~15x speedup without needing to use SSE.

~15x speedup without needing to use SSE.

On my desktop, the bench improves from ~6ms to ~0.4ms.

BUG=skia:

Committed: https://skia.googlesource.com/buildbot/+/0cf4ea002ea41a877c94b713a0b51e766ad8c52e

[mtklein_C, 2015-01-21 19:27:58]

mtklein@chromium.org changed reviewers:
+ jcgregorio@google.com

[mtklein, 2015-01-22 19:07:46]

On 2015/01/21 19:27:58, mtklein_C wrote:

I just posted up PS 5, which is a version that doesn't need cgo (though now it
does need reflect).  It's about 10% slower than the C.memset() version, and
arguably a little more terrifying, but worth a look.

[mtklein, 2015-01-22 19:17:32]

On 2015/01/22 19:07:46, mtklein wrote:
> On 2015/01/21 19:27:58, mtklein_C wrote:
> 
> I just posted up PS 5, which is a version that doesn't need cgo (though now it
> does need reflect).  It's about 10% slower than the C.memset() version, and
> arguably a little more terrifying, but worth a look.

Forgot to mention!  I did try something similar and even more dirty using
complex128, but it looks like that's implemented just as a struct of two
independent float64.  No speed difference.

[mtklein, 2015-01-23 16:05:33]

Bug fixed...

[jcgregorio, 2015-01-23 16:19:54]

lgtm

https://codereview.chromium.org/864083002/diff/100001/golden/go/diff/diff.go
File golden/go/diff/diff.go (right):

https://codereview.chromium.org/864083002/diff/100001/golden/go/diff/diff.go#...
golden/go/diff/diff.go:211: if dr+dg+db > 0 {
I would like to see these colors changed to a closer pair of color-blind safe
colors, such as #CC6677 and #88CCEE, but we don't need to do that in this CL.

[mtklein, 2015-01-23 16:42:15]

The CQ bit was checked by mtklein@google.com

[mtklein, 2015-01-23 16:42:31]

https://codereview.chromium.org/864083002/diff/100001/golden/go/diff/diff.go
File golden/go/diff/diff.go (right):

https://codereview.chromium.org/864083002/diff/100001/golden/go/diff/diff.go#...
golden/go/diff/diff.go:211: if dr+dg+db > 0 {
On 2015/01/23 16:19:54, jcgregorio wrote:
> I would like to see these colors changed to a closer pair of color-blind safe
> colors, such as #CC6677 and #88CCEE, but we don't need to do that in this CL.

SGTM

[commit-bot: I haz the power, 2015-01-23 16:43:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/864083002/100001

[commit-bot: I haz the power, 2015-01-23 16:43:16]

Committed patchset #6 (id:100001) as
https://skia.googlesource.com/buildbot/+/0cf4ea002ea41a877c94b713a0b51e766ad8...