[Pixman] [PATCH 2/5] Add SSE2 fetcher for x8r8g8b8

[Soeren Sandmann]

Siarhei Siamashka <siarhei.siamashka at gmail.com> writes:

> Are we going to have this new code performing linear search in this array
> once per each compositing operation now? It may be bad for performance unless
> some kind of caching (at the time of pixman_image_t creation?) can be
> added later.

Well for now, there are only three fetchers, so a cache seems like
overkill, but yes, some sort of caching could be added. It could be
done similarly to the fast path cache, where the cache is thread
private and indexed by (format, iter_flags, image_flags) or something
like that. Then it wouldn't have to happen at image creation time and
there would be no issues with locking the images.

> Also is there a plan to provide SSE2 optimized store functions in addition
> to fetchers later?

I don't have any plans personally, but if someone wants to write some,
that would certainly be useful.

> Anyway, with such changes coming, I see more and more reasons to avoid general
> compositing path in pixman as much as possible :)

I'm not sure I follow? Certainly, if the general path is getting
faster, that would mean there are fewer reasons to avoid it?


Soren