vpx/vpx_dsp/x86/convolve_ssse3.h

/*
 *  Copyright (c) 2017 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef VPX_DSP_X86_CONVOLVE_SSSE3_H_
#define VPX_DSP_X86_CONVOLVE_SSSE3_H_

#include <assert.h>
#include <tmmintrin.h>  // SSSE3

#include "./vpx_config.h"

static INLINE void shuffle_filter_ssse3(const int16_t *const filter,
                                        __m128i *const f) {
  const __m128i f_values = _mm_load_si128((const __m128i *)filter);
  // pack and duplicate the filter values
  f[0] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x0200u));
  f[1] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x0604u));
  f[2] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x0a08u));
  f[3] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x0e0cu));
}

static INLINE void shuffle_filter_odd_ssse3(const int16_t *const filter,
                                            __m128i *const f) {
  const __m128i f_values = _mm_load_si128((const __m128i *)filter);
  // pack and duplicate the filter values
  // It utilizes the fact that the high byte of filter[3] is always 0 to clean
  // half of f[0] and f[4].
  assert(filter[3] >= 0 && filter[3] < 256);
  f[0] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x0007u));
  f[1] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x0402u));
  f[2] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x0806u));
  f[3] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x0c0au));
  f[4] = _mm_shuffle_epi8(f_values, _mm_set1_epi16(0x070eu));
}

static INLINE __m128i convolve8_8_ssse3(const __m128i *const s,
                                        const __m128i *const f) {
  // multiply 2 adjacent elements with the filter and add the result
  const __m128i k_64 = _mm_set1_epi16(1 << 6);
  const __m128i x0 = _mm_maddubs_epi16(s[0], f[0]);
  const __m128i x1 = _mm_maddubs_epi16(s[1], f[1]);
  const __m128i x2 = _mm_maddubs_epi16(s[2], f[2]);
  const __m128i x3 = _mm_maddubs_epi16(s[3], f[3]);
  __m128i sum1, sum2;

  // sum the results together, saturating only on the final step
  // adding x0 with x2 and x1 with x3 is the only order that prevents
  // outranges for all filters
  sum1 = _mm_add_epi16(x0, x2);
  sum2 = _mm_add_epi16(x1, x3);
  // add the rounding offset early to avoid another saturated add
  sum1 = _mm_add_epi16(sum1, k_64);
  sum1 = _mm_adds_epi16(sum1, sum2);
  // shift by 7 bit each 16 bit
  sum1 = _mm_srai_epi16(sum1, 7);
  return sum1;
}

static INLINE __m128i convolve8_8_even_offset_ssse3(const __m128i *const s,
                                                    const __m128i *const f) {
  // multiply 2 adjacent elements with the filter and add the result
  const __m128i k_64 = _mm_set1_epi16(1 << 6);
  const __m128i x0 = _mm_maddubs_epi16(s[0], f[0]);
  const __m128i x1 = _mm_maddubs_epi16(s[1], f[1]);
  const __m128i x2 = _mm_maddubs_epi16(s[2], f[2]);
  const __m128i x3 = _mm_maddubs_epi16(s[3], f[3]);
  // compensate the subtracted 64 in f[1]. x4 is always non negative.
  const __m128i x4 = _mm_maddubs_epi16(s[1], _mm_set1_epi8(64));
  // add and saturate the results together
  __m128i temp = _mm_adds_epi16(x0, x3);
  temp = _mm_adds_epi16(temp, x1);
  temp = _mm_adds_epi16(temp, x2);
  temp = _mm_adds_epi16(temp, x4);
  // round and shift by 7 bit each 16 bit
  temp = _mm_adds_epi16(temp, k_64);
  temp = _mm_srai_epi16(temp, 7);
  return temp;
}

static INLINE __m128i convolve8_8_odd_offset_ssse3(const __m128i *const s,
                                                   const __m128i *const f) {
  // multiply 2 adjacent elements with the filter and add the result
  const __m128i k_64 = _mm_set1_epi16(1 << 6);
  const __m128i x0 = _mm_maddubs_epi16(s[0], f[0]);
  const __m128i x1 = _mm_maddubs_epi16(s[1], f[1]);
  const __m128i x2 = _mm_maddubs_epi16(s[2], f[2]);
  const __m128i x3 = _mm_maddubs_epi16(s[3], f[3]);
  const __m128i x4 = _mm_maddubs_epi16(s[4], f[4]);
  // compensate the subtracted 64 in f[2]. x5 is always non negative.
  const __m128i x5 = _mm_maddubs_epi16(s[2], _mm_set1_epi8(64));
  __m128i temp;

  // add and saturate the results together
  temp = _mm_adds_epi16(x0, x1);
  temp = _mm_adds_epi16(temp, x2);
  temp = _mm_adds_epi16(temp, x3);
  temp = _mm_adds_epi16(temp, x4);
  temp = _mm_adds_epi16(temp, x5);
  // round and shift by 7 bit each 16 bit
  temp = _mm_adds_epi16(temp, k_64);
  temp = _mm_srai_epi16(temp, 7);
  return temp;
}

#endif  // VPX_DSP_X86_CONVOLVE_SSSE3_H_