[Pixman] [PATCH 2/2] MIPS: DSPr2: Added bilinear over_8888_8_8888 fast path.

Matt Turner mattst88 at gmail.com
Tue May 15 15:34:38 PDT 2012

On Tue, May 15, 2012 at 5:37 PM, Siarhei Siamashka
<siarhei.siamashka at gmail.com> wrote:
>> I still need to add improvement for that packing/unpacking of the RGBA pixels after bilinear/before OVER operation, but I don't expect big improvement there (it is just a couple of instructions).
> It's not just a couple of instructions. By combining the color
> channels in a register, you are also forcing the processor to finish
> the calculations for all the needed data. And this is an extra data
> dependency, which may inhibit instructions reordering.

Indeed. For instance this is part of the reason why [1] made such a
large difference.

[1] http://cgit.freedesktop.org/pixman/commit/?id=7d4beedc612a32b73d7673bbf6447de0f3fca298

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