Reland "lowp bilerp_clamp_8888"
This is a reland of ef96fa9e83c28334b2060607ac9c815521cb18ad
Addition: add the flag SK_SUPPORT_LEGACY_BILERP_HIGHP to
enable fixing chrome unittests and blink tests
Original change's description:
> lowp bilerp_clamp_8888
>
> Use scaling multipy, _mm_mulhrs_epi16(Intel) and vqrdmulhq_s16(ARM),
> to implement bilerp_8888_clamp.
>
> This CL results in 756usec to 590usec improvement for
> samplingoptions_filter_1_mipmap_0 on Intel. For ARM, this improvement
> is 1180usec -> 897usec.
>
> This CL introduces scaled_mult which takes fixed-point numbers on the
> interval [-1, 1) and returns a result which is rescaled to the
> interval [-1, 1).
>
> It also introduces the notion of constrained_add(I16, U16) where the
> result is guaranteed to be U16. This avoids moving to a 32-bit integer
> for during the computation.
>
> Change-Id: I410e494364039df63e5976f433f7e68355e9cfbf
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/443896
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Herb Derby <herb@google.com>
Change-Id: I43e572226e11a75a6e7de5b124f2b1ae3cc37c87
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/453556
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
1 file changed