[Pixman] [PATCH 0/3] ARM NEON optimizations for better results in cairo-perf benchmarks

[Soeren Sandmann]

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

> Here are the updated patches:
> http://cgit.freedesktop.org/~siamashka/pixman/log/?h=neon-cairo-perf-speedup-v2
> 
> Changes since the previous submission:
> 1. Added fast path table entries for ABGR formats
> 2. A bit faster 'neon_composite_over_n_8888_8888_ca' (making use of the
> fact that alpha channel is the same for both updated source and mask
> in 'combine_mask_ca' output)
> 
> Note: an extra table entry for OVER_x888_8888 operation is needed
> because 'pixman_optimize_operator' can't reduce OVER operator to SRC. When
> repeat is set to PIXMAN_REPEAT_NONE, function '_pixman_image_is_opaque'
> returns FALSE. It could be easily fixed by additionally checking whether the
> region to be composited fits source image completely, and not discriminating
> PIXMAN_REPEAT_NONE in this case.

Right. Chris pointed this out as well. It makes sense to do this
(though there it would need to account for transformations
reintroducing transparency).

> I'm going to push these patches to master in a few days unless there are more
> comments/objections.

If you keep the extra table entry for OVER_x888_8888, maybe alse add
it for ABGR?


Soren