Revert of SkHalfToFloat_01 / SkFloatToHalf_01

Revert of SkHalfToFloat_01 / SkFloatToHalf_01 (patchset #11 id:200001 of https://codereview.chromium.org/1685133005/ )

Reason for revert:
Gotta fix Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD

Original issue's description:
> SkHalfToFloat_01 / SkFloatToHalf_01
> 
> These are basically inlined, 4-at-a-time versions of our existing functions,
> but cut down to avoid any work that's only necessary outside [0,1].
> 
> Both f16 and f32 denorms should work fine modulo the usual ARMv7 NEON denorm==zero caveat.
> 
> In exchange for a little speed, f32->f16 does not round properly.
> Instead it truncates, so it's never off by more than 1 bit.
> 
> Support for finite values >1 or <0 is straightforward to add back.
> >1 might already work as-is.
> 
> Getting close to _u16 performance:
>     micros   	bench
>     261.13  	xferu64_bw_1_opaque_u16
>    1833.51  	xferu64_bw_1_alpha_u16
>    2762.32 ?	xferu64_aa_1_opaque_u16
>    3334.29  	xferu64_aa_1_alpha_u16
>     249.78  	xferu64_bw_1_opaque_f16
>    3383.18  	xferu64_bw_1_alpha_f16
>    4214.72  	xferu64_aa_1_opaque_f16
>    4701.19  	xferu64_aa_1_alpha_f16
> 
> 
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1685133005
> 
> Committed: https://skia.googlesource.com/skia/+/9ea11a4235b3e3521cc8bf914a27c2d0dc062db9

TBR=jvanverth@google.com,reed@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Committed: https://skia.googlesource.com/skia/+/cbefc5e4ca7fd7aaa5d2a3aa85b30f16148c3d2f

[mtklein, 2016-02-11 14:00:40]

Created Revert of SkHalfToFloat_01 / SkFloatToHalf_01

[commit-bot: I haz the power, 2016-02-11 14:00:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1693443003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1693443003/1

[commit-bot: I haz the power, 2016-02-11 14:00:52]

Description was changed from

==========
Revert of SkHalfToFloat_01 / SkFloatToHalf_01 (patchset #11 id:200001 of
https://codereview.chromium.org/1685133005/ )

Reason for revert:
Gotta fix Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD

Original issue's description:
> SkHalfToFloat_01 / SkFloatToHalf_01
> 
> These are basically inlined, 4-at-a-time versions of our existing functions,
> but cut down to avoid any work that's only necessary outside [0,1].
> 
> Both f16 and f32 denorms should work fine modulo the usual ARMv7 NEON
denorm==zero caveat.
> 
> In exchange for a little speed, f32->f16 does not round properly.
> Instead it truncates, so it's never off by more than 1 bit.
> 
> Support for finite values >1 or <0 is straightforward to add back.
> >1 might already work as-is.
> 
> Getting close to _u16 performance:
>     micros   	bench
>     261.13  	xferu64_bw_1_opaque_u16
>    1833.51  	xferu64_bw_1_alpha_u16
>    2762.32 ?	xferu64_aa_1_opaque_u16
>    3334.29  	xferu64_aa_1_alpha_u16
>     249.78  	xferu64_bw_1_opaque_f16
>    3383.18  	xferu64_bw_1_alpha_f16
>    4214.72  	xferu64_aa_1_opaque_f16
>    4701.19  	xferu64_aa_1_alpha_f16
> 
> 
> BUG=skia:
> GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
> 
> Committed:
https://skia.googlesource.com/skia/+/9ea11a4235b3e3521cc8bf914a27c2d0dc062db9

TBR=jvanverth@google.com,reed@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:
==========

to

==========
Revert of SkHalfToFloat_01 / SkFloatToHalf_01 (patchset #11 id:200001 of
https://codereview.chromium.org/1685133005/ )

Reason for revert:
Gotta fix Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD

Original issue's description:
> SkHalfToFloat_01 / SkFloatToHalf_01
> 
> These are basically inlined, 4-at-a-time versions of our existing functions,
> but cut down to avoid any work that's only necessary outside [0,1].
> 
> Both f16 and f32 denorms should work fine modulo the usual ARMv7 NEON
denorm==zero caveat.
> 
> In exchange for a little speed, f32->f16 does not round properly.
> Instead it truncates, so it's never off by more than 1 bit.
> 
> Support for finite values >1 or <0 is straightforward to add back.
> >1 might already work as-is.
> 
> Getting close to _u16 performance:
>     micros   	bench
>     261.13  	xferu64_bw_1_opaque_u16
>    1833.51  	xferu64_bw_1_alpha_u16
>    2762.32 ?	xferu64_aa_1_opaque_u16
>    3334.29  	xferu64_aa_1_alpha_u16
>     249.78  	xferu64_bw_1_opaque_f16
>    3383.18  	xferu64_bw_1_alpha_f16
>    4214.72  	xferu64_aa_1_opaque_f16
>    4701.19  	xferu64_aa_1_alpha_f16
> 
> 
> BUG=skia:
> GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
> 
> Committed:
https://skia.googlesource.com/skia/+/9ea11a4235b3e3521cc8bf914a27c2d0dc062db9

TBR=jvanverth@google.com,reed@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Committed:
https://skia.googlesource.com/skia/+/cbefc5e4ca7fd7aaa5d2a3aa85b30f16148c3d2f
==========

[commit-bot: I haz the power, 2016-02-11 14:00:53]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/cbefc5e4ca7fd7aaa5d2a3aa85b30f16148c3d2f