Revert of Add specialized sRGB blitter for SkOpts (patchset #21 id:400001 of https://codereview.chromium.org/1939513002/ )

Reason for revert:
broke some debug bots:

Running LinearSrcOvericonstrip.pngVSkOptsSSE41	nonrendering
../../../bench/SkBlend_optsBench.cpp:118: fatal error: ""fPixmap.colorType() == kRGBA_8888_SkColorType""

Original issue's description:
> Add tests and benches to support the sRGB blitter for SkOpts
>
>  1,370.85 LinearSrcOvericonstrip.pngVSkOptsSSE41
>  2,359.69 LinearSrcOvericonstrip.pngVSkOptsDefault
>  1,828.72 LinearSrcOvericonstrip.pngVSkOptsNonSimdCore
>  3,277.40 LinearSrcOvericonstrip.pngVSkOptsTrivial
>  9,862.34 LinearSrcOvericonstrip.pngVSkOptsBruteForce
>
>    633.55 LinearSrcOvermandrill_512.pngVSkOptsSSE41
>    684.29 LinearSrcOvermandrill_512.pngVSkOptsDefault
>  1,201.88 LinearSrcOvermandrill_512.pngVSkOptsNonSimdCore
>  2,382.63 LinearSrcOvermandrill_512.pngVSkOptsTrivial
> 10,888.74 LinearSrcOvermandrill_512.pngVSkOptsBruteForce
>
>    209.14 LinearSrcOverplane.pngVSkOptsSSE41
>    562.24 LinearSrcOverplane.pngVSkOptsDefault
>    272.64 LinearSrcOverplane.pngVSkOptsNonSimdCore
>    436.46 LinearSrcOverplane.pngVSkOptsTrivial
>  1,327.23 LinearSrcOverplane.pngVSkOptsBruteForce
>
>    318.01 LinearSrcOverbaby_tux.pngVSkOptsSSE41
>    529.05 LinearSrcOverbaby_tux.pngVSkOptsDefault
>    441.33 LinearSrcOverbaby_tux.pngVSkOptsNonSimdCore
>    720.50 LinearSrcOverbaby_tux.pngVSkOptsTrivial
>  2,191.10 LinearSrcOverbaby_tux.pngVSkOptsBruteForce
>
>    479.68 LinearSrcOveryellow_rose.pngVSkOptsSSE41
>  1,095.03 LinearSrcOveryellow_rose.pngVSkOptsDefault
>    668.60 LinearSrcOveryellow_rose.pngVSkOptsNonSimdCore
>  1,257.19 LinearSrcOveryellow_rose.pngVSkOptsTrivial
>  4,970.25 LinearSrcOveryellow_rose.pngVSkOptsBruteForce
>
>
>
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1939513002
> CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
>
> Committed: https://skia.googlesource.com/skia/+/554784cd85029c05d9ed04b1aeb71520d196153a
>
> Committed: https://skia.googlesource.com/skia/+/bc927548db17accec2195af6e15053f7918bb3f5

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

Review-Url: https://codereview.chromium.org/1986763002

2 files changed, 31 insertions, 213 deletions

diff --git a/src/opts/SkBlend_opts.h b/src/opts/SkBlend_opts.h
index 93946438e5..a1067407be 100644
--- a/src/opts/SkBlend_opts.h
+++ b/src/opts/SkBlend_opts.h
@@ -5,233 +5,52 @@
  * found in the LICENSE file.
  */
 
-/*
-ninja -C out/Release dm nanobench ; and ./out/Release/dm --match Blend_opts ; and ./out/Release/nanobench  --samples 300 --nompd --match LinearSrcOver -q
- */
-
 #ifndef SkBlend_opts_DEFINED
 #define SkBlend_opts_DEFINED
 
-#include "SkNx.h"
-#include "SkPM4fPriv.h"
-
 namespace SK_OPTS_NS {
 
-// An implementation of SrcOver from bytes to bytes in linear space that takes advantage of the
-// observation that the 255's cancel.
-//    invA = 1 - (As / 255);
-//
-//    R = 255 * sqrt((Rs/255)^2 + (Rd/255)^2 * invA)
-// => R = 255 * sqrt((Rs^2 + Rd^2 * invA)/255^2)
-// => R = sqrt(Rs^2 + Rd^2 * invA)
-static inline void blend_srgb_srgb_1(uint32_t* dst, const uint32_t pixel) {
-    Sk4f s = srgb_to_linear(to_4f(pixel));
-    Sk4f d = srgb_to_linear(to_4f(*dst));
-    Sk4f invAlpha = 1.0f - Sk4f{s[SkPM4f::A]} * (1.0f / 255.0f);
-    Sk4f r = linear_to_srgb(s + d * invAlpha) + 0.5f;
-    *dst = to_4b(r);
-}
-
-static inline void srcover_srgb_srgb_1(uint32_t* dst, const uint32_t pixel) {
-    if ((~pixel & 0xFF000000) == 0) {
-        *dst = pixel;
-    } else if ((pixel & 0xFF000000) != 0) {
-        blend_srgb_srgb_1(dst, pixel);
-    }
-}
-
-static inline void srcover_srgb_srgb_2(uint32_t* dst, const uint32_t* src) {
-    srcover_srgb_srgb_1(dst++, *src++);
-    srcover_srgb_srgb_1(dst, *src);
-}
-
-static inline void srcover_srgb_srgb_4(uint32_t* dst, const uint32_t* src) {
-    srcover_srgb_srgb_1(dst++, *src++);
-    srcover_srgb_srgb_1(dst++, *src++);
-    srcover_srgb_srgb_1(dst++, *src++);
-    srcover_srgb_srgb_1(dst, *src);
-}
-
-void best_non_simd_srcover_srgb_srgb(
-    uint32_t* dst, const uint32_t* const src, int ndst, const int nsrc) {
-    uint64_t* ddst = reinterpret_cast<uint64_t*>(dst);
+#if 0
 
