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      1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #if defined(_MSC_VER)
      6 #include <intrin.h>
      7 #else
      8 #include <mmintrin.h>
      9 #include <emmintrin.h>
     10 #endif
     11 
     12 #include "media/base/simd/filter_yuv.h"
     13 
     14 namespace media {
     15 
     16 void FilterYUVRows_SSE2(uint8* dest,
     17                         const uint8* src0,
     18                         const uint8* src1,
     19                         int width,
     20                         int fraction) {
     21   int pixel = 0;
     22 
     23   // Process the unaligned bytes first.
     24   int unaligned_width =
     25       (16 - (reinterpret_cast<uintptr_t>(dest) & 15)) & 15;
     26   while (pixel < width && pixel < unaligned_width) {
     27     dest[pixel] = (src0[pixel] * (256 - fraction) +
     28                    src1[pixel] * fraction) >> 8;
     29     ++pixel;
     30   }
     31 
     32   __m128i zero = _mm_setzero_si128();
     33   __m128i src1_fraction = _mm_set1_epi16(fraction);
     34   __m128i src0_fraction = _mm_set1_epi16(256 - fraction);
     35   const __m128i* src0_128 =
     36       reinterpret_cast<const __m128i*>(src0 + pixel);
     37   const __m128i* src1_128 =
     38       reinterpret_cast<const __m128i*>(src1 + pixel);
     39   __m128i* dest128 = reinterpret_cast<__m128i*>(dest + pixel);
     40   __m128i* end128 = reinterpret_cast<__m128i*>(
     41       reinterpret_cast<uintptr_t>(dest + width) & ~15);
     42 
     43   while (dest128 < end128) {
     44     __m128i src0 = _mm_loadu_si128(src0_128);
     45     __m128i src1 = _mm_loadu_si128(src1_128);
     46     __m128i src2 = _mm_unpackhi_epi8(src0, zero);
     47     __m128i src3 = _mm_unpackhi_epi8(src1, zero);
     48     src0 = _mm_unpacklo_epi8(src0, zero);
     49     src1 = _mm_unpacklo_epi8(src1, zero);
     50     src0 = _mm_mullo_epi16(src0, src0_fraction);
     51     src1 = _mm_mullo_epi16(src1, src1_fraction);
     52     src2 = _mm_mullo_epi16(src2, src0_fraction);
     53     src3 = _mm_mullo_epi16(src3, src1_fraction);
     54     src0 = _mm_add_epi16(src0, src1);
     55     src2 = _mm_add_epi16(src2, src3);
     56     src0 = _mm_srli_epi16(src0, 8);
     57     src2 = _mm_srli_epi16(src2, 8);
     58     src0 = _mm_packus_epi16(src0, src2);
     59     *dest128++ = src0;
     60     ++src0_128;
     61     ++src1_128;
     62     pixel += 16;
     63   }
     64 
     65   while (pixel < width) {
     66     dest[pixel] = (src0[pixel] * (256 - fraction) +
     67                    src1[pixel] * fraction) >> 8;
     68     ++pixel;
     69   }
     70 }
     71 
     72 }  // namespace media
     73