Revert of Revert of SSE4 opaque blend using intrinsics instead of assembly. (patchset #1 id:1 of https://codereview.chromium.org/873553003/)

Reason for revert:
Reverted the wrong CL.

Original issue's description:
> Revert of SSE4 opaque blend using intrinsics instead of assembly. (patchset #16 id:300001 of https://codereview.chromium.org/874863002/)
>
> Reason for revert:
> This causes a bug on the 'hittestpath' GM on MacMini 4,1
>
> See:
>
> https://gold.skia.org/#/triage/hittestpath?head=0
>
> for details.
>
> Original issue's description:
> > SSE4 opaque blend using intrinsics instead of assembly.
> >
> > Since we had such a hard time with the assembly versions of this blit (to the
> > point that we have them completely disabled everywhere), I thought I'd take
> > a shot at writing a version of the blit using intrinsics.
> >
> > The key feature of SSE4 we're exploiting is that we can use ptest (_mm_test*)
> > to skip the blend when the 16 src pixels we consider each loop are all opaque
> > or all transparent.  _mm_shuffle_epi8 from SSSE3 also lends a hand to extract
> > all those alphas.
> >
> > It's worth looking to see if we can backport this type of logic to SSE2 using
> > _mm_movemask_epi8, or up to 32 pixels at a time using AVX.
> >
> > My local performance testing doesn't show this to be an unambiguous win
> > (there are probably microbenchmarks and SKPs where we'd be better off just
> > powering through the blend rather than looking at alphas), but the potential
> > does seem tantalizing enough to let skiaperf vet it on the bots.  (< 1.0x is a win.)
> >
> > DM says it draws pixel perfect compare to the old code.
> >
> > Microbenchmarks:
> >                bitmap_RGBA_8888_A_source_stripes_two	  14us -> 14.4us	1.03x
> >              bitmap_RGBA_8888_A_source_stripes_three	14.3us -> 14.5us	1.01x
> >                        bitmap_RGBA_8888_scale_bilerp	61.9us -> 62.2us	1.01x
> > bitmap_RGBA_8888_update_volatile_scale_rotate_bilerp	 102us ->  101us	0.99x
> >                 bitmap_RGBA_8888_scale_rotate_bilerp	 103us ->  101us	0.99x
> >                               bitmap_RGBA_8888_scale	18.4us -> 18.2us	0.99x
> >              bitmap_RGBA_8888_A_scale_rotate_bicubic	  71us ->   70us	0.99x
> >          bitmap_RGBA_8888_update_scale_rotate_bilerp	 103us ->  101us	0.99x
> >               bitmap_RGBA_8888_A_scale_rotate_bilerp	 112us ->  109us	0.98x
> >                     bitmap_RGBA_8888_update_volatile	5.72us -> 5.58us	0.98x
> >                                     bitmap_RGBA_8888	5.73us -> 5.58us	0.97x
> >                              bitmap_RGBA_8888_update	5.78us ->  5.6us	0.97x
> >                      bitmap_RGBA_8888_A_scale_bilerp	70.7us ->   68us	0.96x
> >                     bitmap_RGBA_8888_A_scale_bicubic	23.7us -> 21.8us	0.92x
> >                                   bitmap_RGBA_8888_A	13.9us -> 10.9us	0.78x
> >                     bitmap_RGBA_8888_A_source_opaque	  14us -> 6.29us	0.45x
> >                bitmap_RGBA_8888_A_source_transparent	  14us -> 3.65us	0.26x
> >
> > Running over our ~70 SKP web page captures, this looks like we spend 0.7x
> > the time in S32A_Opaque_BlitRow compared to the SSE2 version, which should
> > be a decent predictor of real-world impact.
> >
> > BUG=chromium:399842
> >
> > Committed: https://skia.googlesource.com/skia/+/04bc91b972417038fecfa87c484771eac2b9b785
> >
> > CQ_EXTRA_TRYBOTS=client.skia:Test-Mac10.6-MacMini4.1-GeForce320M-x86_64-Release-Trybot
> >
> > Committed: https://skia.googlesource.com/skia/+/6dbfb21a6c88af6d94e8c823c3ad559f1a41b493
>
> TBR=henrik.smiding@intel.com,mtklein@google.com,herb@google.com,reed@google.com,thakis@chromium.org,mtklein@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:399842
>
> Committed: https://skia.googlesource.com/skia/+/4988891a1173cd405bf1c1dd3a3668c451f45e4c

TBR=henrik.smiding@intel.com,mtklein@google.com,herb@google.com,reed@google.com,thakis@chromium.org,mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:399842

Review URL: https://codereview.chromium.org/894083002

1 files changed, 8 insertions, 1 deletions

diff --git a/src/opts/SkColor_opts_SSE2.h b/src/opts/SkColor_opts_SSE2.h
index 970abb859b..feb1d98f8d 100644
--- a/src/opts/SkColor_opts_SSE2.h
+++ b/src/opts/SkColor_opts_SSE2.h
@@ -206,7 +206,14 @@ static inline __m128i SkPixel32ToPixel16_ToU16_SSE2(const __m128i& src_pixel1,
     return d_pixel;
 }
 
-// Portable version SkBlendARGB32 is in SkColorPriv.h.
+// Portable version is SkPMSrcOver in SkColorPriv.h.
+static inline __m128i SkPMSrcOver_SSE2(const __m128i& src, const __m128i& dst) {
+    return _mm_add_epi32(src,
+                         SkAlphaMulQ_SSE2(dst, _mm_sub_epi32(_mm_set1_epi32(256),
+                                                             SkGetPackedA32_SSE2(src))));
+}
+
+// Portable version is SkBlendARGB32 in SkColorPriv.h.
 static inline __m128i SkBlendARGB32_SSE2(const __m128i& src, const __m128i& dst,
                                          const __m128i& aa) {
     __m128i src_scale = SkAlpha255To256_SSE2(aa);