skip alpha scale if 256
It's free performance!
Seriously, though, it's a perfectly predictable branch.
On opaque content I'm seeing a small speedup and two
extra instructions in the hot path:
+ cmpl $256, %regs
+ je <to write-it-out>
pmullw %xmm, %xmm
psrlw $8, %xmm
pmullw %xmm, %xmm
psrlw $8, %xmm
write-it-out:
Change-Id: I1c19a9efac62df2bb901ca9eb2679c967729d863
Reviewed-on: https://skia-review.googlesource.com/c/170901
Auto-Submit: Mike Klein <mtklein@google.com>
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Herb Derby <herb@google.com>
1 file changed