-    while (ndst >0) {
-        int count = SkTMin(ndst, nsrc);
-        ndst -= count;
-        const uint64_t* dsrc = reinterpret_cast<const uint64_t*>(src);
-        const uint64_t* end = dsrc + (count >> 1);
-        do {
-            if ((~*dsrc & 0xFF000000FF000000) == 0) {
-                do {
-                    *ddst++ = *dsrc++;
-                } while (dsrc < end && (~*dsrc & 0xFF000000FF000000) == 0);
-            } else if ((*dsrc & 0xFF000000FF000000) == 0) {
-                do {
-                    dsrc++;
-                    ddst++;
-                } while (dsrc < end && (*dsrc & 0xFF000000FF000000) == 0);
-            } else {
-                srcover_srgb_srgb_2(reinterpret_cast<uint32_t*>(ddst++),
-                                    reinterpret_cast<const uint32_t*>(dsrc++));
-            }
-        } while (dsrc < end);
-
-        if ((count & 1) != 0) {
-            srcover_srgb_srgb_1(reinterpret_cast<uint32_t*>(ddst),
-                                *reinterpret_cast<const uint32_t*>(dsrc));
-        }
-    }
-}
-
-void brute_force_srcover_srgb_srgb(
-    uint32_t* dst, const uint32_t* const src, int ndst, const int nsrc) {
-    while (ndst > 0) {
-        int n = SkTMin(ndst, nsrc);
+#else
 
-        for (int i = 0; i < n; i++) {
-            blend_srgb_srgb_1(dst++, src[i]);
+    static inline void srcover_srgb_srgb_1(uint32_t* dst, uint32_t src) {
+        switch (src >> 24) {
+            case 0x00:             return; 
+            case 0xff: *dst = src; return;
         }
-        ndst -= n;
-    }
-}
 
-void trivial_srcover_srgb_srgb(
-    uint32_t* dst, const uint32_t* const src, int ndst, const int nsrc) {
-    while (ndst > 0) {
-        int n = SkTMin(ndst, nsrc);
+        Sk4f d = SkNx_cast<float>(Sk4b::Load( dst)),
+             s = SkNx_cast<float>(Sk4b::Load(&src));
 
-        for (int i = 0; i < n; i++) {
-            srcover_srgb_srgb_1(dst++, src[i]);
-        }
-        ndst -= n;
-    }
-}
+        // Approximate sRGB gamma as 2.0.
+        Sk4f d_sq = d*d,
+             s_sq = s*s;
+        d = Sk4f{d_sq[0], d_sq[1], d_sq[2], d[3]};
+        s = Sk4f{s_sq[0], s_sq[1], s_sq[2], s[3]};
 
-#if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2
+        // SrcOver.
+        Sk4f invA = 1.0f - s[3]*(1/255.0f);
+        d = s + d * invA;
 
-    static inline __m128i load(const uint32_t* p) {
-        return _mm_loadu_si128(reinterpret_cast<const __m128i*>(p));
-    }
+        // Re-apply approximate sRGB gamma.
+        Sk4f d_sqrt = d.sqrt();
+        d = Sk4f{d_sqrt[0], d_sqrt[1], d_sqrt[2], d[3]};
 
-    static inline void store(uint32_t* p, __m128i v) {
-        _mm_storeu_si128(reinterpret_cast<__m128i*>(p), v);
+        SkNx_cast<uint8_t>(d).store(dst);
     }
 
-    #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE41
-
-        void srcover_srgb_srgb(
-            uint32_t* dst, const uint32_t* const srcStart, int ndst, const int nsrc) {
-            const __m128i alphaMask = _mm_set1_epi32(0xFF000000);
-            while (ndst > 0) {
-                int count = SkTMin(ndst, nsrc);
-                ndst -= count;
-                const uint32_t* src = srcStart;
-                const uint32_t* end = src + (count & ~3);
+    static inline void srcover_srgb_srgb(uint32_t* dst, const uint32_t* const src, int ndst, const int nsrc) {
+        while (ndst > 0) {
+            int n = SkTMin(ndst, nsrc);
 
