tree be447867e98e5f67751d3b1ab801271c47b72c68
parent 95fb5786c5549cbe09f9a64c95c6be0920879e8a
author Mike Klein <mtklein@google.com> 1607024248 -0600
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1607031043 +0000

plumb register aliasing hints through on arm64

There's no reason not to do this, though there are so many registers on
arm64 that I doubt we'll see any speed difference here at all.

I let dst() take a second hint, which makes most of these super easy;
double hints don't really come up on x86 because we've got all that
any() register-or-memory-address complexity to deal with instead there.

The most subtle bit is that it's safe to alias the index and destination
registers of the gather ops... we pull an index out of a lane, load the
value, and shove it back into that same lane, all totally safe.

Change-Id: I0f28ead95922e99e712ccb2cf824bf2610f556a6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/340721
Commit-Queue: Herb Derby <herb@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Herb Derby <herb@google.com>