media/base/simd/sinc_resampler_sse.cc

   1 // Copyright 2013 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 "media/base/sinc_resampler.h"
   6
   7 #include <xmmintrin.h>
   8
   9 namespace media {
  10
  11 float SincResampler::Convolve_SSE(const float* input_ptr, const float* k1,
  12                                   const float* k2,
  13                                   double kernel_interpolation_factor) {
  14   __m128 m_input;
  15   __m128 m_sums1 = _mm_setzero_ps();
  16   __m128 m_sums2 = _mm_setzero_ps();
  17
  18   // Based on |input_ptr| alignment, we need to use loadu or load.  Unrolling
  19   // these loops hurt performance in local testing.
  20   if (reinterpret_cast<uintptr_t>(input_ptr) & 0x0F) {
  21     for (int i = 0; i < kKernelSize; i += 4) {
  22       m_input = _mm_loadu_ps(input_ptr + i);
  23       m_sums1 = _mm_add_ps(m_sums1, _mm_mul_ps(m_input, _mm_load_ps(k1 + i)));
  24       m_sums2 = _mm_add_ps(m_sums2, _mm_mul_ps(m_input, _mm_load_ps(k2 + i)));
  25     }
  26   } else {
  27     for (int i = 0; i < kKernelSize; i += 4) {
  28       m_input = _mm_load_ps(input_ptr + i);
  29       m_sums1 = _mm_add_ps(m_sums1, _mm_mul_ps(m_input, _mm_load_ps(k1 + i)));
  30       m_sums2 = _mm_add_ps(m_sums2, _mm_mul_ps(m_input, _mm_load_ps(k2 + i)));
  31     }
  32   }
  33
  34   // Linearly interpolate the two "convolutions".
  35   m_sums1 = _mm_mul_ps(m_sums1, _mm_set_ps1(1.0 - kernel_interpolation_factor));
  36   m_sums2 = _mm_mul_ps(m_sums2, _mm_set_ps1(kernel_interpolation_factor));
  37   m_sums1 = _mm_add_ps(m_sums1, m_sums2);
  38
  39   // Sum components together.
  40   float result;
  41   m_sums2 = _mm_add_ps(_mm_movehl_ps(m_sums1, m_sums1), m_sums1);
  42   _mm_store_ss(&result, _mm_add_ss(m_sums2, _mm_shuffle_ps(
  43       m_sums2, m_sums2, 1)));
  44
  45   return result;
  46 }
  47
  48 }  // namespace media