tree afa5276377bfbdc46b9301ee70ee860f2ae8f8fb
parent fed9eb1b422e124599748ff01ce7182786b3ac8e
author Mike Klein <mtklein@google.com> 1579804469 -0600
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1579806487 +0000

more bits for shader program hash

gm/lumafilter is drawing wrong for me with SkVMBlitter,
but only when I enable its cache.  I thought it must be
a collision between program fingerprints, but on further
inspection that doesn't seem to be the case, even 32-bit.

But now that I've done this, might as well keep it.
Even if p(collision) is small, p^2 is smaller.

Other small cleanups to what we hash and how:
   - don't include derived fields in Instruction equality and hashing
   - use SkOpts::hash() instead of manual std::hash/xor hack

Small struct layout changes to keep everything dense.

Change-Id: I5ba817296f0bfefa0e18f62d103094d0c63bd50d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/266282
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>