gfx/ycbcr/yuv_convert_mmx.cpp

   1 // Copyright (c) 2010 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 #include <mmintrin.h>
   6 #include "yuv_row.h"
   7
   8 namespace mozilla {
   9 namespace gfx {
  10
  11 // FilterRows combines two rows of the image using linear interpolation.
  12 // MMX version does 8 pixels at a time.
  13 void FilterRows_MMX(uint8_t* ybuf, const uint8_t* y0_ptr, const uint8_t* y1_ptr,
  14                     int source_width, int source_y_fraction) {
  15   __m64 zero = _mm_setzero_si64();
  16   __m64 y1_fraction = _mm_set1_pi16(source_y_fraction);
  17   __m64 y0_fraction = _mm_set1_pi16(256 - source_y_fraction);
  18
  19   const __m64* y0_ptr64 = reinterpret_cast<const __m64*>(y0_ptr);
  20   const __m64* y1_ptr64 = reinterpret_cast<const __m64*>(y1_ptr);
  21   __m64* dest64 = reinterpret_cast<__m64*>(ybuf);
  22   __m64* end64 = reinterpret_cast<__m64*>(ybuf + source_width);
  23
  24   do {
  25     __m64 y0 = *y0_ptr64++;
  26     __m64 y1 = *y1_ptr64++;
  27     __m64 y2 = _mm_unpackhi_pi8(y0, zero);
  28     __m64 y3 = _mm_unpackhi_pi8(y1, zero);
  29     y0 = _mm_unpacklo_pi8(y0, zero);
  30     y1 = _mm_unpacklo_pi8(y1, zero);
  31     y0 = _mm_mullo_pi16(y0, y0_fraction);
  32     y1 = _mm_mullo_pi16(y1, y1_fraction);
  33     y2 = _mm_mullo_pi16(y2, y0_fraction);
  34     y3 = _mm_mullo_pi16(y3, y1_fraction);
  35     y0 = _mm_add_pi16(y0, y1);
  36     y2 = _mm_add_pi16(y2, y3);
  37     y0 = _mm_srli_pi16(y0, 8);
  38     y2 = _mm_srli_pi16(y2, 8);
  39     y0 = _mm_packs_pu16(y0, y2);
  40     *dest64++ = y0;
  41   } while (dest64 < end64);
  42 }
  43
  44 } // namespace gfx
  45 } // namespace mozilla