Add Sk4f_RoundToInt

src/opts/SkNx_sse.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkNx_sse_DEFINED
 #define SkNx_sse_DEFINED
 
@@ skipping 359 matching lines @@
 }
 
 template<> /*static*/ inline Sk4h SkNx_cast<uint16_t, uint8_t>(const Sk4b& src) {
     return _mm_unpacklo_epi8(src.fVec, _mm_setzero_si128());
 }
 
 template<> /*static*/ inline Sk4b SkNx_cast<uint8_t, uint16_t>(const Sk4h& src) {
     return _mm_packus_epi16(src.fVec, src.fVec);
 }
 
+template<> inline Sk4b SkNx_cast<uint8_t, int>(const Sk4i& src) {
+    return _mm_packus_epi16(_mm_packus_epi16(src.fVec, src.fVec), src.fVec);
+}
+
+static inline Sk4i Sk4f_round(const Sk4f& x) {
+    return _mm_cvtps_epi32(x.fVec);
+}
+
 #endif//SkNx_sse_DEFINED