Port SkUtils opts to SkOpts.

src/opts/SkOpts_sse2.cpp

Index: src/opts/SkOpts_sse2.cpp
diff --git a/src/opts/SkOpts_sse2.cpp b/src/opts/SkOpts_sse2.cpp
index 31afa8cae7508f6be72c6dc0aef4bdd43b9ec898..69c55bc698856cc27c87d61bbc75b987a4b2bfd2 100644
--- a/src/opts/SkOpts_sse2.cpp
+++ b/src/opts/SkOpts_sse2.cpp
@@ -7,8 +7,49 @@
 
 #include "SkOpts.h"
 
+namespace sse2 {  // This helps identify methods from this file when debugging / profiling.
+
+static void memset16(uint16_t* dst, uint16_t val, int n) {
+    auto dst8 = (__m128i*)dst;
+    auto val8 = _mm_set1_epi16(val);
+    for ( ; n >= 8; n -= 8) {
+        _mm_storeu_si128(dst8++, val8);
+    }
+    dst = (uint16_t*)dst8;
+    if (n & 4) {
+        _mm_storel_epi64((__m128i*)dst, val8);
+        dst += 4;
+    }
+    if (n & 2) {
+        *(uint32_t*)dst = _mm_cvtsi128_si32(val8);
+        dst += 2;
+    }
+    if (n & 1) {
+        *dst = val;
+    }
+}
+
+static void memset32(uint32_t* dst, uint32_t val, int n) {
+    auto dst4 = (__m128i*)dst;
+    auto val4 = _mm_set1_epi32(val);
+    for ( ; n >= 4; n -= 4) {
+        _mm_storeu_si128(dst4++, val4);
+    }
+    dst = (uint32_t*)dst4;
+    if (n & 2) {
+        _mm_storel_epi64((__m128i*)dst, val4);
+        dst += 2;
+    }
+    if (n & 1) {
+        *dst = val;
+    }
+}
+
+}  // namespace sse2
+
 namespace SkOpts {
     void Init_sse2() {
-
+        memset16 = sse2::memset16;
+        memset32 = sse2::memset32;
     }
 }