tree 00d9497049e4beab157f3c1927b02a3edfed2a0b
parent b8410601e4647e9dea79820436afe7fd4d898875
author mtklein <mtklein@chromium.org> 1425493090 -0800
committer Commit bot <commit-bot@chromium.org> 1425493090 -0800

Add SSSE3 implementation for SkPMFloat, with faster get() and set().

With SSSE3, we can use the Swiss Army Knife byte shuffler pshufb,
a.k.a. _mm_shuffle_epi8(), to jump directly between 32 and 128 bits.

In microbench isolation, this looks like an additional 10-15% speedup:

SkPMFloat_get:   2.35ns -> 1.98ns
SkPMFloat_clamp: 2.35ns -> 2.18ns

Before this CL, get() and clamp() were identical code.  The _get benchmark improves because both set() and get() become faster; the _clamp benchmark shows the improvement from set() getting faster with clamp() staying the same.

BUG=skia:

Review URL: https://codereview.chromium.org/976493002