Replace SSE optimization of Color32A_D565

Adds an SSE2 version of the Color32A_D565 function, to replace
the existing SSE4 version. Also does some minor cleanup.

Performance improvement in the following Skia benchmarks.
Measured on Atom Silvermont:
  Xfermode_SrcOver       - x3
  luma_colorfilter_large - x4.6
  luma_colorfilter_small - x2
  tablebench             - ~15%
  chart_bw               - ~10%

Measured on Corei7 Haswell:
luma_colorfilter_large running SSE2 - x2
luma_colorfilter_large running SSE4 - x2.3

Also improves performance in WPS Office application and 2D subtest of 0xbenchmark on Android.

Signed-off-by: Henrik Smiding <henrik.smiding@intel.com>

Review URL: https://codereview.chromium.org/923523002

1 files changed, 1 insertions, 78 deletions

diff --git a/src/opts/SkBlitRow_opts_SSE4.cpp b/src/opts/SkBlitRow_opts_SSE4.cpp
index f4273d27b4..3649d175ef 100644
--- a/src/opts/SkBlitRow_opts_SSE4.cpp
+++ b/src/opts/SkBlitRow_opts_SSE4.cpp
@@ -7,14 +7,9 @@ void S32A_Opaque_BlitRow32_SSE4(SkPMColor* SK_RESTRICT, const SkPMColor* SK_REST
     sk_throw();
 }
 
-void Color32A_D565_SSE4(uint16_t dst[], SkPMColor src, int count, int x, int y) {
-    sk_throw();
-}
-
 #else
 
-#include <smmintrin.h>  // SSE4.1 intrinsics
-
+#include <smmintrin.h>      // SSE4.1 intrinsics
 #include "SkColorPriv.h"
 #include "SkColor_opts_SSE2.h"
 
@@ -66,76 +61,4 @@ void S32A_Opaque_BlitRow32_SSE4(SkPMColor* SK_RESTRICT dst,
     }
 }
 
-static inline uint16_t Color32A_D565_1x(uint16_t dst, unsigned scale, uint32_t src_expand) {
-    uint32_t dst_expand = SkExpand_rgb_16(dst) * scale;
-    return SkCompact_rgb_16((src_expand + dst_expand) >> 5);
-}
-
-void Color32A_D565_SSE4(uint16_t dst[], SkPMColor src, int count, int x, int y) {
-    SkASSERT(count > 0);
-
-    uint32_t src_expand = (SkGetPackedG32(src) << 24) |
-                          (SkGetPackedR32(src) << 13) |
-                          (SkGetPackedB32(src) << 2);
-    unsigned scale = SkAlpha255To256(0xFF - SkGetPackedA32(src)) >> 3;
-
-    // Check if we have enough pixels to run SIMD
-    if (count >= (int)(8 + (((16 - (size_t)dst) & 0x0F) >> 1))) {
-        __m128i* dst_wide;
-        const __m128i src_expand_wide = _mm_set1_epi32(src_expand);
-        const __m128i scale_wide = _mm_set1_epi32(scale);
-        const __m128i mask_green = _mm_set1_epi32(SK_R16_MASK_IN_PLACE |
-                                                  SK_B16_MASK_IN_PLACE |
-                                                 (SK_G16_MASK_IN_PLACE << 16));
-
-        // Align dst to an even 16 byte address (0-7 pixels)
-        while (((((size_t)dst) & 0x0F) != 0) && (count > 0)) {
-            *dst = Color32A_D565_1x(*dst, scale, src_expand);
-            dst += 1;
-            count--;
-        }
-
-        dst_wide = reinterpret_cast<__m128i*>(dst);
-        do {
-            // Load 8 RGB565 pixels
-            __m128i pixels = _mm_load_si128(dst_wide);
-
-            // Duplicate and mask
-            __m128i pixels_high = _mm_unpackhi_epi16(pixels, pixels);
-            pixels_high = _mm_and_si128(mask_green, pixels_high);
-            pixels = _mm_unpacklo_epi16(pixels, pixels);
-            pixels = _mm_and_si128(mask_green, pixels);
-
-            // Scale with alpha
-            pixels_high = _mm_mullo_epi32(pixels_high, scale_wide);
-            pixels = _mm_mullo_epi32(pixels, scale_wide);
-
-            // Add src_expand_wide and shift down again
-            pixels_high = _mm_add_epi32(pixels_high, src_expand_wide);
-            pixels_high = _mm_srli_epi32(pixels_high, 5);
-            pixels = _mm_add_epi32(pixels, src_expand_wide);
-            pixels = _mm_srli_epi32(pixels, 5);
-
-            // Mask
-            pixels_high = _mm_and_si128(mask_green, pixels_high);
-            pixels = _mm_and_si128(mask_green, pixels);
-
-            // Combine into RGB565 and store
-            pixels = _mm_hadd_epi16(pixels, pixels_high);
-            _mm_store_si128(dst_wide, pixels);
-            count -= 8;
-            dst_wide++;
-        } while (count >= 8);
-
-        dst = reinterpret_cast<uint16_t*>(dst_wide);
-    }
-
-    // Small loop to handle remaining pixels.
-    while (count > 0) {
-        *dst = Color32A_D565_1x(*dst, scale, src_expand);
-        dst += 1;
-        count--;
-    }
-}
-
 #endif