Add SSSE3 acceleration for S32_D16_filter_DX

src/opts/SkBitmapProcState_opts_SSSE3.cpp

Index: src/opts/SkBitmapProcState_opts_SSSE3.cpp
diff --git a/src/opts/SkBitmapProcState_opts_SSSE3.cpp b/src/opts/SkBitmapProcState_opts_SSSE3.cpp
index 99bc19216cf68a8fb10295bb108c42bb8e23577e..984a65e5e784997d87ea7c01ef3e839dc7d0ffa4 100644
--- a/src/opts/SkBitmapProcState_opts_SSSE3.cpp
+++ b/src/opts/SkBitmapProcState_opts_SSSE3.cpp
@@ -732,6 +732,17 @@ void S32_alpha_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,
     S32_generic_D32_filter_DXDY_SSSE3<true>(s, xy, count, colors);
 }
 
+void S32_D16_filter_DX_SSSE3(const SkBitmapProcState& s,
+                             const uint32_t* xy,
+                             int count, uint16_t* colors) {
+    SkASSERT(254 >= count);
+    SkAutoSTMalloc<254, uint32_t> colors32(count);
+    S32_generic_D32_filter_DX_SSSE3<false>(s, xy, count, colors32);
+    for(int i = 0; i < count; i++) {
+        *colors++ = SkPixel32ToPixel16(colors32[i]);
+    }
+}
+
 void S32_D16_filter_DXDY_SSSE3(const SkBitmapProcState& s,
                                const uint32_t* xy,
                                int count, uint16_t* colors) {
@@ -769,6 +780,12 @@ void S32_alpha_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,
     sk_throw();
 }
 
+void S32_D16_filter_DX_SSSE3(const SkBitmapProcState& s,
+                             const uint32_t* xy,
+                             int count, uint16_t* colors) {
+    sk_throw();
+}
+
 void S32_D16_filter_DXDY_SSSE3(const SkBitmapProcState& s,
                                const uint32_t* xy,
                                int count, uint16_t* colors) {