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 // Copyright (c) 2010 The Chromium Authors. All rights reserved.

 // Use of this source code is governed by a BSD-style license that can be

 // found in the LICENSE file.

 #include <emmintrin.h>

 #include "yuv_row.h"

 namespace mozilla {

 namespace gfx {

 // FilterRows combines two rows of the image using linear interpolation.

 // SSE2 version does 16 pixels at a time.

 void FilterRows_SSE2(uint8* ybuf, const uint8* y0_ptr, const uint8* y1_ptr,

                      int source_width, int source_y_fraction) {

   __m128i zero = _mm_setzero_si128();

   __m128i y1_fraction = _mm_set1_epi16(source_y_fraction);

   __m128i y0_fraction = _mm_set1_epi16(256 - source_y_fraction);

   const __m128i* y0_ptr128 = reinterpret_cast<const __m128i*>(y0_ptr);

   const __m128i* y1_ptr128 = reinterpret_cast<const __m128i*>(y1_ptr);

   __m128i* dest128 = reinterpret_cast<__m128i*>(ybuf);

   __m128i* end128 = reinterpret_cast<__m128i*>(ybuf + source_width);

   do {

     __m128i y0 = _mm_loadu_si128(y0_ptr128);

     __m128i y1 = _mm_loadu_si128(y1_ptr128);

     __m128i y2 = _mm_unpackhi_epi8(y0, zero);

     __m128i y3 = _mm_unpackhi_epi8(y1, zero);

     y0 = _mm_unpacklo_epi8(y0, zero);

     y1 = _mm_unpacklo_epi8(y1, zero);

     y0 = _mm_mullo_epi16(y0, y0_fraction);

     y1 = _mm_mullo_epi16(y1, y1_fraction);

     y2 = _mm_mullo_epi16(y2, y0_fraction);

     y3 = _mm_mullo_epi16(y3, y1_fraction);

     y0 = _mm_add_epi16(y0, y1);

     y2 = _mm_add_epi16(y2, y3);

     y0 = _mm_srli_epi16(y0, 8);

     y2 = _mm_srli_epi16(y2, 8);

     y0 = _mm_packus_epi16(y0, y2);

     *dest128++ = y0;

     ++y0_ptr128;

     ++y1_ptr128;

   } while (dest128 < end128);

 }

 }

 }