-                while (src < end) {
-                    __m128i pixels = load(src);
-                    if (_mm_testc_si128(pixels, alphaMask)) {
-                        do {
-                            store(dst, pixels);
-                            dst += 4;
-                            src += 4;
-                        } while (src < end && _mm_testc_si128(pixels = load(src), alphaMask));
-                    } else if (_mm_testz_si128(pixels, alphaMask)) {
-                        do {
-                            dst += 4;
-                            src += 4;
-                        } while (src < end && _mm_testz_si128(pixels = load(src), alphaMask));
-                    } else {
-                        do {
-                            srcover_srgb_srgb_4(dst, src);
-                            dst += 4;
-                            src += 4;
-                        } while (src < end && _mm_testnzc_si128(pixels = load(src), alphaMask));
-                    }
-                }
-
-                count = count & 3;
-                while (count-- > 0) {
-                    srcover_srgb_srgb_1(dst++, *src++);
-                }
+            for (int i = 0; i < n; i++) {
+                srcover_srgb_srgb_1(dst++, src[i]);
             }
+            ndst -= n;
         }
-    #else
-    // SSE2 versions
-        static inline bool check_opaque_alphas(__m128i pixels) {
-            int mask =
-                _mm_movemask_epi8(
-                    _mm_cmpeq_epi32(
-                        _mm_andnot_si128(pixels, _mm_set1_epi32(0xFF000000)),
-                        _mm_setzero_si128()));
-            return mask == 0xFFFF;
-        }
-
-        static inline bool check_transparent_alphas(__m128i pixels) {
-            int mask =
-                _mm_movemask_epi8(
-                    _mm_cmpeq_epi32(
-                        _mm_and_si128(pixels, _mm_set1_epi32(0xFF000000)),
-                        _mm_setzero_si128()));
-            return mask == 0xFFFF;
-        }
-
-        static inline bool check_partial_alphas(__m128i pixels) {
-            __m128i alphas = _mm_and_si128(pixels, _mm_set1_epi32(0xFF000000));
-            int mask =
-                _mm_movemask_epi8(
-                    _mm_cmpeq_epi8(
-                        _mm_srai_epi32(alphas, 8),
-                        alphas));
-            return mask == 0xFFFF;
-        }
-
-        void srcover_srgb_srgb(
-            uint32_t* dst, const uint32_t* const srcStart, int ndst, const int nsrc) {
-            while (ndst > 0) {
-                int count = SkTMin(ndst, nsrc);
-                ndst -= count;
-                const uint32_t* src = srcStart;
-                const uint32_t* end = src + (count & ~3);
-
-                __m128i pixels = load(src);
-                do {
-                    if (check_opaque_alphas(pixels)) {
-                        do {
-                            store(dst, pixels);
-                            dst += 4;
-                            src += 4;
-                        } while (src < end && check_opaque_alphas(pixels = load(src)));
-                    } else if (check_transparent_alphas(pixels)) {
-                        const uint32_t* start = src;
-                        do {
-                            src += 4;
-                        } while (src < end && check_transparent_alphas(pixels = load(src)));
-                        dst += src - start;
-                    } else {
-                        do {
-                            srcover_srgb_srgb_4(dst, src);
-                            dst += 4;
-                            src += 4;
-                        } while (src < end && check_partial_alphas(pixels = load(src)));
-                    }
-                } while (src < end);
-
-                count = count & 3;
-                while (count-- > 0) {
-                    srcover_srgb_srgb_1(dst++, *src++);
-                }
-            }
-        }
-    #endif
-#else
-
-    void srcover_srgb_srgb(
-        uint32_t* dst, const uint32_t* const src, int ndst, const int nsrc) {
-        trivial_srcover_srgb_srgb(dst, src, ndst, nsrc);
     }
-
+    
 #endif
 
 }  // namespace SK_OPTS_NS
diff --git a/src/opts/SkOpts_sse41.cpp b/src/opts/SkOpts_sse41.cpp
index f0561a69c6..34b078c2ca 100644
--- a/src/opts/SkOpts_sse41.cpp
+++ b/src/opts/SkOpts_sse41.cpp
@@ -10,7 +10,6 @@
 #define SK_OPTS_NS sk_sse41
 #include "SkBlurImageFilter_opts.h"
 #include "SkBlitRow_opts.h"
-#include "SkBlend_opts.h"
 
 #ifndef SK_SUPPORT_LEGACY_X86_BLITS
 
@@ -212,16 +211,16 @@ static void blit_mask_d32_a8(SkPMColor* dst,     size_t dstRB,
         }
     }
 }
+
 }  // namespace sk_sse41_new
 
 #endif
 
 namespace SkOpts {
     void Init_sse41() {
-        box_blur_xx       = sk_sse41::box_blur_xx;
-        box_blur_xy       = sk_sse41::box_blur_xy;
-        box_blur_yx       = sk_sse41::box_blur_yx;
-        srcover_srgb_srgb = sk_sse41::srcover_srgb_srgb;
+        box_blur_xx = sk_sse41::box_blur_xx;
+        box_blur_xy = sk_sse41::box_blur_xy;
+        box_blur_yx = sk_sse41::box_blur_yx;
 
     #ifndef SK_SUPPORT_LEGACY_X86_BLITS
         blit_row_color32 = sk_sse41_new::blit_row_color32;