Use sk_srgb_to_linear_trunc in SkColorXform_opts

Use sk_srgb_to_linear_trunc in SkColorXform_opts

This gives us a little more control over instruction order, allowing
us to pipeline the muls and get better performance.  Technically,
clang should be able to do this for us anyway...

Performance on HP z620 (201295.jpg):
toSRGB: 371us -> 356us

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2175413002
CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Committed: https://skia.googlesource.com/skia/+/a18c3b8306c08619ad40fe26122462d4c7a9059d

[msarett, 2016-07-25 19:19:01]

Description was changed from

==========
Use sk_srgb_to_linear_trunc in SkColorXform_opts

This gives us a little more control over instruction order, allowing
us to pipeline the muls and get better performance.  Technically,
clang should be able to do this for us anyway...

Performance on HP z620 (201295.jpg):
toSRGB: 371us -> 356us

BUG=skia:
==========

to

==========
Use sk_srgb_to_linear_trunc in SkColorXform_opts

This gives us a little more control over instruction order, allowing
us to pipeline the muls and get better performance.  Technically,
clang should be able to do this for us anyway...

Performance on HP z620 (201295.jpg):
toSRGB: 371us -> 356us

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2175413002
CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
==========

[msarett, 2016-07-25 19:19:37]

msarett@google.com changed reviewers:
+ mtklein@google.com

[mtklein, 2016-07-25 19:28:07]

lgtm

https://codereview.chromium.org/2175413002/diff/1/src/opts/SkColorXform_opts.h
File src/opts/SkColorXform_opts.h (right):

https://codereview.chromium.org/2175413002/diff/1/src/opts/SkColorXform_opts....
src/opts/SkColorXform_opts.h:21: return SkNx_cast<int, float>(x);
probably don't need that ,float ?

[msarett, 2016-07-25 19:54:01]

https://codereview.chromium.org/2175413002/diff/1/src/opts/SkColorXform_opts.h
File src/opts/SkColorXform_opts.h (right):

https://codereview.chromium.org/2175413002/diff/1/src/opts/SkColorXform_opts....
src/opts/SkColorXform_opts.h:21: return SkNx_cast<int, float>(x);
On 2016/07/25 19:28:07, mtklein wrote:
> probably don't need that ,float ?

Removed.

[msarett, 2016-07-26 01:28:19]

The CQ bit was checked by msarett@google.com

[msarett, 2016-07-26 01:28:20]

The patchset sent to the CQ was uploaded after l-g-t-m from mtklein@google.com
Link to the patchset: https://codereview.chromium.org/2175413002/#ps20001
(title: "Remove unnecessary template param")

[commit-bot: I haz the power, 2016-07-26 01:28:23]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-26 01:58:13]

Description was changed from

==========
Use sk_srgb_to_linear_trunc in SkColorXform_opts

This gives us a little more control over instruction order, allowing
us to pipeline the muls and get better performance.  Technically,
clang should be able to do this for us anyway...

Performance on HP z620 (201295.jpg):
toSRGB: 371us -> 356us

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2175413002
CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
==========

to

==========
Use sk_srgb_to_linear_trunc in SkColorXform_opts

This gives us a little more control over instruction order, allowing
us to pipeline the muls and get better performance.  Technically,
clang should be able to do this for us anyway...

Performance on HP z620 (201295.jpg):
toSRGB: 371us -> 356us

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2175413002
CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Committed:
https://skia.googlesource.com/skia/+/a18c3b8306c08619ad40fe26122462d4c7a9059d
==========

[commit-bot: I haz the power, 2016-07-26 01:58:14]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/a18c3b8306c08619ad40fe26122462d4c7a9059d