
Stephen Deken
stephen.deken@xxxxxxxxx
Other related posts:
