tree 3863ccf71690305eda5bf057777fd9cc08c11f0d
parent ce054bd88c7a70fde8514a3248422c940ce44c9d
author Leandro Lovisolo <lovisolo@google.com> 1565377094 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1565378973 +0000

[gold] diff.go: Optimize PixelDiff()'s same-size branch by setting each pixel in the output diff exactly once.

This results in a ~10% reduction in the time it takes to diff images of different sizes. See benchmarks "BenchmarkDiffDifferentSize" below.

Benchmarks before this change:

$ go test -bench=. -benchtime=10s
goos: linux
goarch: amd64
pkg: go.skia.org/infra/golden/go/diff
BenchmarkDiffIdentical-12                  50000            302783 ns/op
BenchmarkDiffSameSize-12                    1000          18130019 ns/op
BenchmarkDiffDifferentSize-12                500          38916445 ns/op
PASS
ok      go.skia.org/infra/golden/go/diff        61.967s

Benchmarks after this change:

$ go test -bench=. -benchtime=10s
goos: linux
goarch: amd64
pkg: go.skia.org/infra/golden/go/diff
BenchmarkDiffIdentical-12                  50000            296255 ns/op
BenchmarkDiffSameSize-12                    1000          18129664 ns/op
BenchmarkDiffDifferentSize-12                500          34837620 ns/op
PASS
ok      go.skia.org/infra/golden/go/diff        59.099s

Bug: skia:9287
Change-Id: Ic87f62f59a33da72702b82ac4d73aa44ea1740a6
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/233464
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Leandro Lovisolo <lovisolo@google.com>